:root {
    --font-sans: "DM Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
    --font-serif: "Source Serif 4", Georgia, "Times New Roman", serif;
    --bg: #f0f2f7;
    --bg-elevated: #ffffff;
    --surface: #ffffff;
    --text: #0c1222;
    --text-secondary: #334155;
    --muted: #64748b;
    --border: #e2e8f0;
    --border-subtle: #eef2f7;
    --primary: #4338ca;
    --primary-hover: #3730a3;
    --primary-soft: #eef2ff;
    --accent: #d97706;
    --accent-soft: #fffbeb;
    --danger: #dc2626;
    --danger-soft: #fef2f2;
    --success: #059669;
    --success-soft: #ecfdf5;
    --radius-sm: 6px;
    --radius: 12px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 2px rgba(12, 18, 34, 0.05);
    --shadow: 0 4px 16px rgba(12, 18, 34, 0.06);
    --shadow-lg: 0 12px 40px rgba(12, 18, 34, 0.1);
    --header-h: 4rem;
    --transition: 0.18s ease;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body,
.app-body {
    margin: 0;
    min-height: 100vh;
    font-family: var(--font-sans);
    font-size: 1rem;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    display: flex;
    flex-direction: column;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(67, 56, 202, 0.07), transparent),
        radial-gradient(ellipse 60% 40% at 100% 100%, rgba(217, 119, 6, 0.04), transparent);
    pointer-events: none;
    z-index: -1;
}

main {
    flex: 1;
}

a {
    color: var(--primary);
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
    min-height: var(--header-h);
    padding: 0.65rem 1.5rem;
    background: rgba(255, 255, 255, 0.88);
    border-bottom: 1px solid var(--border-subtle);
    box-shadow: var(--shadow-sm);
    backdrop-filter: blur(12px);
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.65rem;
}

.brand-mark {
    display: flex;
    color: var(--primary);
    flex-shrink: 0;
}

.brand__title,
.brand h1 {
    margin: 0;
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.brand-link {
    color: inherit;
    text-decoration: none;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.main-nav ul {
    display: flex;
    gap: 0.5rem;
    list-style: none;
    margin: 0;
    padding: 0;
}

.main-nav a {
    text-decoration: none;
    color: var(--muted);
    padding: 0.4rem 0.85rem;
    border-radius: 999px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: background var(--transition), color var(--transition);
}

.main-nav a.active {
    color: var(--primary);
    background: var(--primary-soft);
    font-weight: 600;
}

.main-nav a:hover:not(.active) {
    color: var(--text);
    background: var(--border-subtle);
}

.user-nav {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.user-label {
    color: var(--muted);
    font-size: 0.9rem;
}

.logout-form {
    margin: 0;
}

.page {
    max-width: 920px;
    margin: 0 auto;
    padding: 1.75rem 1.25rem 3rem;
}

.panel {
    background: var(--surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius);
    padding: 1.35rem 1.5rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.25rem;
    transition: box-shadow var(--transition);
}

.panel:hover {
    box-shadow: var(--shadow);
}

.panel h2,
.panel h3 {
    margin-top: 0;
    letter-spacing: -0.02em;
}

.panel h2 {
    font-size: 1.35rem;
}

.lead {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin: 0.35rem 0 0;
    max-width: 42rem;
}

.text-muted {
    color: var(--muted);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.35rem;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.6rem 1.15rem;
    font-family: inherit;
    font-size: 0.92rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    background: var(--primary);
    color: #fff;
    box-shadow: 0 1px 2px rgba(67, 56, 202, 0.25);
    transition: background var(--transition), transform 0.12s ease, box-shadow var(--transition);
}

.btn:hover {
    background: var(--primary-hover);
    box-shadow: 0 2px 8px rgba(67, 56, 202, 0.3);
}

.btn:active {
    transform: translateY(1px);
}

.btn:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    transform: none;
}

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.82rem;
}

.btn-ghost {
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--border);
    box-shadow: none;
}

.btn-ghost:hover {
    background: var(--primary-soft);
    border-color: #c7d2fe;
    box-shadow: none;
}

.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    background: var(--bg);
}

.auth-card {
    width: 100%;
    max-width: 420px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow);
}

.auth-card h1 {
    margin-top: 0;
    font-size: 1.5rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.35rem;
    font-weight: 600;
    font-size: 0.9rem;
}

