:root {
    --bg: #f4efe4;
    --bg-strong: #e5d5bb;
    --surface: rgba(255, 250, 240, 0.82);
    --surface-solid: #fff9ef;
    --ink: #1f2430;
    --ink-soft: #5a6272;
    --accent: #aa3d2d;
    --accent-deep: #7c2418;
    --gold: #d1a24b;
    --line: rgba(31, 36, 48, 0.12);
    --shadow: 0 18px 48px rgba(63, 37, 23, 0.14);
    --radius: 24px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    color: var(--ink);
    background: radial-gradient(circle at top left, rgba(209, 162, 75, 0.28), transparent 22%), linear-gradient(135deg, #f8f1e6 0%, #f1e8d9 50%, #efe4d1 100%);
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
}

a { color: inherit; text-decoration: none; }
p { line-height: 1.6; color: var(--ink-soft); }
h1, h2, h3, strong, .brand { font-family: "Palatino Linotype", "Book Antiqua", Georgia, serif; color: var(--ink); }

.site-shell { max-width: 80%; margin: 0 auto; padding: 24px; }
.topbar, .footer, .nav, .hero-actions, .hero-stats, .section-grid, .cards-grid, .dashboard-grid, .quick-links, .meta-row, .meta-grid, .two-col, .three-col, .tag-row, .filter-bar, .section-heading.inline { display: flex; gap: 16px; }
.topbar, .footer { justify-content: space-between; align-items: center; }
.topbar { margin-bottom: 28px; padding: 18px 22px; border: 1px solid var(--line); border-radius: 999px; background: rgba(255,255,255,0.58); backdrop-filter: blur(14px); position: sticky; top: 10px; z-index: 10; }
.brand { display: inline-flex; gap: 12px; align-items: center; font-size: 1.25rem; }
.brand-mark { width: 40px; height: 40px; border-radius: 50%; display: grid; place-items: center; background: linear-gradient(135deg, var(--accent), var(--gold)); color: #fff; text-transform: lowercase; }
.brand-logo { width: 44px; height: 44px; object-fit: contain; display: block; border-radius: 12px; }
.nav { align-items: center; flex-wrap: wrap; }
.nav a { color: var(--ink-soft); }
.btn { display: inline-flex; justify-content: center; align-items: center; gap: 10px; padding: 14px 22px; border-radius: 999px; background: linear-gradient(135deg, var(--accent), var(--accent-deep)); color: #fff; border: 0; cursor: pointer; box-shadow: var(--shadow); }
.btn-small { padding: 10px 16px; }
.btn-secondary { background: transparent; color: var(--accent-deep); border: 1px solid rgba(170, 61, 45, 0.3); box-shadow: none; }
.text-link { color: var(--accent-deep); font-weight: 700; }
.hero, .profile-hero { display: grid; gap: 24px; grid-template-columns: 1.4fr 0.9fr; }
.messages-layout { display: grid; gap: 24px; grid-template-columns: minmax(220px, 0.78fr) minmax(0, 1.22fr); }
.admin-dispute-layout { display: grid; gap: 24px; grid-template-columns: repeat(2, minmax(0, 1fr)); align-items: start; }
.hero { min-height: 72vh; align-items: center; }
.hero h1, .page-hero h1, .auth-form h1, .profile-hero h1 { font-size: clamp(2.8rem, 5vw, 5rem); line-height: 1; margin: 0 0 18px; }
.hero-text, .lead { font-size: 1.08rem; max-width: 720px; }
.eyebrow { letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent-deep); font-size: 0.78rem; font-weight: 800; margin-bottom: 10px; }
.hero-card, .panel, .teacher-card, .feature-card, .auth-form, .auth-copy { border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface-solid); box-shadow: var(--shadow); }
.glass { background: rgba(255, 249, 239, 0.74); backdrop-filter: blur(14px); }
.panel, .teacher-card, .feature-card, .auth-form, .auth-copy { padding: 26px; }
.hero-stats { flex-wrap: wrap; margin-top: 26px; }
