:root {
    --orange: #ff7a00;
    --orange-dark: #d95f00;
    --orange-soft: #fff2e5;
    --black: #0c0c0c;
    --ink: #1f2328;
    --muted: #667085;
    --line: #e6e8ec;
    --surface: #ffffff;
    --surface-2: #f7f7f8;
    --success: #16794a;
    --danger: #b42318;
    --shadow: 0 18px 50px rgba(16, 24, 40, .09);
    --radius: 18px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    color: var(--ink);
    background: var(--surface);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    line-height: 1.55;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button, input, select, textarea { font: inherit; }
.container { width: min(1160px, calc(100% - 32px)); margin-inline: auto; }
.narrow { width: min(760px, calc(100% - 32px)); margin-inline: auto; }
.site-header { position: sticky; top: 0; z-index: 30; background: rgba(255,255,255,.94); backdrop-filter: blur(14px); border-bottom: 1px solid rgba(230,232,236,.8); }
.nav-wrap { min-height: 74px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand img { width: 174px; }
.main-nav { display: flex; align-items: center; gap: 24px; font-weight: 650; }
.main-nav a:not(.button):hover { color: var(--orange); }
.nav-toggle { display: none; border: 0; background: none; font-size: 1.6rem; }
.button { border: 0; border-radius: 999px; padding: 14px 22px; background: var(--orange); color: white; font-weight: 800; display: inline-flex; align-items: center; justify-content: center; gap: 8px; cursor: pointer; transition: .2s ease; }
.button:hover { background: var(--orange-dark); transform: translateY(-1px); }
.button-small { padding: 10px 17px; font-size: .92rem; }
.button-block { width: 100%; }
.button-dark { background: var(--black); }
.button-dark:hover { background: #2a2a2a; }
.button-ghost { color: var(--ink); background: transparent; border: 1px solid var(--line); }
.button-danger { background: var(--danger); }
.text-link { color: var(--orange-dark); font-weight: 750; }
.hero { padding: 80px 0 56px; background: radial-gradient(circle at 90% 10%, #ffe0c2, transparent 34%), linear-gradient(180deg, #fff 0%, #fffaf5 100%); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; align-items: center; gap: 56px; }
.eyebrow { color: var(--orange-dark); text-transform: uppercase; font-size: .78rem; letter-spacing: .13em; font-weight: 900; }
h1, h2, h3 { line-height: 1.12; margin: 0 0 16px; color: var(--black); }
h1 { font-size: clamp(2.5rem, 6vw, 5.3rem); letter-spacing: -.055em; }
h2 { font-size: clamp(1.75rem, 3.7vw, 3rem); letter-spacing: -.035em; }
h3 { font-size: 1.2rem; }
.hero p { font-size: 1.15rem; color: var(--muted); max-width: 640px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.hero-card { border-radius: 32px; background: var(--black); color: white; padding: 28px; box-shadow: var(--shadow); position: relative; min-height: 420px; }
.hero-card::after { content: ""; position: absolute; inset: auto -40px -40px auto; width: 180px; height: 180px; border-radius: 50%; background: var(--orange); opacity: .85; }
.hero-card h3, .hero-card strong { color: white; }
.hero-card .mini-course { position: relative; z-index: 2; background: #1b1b1b; border: 1px solid #363636; border-radius: 18px; padding: 18px; margin-top: 14px; }
.hero-card .progress { background: #383838; }
.hero-card .progress > span { background: var(--orange); }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 28px; }
.stat { border-top: 1px solid #3f3f3f; padding-top: 15px; }
.stat strong { font-size: 1.65rem; display: block; }
.section { padding: 74px 0; }
.section-muted { background: var(--surface-2); }
.section-head { display: flex; justify-content: space-between; align-items: end; gap: 20px; margin-bottom: 28px; }
.section-head p { margin: 0; color: var(--muted); max-width: 620px; }
.grid { display: grid; gap: 22px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0,1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0,1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0,1fr)); }
.card { background: white; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; box-shadow: 0 6px 22px rgba(16,24,40,.04); }
.card-body { padding: 22px; }
.course-card { display: flex; flex-direction: column; min-height: 100%; }
.course-cover { aspect-ratio: 16/9; background: linear-gradient(135deg, var(--black), #333 60%, var(--orange)); display: flex; align-items: end; padding: 18px; color: white; font-weight: 900; }
