/* ── Reset ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --primary: #818cf8;
    --primary-strong: #6366f1;
    --primary-glow: rgba(129, 140, 248, 0.25);
    --accent: #a78bfa;
    --accent2: #22d3ee;
    --bg: #0b1120;
    --bg-elevated: #111827;
    --bg-card: rgba(17, 24, 39, 0.7);
    --surface: rgba(30, 41, 59, 0.6);
    --border: rgba(255,255,255,.06);
    --border-hover: rgba(129, 140, 248, 0.35);
    --text: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --radius: 16px;
    --radius-sm: 10px;
    --green: #34d399;
    --yellow: #fbbf24;
    --red: #f87171;
    --green-bg: rgba(52,211,153,.15);
    --yellow-bg: rgba(251,191,36,.15);
    --red-bg: rgba(248,113,113,.15);
    --input-bg: rgba(0,0,0,.25);
    --primary-bg: rgba(129,140,248,.12);
    --primary-border: rgba(129,140,248,.2);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-image:
        radial-gradient(ellipse 80% 50% at 50% -20%, var(--surface), transparent),
        radial-gradient(ellipse 40% 70% at 90% 60%, var(--surface), transparent),
        radial-gradient(ellipse 50% 60% at 10% 80%, var(--surface), transparent);
}

a { color: inherit; text-decoration: none; }

/* ── Nav ── */
.nav {
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}
.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 28px;
    height: 64px;
    display: flex;
    align-items: center;
    gap: 36px;
}
.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    flex-shrink: 0;
}
.nav-logo i { font-size: 24px; background: linear-gradient(135deg, var(--primary), var(--accent)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.nav-links { display: flex; gap: 4px; flex: 1; }
.nav-link {
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all .2s;
}
.nav-link:hover { background: var(--primary-bg); color: var(--text); }
.nav-auth { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }

.user-menu { position: relative; }
.user-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 16px;
    background: var(--primary-bg);
    color: var(--primary);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    border: 1px solid var(--primary-border);
    transition: all .15s;
}
.user-badge:hover { background: var(--primary-border); }
.user-badge::after { content: "▾"; font-size: 10px; margin-left: 2px; }
.user-dropdown {
    position: absolute;
    top: calc(100% + 10px);
    right: 0;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    min-width: 170px;
    padding: 6px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: all .15s;
    backdrop-filter: blur(20px);
}
.user-menu:hover .user-dropdown { opacity: 1; visibility: visible; transform: translateY(0); }
.user-dropdown a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    border-radius: 6px;
    font-size: 13px;
    color: var(--text-secondary);
}
.user-dropdown a:hover { background: var(--primary-bg); color: var(--text); }

/* ── Buttons ── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 22px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all .2s;
    white-space: nowrap;
}
.btn-sm { padding: 6px 14px; font-size: 13px; border-radius: 8px; }
.btn-block { display: flex; width: 100%; }
.btn-primary {
    background: linear-gradient(135deg, var(--primary-strong), var(--accent));
    color: #fff;
    box-shadow: 0 4px 20px var(--primary-glow);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px var(--border-hover); }
.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--border-hover);
}
.btn-outline:hover { background: var(--primary-bg); border-color: var(--primary); }
.btn-ghost { background: transparent; color: var(--text-secondary); }
.btn-ghost:hover { background: var(--border); color: var(--text); }

/* ── Particles Canvas ── */
#particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

/* ── Hero ── */
.hero {
    position: relative;
    z-index: 1;
    overflow: hidden;
    padding: 100px 28px 80px;
    text-align: center;
}
.hero-grid-bg {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,.015) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,.015) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: radial-gradient(ellipse 60% 60% at 50% 50%, black 25%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse 60% 60% at 50% 50%, black 25%, transparent 70%);
}
.hero-inner { position: relative; z-index: 1; max-width: 780px; margin: 0 auto; }
.hero-badge {
    display: inline-block;
    margin-bottom: 24px;
    padding: 6px 20px;
    background: var(--surface);
    border: 1px solid var(--primary-bg);
    border-radius: 20px;
    font-size: 11px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: .12em;
}
.hero h1 { margin-bottom: 24px; }
.hero-line {
    display: block;
    font-size: 64px;
    font-weight: 900;
    letter-spacing: -.04em;
    line-height: 1.15;
}
.hero-highlight {
    font-size: 80px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 30%, var(--accent2) 70%, var(--primary) 100%);
    background-size: 200% 200%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: shimmer 4s ease-in-out infinite;
}
.hero-highlight .dot {
    -webkit-text-fill-color: var(--accent2);
}
@keyframes shimmer {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}
.hero-desc {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 540px;
    margin: 0 auto 40px;
    line-height: 1.7;
}
.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 40px;
    margin-bottom: 44px;
}
.hero-stat { text-align: center; }
.hs-num {
    display: block;
    font-size: 36px;
    font-weight: 900;
    background: linear-gradient(180deg, #fff 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -.02em;
}
.hs-label { font-size: 12px; color: var(--text-muted); text-transform: uppercase; letter-spacing: .06em; }
.hero-stat-divider { width: 1px; height: 36px; background: var(--border); }
.hero-actions {
    display: flex;
    gap: 14px;
    justify-content: center;
}

/* Hero buttons */
.btn-hero-primary {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 15px 38px;
    border-radius: 14px;
    font-size: 15px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-strong), #8b5cf6);
    color: #fff;
    box-shadow: 0 0 40px var(--primary-glow), 0 8px 24px var(--primary-bg);
    transition: all .3s;
    position: relative;
    overflow: hidden;
}
.btn-hero-primary::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--border), transparent);
    opacity: 0;
    transition: opacity .3s;
}
.btn-hero-primary:hover { transform: translateY(-3px); box-shadow: 0 0 60px var(--primary-glow), 0 16px 36px var(--primary-border); }
.btn-hero-primary:hover::after { opacity: 1; }
.btn-hero-ghost {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 15px 38px;
    border-radius: 14px;
    font-size: 15px;
    font-weight: 600;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    transition: all .3s;
}
.btn-hero-ghost:hover { border-color: var(--border-hover); color: #fff; background: var(--surface); }

.hero-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: .12;
    pointer-events: none;
    z-index: 0;
}
.hero-orb-1 { width: 500px; height: 500px; top: -150px; right: -120px; background: var(--primary); animation: orb-float 8s ease-in-out infinite; }
.hero-orb-2 { width: 350px; height: 350px; bottom: -100px; left: -80px; background: var(--accent2); animation: orb-float 10s ease-in-out infinite reverse; }
.hero-orb-3 { width: 250px; height: 250px; top: 40%; left: 50%; background: var(--accent); animation: orb-float 12s ease-in-out infinite; }
@keyframes orb-float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(20px, -20px) scale(1.05); }
    66% { transform: translate(-15px, 15px) scale(0.95); }
}

/* ── Category Section ── */
.section-categories { position: relative; z-index: 1; padding: 20px 28px 80px; }
.sec-container { max-width: 1200px; margin: 0 auto; }
.sec-header { text-align: center; margin-bottom: 56px; }
.sec-eyebrow {
    display: inline-block;
    padding: 4px 14px;
    background: var(--surface);
    border: 1px solid var(--primary-bg);
    border-radius: 6px;
    font-size: 10px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: .14em;
    margin-bottom: 16px;
}
.sec-header h2 { font-size: 36px; font-weight: 900; letter-spacing: -.03em; margin-bottom: 10px; }
.sec-header p { color: var(--text-muted); font-size: 15px; max-width: 500px; margin: 0 auto; }

/* Homepage category search */
.hero-search-wrap { display: flex; justify-content: center; margin-bottom: 36px; }
.hero-search {
    display: flex;
    align-items: center;
    gap: 10px;
    max-width: 420px;
    width: 100%;
    padding: 12px 18px;
    border: 1px solid var(--border);
    border-radius: 14px;
    background: var(--surface);
    transition: all .2s;
}
.hero-search:focus-within { border-color: var(--border-hover); background: var(--border); }
.hero-search i { color: var(--text-muted); font-size: 14px; }
.hero-search input {
    flex: 1;
    border: none;
    background: transparent;
    color: var(--text);
    font-size: 14px;
    outline: none;
}
.hero-search input::placeholder { color: var(--text-muted); }

