:root {
  --bg: #f0f4f8;
  --accent: #1e88e5;
  --accent-dark: #1565c0;
  --card-bg: #ffffff;
  --card-border: #dbe8f6;
  --text: #1e293b;
  --text-muted: #64748b;
  --danger: #ef4444;
  --danger-bg: #fef2f2;
  --success: #16a34a;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
}

body {
  min-height: 100vh;
  background:
    radial-gradient(1200px 600px at 50% -10%, #ffffff 0%, rgba(255,255,255,0) 60%),
    var(--bg);
  color: var(--text);
  font-family: "Inter", "Noto Sans TC", system-ui, -apple-system, "PingFang TC",
               "Microsoft JhengHei", sans-serif;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 40px 16px;
}

.card {
  width: 100%;
  max-width: 440px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  box-shadow: 0 8px 28px rgba(30, 64, 128, 0.08);
  padding: 28px 24px 20px;
}

.head { text-align: center; margin-bottom: 22px; }
.head h1 {
  font-size: 22px;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--text);
}
.subtitle {
  font-size: 14px;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.6;
}

.field-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.input {
  width: 100%;
  font-size: 16px; /* ≥16px 避免 iOS 自動放大 */
  padding: 12px 14px;
  border: 1px solid var(--card-border);
  border-radius: 10px;
  color: var(--text);
  background: #fff;
  transition: border-color .15s, box-shadow .15s;
}
.input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(30, 136, 229, 0.15);
}

.turnstile-wrap {
  margin: 14px 0 4px;
  display: flex;
  justify-content: center;
}
.turnstile-wrap[hidden] { display: none; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: inherit;
  font-size: 16px;
  font-weight: 600;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: background .15s, opacity .15s, transform .05s;
}
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .6; cursor: not-allowed; }

.btn-primary {
  width: 100%;
  margin-top: 14px;
  padding: 13px;
  color: #fff;
  background: var(--accent);
}
.btn-primary:not(:disabled):hover { background: var(--accent-dark); }

.error-box {
  margin-top: 18px;
  padding: 12px 14px;
  border: 1px solid #fecaca;
  background: var(--danger-bg);
  color: var(--danger);
  border-radius: 10px;
  font-size: 14px;
  line-height: 1.6;
  text-align: center;
}

.result { margin-top: 22px; }
.product-name {
  text-align: center;
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  padding: 12px;
  background: #f8fbff;
  border: 1px solid var(--card-border);
  border-radius: 10px;
  margin-bottom: 18px;
}

.download-item { margin-bottom: 18px; }
.download-item:last-child { margin-bottom: 6px; }

.btn-download {
  width: 100%;
  padding: 14px;
  color: #fff;
  background: var(--accent);
}
.btn-download:not(:disabled):hover { background: var(--accent-dark); }
.dl-icon { display: inline-flex; }

.dl-hint {
  margin: 6px 2px 2px;
  font-size: 12.5px;
  color: var(--text-muted);
  text-align: center;
}
.dl-date {
  margin: 2px;
  font-size: 12.5px;
  color: var(--text-muted);
  text-align: center;
}

.foot {
  margin-top: 18px;
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
}

/* 手機 */
@media (max-width: 640px) {
  body { padding: 20px 12px; align-items: stretch; }
  .card { max-width: 100%; border-radius: 14px; padding: 22px 16px 16px; }
  .head h1 { font-size: 20px; }
}