@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,500;9..144,600;9..144,700&family=Space+Grotesk:wght@500;600;700&family=IBM+Plex+Sans:wght@400;500;600;700&family=JetBrains+Mono:wght@500;600&display=swap');

/* ============================================================
   OJ Judge — CodeArena Design System
   Warm paper canvas · Deep ink typography · Orange accent
   ============================================================ */

/* --- Design Tokens --- */
:root {
    /* Canvas & Surfaces */
    --ca-canvas:        #faf8f5;
    --ca-card-bg:       #ffffff;
    --ca-navbar-bg:     #ffffff;
    --ca-sidebar-bg:    transparent;

    /* Ink */
    --ca-text-primary:  #1a1a2e;
    --ca-text-secondary:#6b7280;
    --ca-text-muted:    #9ca3af;

    /* Brand Accent — Orange (matches approved sample) */
    --accent-primary:   #E2603B;
    --accent-hover:     #C9502F;
    --accent-light:     #FCEDE7;
    --accent-gradient:  linear-gradient(135deg, #E2603B, #F0906A);

    /* Semantic */
    --diff-easy:        #22c55e;
    --diff-easy-bg:     #f0fdf4;
    --diff-medium:      #f59e0b;
    --diff-medium-bg:   #fffbeb;
    --diff-hard:        #ef4444;
    --diff-hard-bg:     #fef2f2;
    --success:          #22c55e;
    --error:            #ef4444;

    /* Borders & Shadows */
    --ca-border:        #e8e4df;
    --ca-border-light:  #f0ede8;
    --ca-shadow-sm:     0 1px 3px rgba(26,26,46,.06);
    --ca-shadow-md:     0 4px 12px rgba(26,26,46,.08);
    --ca-shadow-lg:     0 8px 30px rgba(26,26,46,.10);

    /* Radius */
    --radius-sm:        6px;
    --radius-md:        10px;
    --radius-lg:        14px;
    --radius-xl:        20px;
    --radius-full:      9999px;

    /* Spacing */
    --space-xs:         4px;
    --space-sm:         8px;
    --space-md:         12px;
    --space-lg:         16px;
    --space-xl:         24px;
    --space-2xl:        32px;
    --space-3xl:        48px;

    /* Typography */
    --font-sans:        "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    --font-display:     "Fraunces", Georgia, "Songti SC", serif;
    --font-mono:        "JetBrains Mono", "SF Mono", "Fira Code", "Consolas", monospace;

    /* Layout */
    --navbar-h:         60px;
    --page-max:         1200px;
    --sidebar-w:        260px;
}

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background: var(--ca-canvas);
    color: var(--ca-text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

a { text-decoration: none; color: inherit; transition: color .15s ease; }
a:hover { color: var(--accent-primary); }
button { cursor: pointer; font-family: inherit; }

/* ============================================================
   NAVBAR
   ============================================================ */
.navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    height: var(--navbar-h);
    padding: 0 var(--space-xl);
    background: var(--ca-navbar-bg);
    border-bottom: 1px solid var(--ca-border);
    box-shadow: var(--ca-shadow-sm);
}

.navbar .brand {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--accent-primary);
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}
.navbar .brand::before {
    content: "";
    display: inline-block;
    width: 28px; height: 28px;
    background: var(--accent-gradient);
    border-radius: 8px;
    vertical-align: middle;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    margin-left: auto;
    font-size: 0.925rem;
    font-weight: 500;
    color: var(--ca-text-secondary);
}
.nav-links a {
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    transition: all .15s ease;
}
.nav-links a:hover {
    color: var(--accent-primary);
    background: var(--accent-light);
}
.user-info {
    font-size: 0.875rem;
    color: var(--ca-text-secondary);
    padding-left: var(--space-lg);
    border-left: 1px solid var(--ca-border);
}
.logout-form { display: inline; margin-left: var(--space-md); }
.logout-form button {
    background: none; border: none;
    color: var(--ca-text-muted); font-size: 0.85rem;
    padding: 4px 8px; border-radius: 4px;
}
.logout-form button:hover { color: var(--error); background: var(--diff-hard-bg); }

/* Mobile hamburger */
.menu-toggle { display: none; }

/* ============================================================
   PAGE WRAPPER
   ============================================================ */
.ca-page {
    max-width: var(--page-max);
    margin: 0 auto;
    padding: var(--space-xl) var(--space-lg) var(--space-3xl);
}

/* Hero (matches approved sample) */
.ca-hero { margin-bottom: var(--space-2xl); }
.ca-hero-eyebrow {
    font-family: "Space Grotesk", var(--font-sans);
    font-size: 0.78rem; font-weight: 700; letter-spacing: 0.18em;
    text-transform: uppercase; color: var(--accent-hover); margin-bottom: 0.5rem;
}
.ca-hero h1 {
    font-family: var(--font-display);
    font-weight: 600; font-size: clamp(2rem, 4vw, 2.8rem);
    line-height: 1.05; letter-spacing: -0.02em; color: var(--ca-text-primary);
}
.ca-hero p { color: var(--ca-text-secondary); margin-top: 0.6rem; font-size: 1.02rem; max-width: 52ch; }

