:root {
  --bg: #f4f6f8;
  --surface: #ffffff;
  --text: #141a1f;
  --muted: #4a5968;
  --border: #d6dde5;
  --accent: #0f4c81;
  --ok: #118a48;
  --warn: #b26a00;
  --err: #be2a2a;
  --shadow: 0 8px 24px rgba(12, 24, 36, 0.08);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

.container { max-width: 800px; margin: 0 auto; padding: 20px; }

/* Header */
header {
  text-align: center;
  padding: 40px 0 24px;
}
header h1 { font-size: 28px; font-weight: 700; }
header p { color: var(--muted); font-size: 15px; margin-top: 4px; }

/* Search Form */
.search-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1.5fr auto;
  gap: 12px;
  align-items: end;
}

.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label {
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
}

.form-group input {
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: inherit;
  font-size: 14px;
  color: var(--text);
  transition: border-color 0.15s;
}
.form-group input:focus {
  outline: none;
  border-color: var(--accent);
}

.btn-search {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 10px 24px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  transition: opacity 0.15s;
}
.btn-search:hover { opacity: 0.9; }
.btn-search:disabled { opacity: 0.5; cursor: not-allowed; }

/* Loading */
.loading {
  display: none;
  text-align: center;
  padding: 40px 0;
}
.loading.active { display: block; }

.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  margin: 0 auto 12px;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.loading p { color: var(--muted); font-size: 14px; }

/* Results */
.results { display: none; }
.results.active { display: block; }

/* Source Summary Bar */
.source-summary {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
  padding: 12px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: var(--shadow);
}

.source-item {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: 6px;
  text-decoration: none;
  transition: background-color 0.15s;
}

.source-ok {
  color: var(--ok);
  background: #e8f4ec;
}
a.source-ok:hover { background: #d0ebd8; }

.source-err {
  color: var(--err);
  background: #fce8e8;
}
a.source-err:hover { background: #f5d4d4; }

.source-missing {
  color: var(--muted);
  background: #eef0f2;
}

.source-count {
  font-weight: 400;
  color: inherit;
  opacity: 0.7;
}

/* Best Offer Card */
.best-offer-card {
  background: var(--surface);
  border: 2px solid var(--ok);
  border-radius: 14px;
  padding: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
  text-align: center;
}
.best-offer-card .label {
  font-size: 13px;
  font-weight: 500;
  color: var(--ok);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.best-offer-card .offer-size {
  font-size: 42px;
  font-weight: 700;
  color: var(--text);
  margin: 8px 0;
}
.best-offer-card .offer-text {
  font-size: 15px;
  color: var(--muted);
  max-width: 500px;
  margin: 0 auto;
}
.best-offer-card .offer-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-top: 10px;
}
.best-offer-card .offer-source {
  font-size: 13px;
  color: var(--muted);
}

/* Source links */
.source-link {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}
.source-link:hover {
  text-decoration: underline;
}

/* Trust badges */
.trust-badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
}

.trust-verified {
  background: #e8f4ec;
  color: var(--ok);
}

.trust-recent {
  background: #e8f0f8;
  color: var(--accent);
}

.trust-score {
  background: #fef3e2;
  color: var(--warn);
}

/* Student tag */
.tag-student {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  background: #f0e8f8;
  color: #6b21a8;
}

/* Sale tag */
.tag-sale {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  background: #fef3e2;
  color: var(--warn);
}

/* Sale offer dimming */
.offer-item.offer-sale {
  opacity: 0.55;
}
.offer-item.offer-sale:hover {
  opacity: 0.85;
}

/* Sale divider */
.sale-divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 18px 0 10px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
}
.sale-divider::before,
.sale-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* Empty section */
.empty-section {
  color: var(--muted);
  font-size: 13px;
  padding: 8px 0;
}

/* No results */
.no-results {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 32px;
  text-align: center;
  box-shadow: var(--shadow);
}
.no-results p { color: var(--muted); font-size: 15px; }

/* All offers list */
.all-offers {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
  box-shadow: var(--shadow);
}
.all-offers h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--text);
}

.offer-item {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 12px;
  align-items: start;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.offer-item:last-child { border-bottom: none; }

.offer-item .size {
  font-size: 16px;
  font-weight: 700;
  color: var(--accent);
  padding-top: 2px;
}

.offer-item .details {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.offer-item .text {
  font-size: 13px;
  color: var(--text);
  line-height: 1.4;
}

.offer-item .meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--muted);
}

.badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  text-transform: uppercase;
}
.badge-pct { background: #e8f4ec; color: var(--ok); }
.badge-money { background: #fef3e2; color: var(--warn); }
.badge-ship { background: #e8f0f8; color: var(--accent); }
.badge-bogof { background: #fce8e8; color: var(--err); }

/* Error */
.error-msg {
  display: none;
  background: #fce8e8;
  border: 1px solid var(--err);
  border-radius: 10px;
  padding: 14px 20px;
  color: var(--err);
  font-size: 14px;
  margin-bottom: 20px;
}
.error-msg.active { display: block; }

/* Responsive */
@media (max-width: 640px) {
  .form-row {
    grid-template-columns: 1fr;
  }
  .source-summary {
    gap: 6px;
  }
  .source-item {
    font-size: 12px;
    padding: 3px 8px;
  }
  .offer-item {
    grid-template-columns: 60px 1fr;
  }
  .best-offer-card .offer-size {
    font-size: 32px;
  }
}