/* 3D Tilt Cards */
.cards-stage {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 28px;
}
.tilt-card {
    perspective: 800px;
    display: block;
    text-decoration: none;
    color: inherit;
}
.tilt-card-inner {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 32px;
    transition: border-color .3s, box-shadow .3s;
    overflow: hidden;
    will-change: transform;
}
.tilt-card:hover .tilt-card-inner {
    border-color: var(--primary-border);
    box-shadow: 0 0 40px var(--primary-bg), 0 20px 50px rgba(0,0,0,.4);
}
.tc-glow {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse 60% 30% at 50% 0%, var(--surface), transparent);
    opacity: 0;
    transition: opacity .3s;
}
.tilt-card:hover .tc-glow { opacity: 1; }
.tc-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    background: linear-gradient(135deg, var(--primary-border), var(--primary-bg));
    border: 1px solid var(--primary-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    color: var(--primary);
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
}
.tc-body { position: relative; z-index: 1; margin-bottom: 24px; }
.tc-name { font-size: 22px; font-weight: 800; letter-spacing: -.02em; margin-bottom: 6px; }
.tc-desc { font-size: 13px; color: var(--text-muted); line-height: 1.5; }
.tc-foot {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 18px;
    border-top: 1px solid var(--border);
    position: relative;
    z-index: 1;
}
.tc-author { display: flex; align-items: center; gap: 10px; }
.tc-avatar {
    width: 32px;
    height: 32px;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--primary-strong), var(--accent));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    font-weight: 700;
    color: #fff;
}
.tc-author-name { font-size: 13px; font-weight: 500; color: var(--text-secondary); }
.tc-stats { display: flex; gap: 16px; }
.tc-qcount {
    font-size: 12px;
    color: var(--text-muted);
    padding: 4px 10px;
    border-radius: 6px;
    background: var(--surface);
    border: 1px solid var(--border);
}

/* tech empty state */
.empty-tech {
    text-align: center;
    padding: 80px 28px;
    background: var(--surface);
    border: 1px solid var(--surface);
    border-radius: 20px;
}
.empty-icon-big {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    border-radius: 18px;
    background: linear-gradient(135deg, var(--primary-bg), var(--surface));
    border: 1px solid var(--primary-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 34px;
    color: var(--primary);
}
.empty-tech h3 { font-size: 22px; font-weight: 800; margin-bottom: 8px; }
.empty-tech p { color: var(--text-muted); margin-bottom: 24px; }

/* ── Container ── */
.container-wide { max-width: 1200px; margin: 0 auto; padding: 60px 28px 80px; }
.main { flex: 1; }
.container { max-width: 1100px; margin: 0 auto; padding: 40px 28px; }

/* ── Section Head ── */
.section-head { margin-bottom: 48px; }
.section-head-left { max-width: 600px; }
.section-tag {
    display: inline-block;
    padding: 4px 12px;
    background: var(--primary-bg);
    border: 1px solid var(--primary-bg);
    border-radius: 6px;
    font-size: 11px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: .08em;
    margin-bottom: 16px;
}
.section-head h2 { font-size: 32px; font-weight: 800; letter-spacing: -.02em; margin-bottom: 8px; }
.section-head p { color: var(--text-muted); font-size: 15px; }

/* Old section header for compatibility */
.section-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 28px;
}
.section-header h2 { font-size: 24px; font-weight: 700; }
.section-sub { color: var(--text-muted); font-size: 14px; }

/* ── Category Grid ── */
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}
.cat-card {
    position: relative;
    display: flex;
    flex-direction: column;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    transition: all .3s;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    overflow: hidden;
}
.cat-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
    box-shadow: 0 20px 50px rgba(0,0,0,.3), 0 0 30px var(--primary-glow);
}
.cat-card-glow {
    position: absolute;
    inset: 0;
    opacity: 0;
    background: radial-gradient(ellipse 50% 30% at 50% 0%, var(--surface), transparent);
    transition: opacity .3s;
}
.cat-card:hover .cat-card-glow { opacity: 1; }
.cat-card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
}
.cat-icon-wrap {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--primary-border), var(--primary-bg));
    border: 1px solid var(--primary-border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: var(--primary);
}
.cat-badge {
    padding: 4px 12px;
    border-radius: 8px;
    font-size: 11px;
    font-weight: 600;
    background: var(--green-bg);
    color: var(--green);
    border: 1px solid var(--green-bg);
    letter-spacing: .03em;
}
.cat-card-body { flex: 1; position: relative; z-index: 1; margin-bottom: 20px; }
.cat-name { font-size: 20px; font-weight: 700; margin-bottom: 6px; letter-spacing: -.01em; }
.cat-desc { font-size: 13px; color: var(--text-muted); line-height: 1.5; }

.cat-card-foot {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 18px;
    border-top: 1px solid var(--border);
    position: relative;
    z-index: 1;
}
.cat-author { display: flex; align-items: center; gap: 10px; }
.cat-author-avatar {
    width: 30px;
    height: 30px;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--primary-strong), var(--accent));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    font-weight: 700;
    color: #fff;
}
.cat-author-name { font-size: 13px; font-weight: 500; color: var(--text-secondary); }
.cat-qcount {
    padding: 5px 12px;
    border-radius: 8px;
    font-size: 12px;
    font-weight: 600;
    background: var(--surface);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

/* Category card wrapper (for delete in my-categories) */
.category-card-wrapper { position: relative; }
.category-card-wrapper .cat-card,
.category-card-wrapper .category-card { width: 100%; }
.category-card-wrapper .btn-delete {
    position: absolute;
    top: 14px;
    right: 14px;
    z-index: 5;
    width: 34px;
    height: 34px;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--bg-elevated);
    color: var(--text-muted);
    cursor: pointer;
    font-size: 13px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all .2s;
    backdrop-filter: blur(10px);
}
.category-card-wrapper .btn-delete:hover { background: var(--red); color: #fff; border-color: var(--red); }

/* Old category card compat */
.category-card {
    display: block;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    transition: all .2s;
}
.category-card:hover {
    border-color: var(--border-hover);
    box-shadow: 0 20px 50px rgba(0,0,0,.3), 0 0 30px var(--primary-glow);
    transform: translateY(-2px);
}
.card-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-border), var(--primary-bg));
    border: 1px solid var(--primary-border);
    color: var(--primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    margin-bottom: 16px;
}
.card-title { font-size: 18px; font-weight: 600; margin-bottom: 6px; }
.card-desc { font-size: 14px; color: var(--text-secondary); margin-bottom: 16px; line-height: 1.5; }
.card-meta {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 13px;
    color: var(--text-muted);
    padding-top: 16px;
    border-top: 1px solid var(--border);
}
.card-creator { font-weight: 500; color: var(--text-secondary); }
.card-visibility { margin-left: auto; }
.card-count { margin-left: auto; }

/* ── Empty State Tech ── */
.empty-state-tech {
    text-align: center;
    padding: 80px 28px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}
.empty-icon-wrap {
    width: 72px;
    height: 72px;
    margin: 0 auto 24px;
    border-radius: 16px;
    background: linear-gradient(135deg, var(--primary-bg), var(--primary-bg));
    border: 1px solid var(--primary-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 30px;
    color: var(--primary);
}
.empty-state-tech h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.empty-state-tech p { color: var(--text-muted); margin-bottom: 24px; }

/* Old empty state */
.empty-state {
    text-align: center;
    padding: 64px 24px;
    color: var(--text-muted);
}
.empty-state i { font-size: 48px; margin-bottom: 16px; opacity: .4; }
.empty-state p { font-size: 16px; margin-bottom: 20px; }

.empty-page {
    text-align: center;
    padding: 80px 24px;
    color: var(--text-muted);
}
.empty-page i { font-size: 56px; margin-bottom: 16px; opacity: .3; }
.empty-page h1 { font-size: 48px; font-weight: 800; color: var(--text); margin-bottom: 8px; }
.empty-page p { font-size: 16px; margin-bottom: 24px; }

/* ── Category Detail ── */
.category-head {
    margin-bottom: 36px;
    padding-bottom: 28px;
    border-bottom: 1px solid var(--border);
}
.category-head h1 { font-size: 30px; font-weight: 800; margin: 8px 0; letter-spacing: -.02em; }
.cat-desc { color: var(--text-secondary); font-size: 15px; margin-bottom: 14px; }
.cat-meta { display: flex; gap: 24px; font-size: 13px; color: var(--text-muted); margin-bottom: 20px; }
.back-link { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; color: var(--text-muted); margin-bottom: 8px; }
.back-link:hover { color: var(--primary); }