.hero-stats div { min-width: 140px; padding: 14px 18px; background: rgba(255,255,255,0.52); border-radius: 20px; border: 1px solid var(--line); }
.hero-stats strong { display: block; font-size: 1.4rem; }
.section-grid, .cards-grid, .dashboard-grid, .quick-links, .meta-grid, .two-col, .three-col { flex-wrap: wrap; }
.section-grid > *, .dashboard-grid > *, .quick-links > * { flex: 1 1 280px; }
.dashboard-grid-compact { gap: 22px; margin-bottom: 10px; }
.teacher-stat-grid > * { flex: 1 1 220px; }
.cards-grid > * { flex: 1 1 320px; }
.features-grid { margin-top: 28px; }
.section-stack { display: grid; gap: 22px; margin: 42px 0; }
.section-heading { margin-top: 36px; }
.teacher-card-top, .section-heading.inline, .list-item, .message-form { display: flex; justify-content: space-between; gap: 16px; }
.meta-row, .meta-grid { justify-content: space-between; color: var(--ink-soft); flex-wrap: wrap; }
.meta-grid span { min-width: 180px; }
.tag-row { flex-wrap: wrap; margin: 16px 0; }
.tag, .badge, .active-pill { display: inline-flex; align-items: center; padding: 8px 12px; border-radius: 999px; }
.tag { background: rgba(209, 162, 75, 0.16); color: var(--accent-deep); }
.badge, .active-pill { background: rgba(170, 61, 45, 0.1); color: var(--accent-deep); font-weight: 700; }
.check-list { margin: 0; padding-left: 18px; color: var(--ink-soft); line-height: 1.7; }
.page-hero.compact { display: flex; justify-content: space-between; align-items: end; gap: 24px; margin-bottom: 26px; }
.filter-bar { align-items: center; }
.marketplace-filter { display: grid; grid-template-columns: repeat(4, minmax(180px, 1fr)); width: 100%; }
.marketplace-hero { align-items: start; }
.marketplace-grid .marketplace-card { background: linear-gradient(180deg, rgba(255, 249, 239, 0.96), rgba(255, 244, 229, 0.92)); }
.marketplace-card h2 { margin-bottom: 6px; }
.meta-grid.compact span { min-width: 140px; }
.teacher-card-header { align-items: start; }
.teacher-metrics { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; justify-content: flex-end; }
.metric-inline { font-size: 0.92rem; color: var(--ink-soft); font-weight: 700; }
.filter-bar input, input, textarea, select { width: 100%; padding: 14px 16px; border-radius: 16px; border: 1px solid rgba(31, 36, 48, 0.16); background: #fffdf8; color: var(--ink); font-size: 16px; }
select[multiple] { min-height: 160px; }
.selected-chip-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.selected-chip { border: 1px solid rgba(170, 61, 45, 0.24); background: rgba(170, 61, 45, 0.1); color: var(--accent-deep); border-radius: 999px; padding: 8px 12px; cursor: pointer; }
.token-picker { display: grid; gap: 10px; }
.token-picker-controls { display: flex; gap: 10px; align-items: center; }
.selected-table { display: grid; gap: 8px; margin-top: 12px; }
.selected-table-row { display: grid; grid-template-columns: 1fr 1fr auto; gap: 10px; align-items: center; padding: 10px 12px; border: 1px solid var(--line); border-radius: 14px; background: rgba(255,255,255,0.65); }
.selected-table-subjects .selected-table-row { grid-template-columns: 1.2fr 1fr 0.7fr auto; }
.subject-grid { display: grid; grid-template-columns: 1.2fr 1fr 0.7fr auto; gap: 12px; }
.subject-summary-list { display: grid; gap: 8px; }
.subject-summary-list p { margin: 0; }
.certificate-upload-list { display: grid; gap: 12px; margin-top: 12px; }
.certificate-upload-row { display: grid; gap: 14px; padding: 14px 16px; border: 1px solid var(--line); border-radius: 18px; background: rgba(255,255,255,0.7); }
.certificate-upload-row p { margin: 4px 0 0; }
.subtle-panel { background: rgba(255,255,255,0.42); box-shadow: none; }