/* ============================================================
   SEARCH BAR
   ============================================================ */
.ca-search-bar {
    position: relative;
    margin-bottom: var(--space-xl);
}
.ca-search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 20px; height: 20px;
    color: var(--ca-text-muted);
    pointer-events: none;
}
.ca-search-input {
    width: 100%;
    padding: 14px 16px 14px 48px;
    font-size: 1rem;
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-lg);
    background: var(--ca-card-bg);
    outline: none;
    transition: border-color .2s, box-shadow .2s;
    box-shadow: var(--ca-shadow-sm);
}
.ca-search-input:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(226,96,59,.10);
}

/* ============================================================
   STATS ROW
   ============================================================ */
.ca-stats-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-lg);
    margin-bottom: var(--space-2xl);
}
.ca-stat-card {
    background: var(--ca-card-bg);
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-md);
    padding: var(--space-xl);
    box-shadow: var(--ca-shadow-sm);
    transition: box-shadow .2s, transform .2s;
}
.ca-stat-card:hover {
    box-shadow: var(--ca-shadow-md);
    transform: translateY(-2px);
}
.ca-stat-num {
    font-family: "Space Grotesk", var(--font-sans);
    font-size: 2rem;
    font-weight: 800;
    color: var(--ca-text-primary);
    line-height: 1.2;
    letter-spacing: -0.03em;
}
.ca-stat-label {
    font-size: 0.85rem;
    color: var(--ca-text-muted);
    margin-top: 4px;
}

/* ============================================================
   MAIN LAYOUT (Sidebar + Content)
   ============================================================ */
.ca-layout {
    display: flex;
    gap: var(--space-2xl);
    align-items: flex-start;
}

/* ============================================================
   SIDEBAR
   ============================================================ */
.ca-sidebar {
    width: var(--sidebar-w);
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
    position: sticky;
    top: calc(var(--navbar-h) + var(--space-xl));
}
.ca-side-section {
    background: var(--ca-card-bg);
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--ca-shadow-sm);
}
.ca-side-title {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--ca-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--ca-border-light);
    background: #fafafa;
}

/* Category list in sidebar */
.ca-cat-list {
    padding: var(--space-sm) var(--space-md);
}
.ca-cat-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    font-size: 0.9rem;
    border-radius: var(--radius-sm);
    transition: all .15s ease;
    color: var(--ca-text-secondary);
}
.ca-cat-item:hover {
    background: var(--accent-light);
    color: var(--accent-primary);
}
.ca-cat-item.active {
    background: var(--accent-light);
    color: var(--accent-primary);
    font-weight: 600;
}
.ca-cat-count {
    font-size: 0.78rem;
    color: var(--ca-text-muted);
    font-weight: 500;
}
.ca-cat-item.active .ca-cat-count {
    color: var(--accent-primary);
}

/* Difficulty dots in sidebar */
.ca-diff-list {
    padding: var(--space-sm) var(--space-md) var(--space-md);
}
.ca-diff-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 14px;
    font-size: 0.88rem;
    border-radius: var(--radius-sm);
    transition: all .15s ease;
    color: var(--ca-text-secondary);
}
.ca-diff-item:hover { background: #f5f5f5; }
.ca-diff-item.active { font-weight: 600; color: var(--ca-text-primary); }

.ca-dot {
    width: 10px; height: 10px;
    border-radius: 50%; display: inline-block; flex-shrink: 0;
}
.ca-dot-easy   { background: var(--diff-easy); }
.ca-dot-medium { background: var(--diff-medium); }
.ca-dot-hard   { background: var(--diff-hard); }

/* ============================================================
   RIGHT CONTENT AREA
   ============================================================ */
.ca-main {
    flex: 1;
    min-width: 0;
}

/* Filter Chips Row */
.ca-chips-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: var(--space-lg);
}
.ca-chip {
    display: inline-flex;
    align-items: center;
    padding: 6px 16px;
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-full);
    background: var(--ca-card-bg);
    color: var(--ca-text-secondary);
    transition: all .15s ease;
}
.ca-chip:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}
.ca-chip.active {
    background: var(--ca-text-primary);
    color: #fff;
    border-color: var(--ca-text-primary);
}

/* List Header */
.ca-list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-md);
    font-size: 0.84rem;
    color: var(--ca-text-muted);
}
.ca-sort-select {
    padding: 6px 30px 6px 12px;
    font-size: 0.83rem;
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-sm);
    background: var(--ca-card-bg);
    color: var(--ca-text-secondary);
    cursor: pointer;
    outline: none;
}
.ca-sort-select:focus { border-color: var(--accent-primary); }