.form-group input {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
}

.alert {
    padding: 0.75rem 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.alert-error {
    background: #fef2f2;
    color: var(--danger);
    border: 1px solid #fecaca;
}

.alert-success {
    background: #f0fdf4;
    color: var(--success);
    border: 1px solid #bbf7d0;
}

.site-footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--muted);
    font-size: 0.85rem;
}

.empty-state {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--muted);
}

/* Modals (see assets/js/modal.js) */
body.courses-modal-open {
    overflow: hidden;
}

.courses-modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 1000;
    background: rgba(15, 23, 42, 0.45);
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.courses-modal-overlay.is-open {
    display: flex;
}

.courses-modal {
    background: var(--surface);
    border-radius: var(--radius);
    max-width: 480px;
    width: 100%;
    box-shadow: 0 20px 40px rgba(15, 23, 42, 0.2);
    border: 1px solid var(--border);
}

.courses-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
}

.courses-modal-header h2 {
    margin: 0;
    font-size: 1.1rem;
}

.courses-modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    line-height: 1;
    cursor: pointer;
    color: var(--muted);
    padding: 0 0.25rem;
}

.courses-modal-body {
    padding: 1.25rem;
}

.courses-modal-footer {
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
    padding: 1rem 1.25rem;
    border-top: 1px solid var(--border);
}

.courses-toast {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    z-index: 1100;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    background: #1e293b;
    color: #fff;
    font-size: 0.9rem;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.2s, transform 0.2s;
    pointer-events: none;
    max-width: 320px;
}

.courses-toast.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.courses-toast--error {
    background: #991b1b;
}

.courses-toast--success {
    background: #166534;
}

.courses-toast--info {
    background: #1e40af;
}

.lesson-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.lesson-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border);
}

.lesson-list a {
    text-decoration: none;
    font-weight: 500;
}

.lesson-type {
    font-size: 0.8rem;
    margin-left: 0.5rem;
}

.badge-high-yield {
    display: inline-block;
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    background: var(--accent-soft);
    color: #b45309;
    padding: 0.15rem 0.45rem;
    border-radius: 4px;
    margin-left: 0.35rem;
}

.lesson-body,
.lesson-article .lesson-body {
    font-family: var(--font-serif);
    font-size: 1.0625rem;
    line-height: 1.75;
    color: var(--text-secondary);
    max-width: 42rem;
}

.lesson-body h1, .lesson-body h2, .lesson-body h3 {
    margin-top: 1.25rem;
}

.lesson-body pre, .lesson-body-plain {
    background: #f1f5f9;
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
}

.breadcrumb {
    font-size: 0.9rem;
    color: var(--muted);
    margin-bottom: 1rem;
}

.lesson-nav {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.alert-success {
    background: #f0fdf4;
    color: var(--success);
    border: 1px solid #bbf7d0;
}

.sync-table-wrap {
    overflow-x: auto;
    margin: 1rem 0;
}

.sync-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.sync-table th,
.sync-table td {
    padding: 0.6rem 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
    vertical-align: top;
}

.sync-table th {
    font-weight: 600;
    color: var(--muted);
}

.sync-table code {
    font-size: 0.85em;
}

.manual-slug {
    margin-top: 1rem;
}

.manual-slug summary {
    cursor: pointer;
    color: var(--muted);
    font-size: 0.9rem;
}

.course-cards {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.course-card {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem 1.15rem;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: #fff;
}

.course-card--enrolled {
    border-color: #bfdbfe;
    background: #f8fafc;
}

.course-card__body {
    flex: 1 1 16rem;
    min-width: 0;
}

.course-card__title {
    margin: 0 0 0.35rem;
    font-size: 1.1rem;
}

.course-card__title a {
    text-decoration: none;
    color: inherit;
}

.course-card__title a:hover {
    color: var(--primary);
}

.course-card__subtitle,
.course-card__desc {
    margin: 0 0 0.5rem;
    color: var(--muted);
    font-size: 0.95rem;
    line-height: 1.45;
}

.course-card__meta {
    margin: 0;
    font-size: 0.85rem;
    color: var(--muted);
}

.course-card__progress {
    margin: 0.5rem 0 0;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--success);
}

.course-card__actions {
    flex-shrink: 0;
    align-self: center;
}

.enroll-form {
    margin: 0;
}

.badge-status {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    padding: 0.15rem 0.45rem;
    border-radius: 4px;
}

