/* China Finance Tools - 样式表 */
/* 配色：深蓝(#1a365d) + 翡翠绿(#38a169) + 金色(#d69e2e) */

:root {
  --navy: #1a365d;
  --navy-light: #2a4a7f;
  --navy-dark: #0f2440;
  --green: #38a169;
  --green-light: #48bb78;
  --green-dark: #2f855a;
  --gold: #d69e2e;
  --gold-light: #ecc94b;
  --bg: #f7fafc;
  --white: #ffffff;
  --gray-50: #f7fafc;
  --gray-100: #edf2f7;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e0;
  --gray-500: #718096;
  --gray-700: #4a5568;
  --gray-900: #1a202c;
  --red: #e53e3e;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);
  --radius: 8px;
  --radius-lg: 12px;
  --transition: 0.25s ease;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--gray-900);
  background: var(--bg);
  line-height: 1.6;
}

a { color: var(--navy); transition: color var(--transition); text-decoration: none; }
a:hover { color: var(--navy-light); }

/* ===== Header ===== */
.header {
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: box-shadow var(--transition);
}
.header.scrolled { box-shadow: var(--shadow-md); }

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--navy);
  text-decoration: none;
}
.logo:hover { color: var(--navy); }
.logo-icon { font-size: 1.5rem; }

.nav { display: flex; gap: 24px; align-items: center; }
.nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--gray-700);
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: all var(--transition);
}
.nav a:hover, .nav a.active {
  color: var(--navy);
  border-bottom-color: var(--green);
}

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 100%);
  color: var(--white);
  padding: 60px 20px 48px;
  text-align: center;
}
.hero h1 {
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.hero p {
  font-size: 1.05rem;
  opacity: 0.85;
  max-width: 600px;
  margin: 0 auto;
}

/* ===== Container ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Tool Card Grid ===== */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  padding: 40px 0;
}

.tool-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px;
  border: 1px solid var(--gray-200);
  transition: all var(--transition);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  display: block;
}
.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--green);
  color: inherit;
}
.tool-card-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}
.tool-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--navy);
}
.tool-card p {
  font-size: 0.88rem;
  color: var(--gray-500);
  line-height: 1.5;
}
.tool-card .arrow {
  display: inline-block;
  margin-top: 12px;
  color: var(--green);
  font-weight: 600;
  font-size: 0.88rem;
}

/* ===== Converter Section ===== */
.converter-section {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 20px;
}

.converter-box {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--gray-200);
}

.converter-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.converter-input-group {
  flex: 1;
}

.converter-input-group label {
  display: block;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--gray-500);
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.converter-input-group input,
.converter-input-group select {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--gray-900);
  background: var(--white);
  transition: border-color var(--transition);
}
.converter-input-group input:focus,
.converter-input-group select:focus {
  outline: none;
  border-color: var(--green);
}

.swap-btn {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--green);
  color: var(--white);
  border: none;
  font-size: 1.2rem;
  cursor: pointer;
  transition: all var(--transition);
  flex-shrink: 0;
  margin-top: 20px;
}
.swap-btn:hover { background: var(--green-dark); transform: rotate(180deg); }

.rate-info {
  text-align: center;
  font-size: 0.85rem;
  color: var(--gray-500);
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--gray-100);
}
.rate-info strong { color: var(--green); }

/* ===== Calculator Form ===== */
.calc-section {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 20px;
}

.calc-box {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--gray-200);
}

.calc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 24px;
}

.calc-field {
  display: flex;
  flex-direction: column;
}
.calc-field.full { grid-column: 1 / -1; }

.calc-field label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: 6px;
}

.calc-field input,
.calc-field select {
  padding: 10px 14px;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 1rem;
  color: var(--gray-900);
  transition: border-color var(--transition);
}
.calc-field input:focus,
.calc-field select:focus {
  outline: none;
  border-color: var(--green);
}

.calc-btn {
  width: 100%;
  padding: 14px;
  background: var(--green);
  color: var(--white);
  border: none;
  border-radius: var(--radius);
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition);
}
.calc-btn:hover { background: var(--green-dark); }

/* ===== Result Box ===== */
.result-box {
  margin-top: 24px;
  background: linear-gradient(135deg, #f0fff4, #ebf8ff);
  border: 1px solid var(--green);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: none;
}
.result-box.show { display: block; }

.result-highlight {
  font-size: 2rem;
  font-weight: 700;
  color: var(--navy);
  text-align: center;
  margin-bottom: 16px;
}
.result-highlight small {
  display: block;
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--gray-500);
  margin-top: 4px;
}

.result-details {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid rgba(0,0,0,0.08);
}