/* ============================================================
   PROBLEM ROWS
   ============================================================ */
.ca-problem-list {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.ca-problem-row {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-lg) var(--space-xl);
    background: var(--ca-card-bg);
    border: 1px solid var(--ca-border-light);
    border-radius: var(--radius-md);
    transition: all .18s ease;
    cursor: pointer;
}
.ca-problem-row:hover {
    border-color: var(--accent-primary);
    box-shadow: var(--ca-shadow-md);
    transform: translateX(4px);
}

/* ID Badge */
.ca-pid {
    flex-shrink: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px; height: 40px;
    padding: 0 10px;
    background: var(--accent-primary);
    color: #fff;
    font-size: 0.88rem;
    font-weight: 700;
    border-radius: var(--radius-sm);
    letter-spacing: -0.01em;
}

/* Body: Title + Tags */
.ca-pbody { flex: 1; min-width: 0; }
.ca-ptitle {
    font-size: 1rem;
    font-weight: 600;
    color: var(--ca-text-primary);
    margin-bottom: 6px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.ca-ptags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

/* Tags / Pills */
.ca-tag {
    display: inline-flex;
    align-items: center;
    padding: 2px 10px;
    font-size: 0.76rem;
    font-weight: 500;
    border-radius: var(--radius-full);
    background: #f0edeb;
    color: var(--ca-text-secondary);
    border: 1px solid var(--ca-border);
}
.ca-tag-easy {
    background: var(--diff-easy-bg);
    color: #15803d;
    border-color: #bbf7d0;
}
.ca-tag-medium {
    background: var(--diff-medium-bg);
    color: #a16207;
    border-color: #fde68a;
}
.ca-tag-hard {
    background: var(--diff-hard-bg);
    color: #b91c1c;
    border-color: #fecaca;
}

/* Acceptance Column (right side of each row) */
.ca-paccept {
    flex-shrink: 0;
    text-align: right;
    min-width: 110px;
}
.ca-pct-num {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--ca-text-primary);
}
.ca-pbar-track {
    width: 100%;
    height: 5px;
    background: #f0ede8;
    border-radius: var(--radius-full);
    margin: 5px 0;
    overflow: hidden;
}
.ca-pbar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--success), #34d399);
    border-radius: var(--radius-full);
    transition: width .4s ease;
    min-width: 2px;
}
.ca-psub {
    font-size: 0.75rem;
    color: var(--ca-text-muted);
}

/* Empty state */
.ca-empty {
    text-align: center;
    padding: var(--space-3xl);
    color: var(--ca-text-muted);
    font-size: 0.95rem;
    background: var(--ca-card-bg);
    border: 1px dashed var(--ca-border);
    border-radius: var(--radius-md);
}

/* ============================================================
   ADMIN PAGES
   ============================================================ */

/* Admin header */
.ca-admin-header {
    display: flex;
    align-items: flex-end;
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
    flex-wrap: wrap;
}
.ca-admin-title {
    font-family: var(--font-display);
    font-size: 1.85rem;
    font-weight: 700;
    color: var(--ca-text-primary);
    letter-spacing: -0.02em;
    flex-shrink: 0;
}
.ca-admin-desc {
    font-size: 0.9rem;
    color: var(--ca-text-muted);
    max-width: 400px;
}

/* Admin filters */
.ca-admin-filters {
    margin-bottom: var(--space-lg);
}
.ca-filter-select {
    padding: 8px 32px 8px 14px;
    font-size: 0.88rem;
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-sm);
    background: var(--ca-card-bg);
    color: var(--ca-text-secondary);
    cursor: pointer;
    outline: none;
}
.ca-filter-select:focus { border-color: var(--accent-primary); }

/* Buttons */
.ca-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 20px;
    font-size: 0.88rem;
    font-weight: 600;
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all .15s ease;
    white-space: nowrap;
    background: var(--ca-card-bg);
    color: var(--ca-text-secondary);
}
.ca-btn:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}
.ca-btn-primary {
    background: var(--accent-primary);
    color: #fff !important;
    border-color: var(--accent-primary);
}
.ca-btn-primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    color: #fff !important;
}
.ca-btn-sm { padding: 5px 14px; font-size: 0.82rem; }
.ca-btn-danger {
    color: var(--error) !important;
    border-color: #fecaca;
}
.ca-btn-danger:hover {
    background: var(--error);
    color: #fff !important;
    border-color: var(--error);
}

/* Admin Card */
.ca-card {
    background: var(--ca-card-bg);
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-md);
    padding: var(--space-xl);
    box-shadow: var(--ca-shadow-sm);
    margin-bottom: var(--space-xl);
}
.ca-card-header {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--ca-text-primary);
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--ca-border-light);
}

/* Form inside admin card */
.ca-form-row {
    display: flex;
    gap: var(--space-md);
    align-items: center;
    flex-wrap: wrap;
}
.ca-input {
    padding: 10px 16px;
    font-size: 0.92rem;
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-sm);
    outline: none;
    transition: border-color .2s;
    background: var(--ca-card-bg);
    color: var(--ca-text-primary);
}
.ca-input:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(226,96,59,.08);
}