.badge-status--published {
    background: #dcfce7;
    color: #166534;
}

.badge-status--draft {
    background: #fef3c7;
    color: #92400e;
}

.badge-status--archived {
    background: #f1f5f9;
    color: #64748b;
}

/* Study UX */
.page--wide {
    max-width: 1200px;
}

.study-hero {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
}

.study-hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.progress-bar {
    height: 8px;
    background: #e2e8f0;
    border-radius: 999px;
    overflow: hidden;
    margin: 0.75rem 0 0.35rem;
}

.progress-bar__fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), #6366f1);
    border-radius: 999px;
    transition: width 0.35s ease;
}

.progress-stats {
    font-size: 0.9rem;
    color: var(--muted);
}

.study-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border);
}

.study-filter {
    margin-left: auto;
    font-size: 0.9rem;
}

.study-filter label {
    cursor: pointer;
    color: var(--muted);
}

.lesson-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.25rem;
}

@media (min-width: 900px) {
    .lesson-layout {
        grid-template-columns: 1fr 280px;
    }
    .lesson-layout__sidebar {
        order: 2;
    }
    .lesson-layout__main {
        order: 1;
    }
}

.course-outline {
    position: sticky;
    top: 1rem;
    max-height: calc(100vh - 2rem);
    overflow-y: auto;
    font-size: 0.85rem;
}

.course-outline h4 {
    margin: 0 0 0.5rem;
    font-size: 0.95rem;
}

.course-outline__module {
    margin-bottom: 0.75rem;
}

.course-outline__module-title {
    font-weight: 600;
    margin: 0 0 0.25rem;
    color: var(--text);
}

.course-outline__lessons {
    list-style: none;
    padding: 0;
    margin: 0;
}

.course-outline__lessons a {
    display: block;
    padding: 0.25rem 0.35rem;
    border-radius: 4px;
    text-decoration: none;
    color: var(--muted);
}

.course-outline__lessons a:hover,
.course-outline__lessons a.is-current {
    background: #eff6ff;
    color: var(--primary);
}

.lesson-row {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
}

.lesson-row__icon {
    flex-shrink: 0;
    width: 1.25rem;
    text-align: center;
    font-size: 0.85rem;
}

.lesson-row--done .lesson-row__icon {
    color: var(--success);
}

.lesson-row--active .lesson-row__icon {
    color: var(--primary);
}

.lesson-row--todo .lesson-row__icon {
    color: #cbd5e1;
}

.lesson-row.is-filtered-out {
    display: none;
}

.module-panel.is-collapsed .lesson-list {
    display: none;
}

.module-panel__head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    cursor: pointer;
}

.module-panel__head h3 {
    margin: 0;
}

.module-meta {
    font-size: 0.85rem;
    color: var(--muted);
}

.lesson-notes {
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

.lesson-notes label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.35rem;
}

.lesson-notes textarea {
    width: 100%;
    min-height: 5rem;
    padding: 0.6rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-family: inherit;
    font-size: 0.95rem;
    resize: vertical;
}

.lesson-notes__hint {
    font-size: 0.8rem;
    color: var(--muted);
    margin-top: 0.35rem;
}

.study-objectives {
    background: #f0f9ff;
    border: 1px solid #bae6fd;
    border-radius: 8px;
    padding: 0.75rem 1rem;
    margin: 1rem 0;
}

.study-objectives h3 {
    margin: 0 0 0.5rem;
    font-size: 0.95rem;
}

/* Quiz player */
.quiz-player__header {
    margin-bottom: 1rem;
}

.quiz-player__progress {
    height: 6px;
    background: #e2e8f0;
    border-radius: 999px;
    overflow: hidden;
}

.quiz-player__progress-fill {
    height: 100%;
    background: var(--primary);
}

.quiz-player__meta {
    margin: 0.35rem 0 0;
    font-size: 0.85rem;
    color: var(--muted);
}

.quiz-card__stem {
    font-size: 1.05rem;
    font-weight: 600;
    margin-top: 0;
}

.quiz-choices {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-top: 1rem;
}

.quiz-choice {
    display: flex;
    align-items: flex-start;
    gap: 0.65rem;
    padding: 0.85rem 1rem;
    border: 2px solid var(--border);
    border-radius: 10px;
    cursor: pointer;
    min-height: 44px;
}

