:root {
  --bg: #0f1419;
  --card: #1a2332;
  --border: #2d3a4f;
  --text: #e8eef7;
  --muted: #8b9cb3;
  --accent: #3b82f6;
  --success: #22c55e;
  --warn: #f59e0b;
  --danger: #ef4444;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: linear-gradient(160deg, #0f1419 0%, #162032 100%);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* --- Nav --- */
.topnav {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 0.75rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background: rgba(15, 20, 25, 0.85);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  margin-right: auto;
}

.nav-links {
  display: flex;
  gap: 0.5rem;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  padding: 0.35rem 0.65rem;
  border-radius: 6px;
  font-size: 0.9rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
  background: var(--card);
}

.lang-switch { display: flex; gap: 0.35rem; }

.lang-btn {
  padding: 0.3rem 0.55rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  color: var(--muted);
  text-decoration: none;
  font-size: 0.75rem;
  font-weight: 600;
}

.lang-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* --- Layout --- */
.container {
  flex: 1;
  max-width: 880px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1rem;
}

.page-header { margin-bottom: 1.5rem; }
.page-header h1 { margin: 0 0 0.35rem; font-size: 1.75rem; }
.subtitle { margin: 0; color: var(--muted); }

.footer {
  text-align: center;
  padding: 1rem;
  color: var(--muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}

/* --- Cards --- */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin-bottom: 1rem;
}

.feature-card h2 { margin: 0 0 0.5rem; font-size: 1.15rem; }
.feature-card p { color: var(--muted); margin: 0 0 1rem; font-size: 0.95rem; }

.hero-card {
  text-align: center;
  padding: 1.75rem 1.25rem;
}

.hero-cta {
  margin-top: 1rem;
  font-size: 1rem;
  padding: 0.75rem 1.5rem;
}

.steps-list {
  margin: 0;
  padding-left: 1.25rem;
  color: var(--muted);
  line-height: 1.6;
}

.steps-list li { margin-bottom: 0.5rem; }

.sample-name-list {
  list-style: none;
  padding-left: 0;
  font-size: 0.9rem;
}

.anti-spoof-notice {
  margin: 0;
  font-size: 0.85rem;
}

.info-card h3 { margin: 0 0 0.75rem; font-size: 1rem; }
.link-list { margin: 0; padding-left: 1.25rem; color: var(--muted); }
.link-list a { color: var(--accent); }

/* --- Verify upload --- */
.upload-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

@media (max-width: 640px) {
  .upload-grid { grid-template-columns: 1fr; }
}

.upload-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  border: 2px dashed var(--border);
  border-radius: 10px;
  padding: 1rem;
  cursor: pointer;
  min-height: 220px;
  position: relative;
  overflow: hidden;
}

.upload-box:hover { border-color: var(--accent); }
.upload-box .label { font-weight: 600; }
.upload-box input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

.placeholder { font-size: 2.5rem; opacity: 0.35; }
.preview {
  max-width: 100%;
  max-height: 180px;
  border-radius: 8px;
  object-fit: contain;
}

.hidden { display: none !important; }

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

.btn {
  display: inline-block;
  border: none;
  border-radius: 8px;
  padding: 0.65rem 1.25rem;
  font-weight: 600;
  cursor: pointer;
  font-size: 0.95rem;
  text-decoration: none;
  text-align: center;
}

.btn.primary { background: var(--accent); color: #fff; }
.btn.primary:disabled { opacity: 0.55; cursor: not-allowed; }
.btn.secondary {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}

/* --- Results --- */
.result .score {
  font-size: 2.5rem;
  font-weight: 700;
  margin: 0.25rem 0;
}

.badge {
  display: inline-block;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
}

.badge.match { background: rgba(34, 197, 94, 0.2); color: var(--success); }
.badge.no-match { background: rgba(239, 68, 68, 0.2); color: var(--danger); }
.badge.ambiguous { background: rgba(245, 158, 11, 0.2); color: var(--warn); }

.meta { color: var(--muted); font-size: 0.9rem; margin-top: 0.75rem; }
.error { color: var(--danger); text-align: center; margin-top: 0.5rem; }