/* Alerts */
.ca-alert-error {
    margin-top: var(--space-md);
    padding: 10px 16px;
    background: var(--diff-hard-bg);
    color: var(--error);
    font-size: 0.87rem;
    border-radius: var(--radius-sm);
    border: 1px solid #fecaca;
}
.ca-alert-success {
    margin-top: var(--space-md);
    padding: 10px 16px;
    background: var(--diff-easy-bg);
    color: #15803d;
    font-size: 0.87rem;
    border-radius: var(--radius-sm);
    border: 1px solid #bbf7d0;
}

/* ============================================================
   ADMIN TABLE
   ============================================================ */
.ca-table-wrap {
    background: var(--ca-card-bg);
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--ca-shadow-sm);
}
.ca-table {
    width: 100%;
    border-collapse: collapse;
}
.ca-table th {
    padding: 12px 16px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--ca-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    text-align: left;
    background: #fafafa;
    border-bottom: 1px solid var(--ca-border);
}
.ca-table td {
    padding: 14px 16px;
    font-size: 0.91rem;
    border-bottom: 1px solid var(--ca-border-light);
    vertical-align: middle;
}
.ca-table tr:last-child td { border-bottom: none; }
.ca-table tr:hover td { background: #fafaf8; }

/* Table cell elements */
.ca-tid {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 30px; height: 28px;
    padding: 0 8px;
    background: var(--accent-light);
    color: var(--accent-primary);
    font-size: 0.8rem;
    font-weight: 700;
    border-radius: 4px;
}
.ca-tlink {
    font-weight: 600;
    color: var(--ca-text-primary);
}
.ca-tlink:hover { color: var(--accent-primary); }
.ca-tmeta {
    font-size: 0.78rem;
    color: var(--ca-text-muted);
    margin-top: 2px;
}
.ca-tag-sm {
    display: inline-block;
    padding: 2px 10px;
    font-size: 0.77rem;
    font-weight: 500;
    border-radius: var(--radius-full);
    background: #f0edeb;
    color: var(--ca-text-secondary);
}
.ca-empty {
    font-style: italic;
    color: var(--ca-text-muted);
}
.ca-count-badge {
    display: inline-block;
    min-width: 24px;
    padding: 1px 8px;
    text-align: center;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--accent-primary);
    background: var(--accent-light);
    border-radius: var(--radius-full);
}
.ca-cat-name { font-weight: 600; }

/* Difficulty badges in table */
.ca-diff-badge {
    display: inline-block;
    padding: 2px 10px;
    font-size: 0.76rem;
    font-weight: 600;
    border-radius: var(--radius-full);
}
.ca-diff-easy {
    background: var(--diff-easy-bg);
    color: #15803d;
}
.ca-diff-medium {
    background: var(--diff-medium-bg);
    color: #a16207;
}
.ca-diff-hard {
    background: var(--diff-hard-bg);
    color: #b91c1c;
}

/* Action buttons in table */
.ca-actions {
    display: flex;
    gap: 6px;
}

/* ============================================================
   SEMANTIC STATUS PILLS (submissions / users)
   ============================================================ */
.ca-pill {
    display: inline-flex;
    align-items: center;
    padding: 3px 11px;
    font-size: 0.78rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    border: 1px solid transparent;
    line-height: 1.4;
    white-space: nowrap;
}
.ca-pill-ok {
    background: var(--diff-easy-bg);
    color: #15803d;
    border-color: #bbf7d0;
}
.ca-pill-err {
    background: var(--diff-hard-bg);
    color: #b91c1c;
    border-color: #fecaca;
}
.ca-pill-warn {
    background: var(--diff-medium-bg);
    color: #a16207;
    border-color: #fde68a;
}
.ca-pill-admin {
    background: var(--accent-light);
    color: var(--accent-hover);
    border-color: #f6cdbd;
}
.ca-pill-user {
    background: #f0edeb;
    color: var(--ca-text-secondary);
    border-color: var(--ca-border);
}

/* ============================================================
   LEGACY GLOBAL CLASSES (kept for other pages)
   ============================================================ */
.container {
    max-width: var(--page-max);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.card {
    background: var(--ca-card-bg);
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-md);
    box-shadow: var(--ca-shadow-sm);
    padding: var(--space-xl);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 22px;
    font-size: 0.9rem;
    font-weight: 600;
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-sm);
    background: var(--ca-card-bg);
    color: var(--ca-text-primary);
    cursor: pointer;
    transition: all .15s ease;
}
.btn:hover { border-color: var(--accent-primary); color: var(--accent-primary); }
.btn-success { background: var(--success); color: #fff; border-color: var(--success); }
.btn-secondary { color: var(--ca-text-secondary); }

.form-group { margin-bottom: var(--space-md); }
.form-group label {
    display: block;
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--ca-text-primary);
    margin-bottom: 6px;
}
.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 14px;
    font-size: 0.92rem;
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-sm);
    background: var(--ca-card-bg);
    color: var(--ca-text-primary);
    outline: none;
    transition: border-color .2s;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(226,96,59,.08);
}
textarea { resize: vertical; }