.quiz-choice:hover {
    border-color: #93c5fd;
}

.quiz-choice.is-selected {
    border-color: var(--primary);
    background: #eff6ff;
}

.quiz-choice input {
    margin-top: 0.2rem;
    flex-shrink: 0;
}

.quiz-choice__label {
    font-weight: 700;
    min-width: 1.5rem;
}

.quiz-player__footer {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: flex-end;
    margin-top: 1rem;
}

.quiz-results__score {
    font-size: 1.5rem;
    font-weight: 700;
}

.text-success {
    color: var(--success);
}

.text-danger {
    color: var(--danger);
}

.quiz-review__item {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border);
}

.quiz-review__item.is-correct {
    border-left: 3px solid var(--success);
    padding-left: 0.5rem;
}

.quiz-review__item.is-wrong {
    border-left: 3px solid var(--danger);
    padding-left: 0.5rem;
}

.quiz-review__choices {
    list-style: none;
    padding: 0;
    margin: 0.5rem 0;
}

.quiz-review__choices li.correct {
    color: var(--success);
}

.quiz-review__choices li.your-answer:not(.correct) {
    color: var(--danger);
}

.quiz-review__explanation {
    font-size: 0.9rem;
    color: var(--muted);
}

.continue-card {
    background: linear-gradient(135deg, #eff6ff 0%, #f8fafc 100%);
    border-color: #93c5fd;
}

.continue-card h3 {
    margin-top: 0;
}

.dashboard-grid {
    display: grid;
    gap: 1rem;
}

@media (min-width: 700px) {
    .dashboard-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.high-yield-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.high-yield-list li {
    padding: 0.4rem 0;
    border-bottom: 1px solid var(--border);
}

.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    z-index: 2000;
    padding: 0.5rem 1rem;
    background: var(--primary);
    color: #fff;
    border-radius: 0 0 8px 0;
    text-decoration: none;
}

.skip-link:focus {
    left: 0;
}

.btn:focus-visible,
a:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.lesson-body code {
    font-size: 0.9em;
    background: #f1f5f9;
    padding: 0.1em 0.35em;
    border-radius: 4px;
}

.lesson-body pre {
    background: #0f172a;
    color: #e2e8f0;
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
}

.lesson-body pre code {
    background: transparent;
    padding: 0;
    color: inherit;
}

.lesson-body table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
    font-size: 0.92rem;
}

.lesson-body th,
.lesson-body td {
    border: 1px solid var(--border);
    padding: 0.5rem 0.65rem;
}

.lesson-body th {
    background: #f8fafc;
}

.lesson-body blockquote {
    margin: 1rem 0;
    padding: 0.5rem 1rem;
    border-left: 4px solid #93c5fd;
    background: #f8fafc;
    color: var(--muted);
}

#lesson-notes-input::placeholder {
    font-style: italic;
    font-weight: 400;
    color: #94a3b8;
    font-size: 0.92em;
}

.badge-type {
    display: inline-block;
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    padding: 0.12rem 0.4rem;
    border-radius: 4px;
    margin-left: 0.35rem;
}

.badge-type--quiz { background: #ede9fe; color: #5b21b6; }
.badge-type--exam { background: #fce7f3; color: #9d174d; }
.badge-type--lab { background: #d1fae5; color: #065f46; }
.badge-type--ref { background: #f1f5f9; color: #475569; }

.module-panel__head-main { flex: 1; min-width: 0; }

.module-progress {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.35rem;
    max-width: 14rem;
}

.module-progress__bar {
    flex: 1;
    height: 4px;
    background: #e2e8f0;
    border-radius: 999px;
    overflow: hidden;
}

.module-progress__fill {
    height: 100%;
    background: var(--success);
}

.module-progress__label {
    font-size: 0.75rem;
    color: var(--muted);
}

.study-toolbar__actions {
    display: flex;
    gap: 0.35rem;
    flex-wrap: wrap;
}

.lesson-row__body { flex: 1; min-width: 0; }

.lesson-meta-bar {
    border-bottom: none;
    margin-bottom: 0.5rem;
    padding-bottom: 0;
}

.lesson-toolbar-mobile {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.75rem;
}

@media (min-width: 900px) {
    .lesson-toolbar-mobile { display: none; }
}

.panel--nested {
    background: #f8fafc;
    border-style: dashed;
    margin-bottom: 1rem;
}