.course-cover img { width: 100%; height: 100%; object-fit: cover; }
.course-card .card-body { display: flex; flex: 1; flex-direction: column; }
.course-card p { color: var(--muted); }
.course-meta { display: flex; flex-wrap: wrap; gap: 10px; color: var(--muted); font-size: .88rem; margin-bottom: 10px; }
.course-price { margin-top: auto; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-top: 18px; }
.badge { display: inline-flex; align-items: center; border-radius: 999px; padding: 6px 10px; background: var(--orange-soft); color: var(--orange-dark); font-size: .78rem; font-weight: 850; }
.badge-dark { background: #efefef; color: var(--black); }
.progress { height: 10px; border-radius: 99px; background: #eceef1; overflow: hidden; }
.progress > span { height: 100%; display: block; background: var(--orange); border-radius: inherit; }
.progress-label { display: flex; justify-content: space-between; font-size: .85rem; color: var(--muted); margin-top: 8px; }
.auth-shell { min-height: calc(100vh - 75px); display: grid; place-items: center; padding: 52px 0; background: linear-gradient(135deg, #fff 20%, #fff4e8); }
.auth-card { width: min(500px, calc(100% - 32px)); background: white; border: 1px solid var(--line); border-radius: 26px; padding: 34px; box-shadow: var(--shadow); }
.form-group { margin-bottom: 17px; }
.form-group label { display: block; font-weight: 750; margin-bottom: 7px; }
.form-control { width: 100%; border: 1px solid #d0d5dd; border-radius: 12px; padding: 13px 14px; outline: none; background: white; }
.form-control:focus { border-color: var(--orange); box-shadow: 0 0 0 4px rgba(255,122,0,.12); }
textarea.form-control { min-height: 130px; resize: vertical; }
.form-row { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 14px; }
.help { color: var(--muted); font-size: .85rem; }
.alert { margin-top: 16px; border-radius: 12px; padding: 13px 16px; font-weight: 700; }
.alert-success { color: var(--success); background: #ecfdf3; border: 1px solid #abefc6; }
.alert-error { color: var(--danger); background: #fef3f2; border: 1px solid #fecdca; }
.dashboard-hero { padding: 48px 0 24px; }
.dashboard-grid { display: grid; grid-template-columns: 1fr 330px; gap: 28px; align-items: start; }
.panel { background: white; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.panel + .panel { margin-top: 18px; }
.kpi-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.kpi { border: 1px solid var(--line); border-radius: 16px; padding: 19px; background: white; }
.kpi strong { display: block; font-size: 1.7rem; color: var(--black); }
.kpi span { color: var(--muted); font-size: .88rem; }
.course-hero { padding: 54px 0; background: var(--black); color: white; }
.course-hero h1, .course-hero h2, .course-hero h3 { color: white; }
.course-hero-grid { display: grid; grid-template-columns: 1fr 360px; gap: 38px; align-items: center; }
.course-purchase-card { background: white; color: var(--ink); border-radius: 22px; padding: 24px; }
.curriculum-section { border: 1px solid var(--line); border-radius: 14px; overflow: hidden; margin-bottom: 14px; }
.curriculum-title { background: var(--surface-2); padding: 15px 18px; font-weight: 850; }
.lesson-row { display: flex; justify-content: space-between; gap: 16px; padding: 14px 18px; border-top: 1px solid var(--line); }
.lesson-row small { color: var(--muted); }
.lesson-layout { display: grid; grid-template-columns: 310px 1fr; min-height: calc(100vh - 75px); }
.lesson-sidebar { background: #111; color: white; padding: 20px; overflow: auto; }
.lesson-sidebar a { display: block; border-radius: 10px; padding: 11px; color: #ddd; }
.lesson-sidebar a:hover, .lesson-sidebar a.active { background: #292929; color: white; }
.lesson-content { padding: 34px; max-width: 980px; width: 100%; }
.video-wrap { position: relative; aspect-ratio: 16/9; background: black; border-radius: 18px; overflow: hidden; margin-bottom: 28px; }
.video-wrap iframe, .video-wrap video { width: 100%; height: 100%; border: 0; }
.lesson-copy { font-size: 1.05rem; }
.lesson-copy img { border-radius: 12px; }
.lesson-actions { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-top: 36px; padding-top: 22px; border-top: 1px solid var(--line); }
.pricing-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 22px; align-items: stretch; }