.alert-error {
    padding: 10px 16px;
    background: var(--diff-hard-bg);
    color: var(--error);
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    margin-bottom: var(--space-md);
}

/* Footer */
.site-footer {
    background: var(--ca-text-primary);
    color: #9aa0ad;
    padding: var(--space-2xl) 0 var(--space-xl);
    margin-top: var(--space-3xl);
    text-align: center;
    font-size: 0.84rem;
    border-top: 3px solid var(--accent-primary);
}
.footer-inner {
    max-width: var(--page-max);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}
.footer-brand {
    font-family: var(--font-display); font-weight: 700; font-size: 1.05rem;
    color: #fff; margin-bottom: var(--space-sm); letter-spacing: .01em;
}
.footer-links { display: flex; flex-wrap: wrap; gap: 1.25rem; justify-content: center; margin-bottom: var(--space-md); }
.footer-links a, .footer-legal a { color: #c2c7d2; text-decoration: none; transition: color .18s; }
.footer-links a:hover, .footer-legal a:hover { color: var(--accent-primary); }
.footer-separator { height: 1px; background: rgba(255,255,255,.08); max-width: 320px; margin: var(--space-md) auto; }
.footer-legal { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; justify-content: center; font-size: .82rem; }
.footer-legal-sep { color: #555c6b; }
.footer-beian { display: inline-flex; align-items: center; }
.beian-icon { height: 18px; width: auto; vertical-align: middle; margin-right: 5px; border-radius: 2px; }
.footer-copy { color: #7b818f; margin-top: var(--space-md); }
.footer-tech { color: #646a78; margin-top: var(--space-xs); }

/* Announcement modal overrides */
.announcement-modal-header { background: var(--accent-primary) !important; }
.announcement-modal-header h2 { color: #fff !important; }
.announcement-modal-footer a { color: var(--accent-primary) !important; }

/* ============================================================
   AUTH — shared tokens (alerts + links)
   ============================================================ */
.alert { padding: 0.7rem 1rem; border-radius: var(--radius-sm); margin-bottom: var(--space-md); font-size: 0.88rem; }
.alert-error { background: #fef2f2; color: #dc2626; border: 1px solid #fecaca; }
.alert-success { background: #f0fdf4; color: #16a34a; border: 1px solid #bbf7d0; }

.auth-link { margin-top: var(--space-xl); font-size: 0.9rem; color: var(--ca-text-secondary); text-align: center; }
.auth-link a { color: var(--accent-primary); font-weight: 600; text-decoration: none; }
.auth-link a:hover { text-decoration: underline; }

/* ============================================================
   AUTH — Orange split (approved board style)
   Replaces the old navy split; later rules win in cascade.
   ============================================================ */
/* ===== Auth pages — refined brand split ===== */
.auth-page {
    min-height: calc(100vh - var(--navbar-h));
    display: flex; align-items: center; justify-content: center;
    padding: var(--space-2xl) var(--space-lg);
    background:
        radial-gradient(120% 70% at 50% -12%, var(--accent-light) 0%, transparent 55%),
        var(--ca-canvas);
}
.auth-card {
    width: 100%; max-width: 440px;
    background: var(--ca-card-bg);
    border: 1px solid var(--ca-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--ca-shadow-lg);
    padding: var(--space-2xl);
    position: relative; overflow: hidden;
}
.auth-card::before {
    content: ""; position: absolute; left: 0; right: 0; top: 0; height: 4px;
    background: var(--accent-gradient);
}
.auth-card-head {
    display: flex; align-items: center; gap: 12px; margin-bottom: var(--space-lg);
}
.auth-badge {
    width: 44px; height: 44px; border-radius: 12px; flex: none;
    display: grid; place-items: center;
    background: var(--accent-gradient); color: #fff;
    font-family: var(--font-display); font-weight: 700; font-size: 1.15rem;
    box-shadow: 0 6px 16px rgba(226,96,59,.3);
}
.auth-card-brand { font-family: var(--font-sans); font-weight: 600; font-size: 1.1rem; color: var(--ca-text-primary); letter-spacing: .01em; }
.auth-card .alert { margin-bottom: var(--space-lg); }

/* --- Left brand panel --- */
.auth-left {
    position: relative;
    overflow: hidden;
    color: #fff;
    padding: var(--space-3xl);
    display: flex; flex-direction: column; justify-content: space-between; gap: var(--space-2xl);
    background:
        radial-gradient(120% 120% at 0% 0%, rgba(255,255,255,.18), transparent 55%),
        linear-gradient(155deg, #E2603B 0%, #d2542f 55%, #b8461f 100%);
}
/* dotted texture, fading toward bottom-right */
.auth-left::before {
    content: ""; position: absolute; inset: 0;
    background-image: radial-gradient(rgba(255,255,255,.12) 1px, transparent 1.5px);
    background-size: 22px 22px;
    -webkit-mask-image: radial-gradient(120% 120% at 18% 0%, #000 28%, transparent 72%);
            mask-image: radial-gradient(120% 120% at 18% 0%, #000 28%, transparent 72%);
    opacity: .55;
}
/* soft glow blob */
.auth-left::after {
    content: ""; position: absolute; right: -130px; bottom: -130px;
    width: 340px; height: 340px; border-radius: 50%;
    background: radial-gradient(circle, rgba(255,255,255,.22), transparent 70%);
}
.auth-left > * { position: relative; z-index: 1; }

