:root {
  --bg: #0f1115;
  --surface: #1a1d24;
  --surface-2: #242830;
  --text: #f2f4f8;
  --muted: #9aa3b2;
  --accent: #f5a623;
  --accent-ink: #1a1205;
  --ok: #3ecf8e;
  --bad: #f07178;
  --border: #2e3440;
  --radius: 12px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

*,
*::before,
*::after { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

a { color: var(--accent); }
a:hover { filter: brightness(1.1); }

.container { width: min(1100px, 100% - 2rem); margin-inline: auto; }

.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(15, 17, 21, 0.92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}
.site-header .inner {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.85rem 0; gap: 1rem;
}
.logo { font-weight: 800; letter-spacing: 0.04em; color: var(--text); text-decoration: none; }
.logo span { color: var(--accent); }
.nav { display: flex; gap: 1rem; flex-wrap: wrap; }
.nav a {
  color: var(--muted); text-decoration: none; font-weight: 600;
}
.nav a.is-active, .nav a:hover { color: var(--accent); }

.hero { padding: 3.5rem 0 2rem; }
.hero h1 { font-size: clamp(2rem, 4vw, 2.75rem); margin: 0 0 0.5rem; }
.hero p { color: var(--muted); margin: 0 0 1.75rem; max-width: 36rem; }

.hero-actions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  display: flex; flex-direction: column;
  transition: border-color 0.15s, transform 0.15s;
}
a.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card img {
  width: 100%; aspect-ratio: 16/9; object-fit: cover; background: var(--surface-2);
  display: block;
}
.card-body { padding: 0.9rem 1rem 1.1rem; }
.card-body h3 { margin: 0 0 0.4rem; font-size: 1.05rem; }
.badges { display: flex; flex-wrap: wrap; gap: 0.35rem; }
.badge {
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.03em;
  padding: 0.2rem 0.45rem; border-radius: 999px;
  background: var(--surface-2); color: var(--muted); border: 1px solid var(--border);
}
.badge-accent { color: var(--accent-ink); background: var(--accent); border-color: transparent; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 0.4rem; padding: 0.65rem 1rem; border-radius: 10px;
  border: 1px solid var(--border); background: var(--surface-2);
  color: var(--text); font-weight: 700; cursor: pointer; text-decoration: none;
}
.btn-primary {
  background: var(--accent); color: var(--accent-ink); border-color: transparent;
}
.btn-primary:hover { filter: brightness(1.05); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.section { padding: 1.5rem 0 2.5rem; }
.section h2 { margin: 0 0 1rem; font-size: 1.35rem; }
.muted { color: var(--muted); }
.error {
  background: color-mix(in srgb, var(--bad) 18%, var(--surface));
  border: 1px solid var(--bad); color: var(--text);
  padding: 0.75rem 1rem; border-radius: var(--radius);
}
.notice {
  background: var(--surface-2); border: 1px solid var(--border);
  padding: 0.75rem 1rem; border-radius: var(--radius); color: var(--muted);
}

.detail-header { display: grid; gap: 1rem; margin-bottom: 1.5rem; }
@media (min-width: 720px) {
  .detail-header { grid-template-columns: 280px 1fr; align-items: start; }
}
.detail-header img {
  width: 100%; aspect-ratio: 16/9; object-fit: cover;
  border-radius: var(--radius); border: 1px solid var(--border);
}
.meta-list { list-style: none; padding: 0; margin: 0.75rem 0 0; }
.meta-list li { margin: 0.25rem 0; color: var(--muted); }
.meta-list strong { color: var(--text); }

.steps { padding-left: 1.2rem; }
.steps li { margin: 0.4rem 0; }

.video-wrap {
  position: relative; width: 100%; aspect-ratio: 16/9;
  border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border);
  margin: 1rem 0;
}
.video-wrap iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }

.checklist { list-style: none; padding: 0; margin: 0; }
.checklist li {
  display: flex; justify-content: space-between; gap: 1rem;
  padding: 0.65rem 0.8rem; border-bottom: 1px solid var(--border);
  background: var(--surface);
}
.checklist li:first-child { border-radius: var(--radius) var(--radius) 0 0; }
.checklist li:last-child { border-radius: 0 0 var(--radius) var(--radius); border-bottom: 0; }
.qty {
  font-weight: 800; color: var(--accent); min-width: 2rem; text-align: right;
}

.qcm { margin-top: 1.5rem; padding: 1rem; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.qcm fieldset { border: 0; padding: 0; margin: 0 0 1rem; }
.qcm legend { font-weight: 700; margin-bottom: 0.4rem; }
.qcm label { display: block; margin: 0.25rem 0; color: var(--muted); cursor: pointer; }
.qcm-result { margin-top: 1rem; padding: 0.85rem 1rem; border-radius: var(--radius); }
.qcm-result.pass { background: color-mix(in srgb, var(--ok) 18%, var(--surface)); border: 1px solid var(--ok); }
.qcm-result.fail { background: color-mix(in srgb, var(--bad) 18%, var(--surface)); border: 1px solid var(--bad); }

.site-footer {
  margin-top: auto; border-top: 1px solid var(--border);
  padding: 1.25rem 0; color: var(--muted); font-size: 0.9rem;
}

.back-link { display: inline-block; margin-bottom: 1rem; color: var(--muted); text-decoration: none; font-weight: 600; }
.back-link:hover { color: var(--accent); }