.question-list { display: flex; flex-direction: column; gap: 14px; }
.question-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px 26px;
    transition: all .2s;
}
.question-item:hover { border-color: var(--border-hover); box-shadow: 0 4px 20px rgba(0,0,0,.15); }
.q-left { flex: 1; min-width: 0; }
.q-left h3 { font-size: 16px; font-weight: 600; margin-bottom: 4px; }
.q-left p { font-size: 13px; color: var(--text-muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.q-right { display: flex; flex-direction: column; align-items: flex-end; gap: 8px; flex-shrink: 0; }
.q-date { font-size: 12px; color: var(--text-muted); }

.difficulty {
    display: inline-block;
    padding: 3px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
}
.difficulty-easy { background: var(--green-bg); color: var(--green); }
.difficulty-medium { background: var(--yellow-bg); color: var(--yellow); }
.difficulty-hard { background: var(--red-bg); color: var(--red); }

/* ── Question Detail ── */
.question-detail { max-width: 800px; }
.q-header { margin-bottom: 32px; }
.q-header h1 { font-size: 28px; font-weight: 800; margin-bottom: 14px; letter-spacing: -.02em; }
.q-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    font-size: 13px;
    color: var(--text-muted);
    align-items: center;
}
.q-content {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 36px;
    font-size: 15px;
    line-height: 1.8;
    white-space: pre-wrap;
}

/* ── Forms ── */
.form-page { max-width: 580px; margin: 56px auto; padding: 0 28px; }
.form-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 40px;
    backdrop-filter: blur(20px);
}
.form-card h1 { font-size: 24px; font-weight: 800; margin-bottom: 6px; display: flex; align-items: center; gap: 12px; }
.form-sub { color: var(--text-muted); font-size: 14px; margin-bottom: 28px; }

.field { margin-bottom: 22px; }
.field label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 8px; color: var(--text-secondary); }
.field .hint { display: block; font-size: 12px; color: var(--text-muted); margin-top: 6px; }
.required { color: var(--red); }

.field input[type="text"],
.field input[type="email"],
.field input[type="password"],
.field textarea,
.field select {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 10px;
    font-size: 14px;
    font-family: inherit;
    background: var(--input-bg);
    color: var(--text);
    transition: border-color .2s, box-shadow .2s;
}
.field input:focus,
.field textarea:focus,
.field select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-bg);
}
.field textarea { resize: vertical; min-height: 100px; }
.field select { cursor: pointer; }
.field select option { background: var(--bg-elevated); color: var(--text); }

.pwd-wrap { position: relative; }
.pwd-wrap input { padding-right: 48px; }
.pwd-toggle {
    position: absolute;
    right: 4px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 10px;
    font-size: 14px;
}
.pwd-toggle:hover { color: var(--text-secondary); }

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 14px;
    color: var(--text-secondary);
}
.checkbox-label input[type="checkbox"] { width: 16px; height: 16px; accent-color: var(--primary); cursor: pointer; }

.form-actions { display: flex; gap: 14px; justify-content: flex-end; margin-top: 28px; }

/* ── Auth ── */
.auth-page { max-width: 440px; margin: 60px auto; padding: 0 28px; }
.auth-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 44px;
    backdrop-filter: blur(20px);
}
.auth-head { text-align: center; margin-bottom: 32px; }
.auth-head h1 { font-size: 26px; font-weight: 800; margin-bottom: 8px; }
.auth-head p { color: var(--text-muted); font-size: 14px; }
.auth-foot {
    text-align: center;
    margin-top: 28px;
    padding-top: 22px;
    border-top: 1px solid var(--border);
    font-size: 14px;
    color: var(--text-muted);
}
.auth-foot a { color: var(--primary); font-weight: 600; }
.auth-foot a:hover { text-decoration: underline; }

/* ── Alert ── */
.alert {
    padding: 12px 18px;
    border-radius: 10px;
    margin-bottom: 22px;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
}
.alert-error { background: var(--red-bg); color: var(--red); border: 1px solid rgba(248,113,113,.2); }

/* ── Footer ── */
.footer {
    background: var(--bg-elevated);
    border-top: 1px solid var(--border);
    padding: 28px;
    text-align: center;
    font-size: 13px;
    color: var(--text-muted);
    margin-top: auto;
}
.footer-inner { max-width: 1200px; margin: 0 auto; }

/* ── Category Layout (left-right) ── */
.category-layout {
    display: flex;
    min-height: calc(100vh - 64px - 60px);
    max-width: 1400px;
    margin: 0 auto;
}
.cat-sidebar {
    width: 300px;
    flex-shrink: 0;
    border-right: 1px solid var(--border);
    background: var(--bg-card);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    height: calc(100vh - 64px);
    position: sticky;
    top: 64px;
    overflow: hidden;
}
.sidebar-section {}
.sidebar-section-scroll {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}
.sidebar-head h2 { font-size: 22px; font-weight: 800; letter-spacing: -.01em; }
.sidebar-desc { font-size: 13px; color: var(--text-muted); margin-top: 6px; }
.sidebar-total { font-size: 15px; font-weight: 700; color: var(--primary); margin-top: 4px; }
.sidebar-meta { font-size: 12px; color: var(--text-muted); margin-top: 8px; }
.sidebar-label {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .06em;
    color: var(--text-muted);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}
.sidebar-label .count { color: var(--primary); }
.sub-list { display: flex; flex-direction: column; gap: 4px; padding-bottom: 8px; }
.sub-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 12px;
    border-radius: 8px;
    font-size: 14px;
    color: var(--text-secondary);
    transition: all .15s;
}
.sub-item:hover { background: var(--surface); color: var(--text); }
.sub-item.active { background: var(--primary-bg); color: var(--primary); font-weight: 600; }
.sub-delete-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 2px 4px;
    font-size: 10px;
    opacity: 0;
    transition: all .15s;
}
.sub-item:hover .sub-delete-btn { opacity: 1; }
.sub-delete-btn:hover { color: var(--red); }

.sub-form { display: flex; gap: 6px; }
.sub-form input {
    flex: 1;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--input-bg);
    color: var(--text);
    font-size: 13px;
}
.sub-form input:focus { outline: none; border-color: var(--primary); }
.sub-form button {
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--primary-bg);
    color: var(--primary);
    cursor: pointer;
    font-size: 13px;
    transition: all .15s;
}
.sub-form button:hover { background: var(--primary-glow); }

.sidebar-actions { display: flex; flex-direction: column; gap: 8px; margin-top: auto; padding-top: 16px; border-top: 1px solid var(--border); flex-shrink: 0; }

.cat-main {
    flex: 1;
    padding: 24px 32px;
    overflow-y: auto;
}
.cat-main-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
}
.cat-main-head h3 { font-size: 20px; font-weight: 700; display: flex; align-items: center; gap: 12px; }
.q-count-badge {
    padding: 3px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    background: var(--primary-bg);
    color: var(--primary);
}

/* Tags */
.q-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 8px; align-items: center; }
.q-tag {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 500;
    background: var(--surface);
    color: var(--accent2);
    border: 1px solid var(--primary-bg);
}
.q-meta-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.q-author { font-size: 12px; color: var(--text-muted); }
.q-delete-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px 6px;
    font-size: 12px;
    border-radius: 4px;
    transition: all .15s;
}
.q-delete-btn:hover { color: var(--red); background: var(--red-bg); }
.q-edit-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px 6px;
    font-size: 12px;
    border-radius: 4px;
    transition: all .15s;
    text-decoration: none;
}
.q-edit-btn:hover { color: var(--primary); background: var(--primary-bg); }

/* ── Question Type Badge ── */
.q-type-badge {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 600;
}
.q-type-single_choice { background: var(--primary-bg); color: var(--primary); border: 1px solid var(--primary-border); }
.q-type-multiple_choice { background: var(--primary-bg); color: var(--accent); border: 1px solid var(--primary-border); }
.q-type-fill_blank { background: var(--green-bg); color: var(--green); border: 1px solid var(--green); }
.q-type-true_false { background: var(--yellow-bg); color: var(--yellow); border: 1px solid var(--yellow); }
.q-type-short_answer { background: var(--surface); color: var(--text-secondary); border: 1px solid var(--border); }

