:root {
    --brand: #0f62fe;
    --ink: #111827;
    --muted: #64748b;
    --line: #e2e8f0;
    --soft: #f1f5f9;
    --card: #ffffff;
    --ok: #16a34a;
    --error: #ef4444;
    --border-radius-md: 12px;
    --border-radius-sm: 8px;
    --shadow-sm: 0 1px 3px rgba(15, 23, 42, .08);
    --transition-fast: .18s ease
}

body.dark-mode {
    --card: #1e293b;
    --ink: #e2e8f0;
    --muted: #94a3b8;
    --line: #334155;
    --soft: #0f172a;
    background: #0f172a
}

* {
    box-sizing: border-box
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    background: #f8fafc;
    color: var(--ink);
    line-height: 1.55
}

body.dark-mode {
    background: #0f172a
}

.navbar {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: .7rem 1.25rem;
    background: #0f172a;
    color: #fff;
    flex-wrap: wrap
}

body.dark-mode .navbar {
    background: #020617
}

.navbar .brand {
    color: #fff;
    font-weight: 800;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: .5rem
}

.navbar .brand .dot {
    background: linear-gradient(135deg, #6d28d9, #4c1d95);
    width: 34px;
    height: 34px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    font-size: .8rem
}

.navbar a {
    color: #cbd5e1;
    text-decoration: none;
    font-size: .95rem
}

.navbar a:hover {
    color: #fff
}

.navbar .spacer {
    flex: 1
}

.navbtn {
    border: 1px solid #334155;
    background: #1e293b;
    color: #e2e8f0;
    border-radius: 8px;
    padding: .35rem .7rem;
    cursor: pointer;
    font: inherit
}

.navbtn:hover {
    background: #334155
}

.container {
    max-width: 960px;
    margin: 1.25rem auto;
    padding: 0 1rem
}

.crumb {
    font-size: .85rem;
    color: var(--muted);
    margin-bottom: 1rem
}

.crumb a {
    color: var(--brand);
    text-decoration: none
}

.coursehead {
    display: flex;
    gap: 1.1rem;
    align-items: center;
    margin-bottom: 1.25rem
}

.swatch {
    width: 74px;
    height: 74px;
    min-width: 74px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #6d28d9, #4c1d95)
}

.course-info h1 {
    font-size: 1.35rem;
    margin: 0 0 .35rem
}

.category-badge {
    background: #eff6ff;
    color: #1e40af;
    font-size: .72rem;
    font-weight: 700;
    padding: .2rem .6rem;
    border-radius: 999px
}

body.dark-mode .category-badge {
    background: #1e3a8a;
    color: #93c5fd
}

.sec-toolbar {
    margin: 0 0 .75rem
}

.expandbtn {
    border: 1px solid var(--line);
    background: var(--card);
    color: var(--ink);
    border-radius: 8px;
    padding: .4rem .8rem;
    font-weight: 600;
    cursor: pointer
}

.section {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    margin-bottom: 1rem;
    overflow: hidden
}

.sec-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem 1.25rem;
    cursor: pointer;
    font-size: 1.05rem;
    margin: 0
}

.sec-head .chevron {
    transition: transform var(--transition-fast)
}

.section.closed .chevron {
    transform: rotate(-90deg)
}

.sec-body {
    padding: 0 1.25rem 1.25rem
}

.section.closed .sec-body {
    display: none
}

.subsec-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: .75rem .5rem;
    cursor: pointer;
    margin: 0;
    font-size: 1rem
}

.subsec-chevron {
    transition: transform var(--transition-fast)
}

.subsection.closed .subsec-chevron {
    transform: rotate(-90deg)
}

.subsec-body {
    padding: .75rem .25rem
}

.subsection.closed .subsec-body {
    display: none
}

.quiz-card,
.quiz-score {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--border-radius-md);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm)
}

.quiz-score {
    text-align: center
}

.quiz-instruction {
    display: block;
    margin-bottom: 1.25rem
}

.progress {
    display: flex;
    gap: 6px;
    margin: 0 0 1.125rem;
    flex-wrap: wrap
}

.dot-q {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--line);
    transition: all .2s ease
}

.dot-q.current {
    background: var(--brand);
    transform: scale(1.25)
}

.dot-q.ok {
    background: var(--ok)
}

.dot-q.bad {
    background: var(--error)
}

.question-text {
    font-size: 1.12rem;
    font-weight: 700;
    margin: 0 0 .5rem
}

.hint {
    color: var(--muted);
    font-size: .85rem;
    margin: 0 0 1rem
}

.feedback {
    margin-top: 1rem;
    padding: .75rem 1rem;
    border-radius: var(--border-radius-md);
    font-weight: 600;
    font-size: .95rem;
    display: none
}

.feedback.ok {
    display: block;
    background: #dcfce7;
    color: #166534
}

.feedback.bad {
    display: block;
    background: #fee2e2;
    color: #991b1b
}

body.dark-mode .feedback.ok {
    background: rgba(22, 163, 74, .15);
    color: #4ade80
}

body.dark-mode .feedback.bad {
    background: rgba(239, 68, 68, .15);
    color: #f87171
}

