:root {
    --bg: #0d1117;
    --panel: #161b22;
    --panel-2: #1f2937;
    --text: #c9d1d9;
    --muted: #8b949e;
    --line: #30363d;
    --blue: #58a6ff;
    --green: #3fb950;
    --gold: #d29922;
    --red: #f85149;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    line-height: 1.55;
}

a { color: inherit; }

.wrap {
    width: min(1120px, calc(100% - 40px));
    margin: 0 auto;
}

header {
    border-bottom: 1px solid var(--line);
    background: rgba(13, 17, 23, 0.92);
    position: sticky;
    top: 0;
    z-index: 5;
}

nav {
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.brand {
    font-weight: 800;
    color: #fff;
    text-decoration: none;
    letter-spacing: 0.02em;
}

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

.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-size: 0.92rem;
}

.nav-links a:hover { color: var(--blue); }

.hero {
    padding: 4rem 0 2.5rem;
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
    gap: 2rem;
    align-items: center;
}

.eyebrow {
    color: var(--green);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-weight: 800;
    margin: 0 0 0.8rem;
}

h1 {
    color: #fff;
    font-size: clamp(2rem, 5vw, 4rem);
    line-height: 1.05;
    margin: 0;
}

.hero p,
.lead {
    color: var(--muted);
    font-size: 1.08rem;
    max-width: 780px;
}

.hero-panel,
.panel,
.course-card,
.module,
.question,
.sample-card {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 8px;
}

.hero-panel {
    padding: 1.25rem;
}

.stat-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.75rem;
}

.stat {
    background: var(--bg);
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 0.9rem;
}

.stat strong {
    display: block;
    color: #fff;
    font-size: 1.4rem;
}

.stat span {
    color: var(--muted);
    font-size: 0.82rem;
}

.btn-row {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-top: 1.25rem;
}

.btn,
button.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: 0;
    border-radius: 6px;
    min-height: 42px;
    padding: 0.65rem 1rem;
    text-decoration: none;
    cursor: pointer;
    font: inherit;
    font-weight: 750;
}

.btn-primary { background: var(--green); color: #fff; }
.btn-secondary { background: var(--panel-2); color: var(--text); border: 1px solid var(--line); }
.btn-blue { background: var(--blue); color: #08111f; }
.btn:disabled { opacity: 0.55; cursor: default; }
.btn-small { min-height: 32px; padding: 0.35rem 0.65rem; font-size: 0.82rem; }

section { padding: 2rem 0; }

h2 {
    color: #fff;
    font-size: 1.55rem;
    margin: 0 0 1rem;
}

.trend-grid,
.course-grid,
.sample-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.certificate-hero {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 340px;
    gap: 1.5rem;
    align-items: end;
    padding: 4rem 0 2rem;
}

.credential-summary {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 1rem;
}

.credential-summary div {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--line);
}

.credential-summary div:last-child { border-bottom: 0; }

.credential-summary span {
    color: var(--muted);
    font-size: 0.82rem;
}

.credential-summary strong {
    color: #fff;
    text-align: right;
    font-size: 0.92rem;
}

.certificate-showcase {
    padding-top: 0;
}

.certificate-frame {
    background: #0a0f18;
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: clamp(0.75rem, 2vw, 1.4rem);
}

.certificate-frame img,
.sample-card img {
    display: block;
    width: 100%;
    height: auto;
    border-radius: 6px;
}

.compact-samples {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.compact-samples .sample-card {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.panel,
.course-card,
.sample-card {
    padding: 1rem;
}

.panel h3,
.course-card h3,
.module h3 {
    margin: 0 0 0.45rem;
    color: #fff;
}

.panel p,
.course-card p,
.module p {
    color: var(--muted);
    margin: 0;
    font-size: 0.92rem;
}

.tag-row {
    display: flex;
    gap: 0.4rem;
    flex-wrap: wrap;
    margin: 0.8rem 0;
}

.tag {
    border: 1px solid rgba(88, 166, 255, 0.35);
    background: rgba(88, 166, 255, 0.1);
    color: var(--blue);
    border-radius: 999px;
    padding: 0.18rem 0.55rem;
    font-size: 0.75rem;
    font-weight: 700;
}