/* ── Question Options Display ── */
.q-options {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px 28px;
    margin-bottom: 20px;
}
.q-options-label {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 16px;
}
.q-option-item {
    padding: 12px 16px;
    border-radius: 8px;
    background: var(--surface);
    border: 1px solid var(--border);
    margin-bottom: 8px;
    font-size: 15px;
    transition: all .15s;
}
.q-option-item:hover { background: var(--surface); border-color: var(--primary-bg); }
.q-option-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    border-radius: 6px;
    background: var(--primary-bg);
    color: var(--primary);
    font-size: 12px;
    font-weight: 700;
    margin-right: 10px;
    flex-shrink: 0;
}
.q-option-correct {
    background: var(--surface);
    border-color: var(--border-hover);
}
.q-option-correct .q-option-letter {
    background: var(--green);
    color: #000;
}
.q-option-check {
    color: var(--green);
    margin-left: auto;
    font-size: 16px;
}

/* ── Answer Box ── */
.q-answer-box {
    margin-top: 20px;
    padding: 16px 20px;
    border-radius: 10px;
    background: var(--surface);
    border: 1px solid var(--primary-border);
    font-size: 15px;
}
.q-answer-label { color: var(--green); font-weight: 600; margin-right: 6px; }

/* ── True/False Display ── */
.q-tf-display { margin: 20px 0; text-align: center; }
.q-tf-result {
    display: inline-block;
    padding: 10px 36px;
    border-radius: 12px;
    font-size: 20px;
    font-weight: 800;
}
.q-tf-correct { background: var(--green-bg); color: var(--green); border: 2px solid var(--border-hover); }
.q-tf-wrong { background: var(--red-bg); color: var(--red); border: 2px solid var(--red-bg); }

/* ── Question item clickable ── */
.question-item { cursor: pointer; }

/* ── Question Filter Bar ── */
.q-filter-bar {
    display: flex;
    gap: 10px;
    margin-bottom: 18px;
    flex-wrap: wrap;
}
.q-filter-search {
    flex: 1;
    min-width: 160px;
    padding: 9px 14px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--input-bg);
    color: var(--text);
    font-size: 13px;
    transition: border-color .2s;
}
.q-filter-search:focus { outline: none; border-color: var(--primary); }
.q-filter-search::placeholder { color: var(--text-muted); }
.q-filter-select {
    padding: 9px 14px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--input-bg);
    color: var(--text);
    font-size: 13px;
    cursor: pointer;
    min-width: 100px;
}
.q-filter-select:focus { outline: none; border-color: var(--primary); }
.q-filter-select option { background: var(--bg-elevated); color: var(--text); }

/* ── Batch Action Bar ── */
.q-batch-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 16px;
    margin-bottom: 10px;
    background: var(--primary-bg);
    border: 1px solid var(--primary-border);
    border-radius: 10px;
    flex-wrap: wrap;
}
.q-batch-check { display: flex; align-items: center; gap: 6px; font-size: 13px; color: var(--text); cursor: pointer; }
.q-batch-count { font-size: 13px; font-weight: 600; color: var(--primary); margin-right: auto; }
.q-check-col { flex-shrink: 0; display: flex; align-items: center; padding-right: 12px; }
.q-checkbox { width: 17px; height: 17px; cursor: pointer; accent-color: var(--primary); }

/* ═══════════════════════════════════════════════════════════════════════
   PRACTICE MODE
   ═══════════════════════════════════════════════════════════════════════ */
.practice-app {
    min-height: calc(100vh - 64px);
    display: flex;
    flex-direction: column;
    background: var(--bg);
}

/* Top bar */
.practice-topbar {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 12px 24px;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    flex-wrap: wrap;
    position: sticky;
    top: 64px;
    z-index: 50;
}
.p-back {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--text-muted);
    padding: 6px 12px;
    border-radius: 8px;
    transition: all .15s;
}
.p-back:hover { background: var(--border); color: var(--text); }
.p-title { font-size: 15px; font-weight: 700; color: var(--text); margin-right: auto; }
.p-filters { display: flex; gap: 8px; flex-wrap: wrap; }
.p-select {
    padding: 7px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--input-bg);
    color: var(--text);
    font-size: 12px;
    cursor: pointer;
}
.p-select:focus { outline: none; border-color: var(--primary); }
.p-select option { background: var(--bg-elevated); }
.p-stats { display: flex; gap: 12px; align-items: center; }
.p-total { font-size: 13px; color: var(--text-muted); }
.p-progress { font-size: 14px; font-weight: 700; color: var(--primary); }
.p-toggle-random {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    color: var(--text-muted);
    cursor: pointer;
}
.p-toggle-random input { accent-color: var(--primary); }

/* Main card area */
.practice-main {
    flex: 1;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 40px 28px 20px;
}
.p-card-wrap {
    width: 100%;
    max-width: 720px;
}
.p-empty { text-align: center; padding: 80px 28px; color: var(--text-muted); }
.p-empty i { font-size: 56px; margin-bottom: 16px; opacity: .3; }
.p-empty h3 { font-size: 20px; color: var(--text); margin-bottom: 8px; }
.p-empty p { margin-bottom: 20px; }

/* Question card */
.p-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 40px;
    backdrop-filter: blur(20px);
    animation: fadeUpIn .3s ease-out;
    overflow: hidden;
    min-width: 0;
}
@keyframes fadeUpIn {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}
.p-card-head {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
    margin-bottom: 20px;
}
.p-q-title {
    font-size: 22px;
    font-weight: 800;
    line-height: 1.5;
    margin-bottom: 28px;
    letter-spacing: -.01em;
    word-break: break-word;
    overflow-wrap: break-word;
}

/* Options */
.p-options { margin-bottom: 24px; }
.p-options-hint { font-size: 13px; color: var(--text-muted); margin-bottom: 12px; }
.p-option-btn {
    display: block;
    width: 100%;
    text-align: left;
    padding: 14px 18px;
    margin-bottom: 8px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--surface);
    color: var(--text);
    font-size: 15px;
    cursor: pointer;
    transition: all .15s;
}
.p-option-btn:hover { background: var(--surface); border-color: var(--primary-border); }
.p-option-btn.selected { background: var(--primary-bg); border-color: var(--primary); color: var(--primary); font-weight: 600; }
.p-option-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    border-radius: 6px;
    background: var(--primary-bg);
    color: var(--primary);
    font-size: 12px;
    font-weight: 700;
    margin-right: 10px;
    flex-shrink: 0;
}
.p-option-btn.selected .p-option-letter { background: var(--primary); color: #fff; }
.p-option-text { flex: 1; }

/* Text input area */
.p-input-area { margin-bottom: 24px; }
.p-input-area textarea {
    width: 100%;
    padding: 14px 18px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--input-bg);
    color: var(--text);
    font-size: 15px;
    line-height: 1.6;
    resize: vertical;
    font-family: inherit;
    min-height: 120px;
}
.p-input-area textarea:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-bg); }
.p-input-area .btn { margin-top: 12px; }

/* True/False */
.p-tf-area { display: none; gap: 14px; margin-bottom: 24px; }
.p-tf-btn {
    flex: 1;
    padding: 20px;
    border-radius: 14px;
    font-size: 20px;
    font-weight: 800;
    border: 2px solid var(--border);
    background: var(--surface);
    color: var(--text);
    cursor: pointer;
    transition: all .15s;
}
.p-tf-btn:hover { border-color: var(--border-hover); }
.p-tf-btn.p-tf-correct.selected { background: var(--green-bg); border-color: var(--green); color: var(--green); }
.p-tf-btn.p-tf-wrong.selected { background: rgba(248,113,113,.15); border-color: var(--red); color: var(--red); }

/* Answer reveal */
.p-reveal {
    margin-top: 20px;
    padding: 20px 24px;
    border-radius: 12px;
    background: var(--surface);
    border: 1px solid var(--green-bg);
    overflow: hidden;
    min-width: 0;
}
.p-reveal-head { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; color: var(--green); margin-bottom: 8px; }
.p-reveal-body { font-size: 16px; font-weight: 600; color: var(--text); word-break: break-word; overflow-wrap: break-word; }
.p-reveal-body :is(table, pre, blockquote) { max-width: 100%; overflow-x: auto; }
.p-reveal-body img { max-width: 100%; height: auto; }
.p-reveal-explain { margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--border); font-size: 14px; color: var(--text-secondary); line-height: 1.7; overflow: hidden; }
.p-q-content { margin-bottom: 16px; padding: 14px 18px; background: var(--surface); border-radius: var(--radius-sm); border: 1px solid var(--border); }