.assessment-banner__type {
    font-weight: 700;
    margin: 0 0 0.35rem;
    font-size: 0.85rem;
    text-transform: uppercase;
    color: var(--primary);
}

.assessment-banner__meta {
    list-style: none;
    padding: 0;
    margin: 0.5rem 0 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    font-size: 0.85rem;
    color: var(--muted);
}

.lesson-prep {
    margin-top: 1.25rem;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
}

.lesson-prep summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--muted);
}

.lesson-notes__actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-top: 0.5rem;
}

.lesson-notes__status {
    font-size: 0.8rem;
    color: var(--muted);
}

.outline-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.4);
    z-index: 90;
}

.outline-backdrop.is-visible { display: block; }

@media (max-width: 899px) {
    .lesson-layout__sidebar {
        display: none;
        position: fixed;
        top: 0;
        right: 0;
        bottom: 0;
        width: min(320px, 92vw);
        z-index: 100;
        padding: 1rem;
        background: var(--bg);
        box-shadow: -4px 0 24px rgba(15, 23, 42, 0.15);
        overflow-y: auto;
    }
    .lesson-layout__sidebar.is-open { display: block; }
    .lesson-layout__sidebar .course-outline {
        position: static;
        max-height: none;
    }
}

.quiz-player__title {
    font-size: 1.1rem;
    font-weight: 700;
    margin: 0 0 0.75rem;
}

.quiz-player__nav {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
    margin-bottom: 1rem;
}

.quiz-player__nav-btn {
    min-width: 2rem;
    height: 2rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: #fff;
    font-size: 0.8rem;
    cursor: pointer;
    color: var(--muted);
}

.quiz-player__nav-btn.is-current {
    border-color: var(--primary);
    background: #eff6ff;
    color: var(--primary);
    font-weight: 700;
}

.quiz-player__nav-btn.is-answered:not(.is-current) {
    border-color: #86efac;
    background: #f0fdf4;
}

.lesson-nav {
    clear: both;
}

.lesson-nav::after {
    content: '';
    display: table;
    clear: both;
}

/* ——— Design system: pages & components ——— */

.dashboard-welcome {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-end;
    justify-content: space-between;
    gap: 1.25rem;
    margin-bottom: 1.75rem;
}

.dashboard-welcome__eyebrow {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--primary);
    margin: 0 0 0.35rem;
}

.dashboard-welcome h1 {
    margin: 0;
    font-size: clamp(1.65rem, 4vw, 2.1rem);
    letter-spacing: -0.03em;
    line-height: 1.15;
}

.dashboard-welcome__cta {
    white-space: normal;
    text-align: center;
    max-width: 20rem;
}

.stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr));
    gap: 0.85rem;
    margin-bottom: 1.25rem;
}

.stat-tile {
    background: var(--surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius);
    padding: 1rem 1.1rem;
    box-shadow: var(--shadow-sm);
}

.stat-tile__value {
    display: block;
    font-size: 1.65rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--text);
    line-height: 1.1;
}

.stat-tile__label {
    display: block;
    font-size: 0.82rem;
    color: var(--muted);
    margin-top: 0.25rem;
}

.panel__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.panel__title {
    margin: 0;
    font-size: 1.15rem;
    letter-spacing: -0.02em;
}

.panel--accent {
    background: linear-gradient(135deg, var(--primary-soft) 0%, var(--surface) 55%);
    border-color: #c7d2fe;
}

.panel--flat {
    background: transparent;
    border: none;
    box-shadow: none;
    padding: 0.75rem 0;
    margin-bottom: 0.5rem;
}

.link-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.link-list__item {
    border-bottom: 1px solid var(--border-subtle);
}

.link-list__item:last-child {
    border-bottom: none;
}

.link-list__item a {
    display: block;
    padding: 0.85rem 0.25rem;
    text-decoration: none;
    color: inherit;
    border-radius: var(--radius-sm);
    transition: background var(--transition);
}

.link-list__item a:hover {
    background: rgba(67, 56, 202, 0.06);
}

.link-list__primary {
    display: block;
    font-weight: 600;
    color: var(--text);
}

.link-list__secondary {
    display: block;
    font-size: 0.85rem;
    color: var(--muted);
    margin-top: 0.15rem;
}