.confirm-dialog { border: 1px solid var(--line); border-radius: 26px; padding: 0; width: min(560px, calc(100vw - 32px)); background: var(--surface-solid); box-shadow: var(--shadow); }
.review-dialog { width: min(85vw, 1200px); max-height: 85vh; overflow: auto; }
.confirm-dialog::backdrop { background: rgba(31, 36, 48, 0.45); backdrop-filter: blur(4px); }
.confirm-dialog-shell, .confirm-dialog-form { display: grid; gap: 18px; padding: 24px 26px; }
.confirm-dialog-copy h2 { margin: 0 0 10px; }
.confirm-dialog-copy p { margin: 0; }
.tour-progress { text-align: right; font-weight: 700; color: var(--accent-deep); margin: 0; }
.confirm-dialog-actions { display: flex; gap: 12px; justify-content: flex-end; flex-wrap: wrap; }
.confirm-checkbox { grid-template-columns: auto 1fr; align-items: start; gap: 12px; font-weight: 600; }
.confirm-checkbox input { width: auto; margin-top: 4px; }
.tour-step[hidden] { display: none !important; }
.pair-action { display: flex; align-items: end; }
.filter-inline { display: flex; gap: 16px; align-items: end; flex-wrap: wrap; }
.pagination-row { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 24px; }
.availability-grid { display: grid; grid-template-columns: 110px repeat(7, minmax(90px, 1fr)); gap: 8px; overflow-x: auto; }
.availability-head, .availability-time, .availability-cell { min-height: 52px; border-radius: 14px; border: 1px solid var(--line); background: rgba(255,255,255,0.72); display: grid; place-items: center; text-align: center; }
.availability-head, .availability-time { font-weight: 700; color: var(--accent-deep); }
.availability-cell { position: relative; cursor: pointer; padding: 0; }
.availability-cell input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }
.availability-cell span { font-size: 0.88rem; color: var(--ink-soft); }
.availability-cell.available { background: rgba(69, 140, 87, 0.16); border-color: rgba(69, 140, 87, 0.48); }
.availability-cell.available span { color: #2d6b3c; font-weight: 700; }
.availability-cell.taken { background: rgba(170, 61, 45, 0.12); border-color: rgba(170, 61, 45, 0.4); }
.availability-cell.taken span { color: #8f3325; font-weight: 700; }
.availability-cell.static { cursor: default; }
.availability-cell.static input { display: none; }
.availability-legend { display: flex; gap: 10px; flex-wrap: wrap; margin: 0 0 14px; }
.availability-key { display: inline-flex; align-items: center; gap: 6px; border-radius: 999px; padding: 8px 12px; font-size: 0.85rem; font-weight: 700; border: 1px solid var(--line); }
.availability-key.available { background: rgba(69, 140, 87, 0.16); border-color: rgba(69, 140, 87, 0.48); color: #2d6b3c; }
.availability-key.taken { background: rgba(170, 61, 45, 0.12); border-color: rgba(170, 61, 45, 0.4); color: #8f3325; }
.availability-grid.compact { grid-template-columns: 84px repeat(7, minmax(70px, 1fr)); }
.availability-grid.availability-grid-dual-time.compact { grid-template-columns: 92px 92px repeat(7, minmax(70px, 1fr)); }
.availability-compare-grid { display: grid; grid-template-columns: 100px minmax(0, 1fr) minmax(0, 1fr) 100px; gap: 10px; margin: 0 0 16px; }
.availability-compare-head,
.availability-compare-day,
.availability-compare-cell { border: 1px solid var(--line); border-radius: 16px; background: rgba(255,255,255,0.68); padding: 12px 14px; }
.availability-compare-title { grid-column: 1 / -1; font-weight: 800; color: var(--accent-deep); text-align: center; }
.availability-compare-head { font-weight: 800; color: var(--accent-deep); text-align: center; }
