/* =====================================================================
   Bynteq 4.0 - Lesson pages (lessons.css)
   Uses design tokens from themes.css. This is the ONLY place lesson
   layout/interaction styling lives (no per-page duplicated CSS).
   ===================================================================== */

.lesson-body {
    overflow-x: hidden;
}

.lesson-page {
    display: grid;
    grid-template-columns: 260px 1fr;
    gap: 50px;
    max-width: var(--maxw);
    margin: auto;
    padding: 50px 30px 80px;
}

/* ---- Sidebar ---- */
.lesson-sidebar {
    background: var(--surface);
    padding: 26px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    height: fit-content;
    position: sticky;
    top: 90px;
}

.lesson-sidebar h3 {
    font-size: 15px;
    margin-top: 4px;
}

.lesson-sidebar hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 18px 0 6px;
}

.lesson-sidebar a,
.lesson-link {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    margin-top: 14px;
    font-size: 14px;
    line-height: 1.4;
    padding-left: 12px;
    border-left: 2px solid transparent;
}

.lesson-sidebar a:hover,
.lesson-link:hover {
    color: var(--text-primary);
}

.lesson-link.active {
    color: var(--text-primary);
    font-weight: 600;
    border-left-color: var(--accent);
}

.course-label {
    color: var(--accent);
    font-weight: 700;
    letter-spacing: 0.1em;
    font-size: 12px;
    text-transform: uppercase;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-pill);
    margin: 14px 0;
    overflow: hidden;
}

.progress {
    width: 10%;
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--accent-secondary));
    border-radius: var(--radius-pill);
    transition: width var(--t-slow);
}

.progress-text {
    color: var(--text-secondary);
    font-size: 13px;
    margin-top: 4px;
}

/* ---- Lesson content ---- */
.lesson-content {
    max-width: var(--reading);
    overflow-wrap: break-word;
    word-wrap: break-word;
}

.lesson-number {
    color: var(--accent);
    font-weight: 700;
    letter-spacing: 0.1em;
    font-size: 13px;
    text-transform: uppercase;
}

.lesson-content h2 {
    font-size: clamp(34px, 5vw, 48px);
    margin: 12px 0;
    letter-spacing: -1px;
    line-height: 1.1;
}

.lesson-intro {
    color: var(--text-secondary);
    font-size: 19px;
    margin-bottom: 44px;
    line-height: 1.6;
}

.lesson-content section {
    margin-bottom: 28px;
}

.lesson-content section h3 {
    font-size: 22px;
    margin-bottom: 14px;
}

.lesson-content p {
    color: #d4d4dc;
    line-height: 1.8;
    margin-bottom: 14px;
}

.lesson-content ol,
.lesson-content ul {
    color: #d4d4dc;
    line-height: 1.8;
    padding-left: 22px;
    margin-bottom: 14px;
}

/* Lesson sections reuse the shared .lesson-card class. Neutralize the
   course-card hover-lift here and give each section a clear identity. */
.lesson-content .lesson-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-left: 3px solid var(--border-strong);
    border-radius: var(--radius);
    padding: 24px 26px;
}

.lesson-content .lesson-card:hover {
    transform: none;
    box-shadow: none;
    border-color: var(--border);
    border-left-color: inherit;
}

.lesson-content .lesson-card h3::before {
    margin-right: 8px;
}

/* Section-type identity (class added by js/lessons.js) */
.lesson-content .lc-understand { border-left-color: var(--accent); }
.lesson-content .lc-understand h3::before { content: "\1F9E0"; }

.lesson-content .lc-see { border-left-color: #38bdf8; }
.lesson-content .lc-see h3::before { content: "\1F441\FE0F"; }

.lesson-content .lc-practice { border-left-color: var(--success); }
.lesson-content .lc-practice h3::before { content: "\2328\FE0F"; }

.lesson-content .quiz-card,
.lesson-content .lc-quiz { border-left-color: var(--xp); }
.lesson-content .quiz-card h3::before { content: "\2753"; }

.lesson-content .lc-challenge { border-left-color: #f472b6; }
.lesson-content .lc-challenge h3::before { content: "\1F3C6"; }

/* ---- Code blocks (code-window motif) ---- */
pre {
    position: relative;
    background: #0a0a0e;
    padding: 44px 24px 22px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow-x: auto;
    margin: 8px 0 4px;
}

pre::before {
    content: "";
    position: absolute;
    top: 17px;
    left: 22px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #f87171;
    box-shadow: 18px 0 0 #facc15, 36px 0 0 #4ade80;
}

pre code {
    color: #c7c1ff;
    font-family: var(--font-mono);
    font-size: 14px;
    line-height: 1.7;
}

code {
    color: var(--accent-secondary);
    font-family: var(--font-mono);
}

.code-result {
    background: var(--surface-2);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-left: 3px solid #38bdf8;
    padding: 18px 22px;
    border-radius: var(--radius);
    margin-top: 16px;
}