.progress-ring {
    width: 4.25rem;
    height: 4.25rem;
    border-radius: 50%;
    background: conic-gradient(var(--primary) var(--progress, 0deg), var(--border) 0);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.progress-ring__inner {
    width: calc(100% - 10px);
    height: calc(100% - 10px);
    border-radius: 50%;
    background: var(--surface);
    display: flex;
    align-items: center;
    justify-content: center;
}

.progress-ring__value {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--primary);
}

.course-card--enrolled {
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: 1rem;
    border-color: #c7d2fe;
    background: linear-gradient(90deg, #fafbff 0%, #fff 40%);
    transition: box-shadow var(--transition), border-color var(--transition);
}

.course-card--enrolled:hover {
    border-color: #a5b4fc;
    box-shadow: var(--shadow);
}

.page-intro {
    margin-bottom: 1.5rem;
}

.page-intro h1 {
    margin: 0 0 0.35rem;
    font-size: 1.75rem;
    letter-spacing: -0.03em;
}

.breadcrumb ol {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.35rem 0.5rem;
    list-style: none;
    padding: 0;
    margin: 0 0 1.25rem;
    font-size: 0.85rem;
    color: var(--muted);
}

.breadcrumb li:not(:last-child)::after {
    content: "›";
    margin-left: 0.5rem;
    color: #cbd5e1;
    font-weight: 600;
}

.breadcrumb a {
    text-decoration: none;
    color: var(--muted);
}

.breadcrumb a:hover {
    color: var(--primary);
}

.breadcrumb [aria-current="page"] {
    color: var(--text);
    font-weight: 500;
}

.page-hero {
    display: grid;
    grid-template-columns: auto 1fr;
    grid-template-areas:
        "ring main"
        "ring actions";
    gap: 0 1.5rem;
    align-items: start;
    background: linear-gradient(135deg, var(--primary-soft) 0%, var(--surface) 42%);
    border-color: #c7d2fe;
}

.page-hero__ring {
    grid-area: ring;
    padding-top: 0.25rem;
}

.page-hero__main {
    grid-area: main;
    min-width: 0;
}

.page-hero__actions {
    grid-area: actions;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.page-hero__title {
    margin: 0 0 0.35rem;
    font-size: clamp(1.35rem, 3vw, 1.75rem);
    letter-spacing: -0.03em;
}

.page-hero__meta {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--primary);
    margin: 0 0 0.5rem;
}

.study-toolbar__label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text);
}

.lesson-article__title {
    margin: 0 0 0.75rem;
    font-size: clamp(1.4rem, 3vw, 1.85rem);
    letter-spacing: -0.03em;
    line-height: 1.2;
    font-family: var(--font-sans);
    color: var(--text);
}

.lesson-complete-action {
    margin-top: 1.75rem;
}

.lesson-nav--bar {
    position: sticky;
    bottom: 0;
    z-index: 50;
    margin-top: 0.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
}

@media (max-width: 899px) {
    .lesson-nav--bar {
        position: fixed;
        left: 1rem;
        right: 1rem;
        bottom: 1rem;
        margin: 0;
        padding: 0.75rem 1rem;
    }

    .lesson-page {
        padding-bottom: 5rem;
    }

    .page-hero {
        grid-template-columns: 1fr;
        grid-template-areas: "ring" "main" "actions";
    }

    .page-hero__ring {
        justify-self: start;
    }
}

.site-footer {
    margin-top: auto;
    padding: 2rem 1.5rem;
    border-top: 1px solid var(--border-subtle);
    background: rgba(255, 255, 255, 0.6);
}

.site-footer__copy {
    margin: 0;
    font-size: 0.85rem;
    color: var(--muted);
}

.site-footer__tagline {
    margin: 0.25rem 0 0;
    font-size: 0.78rem;
    color: #94a3b8;
}

.auth-card {
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-lg);
}

.auth-card__subtitle {
    margin-top: 0;
    margin-bottom: 1.5rem;
}

.btn-block {
    width: 100%;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(67, 56, 202, 0.15);
}

.module-panel {
    transition: border-color var(--transition);
}

.module-panel:hover {
    border-color: #cbd5e1;
}

.module-panel__head .text-muted[aria-hidden] {
    transition: transform var(--transition);
}

.module-panel.is-collapsed .module-panel__head .text-muted[aria-hidden] {
    transform: rotate(-90deg);
}

.lesson-list li:last-child {
    border-bottom: none;
}

.lesson-row a {
    font-weight: 500;
    text-decoration: none;
    color: var(--text);
}