.price-card { border: 1px solid var(--line); border-radius: 24px; padding: 28px; position: relative; background: white; }
.price-card.featured { border-color: var(--orange); box-shadow: var(--shadow); transform: translateY(-8px); }
.price { font-size: 2.55rem; font-weight: 950; letter-spacing: -.04em; }
.price small { font-size: .95rem; color: var(--muted); font-weight: 650; }
.check-list { padding: 0; margin: 22px 0; list-style: none; }
.check-list li { padding: 8px 0 8px 28px; position: relative; }
.check-list li::before { content: "✓"; position: absolute; left: 0; color: var(--orange); font-weight: 950; }
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 14px; }
table { width: 100%; border-collapse: collapse; background: white; }
th, td { padding: 13px 15px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: var(--surface-2); font-size: .78rem; text-transform: uppercase; letter-spacing: .05em; }
.admin-layout { display: grid; grid-template-columns: 230px 1fr; min-height: calc(100vh - 75px); }
.admin-nav { background: #111; padding: 22px 14px; }
.admin-nav a { display: block; color: #ddd; padding: 11px 13px; border-radius: 10px; margin-bottom: 4px; }
.admin-nav a:hover { background: #292929; color: white; }
.admin-content { padding: 32px; background: var(--surface-2); min-width: 0; }
.certificate-page { background: #ececec; padding: 40px 0; }
.certificate { width: min(1120px, calc(100% - 24px)); aspect-ratio: 1.414/1; margin: auto; background: white; border: 16px solid #111; padding: 46px; display: grid; place-items: center; text-align: center; position: relative; box-shadow: var(--shadow); }
.certificate::before { content: ""; position: absolute; inset: 16px; border: 3px solid var(--orange); pointer-events: none; }
.certificate-logo { width: 230px; margin: 0 auto 28px; }
.certificate-name { font-size: clamp(2rem, 5vw, 4.4rem); border-bottom: 2px solid #bbb; padding: 0 28px 8px; display: inline-block; }
.certificate-course { font-size: clamp(1.4rem, 3vw, 2.4rem); color: var(--orange-dark); }
.certificate-meta { display: flex; justify-content: center; gap: 32px; flex-wrap: wrap; margin-top: 28px; font-size: .9rem; }
.verify-box { width: min(680px, calc(100% - 32px)); margin: 60px auto; }
.empty { padding: 40px; text-align: center; border: 1px dashed #cdd1d6; border-radius: 16px; color: var(--muted); }
.site-footer { background: #0c0c0c; color: #c7c7c7; padding: 52px 0 18px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 30px; }
.footer-grid strong { display: block; color: white; margin-bottom: 14px; }
.footer-grid a { display: block; margin: 9px 0; }
.footer-logo { width: 170px; margin-bottom: 16px; }
.footer-bottom { border-top: 1px solid #2c2c2c; margin-top: 35px; padding-top: 18px; font-size: .85rem; }
.muted { color: var(--muted); }
.inline { display: inline-flex; gap: 8px; align-items: center; }
.stack { display: grid; gap: 14px; }
.spacer { height: 24px; }

@media (max-width: 900px) {
    .hero-grid, .course-hero-grid, .dashboard-grid, .lesson-layout, .admin-layout { grid-template-columns: 1fr; }
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .grid-3, .pricing-grid { grid-template-columns: 1fr 1fr; }
    .kpi-grid { grid-template-columns: repeat(2, 1fr); }
    .lesson-sidebar { max-height: 320px; }
    .admin-nav { display: flex; overflow-x: auto; gap: 6px; }
    .admin-nav a { white-space: nowrap; }
}
@media (max-width: 700px) {
    .container { width: min(100% - 22px, 1160px); }
    .nav-toggle { display: block; }
    .main-nav { display: none; position: absolute; top: 73px; left: 0; right: 0; flex-direction: column; align-items: stretch; gap: 0; padding: 14px 20px 22px; background: white; border-bottom: 1px solid var(--line); box-shadow: var(--shadow); }
    .main-nav.open { display: flex; }
    .main-nav a { padding: 11px 0; }
    .hero { padding-top: 54px; }
    .hero-grid, .grid-2, .grid-3, .grid-4, .pricing-grid, .footer-grid, .form-row { grid-template-columns: 1fr; }
    .stats { grid-template-columns: 1fr; }
    .section { padding: 52px 0; }
    .section-head { align-items: start; flex-direction: column; }
    .kpi-grid { grid-template-columns: 1fr 1fr; }
    .lesson-content, .admin-content { padding: 22px 15px; }
    .certificate { aspect-ratio: auto; min-height: 720px; padding: 36px 20px; border-width: 9px; }
    .course-purchase-card { margin-top: 8px; }
}