.timezone-stack { display: inline-grid; gap: 2px; line-height: 1.2; }
.timezone-stack span:last-child { font-size: 0.92em; font-weight: 600; color: var(--ink-soft); }
.availability-compare-day { font-weight: 700; color: var(--ink); display: grid; place-items: center; }
.availability-compare-day-span { grid-column: 2 / 4; }
.availability-compare-cell span { color: var(--ink-soft); }
.availability-compare-cell { min-height: 52px; display: grid; align-items: center; }
.availability-compare-student { background: rgba(255,255,255,0.82); }
.availability-summary { display: grid; gap: 6px; margin-top: 12px; }
label { display: grid; gap: 8px; font-weight: 700; color: var(--ink); }
label span { font-size: 0.92rem; }
.auth-shell { display: grid; gap: 24px; grid-template-columns: 0.82fr 1.18fr; align-items: start; }
.auth-shell.single { grid-template-columns: minmax(320px, 620px); justify-content: center; }
.auth-shell.wide { grid-template-columns: minmax(320px, 940px); }
.booking-layout { align-items: start; }
.booking-balance-note { margin: 14px 0; }
.booking-balance-note p { margin: 0 0 8px; }
.booking-balance-note p:last-child { margin-bottom: 0; }
.booking-card .price-box { display: flex; justify-content: space-between; padding: 12px 0; border-bottom: 1px solid var(--line); }
.flash-stack { display: grid; gap: 12px; margin-bottom: 18px; }
.flash { padding: 14px 18px; border-radius: 18px; font-weight: 700; }
.flash-success { background: rgba(67, 146, 86, 0.12); color: #1b5c2a; }
.flash-error { background: rgba(170, 61, 45, 0.14); color: #7c2418; }
.stat-panel { display: grid; gap: 10px; align-content: start; min-height: 150px; padding: 24px 26px; }
.stat-panel span { font-size: 0.9rem; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.06em; }
.stat-panel strong { font-size: clamp(1.45rem, 2.2vw, 2rem); line-height: 1.25; display: block; }
.list-item { padding: 14px 0; border-bottom: 1px solid var(--line); flex-direction: column; }
.lesson-card-shell { padding: 18px 22px; }
.lesson-dashboard-card { display: grid; gap: 10px; border: 1px solid rgba(170, 61, 45, 0.22); }
.lesson-card-summary { display: flex; justify-content: space-between; gap: 16px; align-items: center; flex-wrap: wrap; }
.lesson-card-summary strong { display: block; margin-bottom: 4px; }
.lesson-card-summary span { color: var(--ink-soft); }
.lesson-card-meta { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; justify-content: flex-end; }
.lesson-card-details[hidden] { display: none !important; }
.lesson-card-details { margin-top: 18px; padding-top: 18px; border-top: 1px solid var(--line); display: grid; gap: 18px; }
.completion-compare { display: grid; gap: 10px; }
.completion-compare-row { display: flex; justify-content: space-between; gap: 16px; padding: 12px 14px; border: 1px solid var(--line); border-radius: 14px; background: rgba(255,255,255,0.68); flex-wrap: wrap; }
.messages-layout { align-items: start; }
.conversation-list { display: grid; gap: 10px; }
.conversation-group { display: grid; gap: 10px; }
.conversation-group h3 { margin: 4px 0 0; font-size: 0.95rem; color: var(--muted); }
.conversation-row { display: grid; grid-template-columns: 1fr auto; gap: 10px; align-items: center; padding: 10px; border: 1px solid var(--line); border-radius: 16px; background: rgba(255,255,255,0.62); }
.conversation-row.active { border-color: rgba(170, 61, 45, 0.45); background: rgba(170, 61, 45, 0.12); }
.conversation-link { display: grid; gap: 6px; padding: 2px 4px; }
.conversation-link.active { color: var(--accent-deep); }