.quiz-btn {
    margin-top: 1.25rem;
    padding: .5rem 1.25rem;
    border: 0;
    background: var(--brand);
    color: #fff;
    border-radius: var(--border-radius-md);
    font-weight: 600;
    font-size: .95rem;
    cursor: pointer;
    font-family: inherit
}

.quiz-btn:hover:not(:disabled) {
    background: #0d5bd6
}

.quiz-btn:disabled {
    background: var(--line);
    color: var(--muted);
    cursor: default
}

.quiz-score .emoji {
    font-size: 3rem
}

.quiz-score .value {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--brand);
    margin: .5rem 0
}

.quiz-score .subtitle {
    color: var(--muted);
    margin: 0 0 1.25rem
}

.hidden {
    display: none
}

.qcm-list {
    display: flex;
    flex-direction: column;
    gap: .625rem
}

.qcm-item {
    display: flex;
    align-items: center;
    gap: .75rem;
    border: 1px solid var(--line);
    border-radius: var(--border-radius-sm);
    padding: .75rem .875rem;
    cursor: pointer;
    background: var(--card);
    font: inherit;
    text-align: left;
    color: var(--ink);
    transition: border-color var(--transition-fast)
}

.qcm-item:hover:not(:disabled) {
    border-color: var(--brand);
    background: var(--soft)
}

.qcm-item .box {
    width: 20px;
    height: 20px;
    min-width: 20px;
    border: 2px solid #94a3b8;
    border-radius: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    color: transparent;
    font-weight: 800
}

.qcm-item.correct {
    border-color: var(--ok);
    background: rgba(22, 163, 74, .08)
}

.qcm-item.wrong {
    border-color: var(--error);
    background: rgba(239, 68, 68, .08)
}

.qcm-item.correct .box {
    border-color: var(--ok);
    color: var(--ok)
}

.qcm-item.wrong .box {
    border-color: var(--error);
    color: var(--error)
}

.inline-quiz {
    background: var(--soft);
    border: 1px solid var(--line);
    border-radius: var(--border-radius-md);
    padding: 1rem 1.1rem;
    margin: 0 0 1.25rem
}

.inline-quiz .iq-text {
    font-weight: 700;
    margin: 0 0 .6rem
}

.inline-quiz .qcm-list {
    margin-bottom: 0
}

.inline-quiz .feedback {
    margin-top: .75rem;
    margin-bottom: 0
}

.act-card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--border-radius-md);
    padding: 1.25rem;
    box-shadow: var(--shadow-sm)
}

.act-text {
    font-size: .97rem;
    margin: 0 0 1rem
}

.act-title {
    font-size: 1.08rem;
    font-weight: 700;
    margin: 1.5rem 0 .75rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--line)
}

.act-card>.act-title:first-child {
    margin-top: 0;
    padding-top: 0;
    border-top: 0
}

.act-list {
    margin: 0 0 1.25rem;
    padding-left: 1.5rem;
    font-size: .95rem
}

.act-question {
    background: #eff6ff;
    border: 1px solid #bfdbfe;
    border-radius: var(--border-radius-md);
    padding: .75rem 1rem;
    font-size: .95rem;
    color: #1e40af;
    font-weight: 600;
    text-align: center
}

body.dark-mode .act-question {
    background: rgba(59, 130, 246, .12);
    border-color: #1e40af;
    color: #93c5fd
}

.retenir {
    background: #fefce8;
    border: 1px solid #fde047;
    border-radius: var(--border-radius-md);
    padding: 1rem 1.25rem;
    margin: 0 0 1.25rem
}

body.dark-mode .retenir {
    background: rgba(234, 179, 8, .08);
    border-color: #a16207
}

.retenir ul {
    margin: 0;
    padding-left: 1.4rem;
    font-size: .95rem;
    line-height: 1.8
}

.formule {
    background: var(--soft);
    border: 2px solid var(--brand);
    border-radius: var(--border-radius-md);
    padding: 1rem 1.25rem;
    text-align: center;
    font-size: 1.1rem;
    font-weight: 600;
    margin: 0 0 1.25rem
}

.formule .big {
    font-size: 1.25rem
}

.figure {
    margin: 0 0 1.25rem;
    text-align: center
}

.figure svg {
    max-width: 100%;
    height: auto;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--border-radius-md)
}

.figure figcaption {
    margin-top: .5rem;
    font-size: .85rem;
    color: var(--muted);
    font-style: italic
}

.correction {
    margin: 0 0 1.25rem;
    border: 1px solid var(--line);
    border-radius: var(--border-radius-sm);
    background: var(--soft)
}

.correction summary {
    cursor: pointer;
    padding: .625rem .875rem;
    font-weight: 700;
    color: var(--ok);
    user-select: none
}

.correction summary:hover {
    text-decoration: underline
}

.correction[open] summary {
    border-bottom: 1px solid var(--line)
}

.correction .act-text,
.correction .figure {
    margin: .875rem
}

.exo-question {
    font-weight: 600
}

footer {
    color: var(--muted);
    font-size: .8rem;
    text-align: center;
    margin: 2rem 0 1rem
}

body.dys {
    letter-spacing: .06em;
    word-spacing: .12em
}