/* Feedback */
.p-feedback { margin-top: 16px; }
.p-fb-correct { color: var(--green); font-weight: 600; display: flex; align-items: center; gap: 8px; }
.p-fb-wrong { color: var(--red); font-weight: 600; display: flex; align-items: center; gap: 8px; }
.p-fb-submitted { color: var(--primary); font-weight: 600; display: flex; align-items: center; gap: 8px; }

/* Bottom bar */
.practice-bottom {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    padding: 16px 24px;
    background: var(--bg-elevated);
    border-top: 1px solid var(--border);
    position: sticky;
    bottom: 0;
    z-index: 50;
}
.p-toggle-answer {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--text-muted);
    cursor: pointer;
}
.p-toggle-answer input { accent-color: var(--primary); }
.p-loading {
    text-align: center;
    padding: 20px;
    color: var(--text-muted);
    font-size: 13px;
}

/* ── Tree Dropdown (subcategory filter) ── */
.p-tree-dropdown { position: relative; }
.p-tree-btn {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 14px; border-radius: var(--radius-sm);
    background: var(--bg); border: 1.5px solid var(--border);
    color: var(--text); font-size: 13px; cursor: pointer;
    white-space: nowrap; transition: border-color .2s;
    font-family: inherit;
}
.p-tree-btn:hover { border-color: var(--border-hover); }
.p-tree-btn-arrow { font-size: 10px; color: var(--text-muted); transition: transform .2s; }
.p-tree-btn.open .p-tree-btn-arrow { transform: rotate(180deg); }

.p-tree-panel {
    position: absolute; top: 100%; left: 0; margin-top: 4px;
    background: var(--bg-elevated); border: 1px solid var(--border);
    border-radius: var(--radius-sm); box-shadow: 0 12px 32px rgba(0,0,0,.5);
    z-index: 500; min-width: 260px; max-width: 340px;
}
.p-tree-search-wrap { padding: 10px 12px 6px; }
.p-tree-search {
    width: 100%; padding: 7px 12px; border-radius: 6px;
    background: var(--bg); border: 1px solid var(--border);
    color: var(--text); font-size: 12px; outline: none; font-family: inherit;
}
.p-tree-search:focus { border-color: var(--primary); }
.p-tree-search::placeholder { color: var(--text-muted); }

.p-tree-scroll { max-height: 340px; overflow-y: auto; padding: 4px 8px 8px; }
.p-tree-scroll::-webkit-scrollbar { width: 3px; }
.p-tree-scroll::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.p-tree-row {
    display: flex; align-items: center; gap: 6px;
    width: 100%; padding: 6px 10px; border-radius: 6px;
    background: none; border: none; color: var(--text);
    font-size: 13px; cursor: pointer; text-align: left;
    font-family: inherit; transition: background .15s; white-space: nowrap;
}
.p-tree-row:hover { background: var(--surface); }
.p-tree-row.active { background: var(--primary-bg); color: var(--primary); font-weight: 600; }
.p-tree-row.active .p-tree-count { color: var(--primary); }

.p-tree-all { border-bottom: 1px solid var(--border); margin-bottom: 4px; padding-bottom: 10px; }
.p-tree-all i { width: 14px; text-align: center; font-size: 11px; color: var(--text-muted); }

.p-tree-indent { flex-shrink: 0; }
.p-tree-caret {
    width: 14px; text-align: center; font-size: 10px;
    color: var(--text-muted); cursor: pointer; transition: transform .15s;
    flex-shrink: 0;
}
.p-tree-caret.expanded { transform: rotate(90deg); }
.p-tree-dot {
    width: 14px; text-align: center; font-size: 5px;
    color: var(--text-muted); flex-shrink: 0;
}
.p-tree-name { flex: 1; overflow: hidden; text-overflow: ellipsis; }
.p-tree-count {
    font-size: 11px; color: var(--text-muted); flex-shrink: 0;
    min-width: 24px; text-align: right;
}
.p-tree-node.hidden { display: none; }

@media (max-width: 768px) {
    .p-tree-panel { right: 0; left: auto; min-width: 220px; max-width: 280px; }
    .p-tree-scroll { max-height: 260px; }
}
.p-sheet-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.6);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}
.p-sheet-panel {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    max-width: 520px;
    width: 90vw;
    max-height: 80vh;
    overflow-y: auto;
}
.p-sheet-head {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}
.p-sheet-head h3 { font-size: 18px; margin: 0; display: flex; align-items: center; gap: 8px; }
.p-sheet-legend {
    display: flex;
    gap: 14px;
    font-size: 12px;
    color: var(--text-muted);
    align-items: center;
}
.p-sheet-legend span { display: flex; align-items: center; gap: 4px; }
.p-sheet-dot {
    width: 10px; height: 10px;
    border-radius: 3px;
    background: var(--text-muted);
    display: inline-block;
}
.p-sheet-dot.done { background: var(--primary); }
.p-sheet-dot.correct { background: var(--green); }
.p-sheet-dot.wrong { background: var(--red); }
.p-sheet-close {
    margin-left: auto;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 24px;
    cursor: pointer;
    line-height: 1;
}
.p-sheet-close:hover { color: var(--text); }
.p-sheet-grid {
    display: grid;
    grid-template-columns: repeat(10, 1fr);
    gap: 8px;
}
.p-sheet-num {
    aspect-ratio: 1;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--input-bg);
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all .15s;
}
.p-sheet-num:hover { border-color: var(--primary); color: var(--text); }
.p-sheet-num.current {
    border-color: var(--accent2);
    box-shadow: 0 0 8px var(--border-hover);
    color: var(--accent2);
}
.p-sheet-num.correct { background: var(--green-bg); border-color: var(--green); color: var(--green); }
.p-sheet-num.wrong { background: var(--red-bg); border-color: var(--red); color: var(--red); }
.p-sheet-num.done { background: var(--primary-bg); border-color: var(--primary); color: var(--primary); }
.p-sheet-num.pending {
    cursor: default;
    color: var(--text-muted);
    opacity: .4;
}

/* Mobile */
@media (max-width: 768px) {
    .practice-topbar { gap: 8px; padding: 10px 16px; }
    .p-title { width: 100%; }
    .p-filters { width: 100%; }
    .p-filters .p-select { flex: 1; min-width: 0; }
    .p-card { padding: 24px; }
    .p-q-title { font-size: 18px; }
    .practice-bottom { gap: 10px; padding: 12px 16px; }
    .p-sheet-grid { grid-template-columns: repeat(5, 1fr); }
    .p-sheet-panel { padding: 20px; width: 95vw; }
}

.tag-checkboxes { display: flex; flex-wrap: wrap; gap: 8px; }
.tag-checkbox {
    padding: 6px 14px !important;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 13px !important;
    color: var(--text-secondary);
    transition: all .15s;
    cursor: pointer;
}
.tag-checkbox:has(input:checked) {
    background: var(--primary-bg);
    border-color: var(--primary);
    color: var(--primary);
}
.tag-checkbox input[type="checkbox"] { display: none; }

/* ── Tag Input Component ── */
.tag-input {
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--input-bg);
    padding: 8px 10px;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
    cursor: text;
    transition: border-color .2s, box-shadow .2s;
    min-height: 46px;
}
.tag-input:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-bg);
}
.tag-input-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
}
.tag-input-chip {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 500;
    background: var(--primary-bg);
    color: var(--primary);
    border: 1px solid var(--primary-glow);
    animation: chip-in .15s ease-out;
}
@keyframes chip-in {
    from { transform: scale(.8); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}
.tag-input-remove {
    background: none;
    border: none;
    color: var(--primary);
    cursor: pointer;
    font-size: 15px;
    line-height: 1;
    padding: 0 2px;
    opacity: .6;
    transition: opacity .15s;
}
.tag-input-remove:hover { opacity: 1; color: var(--red); }
.tag-input-text {
    flex: 1;
    min-width: 120px;
    padding: 4px 6px !important;
    border: none !important;
    background: transparent !important;
    color: var(--text) !important;
    font-size: 13px !important;
    outline: none !important;
    box-shadow: none !important;
    border-radius: 0 !important;
}
.tag-input-text::placeholder { color: var(--text-muted); }

/* Tag suggestions */
.tag-suggestions {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
    margin-top: 10px;
}
.tag-suggest-label {
    font-size: 12px;
    color: var(--text-muted);
    margin-right: 2px;
}
.tag-suggest-chip {
    padding: 3px 12px;
    border-radius: 12px;
    font-size: 12px;
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all .15s;
}
.tag-suggest-chip:hover {
    background: var(--primary-bg);
    border-color: var(--primary-border);
    color: var(--primary);
}