.meta {
    color: var(--muted);
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    font-size: 0.84rem;
    margin-top: 0.8rem;
}

.course-shell {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 1.25rem;
    align-items: start;
    padding: 2rem 0;
}

.sidebar {
    position: sticky;
    top: 88px;
}

.module,
.question {
    padding: 1rem;
    margin-bottom: 0.85rem;
}

.lesson-list {
    margin: 0.75rem 0 0;
    padding-left: 1.15rem;
    color: var(--text);
}

.lesson-list li { margin: 0.35rem 0; }

.question label {
    display: flex;
    gap: 0.5rem;
    padding: 0.45rem 0;
    cursor: pointer;
}

.question input { accent-color: var(--green); }

.result {
    display: none;
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
    border: 1px solid var(--line);
    background: var(--panel);
}

.result.pass { border-color: var(--green); }
.result.fail { border-color: var(--red); }

.paywall {
    border: 1px solid rgba(210, 153, 34, 0.45);
    background: rgba(210, 153, 34, 0.08);
    border-radius: 8px;
    padding: 1rem;
    margin: 1rem 0;
}

.paywall h3 {
    color: #fff;
    margin: 0 0 0.4rem;
}

.paywall p {
    color: var(--muted);
    margin: 0 0 0.9rem;
}

.paid-badge {
    display: none;
    border: 1px solid rgba(63, 185, 80, 0.45);
    background: rgba(63, 185, 80, 0.1);
    color: var(--green);
    border-radius: 999px;
    padding: 0.25rem 0.65rem;
    font-size: 0.8rem;
    font-weight: 800;
}

.assessment-locked { display: none; }

.field {
    width: 100%;
    border: 1px solid var(--line);
    background: var(--bg);
    color: var(--text);
    border-radius: 6px;
    padding: 0.7rem 0.8rem;
    font: inherit;
}

.form-grid {
    display: grid;
    gap: 0.75rem;
    margin: 1rem 0;
}

.form-grid.two {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

textarea.field {
    min-height: 92px;
    resize: vertical;
}

.mono {
    font-family: ui-monospace, SFMono-Regular, SF Mono, Menlo, Consolas, Liberation Mono, monospace;
    font-size: 0.84rem;
}

.tall { min-height: 220px !important; }

.auth-panel {
    max-width: 560px;
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 1rem;
}

.table-wrap { overflow-x: auto; }

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

th, td {
    border: 1px solid var(--line);
    padding: 0.65rem;
    text-align: left;
}

th { color: #fff; background: var(--panel); }

.admin-layout {
    display: grid;
    grid-template-columns: 330px minmax(0, 1fr);
    gap: 1rem;
    padding-top: 1rem;
}

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

.admin-list-item {
    background: var(--bg);
    color: var(--text);
    border: 1px solid var(--line);
    border-radius: 6px;
    text-align: left;
    padding: 0.75rem;
    cursor: pointer;
}

.admin-list-item strong,
.admin-list-item span {
    display: block;
}

.admin-list-item span {
    color: var(--muted);
    font-size: 0.82rem;
}

.verified-panel {
    border-color: var(--green);
}

.cert-area { display: none; margin-top: 1rem; }
.cert-canvas {
    width: 100%;
    max-width: 860px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
}

.source-list {
    color: var(--muted);
    font-size: 0.86rem;
}

.source-list a { color: var(--blue); }

footer {
    border-top: 1px solid var(--line);
    color: var(--muted);
    padding: 2rem 0;
    margin-top: 2rem;
}

@media (max-width: 860px) {
    .hero,
    .course-shell,
    .admin-layout,
    .certificate-hero {
        grid-template-columns: 1fr;
    }
    .sidebar { position: static; }
    nav { align-items: flex-start; flex-direction: column; padding: 1rem 0; }
}

@media (max-width: 520px) {
    .wrap { width: min(100% - 28px, 1120px); }
    .stat-grid { grid-template-columns: 1fr; }
    .form-grid.two { grid-template-columns: 1fr; }
    .btn { width: 100%; }
}

@media print {
    header, footer, .no-print { display: none !important; }
    body { background: #fff; color: #000; }
    .wrap { width: 100%; }
    .cert-area { display: block !important; }
}