.auth-brand { display: flex; align-items: center; gap: 12px; }
.auth-brand-mark {
    width: 46px; height: 46px; border-radius: 13px;
    display: grid; place-items: center;
    background: rgba(255,255,255,.18); border: 1px solid rgba(255,255,255,.4);
    font-family: var(--font-display); font-weight: 700; font-size: 1.2rem;
    backdrop-filter: blur(6px);
}
.auth-brand-name { font-family: var(--font-sans); font-weight: 600; font-size: 1.05rem; letter-spacing: .02em; }

.auth-hero { margin-top: var(--space-3xl); }
.auth-eyebrow {
    font-family: var(--font-sans); font-size: .76rem; font-weight: 600; letter-spacing: .2em;
    text-transform: uppercase; opacity: .85; margin-bottom: 14px;
}
.auth-left h1 {
    font-family: var(--font-display); font-weight: 700; font-size: 2.7rem;
    line-height: 1.08; letter-spacing: -0.02em;
}
.auth-left p { opacity: .92; margin-top: var(--space-md); font-size: 1rem; max-width: 34ch; line-height: 1.6; }

.auth-features { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.auth-features li { display: flex; align-items: center; gap: 14px; font-size: .95rem; }
.auth-features .dot {
    width: 36px; height: 36px; border-radius: 11px; flex: none;
    display: grid; place-items: center;
    background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.28);
}
.auth-features .dot svg { width: 19px; height: 19px; color: rgba(255,255,255,.95); }

.auth-left-foot { margin-top: var(--space-lg); }
.auth-quote {
    font-family: var(--font-display); font-style: italic; font-size: 1.02rem; line-height: 1.5;
    opacity: .92; border-left: 3px solid rgba(255,255,255,.5); padding-left: 14px;
}

/* --- Right form panel --- */
.auth-right {
    background:
        radial-gradient(140% 100% at 100% 0%, #fff5ef 0%, transparent 46%),
        var(--ca-canvas);
    padding: var(--space-3xl);
    display: flex; align-items: center; justify-content: center;
}
.auth-form-card { width: 100%; max-width: 400px; }
.auth-mobile-brand { display: none; align-items: center; gap: 10px; margin-bottom: var(--space-xl); font-weight: 600; color: var(--ca-text-primary); }
.auth-mobile-brand .m {
    width: 38px; height: 38px; border-radius: 10px; display: grid; place-items: center;
    background: var(--accent-gradient); color: #fff; font-family: var(--font-display); font-weight: 700; font-size: .95rem;
}
.auth-form-card .alert { margin-bottom: var(--space-lg); }

.auth-card h2 {
    font-family: var(--font-display); font-weight: 700; font-size: 1.9rem;
    letter-spacing: -0.02em; color: var(--ca-text-primary); margin: 0 0 6px;
}
.auth-card .sub { color: var(--ca-text-secondary); font-size: .92rem; margin: 0 0 var(--space-xl); }

/* field + icon input */
.field { margin-bottom: var(--space-lg); }
.field label {
    display: block; font-family: var(--font-sans); font-size: .82rem; font-weight: 600;
    color: var(--ca-text-primary); margin-bottom: 7px;
}
.field input, .field select {
    width: 100%; padding: 0.8rem 0.95rem; border: 1px solid var(--ca-border);
    border-radius: var(--radius-md); font-size: 0.95rem; font-family: var(--font-sans);
    background: #fff; color: var(--ca-text-primary); transition: .18s;
}
.field input:focus, .field select:focus {
    outline: none; border-color: var(--accent-primary); box-shadow: 0 0 0 4px var(--accent-light); background: #fff;
}
.auth-input { position: relative; display: flex; align-items: center; }
.auth-input > svg.ic {
    position: absolute; left: 14px; width: 18px; height: 18px; color: var(--ca-text-muted);
    pointer-events: none; transition: .18s;
}
.auth-input input {
    width: 100%; padding: 0.82rem 0.95rem 0.82rem 2.65rem;
    border: 1px solid var(--ca-border); border-radius: var(--radius-md);
    font-size: 0.95rem; font-family: var(--font-sans);
    background: #fff; color: var(--ca-text-primary); transition: .18s;
}
.auth-input input::placeholder { color: var(--ca-text-muted); }
.auth-input input:focus {
    outline: none; border-color: var(--accent-primary); box-shadow: 0 0 0 4px var(--accent-light); background: #fff;
}
.auth-input:focus-within > svg.ic { color: var(--accent-primary); }
.auth-pwd-toggle {
    position: absolute; right: 8px; top: 50%; transform: translateY(-50%);
    background: none; border: none; color: var(--ca-text-muted); cursor: pointer;
    padding: 7px; display: grid; place-items: center; border-radius: 8px; transition: .18s;
}
.auth-pwd-toggle:hover { color: var(--accent-primary); background: var(--accent-light); }
.auth-pwd-toggle svg { width: 18px; height: 18px; display: block; }
.auth-pwd-toggle .eye-off { display: none; }
.auth-pwd-toggle.is-on .eye { display: none; }
.auth-pwd-toggle.is-on .eye-off { display: block; }