/* Answer choice selector */
.answer-choice-list { display: flex; flex-direction: column; gap: 6px; }
.answer-choice-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--input-bg);
    cursor: pointer;
    transition: all .15s;
}
.answer-choice-item:hover { border-color: var(--primary-glow); background: var(--surface); }
.answer-choice-item:has(input:checked) {
    background: var(--primary-bg);
    border-color: var(--primary);
}
.answer-choice-item input[type="radio"],
.answer-choice-item input[type="checkbox"] { accent-color: var(--primary); width: 16px; height: 16px; cursor: pointer; }
.answer-choice-letter {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    background: var(--primary-bg);
    color: var(--primary);
    font-size: 13px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.answer-choice-item:has(input:checked) .answer-choice-letter {
    background: var(--primary);
    color: #fff;
}
.answer-choice-text { font-size: 14px; color: var(--text); }

/* Options preview */
.options-preview { margin-top: 10px; }
.options-preview .hint { margin-bottom: 6px; }
.options-preview-list { display: flex; flex-direction: column; gap: 3px; }
.opt-preview-item { font-size: 13px; color: var(--text-muted); display: flex; align-items: center; gap: 8px; }
.opt-preview-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 22px;
    border-radius: 4px;
    background: var(--primary-bg);
    color: var(--primary);
    font-size: 11px;
    font-weight: 700;
}

/* ── Subcategory Tree ── */
.sub-tree-item { }
.sub-tree-row {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 6px 8px;
    border-radius: 8px;
    transition: all .15s;
}
.sub-tree-row:hover { background: var(--surface); }
.sub-tree-row.active { background: var(--primary-bg); }
.sub-tree-row.active .sub-tree-link { color: var(--primary); font-weight: 600; }
.sub-tree-link {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: var(--text-secondary);
    text-decoration: none;
    min-width: 0;
}
.sub-tree-link:hover { color: var(--text); }
.sub-tree-indent { flex-shrink: 0; }
.sub-tree-caret {
    font-size: 10px;
    width: 14px;
    text-align: center;
    color: var(--text-muted);
    cursor: pointer;
    flex-shrink: 0;
    transition: transform .15s;
}
.sub-tree-caret:hover { color: var(--text-secondary); }
.sub-tree-dot {
    font-size: 5px;
    color: var(--text-muted);
    width: 14px;
    text-align: center;
    flex-shrink: 0;
}
.sub-tree-count {
    margin-left: auto;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
    padding: 1px 8px;
    border-radius: 10px;
    background: var(--surface);
}
.sub-add-btn {
    background: none;
    border: 1px solid transparent;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 16px;
    font-weight: 700;
    padding: 0 6px;
    border-radius: 4px;
    line-height: 1;
    opacity: 0;
    transition: all .15s;
}
.sub-tree-row:hover .sub-add-btn { opacity: 1; }
.sub-add-btn:hover { color: var(--primary); background: var(--primary-bg); border-color: var(--primary-border); }
.sub-delete-form {
    display: inline;
    margin: 0;
}
.sub-tree-row .sub-delete-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 2px 4px;
    font-size: 10px;
    opacity: 0;
    transition: all .15s;
}
.sub-tree-row:hover .sub-delete-btn { opacity: 1; }
.sub-delete-btn:hover { color: var(--red); }
.sub-drag-handle {
    color: var(--text-muted);
    cursor: grab;
    font-size: 11px;
    padding: 2px 4px;
    flex-shrink: 0;
    opacity: 0;
    transition: opacity .15s;
}
.sub-tree-row:hover .sub-drag-handle { opacity: 1; }
.sub-drag-handle:active { cursor: grabbing; }
.sub-tree-item.drag-before > .sub-tree-row {
    border-top: 2px solid var(--accent2);
    border-radius: 0;
}
.sub-tree-item.drag-after > .sub-tree-row {
    border-bottom: 2px solid var(--accent2);
    border-radius: 0;
}
.sub-tree-item.drag-into > .sub-tree-row {
    outline: 2px solid var(--primary);
    outline-offset: -2px;
    border-radius: 8px;
    background: var(--primary-bg);
    box-shadow: 0 0 12px var(--primary-glow);
}
.sub-tree-row[draggable] { cursor: default; }
.sub-tree-row[draggable]:active { cursor: grabbing; }
.sub-inline-form {
    display: none;
    gap: 4px;
    padding: 4px 0 6px 28px;
}
.sub-inline-form.visible { display: flex; }
.sub-inline-form input {
    flex: 1;
    padding: 6px 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--input-bg);
    color: var(--text);
    font-size: 12px;
}
.sub-inline-form input:focus { outline: none; border-color: var(--primary); }
.sub-inline-form button {
    padding: 6px 10px;
    border: 1px solid var(--border-hover);
    border-radius: 6px;
    background: var(--green-bg);
    color: var(--green);
    cursor: pointer;
    font-size: 12px;
    transition: all .15s;
}
.sub-inline-form button:hover { background: var(--primary-glow); }
.sub-tree-children.collapsed { display: none; }

/* ── Rich Content (Quill rendered HTML) ── */
.rich-content { line-height: 1.8; word-break: break-word; }
.rich-content p { margin: 0 0 10px; }
.rich-content h1, .rich-content h2 { margin: 16px 0 10px; font-weight: 600; }
.rich-content h1 { font-size: 1.4em; }
.rich-content h2 { font-size: 1.2em; }
.rich-content ul, .rich-content ol { margin: 8px 0; padding-left: 24px; }
.rich-content li { margin: 4px 0; }
.rich-content blockquote {
    border-left: 3px solid var(--primary);
    padding: 8px 16px;
    margin: 12px 0;
    background: var(--surface);
    border-radius: 0 8px 8px 0;
    color: var(--text-secondary);
}
.rich-content pre {
    background: var(--input-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 16px;
    overflow-x: auto;
    margin: 12px 0;
    font-size: 13px;
    line-height: 1.5;
}
.rich-content code {
    font-family: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;
    background: var(--input-bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: .9em;
    color: var(--accent2);
}
.rich-content pre code {
    background: none;
    padding: 0;
    border-radius: 0;
    color: var(--text);
    font-size: inherit;
}
.rich-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 12px 0;
    font-size: 14px;
}
.rich-content th, .rich-content td {
    border: 1px solid var(--border);
    padding: 8px 12px;
    text-align: left;
}
.rich-content th {
    background: var(--primary-bg);
    font-weight: 600;
    color: var(--text);
}
.rich-content td {
    background: var(--input-bg);
}
.rich-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-sm);
    margin: 8px 0;
}
.rich-content a {
    color: var(--primary);
    text-decoration: underline;
}
.rich-content a:hover { color: var(--accent2); }
.rich-content hr { border: none; border-top: 1px solid var(--border); margin: 16px 0; }
.rich-content strong { font-weight: 600; color: var(--text); }
.rich-content em { font-style: italic; }
.rich-content u { text-decoration: underline; }
.rich-content s { text-decoration: line-through; color: var(--text-muted); }

/* ── Explanation section on detail page ── */
.q-explanation {
    margin-top: 20px;
    padding: 20px;
    background: var(--surface);
    border: 1px solid var(--primary-bg);
    border-radius: var(--radius-sm);
}
.q-explanation-label {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 6px;
}

/* ── Responsive ── */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .nav-inner { gap: 14px; padding: 0 20px; }
    .hero { padding: 64px 20px 56px; }
    .hero-line { font-size: 36px; }
    .hero-highlight { font-size: 48px; }
    .hero-desc { font-size: 14px; }
    .hero-stats { gap: 24px; }
    .hs-num { font-size: 26px; }
    .cards-stage { grid-template-columns: 1fr; }
    .question-item { flex-direction: column; align-items: flex-start; }
    .q-right { flex-direction: row; }
    .form-card, .auth-card { padding: 28px; }
    .container-wide { padding: 40px 20px 60px; }
    .section-head h2 { font-size: 26px; }
    .category-layout { flex-direction: column; }
    .cat-sidebar { width: 100%; border-right: none; border-bottom: 1px solid var(--border); height: auto; position: static; max-height: none; }
    .sidebar-section-scroll { overflow-y: visible; flex: none; max-height: none; }
    .cat-main { padding: 20px; }
    .sec-header h2 { font-size: 28px; }
}


