/* style.css — CalcGuide 计算器设计系统（与现有 time 站同源调色板） */
:root {
  --bg: #eee;
  --card: #fff;
  --fg: #555;
  --border: #ddd;
  --link: #258fb8;
  --link-hover: #1a6f99;
  --accent: #0C447C;
  --hero-start: #1a1a2e;
  --hero-end: #16213e;
  --error: #c0392b;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-hover: 0 8px 24px rgba(0,0,0,0.12);
  --radius: 8px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, sans-serif;
}

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--fg);
  font-size: 14px;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--link); text-decoration: none; }
a:hover { color: var(--link-hover); text-decoration: underline; }

/* Top nav */
.top-nav {
  background: var(--hero-start);
  color: #fff;
  height: 50px;
  display: flex;
  align-items: center;
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 100;
}
.top-nav .brand { color: #fff; font-weight: 300; letter-spacing: 1px; margin-right: auto; }
.top-nav .brand span { opacity: 0.7; font-size: 0.85rem; margin-left: 6px; }
.top-nav .links { display: flex; gap: 4px; align-items: center; }
.top-nav .links a {
  color: rgba(255,255,255,0.7);
  padding: 6px 12px;
  border-radius: 4px;
  font-size: 0.9rem;
}
.top-nav .links a:hover { background: rgba(255,255,255,0.08); color: #fff; text-decoration: none; }
.top-nav .links a.active { background: rgba(255,255,255,0.12); color: #fff; }
.top-nav .lang-switch {
  background: rgba(255,255,255,0.1);
  color: #fff;
  border: 1px solid rgba(255,255,255,0.2);
  padding: 4px 8px;
  border-radius: 4px;
  font-size: 0.85rem;
  margin-left: 8px;
}

/* 下拉打开后的选项：黑字白底（避免继承白字看不见） */
.top-nav .lang-switch option {
  color: #333;
  background: #fff;
  padding: 6px 8px;
}
.top-nav .lang-switch option:checked {
  font-weight: 600;
  background: #e8f4fb;
  color: #0C447C;
}

/* Main */
main { flex: 1; padding: 32px 20px; max-width: 720px; margin: 0 auto; width: 100%; }
h1 { font-size: 1.8rem; color: var(--accent); margin-bottom: 8px; font-weight: 500; }
.intro { color: var(--fg); margin-bottom: 24px; }

/* Form card */
.calc-card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  margin-bottom: 24px;
}
.calc-card label {
  display: block;
  margin-bottom: 16px;
  font-weight: 500;
  color: var(--accent);
}
.calc-card label .hint {
  display: block;
  font-weight: 400;
  color: #888;
  font-size: 0.85rem;
  margin-top: 4px;
}
.calc-card input[type="number"],
.calc-card select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 1rem;
  font-family: var(--font);
  margin-top: 6px;
  background: #fff;
  color: var(--fg);
}
.calc-card input[type="number"]:focus,
.calc-card select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(12,68,124,0.1);
}
.calc-card input.error { border-color: var(--error); }
.calc-card .err-msg {
  color: var(--error);
  font-size: 0.85rem;
  margin-top: 4px;
  display: none;
}
.calc-card .err-msg.show { display: block; }

/* Buttons */
.btn-row { display: flex; gap: 12px; margin-top: 8px; }
.btn {
  padding: 10px 24px;
  border-radius: 4px;
  border: none;
  font-size: 1rem;
  cursor: pointer;
  font-family: var(--font);
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: #083358; }
.btn-secondary { background: #fff; color: var(--accent); border: 1px solid var(--accent); }
.btn-secondary:hover { background: var(--accent); color: #fff; }

/* Result */
.result-card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  margin-bottom: 24px;
}
.result-row {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
}
.result-row:last-child { border-bottom: none; }
.result-row .k { color: #888; }
.result-row .v { font-weight: 600; color: var(--accent); font-size: 1.1rem; }

/* Yearly curve */
.curve-title { margin: 24px 0 12px; color: var(--accent); }
.curve-table { width: 100%; border-collapse: collapse; }
.curve-table th, .curve-table td {
  padding: 8px 12px;
  text-align: right;
  border-bottom: 1px solid var(--border);
  font-variant-numeric: tabular-nums;
}
.curve-table th { background: var(--bg); font-weight: 600; text-align: right; }
.curve-table th:first-child, .curve-table td:first-child { text-align: left; }

/* E-E-A-T / Trust block */
.trust-block {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  margin: 32px 0 16px;
  font-size: 0.92rem;
  line-height: 1.7;
}
.trust-block h2 {
  font-size: 1.1rem;
  color: var(--accent);
  margin: 0 0 12px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--border);
  font-weight: 600;
}
.trust-block h3 {
  font-size: 0.95rem;
  color: var(--accent);
  margin: 14px 0 6px;
  font-weight: 600;
}
.trust-block p { margin: 6px 0; color: var(--fg); }
.trust-block .placeholder {
  background: #fff4e0;
  border-left: 3px solid #c95a13;
  padding: 6px 10px;
  margin: 8px 0;
  color: #6a3a0a;
  border-radius: 3px;
}
.trust-block details {
  margin: 8px 0;
  padding: 8px 12px;
  background: var(--bg);
  border-radius: 4px;
}
.trust-block details summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--accent);
  padding: 2px 0;
}
.trust-block details[open] summary { margin-bottom: 6px; }
.trust-block details p { margin: 4px 0; color: var(--fg); }
.trust-block .related {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
  font-size: 0.88rem;
}
.trust-block .related a { color: var(--link); }
.disclaimer {
  background: #fdf4f4;
  border-left: 3px solid #c0392b;
  padding: 10px 12px;
  border-radius: 3px;
  color: #6a2828;
  margin: 12px 0;
}
footer {
  background: #262a30;
  color: #aab;
  text-align: center;
  padding: 24px 20px;
  font-size: 0.85rem;
}
footer a { color: #aab; }

/* AdSense */
.adsbygoogle { background: #f5f5f5; border: 1px dashed #ccc; }

/* Responsive */
@media (max-width: 600px) {
  .top-nav { padding: 0 12px; }
  .top-nav .brand span { display: none; }
  main { padding: 16px 12px; }
  h1 { font-size: 1.4rem; }
  .calc-card, .result-card { padding: 16px; }
  .btn-row { flex-direction: column; }
  .btn { width: 100%; }
}