@media print {
    .site-header, .site-footer, .print-hide, .alert { display: none !important; }
    .certificate-page { padding: 0; background: white; }
    .certificate { width: 100%; height: 100vh; box-shadow: none; margin: 0; }
}

/* Quiz engine */
.quiz-option-editor { display: grid; gap: 10px; margin: 14px 0; }
.quiz-option-edit-row { display: grid; grid-template-columns: 110px 1fr; align-items: center; gap: 10px; }
.quiz-correct-toggle { display: inline-flex; gap: 7px; align-items: center; font-weight: 750; }
.quiz-admin-question { border: 1px solid var(--line); border-radius: 16px; padding: 18px; background: var(--surface-2); }
.quiz-admin-options { margin: 0; padding-left: 24px; color: var(--muted); }
.quiz-admin-options li { padding: 4px 0; }
.quiz-admin-options li.correct { color: var(--success); font-weight: 750; }
.quiz-header-panel { margin-bottom: 18px; }
.quiz-form { display: grid; gap: 18px; }
.quiz-question-card { margin: 0; }
.quiz-question-card legend { padding: 0 8px; font-size: .82rem; font-weight: 850; color: var(--orange-dark); text-transform: uppercase; letter-spacing: .06em; }
.quiz-options { display: grid; gap: 10px; margin-top: 18px; }
.quiz-option { display: flex; align-items: center; justify-content: space-between; gap: 12px; border: 1px solid var(--line); border-radius: 14px; padding: 14px 16px; background: white; cursor: pointer; }
label.quiz-option:hover { border-color: var(--orange); background: var(--orange-soft); }
.quiz-option input { width: 18px; height: 18px; accent-color: var(--orange); flex: 0 0 auto; }
.quiz-option > span { flex: 1; }
.quiz-option.correct { border-color: #75c69a; background: #ecfdf3; }
.quiz-option.selected { box-shadow: inset 0 0 0 2px var(--orange); }
.quiz-options.review .quiz-option { cursor: default; }
.quiz-submit-bar { display: flex; justify-content: space-between; align-items: center; gap: 18px; position: sticky; bottom: 14px; box-shadow: var(--shadow); }
.quiz-timer { min-width: 150px; border-radius: 16px; background: var(--black); color: white; padding: 14px 18px; text-align: center; }
.quiz-timer span { display: block; font-size: .75rem; color: #ccc; text-transform: uppercase; letter-spacing: .08em; }
.quiz-timer strong { display: block; font-size: 1.8rem; font-variant-numeric: tabular-nums; }
.quiz-result { text-align: center; }
.quiz-result.passed { border-color: #75c69a; }
.quiz-result.failed { border-color: #f2a9a3; }
.quiz-score { font-size: clamp(4rem, 12vw, 7rem); line-height: 1; font-weight: 950; letter-spacing: -.07em; color: var(--orange-dark); margin: 12px 0; }
.quiz-review-question { border: 1px solid var(--line); border-radius: 16px; padding: 18px; background: white; }
.quiz-review-question + .quiz-review-question { margin-top: 14px; }
.quiz-explanation { margin-top: 15px; border-left: 4px solid var(--orange); padding: 12px 14px; background: var(--orange-soft); border-radius: 0 10px 10px 0; }
.quiz-rule-grid { display: grid; grid-template-columns: repeat(4, minmax(0,1fr)); gap: 12px; margin: 24px 0; }
.quiz-rule-grid.compact { grid-template-columns: repeat(3, minmax(0,1fr)); }
.quiz-rule-grid > div { border: 1px solid var(--line); border-radius: 14px; padding: 16px; background: var(--surface-2); }
.quiz-rule-grid strong { display: block; font-size: 1.35rem; color: var(--black); }
.quiz-rule-grid span { color: var(--muted); font-size: .82rem; }
.quiz-lesson-card { margin-top: 28px; }

@media (max-width: 700px) {
    .quiz-option-edit-row { grid-template-columns: 1fr; }
    .quiz-rule-grid, .quiz-rule-grid.compact { grid-template-columns: 1fr 1fr; }
    .quiz-submit-bar { align-items: stretch; flex-direction: column; bottom: 8px; }
    .quiz-submit-bar .button { width: 100%; }
    .quiz-timer { width: 100%; }
}

/* Automatic lesson progress */
.lesson-completion-panel { margin-top: 28px; }
.lesson-progress-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; }
.lesson-progress-heading h3 { margin-bottom: 6px; }
.lesson-auto-progress { margin-top: 18px; }
.lesson-completion-fallback { display: flex; align-items: center; gap: 12px; margin-top: 18px; flex-wrap: wrap; }
.lesson-completion-fallback button:disabled { opacity: .7; cursor: default; }
.lesson-nav-state { display: inline-block; width: 18px; font-weight: 900; }
@media (max-width: 640px) {
    .lesson-progress-heading { flex-direction: column; }
}