/* ═══════════════════════════════════════════════════════════════════════
   CROSS-CATEGORY PRACTICE: Setup
   ═══════════════════════════════════════════════════════════════════════ */

.cross-practice-app { min-height: calc(100vh - 64px); background: var(--bg); }
.cross-practice-runner { display: flex; flex-direction: column; min-height: calc(100vh - 64px); }

.cross-setup { max-width: 900px; margin: 0 auto; padding: 56px 28px 80px; }
.cross-setup-inner h1 {
    font-size: 28px; font-weight: 800; letter-spacing: -.02em;
    display: flex; align-items: center; gap: 10px; margin-bottom: 8px;
}
.cross-setup-desc { color: var(--text-muted); font-size: 15px; margin-bottom: 42px; }

#session-name {
    width: 100%; max-width: 400px; padding: 12px 16px; border-radius: var(--radius-sm);
    background: var(--bg); border: 1.5px solid var(--border); color: var(--text);
    font-size: 15px; outline: none; transition: border-color .2s;
}
#session-name:focus { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-bg); }
#session-name::placeholder { color: var(--text-muted); }

.cross-cat-label {
    font-size: 14px; font-weight: 600; color: var(--text-secondary);
    margin: 28px 0 12px; display: flex; align-items: center; gap: 8px;
}
.cross-cat-label .count { color: var(--primary); }

.cross-search-wrap { margin-bottom: 16px; }
.cross-search-wrap .q-filter-search { max-width: 100%; }

.cross-cat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
    gap: 12px;
    margin-bottom: 32px;
    max-height: 420px;
    overflow-y: auto;
    padding-right: 4px;
}
.cross-cat-grid::-webkit-scrollbar { width: 4px; }
.cross-cat-grid::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.cross-cat-card {
    position: relative;
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 18px 40px 18px 18px;
    cursor: pointer;
    transition: all .2s;
    user-select: none;
    display: flex; flex-direction: column; gap: 6px;
}
.cross-cat-card:hover { border-color: var(--primary-border); background: var(--surface); }
.cross-cat-card.selected {
    border-color: var(--primary);
    background: var(--surface);
    box-shadow: 0 0 18px var(--primary-bg);
}
.cross-cat-card .cat-check {
    position: absolute; top: 14px; right: 14px;
    width: 22px; height: 22px; border-radius: 6px;
    border: 2px solid var(--text-muted);
    display: flex; align-items: center; justify-content: center;
    font-size: 11px; color: transparent; transition: all .15s;
}
.cross-cat-card.selected .cat-check {
    background: var(--primary); border-color: var(--primary); color: #fff;
}
.cross-cat-card .cat-name { font-size: 15px; font-weight: 700; }
.cross-cat-card .cat-meta { font-size: 12px; color: var(--text-muted); }
.cross-cat-card .cat-creator { font-size: 11px; color: var(--text-muted); }

.cross-filters {
    display: flex; gap: 12px; align-items: center; flex-wrap: wrap; margin-bottom: 28px;
}

#cross-start-btn { padding: 14px 52px; font-size: 16px; font-weight: 700; }
#cross-start-btn:disabled { opacity: .35; cursor: not-allowed; }

/* ── Runner extras ── */

.cross-cat-badges { display: flex; gap: 6px; flex-wrap: wrap; max-width: 300px; }
.cross-cat-badge {
    padding: 3px 10px; border-radius: 6px; font-size: 11px; font-weight: 600;
    background: rgba(167,139,250,.12); color: var(--accent);
    border: 1px solid var(--primary-border); white-space: nowrap;
}

.cross-p-cat {
    padding: 2px 10px; border-radius: 6px; font-size: 11px; font-weight: 600;
    background: var(--surface); color: var(--accent2);
    border: 1px solid var(--primary-bg);
}

/* ── Report Overlay ── */

.cross-report-overlay {
    position: fixed; inset: 0; background: rgba(0,0,0,.6);
    z-index: 1000; display: flex; align-items: center; justify-content: center;
    backdrop-filter: blur(4px);
}
.cross-report-panel {
    background: var(--bg-elevated); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 32px;
    max-width: 680px; width: 92vw; max-height: 85vh; overflow-y: auto;
}
.cross-report-head {
    display: flex; align-items: center; justify-content: space-between; margin-bottom: 28px;
}
.cross-report-head h3 { font-size: 20px; font-weight: 800; display: flex; align-items: center; gap: 10px; }

.cross-report-summary {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-bottom: 32px;
}
.cross-stat-card {
    text-align: center; padding: 20px 12px; border-radius: var(--radius-sm);
    background: var(--surface); border: 1px solid var(--border);
}
.cross-stat-num { font-size: 30px; font-weight: 900; line-height: 1.1; }
.cross-stat-label { font-size: 12px; color: var(--text-muted); margin-top: 4px; }
.cross-stat-card.total .cross-stat-num { color: var(--text); }
.cross-stat-card.correct .cross-stat-num { color: var(--green); }
.cross-stat-card.wrong .cross-stat-num { color: var(--red); }
.cross-stat-card.rate .cross-stat-num { color: var(--primary); }

.cross-report-section { margin-bottom: 24px; }
.cross-report-section h4 {
    font-size: 14px; font-weight: 700; color: var(--text-secondary);
    margin-bottom: 10px; display: flex; align-items: center; gap: 6px;
}
.cross-report-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.cross-report-table th, .cross-report-table td {
    padding: 9px 14px; text-align: left; border-bottom: 1px solid var(--border);
}
.cross-report-table th {
    font-weight: 600; color: var(--text-secondary);
    font-size: 11px; text-transform: uppercase; letter-spacing: .04em;
}
.cross-report-table td { color: var(--text); }
.cross-report-table .r-correct { color: var(--green); font-weight: 600; }
.cross-report-table .r-wrong { color: var(--red); font-weight: 600; }
.cross-report-table .r-rate {
    padding: 3px 10px; border-radius: 10px; font-size: 11px; font-weight: 600;
    background: var(--primary-bg); color: var(--primary);
}
.cross-report-table .r-name { font-weight: 600; }

@media (max-width: 768px) {
    .cross-cat-grid { grid-template-columns: 1fr; max-height: 340px; }
    .cross-report-summary { grid-template-columns: repeat(2, 1fr); }
    .cross-report-panel { padding: 24px 18px; }
    .cross-setup { padding: 36px 18px 60px; }
    .cross-cat-badges { max-width: 200px; }
    .cross-filters { flex-direction: column; align-items: stretch; }
    .cross-session-meta { flex-wrap: wrap; }
    .cross-create-cat-arrow { right: 8px; }
}

/* ═══════════════════════════════════════════════════════════════════════
   CROSS-PRACTICE: Session List
   ═══════════════════════════════════════════════════════════════════════ */

.cross-session-actions { margin-bottom: 28px; }

.cross-session-list { display: flex; flex-direction: column; gap: 10px; }
.cross-session-card {
    display: flex; align-items: center; justify-content: space-between;
    background: var(--bg-card); border: 1.5px solid var(--border);
    border-radius: var(--radius-sm); padding: 18px 22px;
    cursor: pointer; transition: all .2s; gap: 16px;
}
.cross-session-card:hover { border-color: var(--primary-border); background: var(--surface); }
.cross-session-info { flex: 1; min-width: 0; }
.cross-session-name { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.cross-session-meta {
    display: flex; gap: 14px; font-size: 12px; color: var(--text-muted);
    flex-wrap: wrap; margin-bottom: 6px;
}
.cross-session-meta span { display: flex; align-items: center; gap: 4px; }
.cross-session-progress { font-size: 12px; color: var(--accent2); margin-bottom: 4px; }
.cross-session-time { font-size: 11px; color: var(--border-hover); }
.cross-session-btns { display: flex; gap: 8px; flex-shrink: 0; }

.cross-empty-hint {
    text-align: center; padding: 60px 20px; color: var(--text-muted);
}
.cross-empty-hint i { font-size: 40px; margin-bottom: 12px; display: block; opacity: .4; }

.cross-login-prompt {
    text-align: center; padding: 80px 20px; color: var(--text-muted);
}
.cross-login-prompt i { font-size: 48px; margin-bottom: 16px; display: block; opacity: .3; }
.cross-login-prompt p { margin-bottom: 20px; font-size: 15px; }

/* ═══════════════════════════════════════════════════════════════════════
   CROSS-PRACTICE: Create Form (Category + Subcategory tree)
   ═══════════════════════════════════════════════════════════════════════ */