.conversation-action { margin: 0; }
.message-thread { display: grid; gap: 16px; min-width: 0; }
.messages-box { display: grid; gap: 12px; max-height: 520px; overflow: auto; min-width: 0; }
.message { max-width: 82%; padding: 14px 16px; border-radius: 18px; background: rgba(255,255,255,0.85); border: 1px solid var(--line); min-width: 0; }
.message.mine { margin-left: auto; background: rgba(170, 61, 45, 0.1); }
.message.admin-message { max-width: 100%; background: rgba(170, 30, 30, 0.12); border-color: rgba(170, 30, 30, 0.42); }
.message-form { align-items: end; }
.message-form textarea { flex: 1; }
.message p { margin: 8px 0 0; overflow-wrap: anywhere; word-break: break-word; }
.admin-notice-banner { width: fit-content; }
.admin-thread-box { max-height: 760px; }
.admin-attachment { display: grid; gap: 10px; margin-top: 12px; }
.admin-attachment img, .admin-attachment video { width: min(100%, 420px); border-radius: 16px; border: 1px solid var(--line); background: #fff; }
.progress-entry p { margin: 8px 0; }
.footer { margin-top: 48px; padding: 28px 10px 12px; border-top: 1px solid var(--line); align-items: flex-start; }
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }
.footer-copy { margin-top: 10px; font-size: 0.92rem; }
.helper { font-size: 0.9rem; }
.empty-state { text-align: center; }
.review-item { padding: 14px 0; border-bottom: 1px solid var(--line); }
.legal-page { max-width: 980px; margin: 0 auto; }
.legal-copy h2 { margin-top: 0; }
.tour-active .topbar,
.tour-active .flash-stack,
.tour-active .footer,
.tour-active main > *:not(dialog[open]) {
    filter: blur(8px);
    opacity: 0.55;
    pointer-events: none;
    transition: filter 180ms ease, opacity 180ms ease;
}
.course-protected-shell { user-select: none; -webkit-user-select: none; }

@media (max-width: 640px) {
    .topbar { border-radius: 28px; }
    .hero h1, .page-hero h1, .auth-form h1, .profile-hero h1 { font-size: clamp(2.1rem, 11vw, 3.2rem); }
    .btn, .btn-small { width: 100%; }
    .hero-actions, .footer { flex-direction: column; align-items: stretch; }
    .message { max-width: 100%; }
    .token-picker-controls, .selected-table-row { grid-template-columns: 1fr; display: grid; }
    .subject-grid, .selected-table-subjects .selected-table-row, .certificate-upload-row, .auth-shell.wide { grid-template-columns: 1fr; }
    .teacher-metrics { justify-content: flex-start; }
    .lesson-card-meta, .lesson-card-summary { justify-content: flex-start; }
    .confirm-dialog-actions { flex-direction: column; align-items: stretch; }
    .panel, .teacher-card, .feature-card, .auth-form, .auth-copy { padding: 20px; }
    .availability-grid { grid-template-columns: 84px repeat(7, minmax(68px, 1fr)); }
    .availability-grid.availability-grid-dual-time.compact { grid-template-columns: 84px 84px repeat(7, minmax(68px, 1fr)); }
    .availability-compare-grid { grid-template-columns: 1fr; }
    .availability-compare-title { grid-column: auto; }
}

@media (max-width: 900px) {
    .hero, .profile-hero, .messages-layout, .auth-shell, .admin-dispute-layout { grid-template-columns: 1fr; }
    .topbar, .page-hero.compact, .message-form { flex-direction: column; align-items: stretch; }
    .nav { justify-content: flex-start; }
    .site-shell { padding: 16px; }
    .marketplace-filter { grid-template-columns: 1fr; }
    .availability-grid { grid-template-columns: 90px repeat(7, minmax(72px, 1fr)); }
    .two-col, .three-col, .section-heading.inline, .teacher-card-top, .meta-grid, .meta-row, .filter-inline { flex-direction: column; align-items: stretch; }
}