.lesson-row a:hover {
    color: var(--primary);
}

.lesson-row--hy {
    background: linear-gradient(90deg, var(--accent-soft) 0%, transparent 70%);
    margin: 0 -0.5rem;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
}

.quiz-card {
    border: none;
    box-shadow: none;
    padding: 0;
}

.quiz-choice:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(67, 56, 202, 0.12);
}

.empty-state h3 {
    margin-top: 0;
    color: var(--text);
}

/* Module self-rating */
.module-self-rating {
    margin-top: 1.25rem;
    padding-top: 1.15rem;
    border-top: 1px solid var(--border-subtle);
}

.module-panel .module-self-rating {
    margin: 0.75rem 0 0.25rem;
    padding: 1rem;
    background: #f8fafc;
    border: 1px dashed var(--border);
    border-radius: var(--radius-sm);
}

.module-self-rating-panel {
    margin-top: 0;
}

.module-self-rating__heading {
    margin: 0 0 0.25rem;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text);
}

.module-self-rating__prompt {
    margin: 0 0 0.85rem;
    font-size: 0.9rem;
    color: var(--muted);
    line-height: 1.5;
}

.module-self-rating__options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
}

@media (min-width: 560px) {
    .module-self-rating__options {
        grid-template-columns: repeat(4, 1fr);
    }
}

.module-self-rating__option {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 2.75rem;
    padding: 0.5rem 0.65rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    font-family: inherit;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    text-align: center;
    line-height: 1.25;
    transition: border-color var(--transition), background var(--transition), color var(--transition);
}

.module-self-rating__option:hover {
    border-color: #a5b4fc;
    background: var(--primary-soft);
}

.module-self-rating__option.is-selected {
    border-color: var(--primary);
    background: var(--primary-soft);
    color: var(--primary);
    box-shadow: 0 0 0 1px rgba(67, 56, 202, 0.15);
}

.module-self-rating__option[data-rating="needs_improvement"].is-selected {
    border-color: #dc2626;
    background: #fef2f2;
    color: #b91c1c;
}

.module-self-rating__option[data-rating="proficient"].is-selected {
    border-color: var(--success);
    background: var(--success-soft);
    color: #047857;
}

.module-self-rating__status {
    margin: 0.65rem 0 0;
    font-size: 0.82rem;
    color: var(--muted);
}

.module-self-rating-panel .module-self-rating {
    margin-top: 0;
    padding-top: 0;
    border-top: none;
}

.module-self-rating__option:disabled {
    opacity: 0.6;
    cursor: wait;
}

/* Dashboard module self-ratings */
.module-ratings-dashboard__lead {
    margin: 0 0 1.25rem;
    font-size: 0.95rem;
    color: var(--muted);
    line-height: 1.5;
}

.module-ratings-dashboard__course {
    margin-bottom: 1.25rem;
}

.module-ratings-dashboard__course:last-child {
    margin-bottom: 0;
}

.module-ratings-dashboard__course-title {
    margin: 0 0 0.5rem;
    font-size: 1rem;
}

.module-ratings-dashboard__course-title a {
    color: var(--text);
    text-decoration: none;
}

.module-ratings-dashboard__course-title a:hover {
    color: var(--primary);
}

.module-ratings-dashboard__list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.module-ratings-dashboard__item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    padding: 0.55rem 0;
    border-bottom: 1px solid var(--border-subtle);
}

.module-ratings-dashboard__item:last-child {
    border-bottom: none;
}

.module-ratings-dashboard__module-link {
    flex: 1;
    min-width: 0;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-decoration: none;
}

.module-ratings-dashboard__module-link:hover {
    color: var(--primary);
}

.module-rating-chip {
    flex-shrink: 0;
    display: inline-block;
    padding: 0.2rem 0.55rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    background: #f1f5f9;
    color: var(--muted);
}

.module-rating-chip--unrated {
    background: #fef3c7;
    color: #92400e;
}

.module-rating-chip--needs_improvement {
    background: #fef2f2;
    color: #b91c1c;
}

.module-rating-chip--understands {
    background: #eff6ff;
    color: #1d4ed8;
}

.module-rating-chip--confident {
    background: var(--primary-soft);
    color: var(--primary);
}

.module-rating-chip--proficient {
    background: var(--success-soft);
    color: #047857;
}