.cross-create-grid {
    display: flex; flex-direction: column; gap: 8px; margin-bottom: 16px;
    max-height: 500px; overflow-y: auto; padding-right: 4px;
}
.cross-create-grid::-webkit-scrollbar { width: 4px; }
.cross-create-grid::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.cross-create-cat-card {
    background: var(--bg-card); border: 1.5px solid var(--border);
    border-radius: var(--radius-sm); transition: all .2s;
}
.cross-create-cat-card.selected { border-color: var(--primary); background: var(--surface); }

.cross-create-cat-head {
    display: flex; align-items: center; gap: 10px; padding: 14px 16px;
    cursor: pointer; user-select: none; position: relative;
}
.cross-create-cat-head:hover { background: var(--surface); }
.cross-create-cat-check {
    width: 20px; height: 20px; border-radius: 5px; border: 2px solid var(--text-muted);
    display: flex; align-items: center; justify-content: center;
    font-size: 10px; color: transparent; transition: all .15s; flex-shrink: 0;
}
.cross-create-cat-card.selected .cross-create-cat-check {
    background: var(--primary); border-color: var(--primary); color: #fff;
}
.cross-create-cat-name { font-size: 15px; font-weight: 700; flex: 1; }
.cross-create-cat-meta { font-size: 12px; color: var(--text-muted); }
.cross-create-cat-arrow {
    font-size: 11px; color: var(--text-muted); transition: transform .2s;
    position: absolute; right: 14px; top: 50%; transform: translateY(-50%);
}
.cross-create-cat-card.selected .cross-create-cat-arrow { transform: translateY(-50%) rotate(180deg); }

.cross-create-subtree { border-top: 1px solid var(--border); padding: 6px 0; }

.cross-create-sub-row {
    display: flex; align-items: center; gap: 8px; padding: 7px 12px 7px 16px;
    cursor: pointer; transition: background .12s; font-size: 13px;
}
.cross-create-sub-row:hover { background: var(--surface); }
.cross-create-sub-row.selected {
    background: var(--primary-bg); color: var(--primary);
}
.cross-create-sub-row.selected .cross-create-sub-name { font-weight: 600; }
.cross-create-sub-check {
    width: 16px; height: 16px; border-radius: 4px; border: 1.5px solid var(--text-muted);
    flex-shrink: 0; display: flex; align-items: center; justify-content: center;
    font-size: 9px; color: transparent; transition: all .15s;
}
.cross-create-sub-row.selected .cross-create-sub-check {
    background: var(--primary); border-color: var(--primary); color: #fff;
}
.cross-create-sub-icon { font-size: 10px; color: var(--text-muted); width: 14px; text-align: center; flex-shrink: 0; }
.cross-create-sub-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.cross-create-sub-count { font-size: 11px; color: var(--text-muted); flex-shrink: 0; }
.cross-create-sub-none { padding: 12px 20px; font-size: 12px; color: var(--text-muted); }


/* ═══════════════════════════════════════
   THEME SETTINGS PAGE
   ═══════════════════════════════════════ */

.theme-page { max-width: 800px; margin: 0 auto; padding: 40px 20px 60px; }

.theme-page-header { text-align: center; margin-bottom: 36px; }
.theme-page-header h1 { font-size: 28px; margin: 0 0 6px; display: flex; align-items: center; justify-content: center; gap: 10px; }
.theme-page-header p { color: var(--text-secondary); font-size: 14px; margin: 0; }

.theme-section { margin-bottom: 32px; }
.theme-section-title { font-size: 15px; font-weight: 600; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.5px; margin: 0 0 14px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }

/* Presets */
.theme-presets { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 12px; }

.theme-preset-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 14px; cursor: pointer; text-align: center; transition: all .2s;
}
.theme-preset-card:hover { border-color: var(--border-hover); transform: translateY(-2px); box-shadow: 0 4px 16px rgba(0,0,0,.3); }
.theme-preset-card.active { border-color: var(--primary); background: var(--surface); box-shadow: 0 0 0 1px var(--primary); }

.theme-preset-swatches { display: flex; justify-content: center; gap: 8px; margin-bottom: 10px; }
.theme-swatch { width: 28px; height: 28px; border-radius: 50%; border: 2px solid var(--border); display: inline-block; }
.theme-preset-name { font-size: 13px; font-weight: 600; }

/* Color rows */
.theme-color-grid { display: flex; flex-direction: column; gap: 8px; }

.theme-color-row {
    display: flex; align-items: center; justify-content: space-between;
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-sm);
    padding: 12px 16px; gap: 16px; transition: border-color .15s;
}
.theme-color-row:hover { border-color: var(--border-hover); }
.theme-color-row label { font-size: 14px; font-weight: 500; display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.theme-color-desc { font-size: 11px; color: var(--text-muted); font-weight: 400; }
.theme-color-input { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.theme-color-input input[type="color"] {
    width: 36px; height: 36px; border: 2px solid var(--border); border-radius: 8px;
    cursor: pointer; padding: 0; background: none; transition: border-color .15s;
}
.theme-color-input input[type="color"]:hover { border-color: var(--border-hover); }
.theme-color-input input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
.theme-color-input input[type="color"]::-webkit-color-swatch { border: none; border-radius: 6px; }
.theme-hex-input {
    width: 160px; background: var(--input-bg); border: 1px solid var(--border); border-radius: 6px;
    color: var(--text); font-size: 13px; font-family: 'SF Mono', 'Fira Code', monospace; padding: 6px 10px;
    transition: border-color .15s;
}
.theme-hex-input:focus { outline: none; border-color: var(--primary); }

.theme-swatch-mini { width: 14px; height: 14px; border-radius: 4px; display: inline-block; vertical-align: middle; margin-right: 4px; }

/* Actions */
.theme-actions {
    display: flex; justify-content: flex-end; gap: 12px; margin-top: 36px;
    padding-top: 24px; border-top: 1px solid var(--border);
}

/* Toast */
.theme-toast {
    position: fixed; bottom: 40px; left: 50%; transform: translateX(-50%);
    padding: 12px 28px; border-radius: 30px; font-size: 14px; font-weight: 600;
    z-index: 9999; transition: opacity .3s; pointer-events: none;
}
.theme-toast-success { background: var(--green); color: #000; }
.theme-toast-error { background: var(--red); color: #fff; }
.theme-toast-info { background: var(--primary); color: #fff; }

@media (max-width: 768px) {
    .theme-color-row { flex-direction: column; align-items: flex-start; gap: 10px; }
    .theme-color-input { width: 100%; }
    .theme-hex-input { flex: 1; }
    .theme-presets { grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)); }
}


/* ═══════════════════════════════════════
   QUESTION MODAL
   ═══════════════════════════════════════ */

.q-modal-overlay {
    position: fixed; inset: 0; z-index: 1000;
    display: flex; align-items: center; justify-content: center;
    background: rgba(0,0,0,.6);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    padding: 20px;
}

.q-modal-panel {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 24px 64px rgba(0,0,0,.5);
    width: 100%; max-width: 740px; max-height: 90vh;
    display: flex; flex-direction: column;
    overflow: hidden;
}

.q-modal-head {
    display: flex; align-items: center; justify-content: space-between;
    padding: 18px 24px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}
.q-modal-head h3 { margin: 0; font-size: 18px; display: flex; align-items: center; gap: 8px; }

.q-modal-close {
    width: 36px; height: 36px; border-radius: 50%;
    border: none; background: none;
    color: var(--text-muted); font-size: 24px;
    cursor: pointer; transition: all .15s;
    display: flex; align-items: center; justify-content: center;
}
.q-modal-close:hover { background: var(--surface); color: var(--text); }

.q-modal-body {
    padding: 24px; overflow-y: auto; flex: 1;
    display: flex; flex-direction: column; gap: 2px;
}
.q-modal-body .field { margin-bottom: 18px; }

.q-modal-foot {
    display: flex; justify-content: flex-end; gap: 10px;
    padding: 16px 24px; border-top: 1px solid var(--border);
    flex-shrink: 0;
}

@media (max-width: 768px) {
    .q-modal-overlay { padding: 10px; align-items: flex-end; }
    .q-modal-panel { max-width: 100%; max-height: 95vh; border-radius: var(--radius) var(--radius) 0 0; }
    .q-modal-body { padding: 16px; }
    .q-modal-head { padding: 14px 16px; }
    .q-modal-foot { padding: 12px 16px; }
}