.result-item {
  text-align: center;
}
.result-item .label {
  font-size: 0.78rem;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.result-item .value {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--navy);
  margin-top: 2px;
}

/* ===== Amortization Table ===== */
.amort-toggle {
  margin-top: 16px;
  text-align: center;
}
.amort-toggle button {
  background: none;
  border: 1px solid var(--gray-300);
  padding: 8px 20px;
  border-radius: var(--radius);
  color: var(--gray-700);
  cursor: pointer;
  font-size: 0.88rem;
}
.amort-toggle button:hover { border-color: var(--green); color: var(--green); }

.amort-table {
  margin-top: 16px;
  max-height: 400px;
  overflow-y: auto;
  display: none;
}
.amort-table.show { display: block; }

.amort-table table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
}
.amort-table th {
  background: var(--navy);
  color: var(--white);
  padding: 8px 12px;
  text-align: left;
  position: sticky;
  top: 0;
}
.amort-table td {
  padding: 6px 12px;
  border-bottom: 1px solid var(--gray-100);
}
.amort-table tr:nth-child(even) { background: var(--gray-50); }

/* ===== SEO Content Section ===== */
.seo-content {
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--gray-700);
}
.seo-content h2 {
  font-size: 1.3rem;
  color: var(--navy);
  margin: 28px 0 12px;
}
.seo-content p { margin-bottom: 14px; }
.seo-content strong { color: var(--navy); }

/* ===== Currency Pair Grid (Programmatic SEO) ===== */
.currency-pair-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 12px;
  padding: 20px 0;
}

.currency-pair-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 14px;
  text-decoration: none;
  color: inherit;
  text-align: center;
  transition: all var(--transition);
}
.currency-pair-card:hover {
  border-color: var(--green);
  box-shadow: var(--shadow-sm);
  transform: translateY(-2px);
  color: inherit;
}
.currency-pair-card .flag { font-size: 1.5rem; }
.currency-pair-card .pair {
  font-weight: 600;
  font-size: 0.9rem;
  margin-top: 4px;
  color: var(--navy);
}
.currency-pair-card .rate {
  font-size: 0.8rem;
  color: var(--gray-500);
  margin-top: 2px;
}

/* ===== Footer ===== */
.footer {
  background: var(--navy-dark);
  color: rgba(255,255,255,0.7);
  padding: 40px 20px 24px;
  margin-top: 60px;
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 32px;
}
.footer-about h3 {
  color: #fff;
  font-size: 1.1rem;
  margin-bottom: 10px;
}
.footer-about p {
  font-size: 0.85rem;
  line-height: 1.6;
}
.footer-links h4 {
  color: #fff;
  font-size: 0.9rem;
  margin-bottom: 10px;
}
.footer-links a {
  display: block;
  color: rgba(255,255,255,0.6);
  font-size: 0.85rem;
  padding: 3px 0;
  transition: color var(--transition);
}
.footer-links a:hover { color: #fff; }

.footer-sister {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,0.1);
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}
.footer-sister p {
  font-size: 0.82rem;
  color: #999;
  margin-bottom: 10px;
}
.footer-sister .sister-links {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-sister .sister-links a {
  color: #bbb;
  font-size: 0.85rem;
}

.footer-bottom {
  max-width: 1200px;
  margin: 20px auto 0;
  padding-top: 16px;
  border-top: 1px solid rgba(255,255,255,0.1);
  text-align: center;
  font-size: 0.82rem;
  color: rgba(255,255,255,0.4);
}

/* ===== Section Title ===== */
.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--navy);
  text-align: center;
  margin-bottom: 8px;
}
.section-subtitle {
  font-size: 0.92rem;
  color: var(--gray-500);
  text-align: center;
  margin-bottom: 32px;
}

/* ===== Ad Slot ===== */
.ad-slot {
  max-width: 728px;
  margin: 24px auto;
  min-height: 90px;
  text-align: center;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero h1 { font-size: 1.6rem; }
  .hero p { font-size: 0.92rem; }
  .nav { gap: 14px; }
  .nav a { font-size: 0.82rem; }
  .calc-grid { grid-template-columns: 1fr; }
  .result-details { grid-template-columns: 1fr 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 20px; }
  .converter-row { flex-direction: column; }
  .swap-btn { margin-top: 0; transform: rotate(90deg); }
  .swap-btn:hover { transform: rotate(270deg); }
  .tool-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .header-inner { height: 56px; }
  .logo { font-size: 1.05rem; }
  .hero { padding: 40px 16px 32px; }
  .converter-box, .calc-box { padding: 20px; }
  .result-highlight { font-size: 1.5rem; }
}