.field-row { display: flex; gap: var(--space-sm); align-items: stretch; }
.field-row .auth-input { flex: 1; min-width: 0; }
.btn-code {
    white-space: nowrap; padding: 0 1.05rem; border: 1px solid var(--ca-border); border-radius: var(--radius-md);
    background: #fff; color: var(--accent-primary); font-weight: 600; font-size: .85rem; cursor: pointer; transition: .18s;
    flex: none;
}
.btn-code:hover:not(:disabled) { border-color: var(--accent-primary); background: var(--accent-light); }
.btn-code:disabled { opacity: .55; cursor: not-allowed; }

.agreement-label { display: flex; align-items: flex-start; gap: 8px; font-size: .85rem; color: var(--ca-text-secondary); line-height: 1.5; }
.agreement-label input { margin-top: 2px; accent-color: var(--accent-primary); }
.agreement-label a { color: var(--accent-primary); text-decoration: none; }
.agreement-label a:hover { text-decoration: underline; }

.auth-card .btn.btn-primary {
    width: 100%; padding: 0.9rem 1rem; font-size: 1rem; margin-top: var(--space-sm);
    background: var(--accent-gradient); border: none; color: #fff;
    box-shadow: 0 6px 18px rgba(226,96,59,.28);
}
.auth-card .btn.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 10px 24px rgba(226,96,59,.34); }

.auth-link { margin-top: var(--space-xl); font-size: .9rem; color: var(--ca-text-secondary); text-align: center; }
.auth-link a { color: var(--accent-primary); font-weight: 600; text-decoration: none; }
.auth-link a:hover { text-decoration: underline; }

@media (max-width: 520px) {
    .auth-card { padding: var(--space-xl) var(--space-lg); border-radius: var(--radius-lg); }
    .auth-card h2 { font-size: 1.6rem; }
}

/* ============================================================
   BUTTONS (global variants)
   ============================================================ */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    font-family: var(--font-sans); font-weight: 600; font-size: 0.92rem;
    padding: 0.7rem 1.25rem; border-radius: var(--radius-md);
    border: 1px solid transparent; cursor: pointer; transition: .18s; text-decoration: none;
}
.btn-primary { background: var(--accent-primary); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); box-shadow: var(--ca-shadow-md); }
.btn-ghost { background: #fff; border-color: var(--ca-border); color: var(--ca-text-primary); }
.btn-ghost:hover { border-color: var(--accent-primary); color: var(--accent-primary); }
.btn-sm { padding: 0.45rem 0.9rem; font-size: 0.82rem; border-radius: var(--radius-sm); }
.btn-danger { background: var(--diff-hard-bg); color: var(--diff-hard); border: 1px solid #f1d2de; }
.btn-danger:hover { background: var(--diff-hard); color: #fff; }

/* ============================================================
   HOME HERO (approved board style)
   ============================================================ */
.hero {
    background: radial-gradient(120% 130% at 12% 0%, #fff6f1 0%, var(--ca-canvas) 42%);
    padding: var(--space-3xl) var(--space-xl) calc(var(--space-3xl) + 1rem);
    text-align: center; border-bottom: 1px solid var(--ca-border);
}
.hero .eyebrow {
    font-family: var(--font-sans); font-size: 0.8rem; letter-spacing: .14em; text-transform: uppercase;
    color: var(--accent-primary); font-weight: 600;
}
.hero h1 {
    font-family: var(--font-display); font-weight: 700; font-size: 3rem; line-height: 1.08;
    margin: var(--space-lg) auto; max-width: 760px; letter-spacing: -0.02em; color: var(--ca-text-primary);
}
.hero h1 b { color: var(--accent-primary); }
.hero p { color: var(--ca-text-secondary); font-size: 1.05rem; max-width: 580px; margin: 0 auto var(--space-xl); }
.hero .btns { display: flex; gap: var(--space-md); justify-content: center; flex-wrap: wrap; }
.hero .feature { display: flex; gap: var(--space-md); justify-content: center; margin-top: calc(var(--space-2xl) + 1rem); flex-wrap: wrap; }
.hero .feature .f {
    background: var(--ca-card-bg); border: 1px solid var(--ca-border); border-radius: var(--radius-lg);
    padding: var(--space-lg) var(--space-xl); width: 220px; text-align: left; box-shadow: var(--ca-shadow-sm); transition: .2s;
}
.hero .feature .f:hover { transform: translateY(-3px); box-shadow: var(--ca-shadow-md); }
.hero .feature .f .ic { font-size: 1.5rem; }
.hero .feature .f .t { font-family: var(--font-sans); font-weight: 600; margin-top: var(--space-sm); color: var(--ca-text-primary); }
.hero .feature .f .d { font-size: 0.82rem; color: var(--ca-text-secondary); margin-top: 4px; }