.concept-box {
    background: var(--surface);
    border: 1px solid var(--border);
    padding: 20px;
    border-radius: var(--radius);
    margin-top: 14px;
}

.lesson-checkpoint {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
}

/* ---- Quiz (scoped to beat the shared .lesson-card button rule) ---- */
.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin: 20px 0;
}

.lesson-content .quiz-answer {
    display: block;
    width: 100%;
    text-align: left;
    padding: 15px 18px;
    border-radius: var(--radius-sm);
    background: var(--surface-2);
    color: var(--text-primary);
    border: 1px solid var(--border);
    font-weight: 500;
    font-size: 15px;
}

.lesson-content .quiz-answer:hover {
    background: var(--surface-raised);
    border-color: var(--accent);
    transform: translateX(3px);
    box-shadow: none;
}

.lesson-content .quiz-answer.is-correct {
    background: var(--success-soft);
    border-color: var(--success);
    color: var(--success);
}

.lesson-content .quiz-answer.is-wrong {
    background: var(--error-soft);
    border-color: var(--error);
    color: var(--error);
}

.quiz-feedback {
    margin-top: 18px;
    font-weight: 600;
    min-height: 1.2em;
}

.correct-feedback { color: var(--success); }
.wrong-feedback { color: var(--error); }

/* ---- Completion experience ---- */
.lesson-complete {
    margin-top: 28px;
    padding: 34px 28px 30px;
    background:
        radial-gradient(120% 90% at 50% 0%, var(--accent-soft) 0%, transparent 60%),
        var(--surface);
    border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--border));
    border-radius: var(--radius-lg);
    text-align: center;
    position: relative;
}

.lesson-complete::before {
    content: "\2713";
    display: grid;
    place-items: center;
    width: 56px;
    height: 56px;
    margin: 0 auto 14px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    color: var(--accent-contrast);
    font-size: 30px;
    font-weight: 700;
    box-shadow: var(--glow);
}

.lesson-complete h3 {
    font-size: 24px;
    margin-bottom: 8px;
}

.lesson-complete p {
    color: var(--text-secondary);
    max-width: 420px;
    margin: 0 auto 8px;
}

.lesson-complete.celebrate {
    animation: bqPop 0.45s ease both;
}

.lesson-complete.celebrate::before {
    animation: bqCheck 0.5s ease both;
}

@keyframes bqPop {
    0% { transform: scale(0.97); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}

@keyframes bqCheck {
    0% { transform: scale(0); }
    60% { transform: scale(1.15); }
    100% { transform: scale(1); }
}

.xp-reward {
    display: inline-block;
    margin: 0 0 16px;
    padding: 8px 18px;
    background: rgba(250, 204, 21, 0.12);
    border: 1px solid rgba(250, 204, 21, 0.35);
    border-radius: var(--radius-pill);
    color: var(--xp);
    font-weight: 700;
}

.continue-button {
    display: inline-block;
    margin-top: 16px;
    padding: 14px 32px;
    border-radius: var(--radius-pill);
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    color: var(--accent-contrast);
    text-decoration: none;
    font-weight: 600;
}

.continue-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--glow);
}

/* ---- Lesson navigation ---- */
.lesson-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
    margin-top: 44px;
}

.lesson-navigation a {
    color: var(--text-secondary);
    text-decoration: none;
}

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

.lesson-content img {
    max-width: 100%;
    height: auto;
}

/* ---- Mobile ---- */
@media (max-width: 900px) {
    .lesson-page {
        grid-template-columns: 1fr;
        gap: 30px;
        padding: 30px 22px 60px;
    }
    .lesson-sidebar {
        order: 2;
        position: static;
    }
}

@media (max-width: 700px) {
    .lesson-content h2 { word-break: break-word; }
    .lesson-content .lesson-card { padding: 20px; }
    .lesson-navigation {
        flex-direction: column;
        align-items: stretch;
    }
}

/* ---- Sidebar: completed lesson links (driven by progress.js) ---- */
.lesson-sidebar .lesson-link.is-complete {
    color: var(--text-primary);
}

.lesson-sidebar .lesson-link.is-complete::before {
    content: "\2713";
    display: inline-block;
    width: 1.1em;
    margin-right: 4px;
    color: var(--success);
    font-weight: 700;
}


/* ---- Lesson pager (prev / next) ---- */
.lesson-pager {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    margin-top: 28px;
}
.lesson-pager .pager-link {
    flex: 1;
    max-width: 48%;
    padding: 14px 18px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    transition: border-color var(--t), color var(--t);
}
.lesson-pager .pager-link:hover { border-color: var(--accent); color: var(--text-primary); }
.lesson-pager .pager-next { text-align: right; }
@media (max-width: 600px) { .lesson-pager { flex-direction: column; } .lesson-pager .pager-link { max-width: 100%; text-align: center; } }