/* ============================================================
   ADMIN PAGE HEADER (ca-head)
   ============================================================ */
.ca-head {
    display: flex; align-items: center; gap: var(--space-lg); flex-wrap: wrap;
    margin-bottom: var(--space-xl);
}
.ca-head h1 { font-family: var(--font-display); font-weight: 700; font-size: 1.7rem; color: var(--ca-text-primary); letter-spacing: -0.02em; }
.ca-head .desc { color: var(--ca-text-secondary); font-size: 0.9rem; flex: 1; min-width: 200px; }
.ca-head .btn { margin-left: auto; }

/* ============================================================
   ADMIN PROBLEM FORM (ca- grid form)
   ============================================================ */
.ca-form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-lg); }
.ca-form-grid .full { grid-column: 1 / -1; }
.fg { margin-bottom: var(--space-sm); }
.fg label {
    display: block; font-family: var(--font-sans); font-size: 0.82rem; font-weight: 600;
    color: var(--ca-text-primary); margin-bottom: 7px;
}
.fg input, .fg select, .fg textarea {
    width: 100%; padding: 0.7rem 0.9rem; border: 1px solid var(--ca-border); border-radius: var(--radius-md);
    font-family: var(--font-sans); font-size: 0.92rem; background: #fcfaf6; color: var(--ca-text-primary); transition: .18s;
}
.fg input:focus, .fg select:focus, .fg textarea:focus {
    outline: none; border-color: var(--accent-primary); box-shadow: 0 0 0 4px var(--accent-light); background: #fff;
}
.fg textarea { resize: vertical; }
.sample { background: #1e1e1e !important; color: #d4d4d4 !important; font-family: var(--font-mono) !important; }
.note { background: #fff7ec; border: 1px solid #f3e0bf; border-radius: var(--radius-md); padding: var(--space-lg) var(--space-xl); margin: var(--space-md) 0; }
.note h3 { color: #9a6b16; font-family: var(--font-sans); font-size: 0.95rem; margin-bottom: var(--space-sm); }
.note p { color: #9a6b16; font-size: 0.84rem; }

/* ============================================================
   RESPONSIVE — new auth / hero / form
   ============================================================ */
@media (max-width: 820px) {
    .auth { grid-template-columns: 1fr; }
    .auth-left { display: none; }
    .ca-form-grid { grid-template-columns: 1fr; }
    .hero h1 { font-size: 2.1rem; }
    .hero .feature { flex-direction: column; align-items: center; }
}

/* Home page hero */
.home-hero {
    text-align: center;
    padding: var(--space-3xl) var(--space-lg);
}
.home-hero h1 {
    font-size: 2.5rem;
    font-weight: 900;
    letter-spacing: -0.04em;
    color: var(--ca-text-primary);
    margin-bottom: var(--space-md);
}
.home-hero p {
    font-size: 1.1rem;
    color: var(--ca-text-secondary);
    max-width: 520px;
    margin: 0 auto var(--space-xl);
}

/* Hamburger (mobile only) */
.hamburger span { display: block; width: 22px; height: 2px; background: var(--ca-text-primary); margin: 4px 0; transition: .3s; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
    .ca-stats-row { grid-template-columns: repeat(2, 1fr); }
    .ca-layout { flex-direction: column; }
    .ca-sidebar {
        width: 100%;
        position: static;
        flex-direction: row;
        flex-wrap: wrap;
        gap: var(--space-md);
    }
    .ca-side-section { flex: 1; min-width: 200px; }
}

@media (max-width: 768px) {
    .nav-links { display: none; }
    .menu-toggle { display: block; }
    .nav-links.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: var(--navbar-h);
        left: 0; right: 0;
        background: var(--ca-navbar-bg);
        padding: var(--space-lg);
        border-bottom: 1px solid var(--ca-border);
        box-shadow: var(--ca-shadow-md);
    }
    .ca-stats-row { grid-template-columns: repeat(2, 1fr); gap: var(--space-md); }
    .ca-stat-num { font-size: 1.5rem; }
    .ca-problem-row { flex-wrap: wrap; gap: var(--space-md); }
    .ca-paccept { width: 100%; text-align: left; }
    .ca-admin-header { flex-direction: column; align-items: flex-start; }
    .ca-form-row { flex-direction: column; align-items: stretch; }
    .ca-table-wrap { overflow-x: auto; }
    .ca-table { min-width: 500px; }
}

@media (max-width: 480px) {
    .ca-stats-row { grid-template-columns: 1fr 1fr; }
    .ca-page { padding: var(--space-md); }
    .navbar { padding: 0 var(--space-md); }
}