:root {
  --bg-color: #0b0f19;
  --bg-card: #131b2e;
  --bg-card-hover: #19243d;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --border-color: #24324f;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --accent-cyan: #06b6d4;
  --accent-green: #10b981;
  --accent-red: #ef4444;
  --accent-amber: #f59e0b;
  --card-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-color: #f8fafc;
    --bg-card: #ffffff;
    --bg-card-hover: #f1f5f9;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --card-shadow: 0 4px 20px -4px rgba(0, 0, 0, 0.08);
  }
}

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

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

.container {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 1.25rem;
  width: 100%;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-card);
  padding: 0.85rem 1.25rem;
}

.header-content {
  max-width: 1040px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand-link {
  text-decoration: none;
}

.brand-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: color 0.2s;
}

.brand-badge:hover {
  color: var(--primary);
}

.header-badges {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.live-dot {
  width: 9px;
  height: 9px;
  background-color: var(--accent-green);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--accent-green);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.15); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.source-tag {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.12);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  border: 1px solid rgba(6, 182, 212, 0.3);
}

/* Hero */
.hero-section {
  text-align: center;
  padding: 2.75rem 0 1.5rem;
}

.hero-icon {
  font-size: 3rem;
  margin-bottom: 0.5rem;
}

.hero-section h1 {
  font-size: 2.3rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  margin-bottom: 0.75rem;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto;
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: var(--card-shadow);
  display: flex;
  flex-direction: column;
}

.stat-card-highlight {
  border-color: rgba(6, 182, 212, 0.4);
}

.stat-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.6rem;
}

.stat-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
}

.stat-chip {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  background: rgba(59, 130, 246, 0.15);
  color: var(--primary);
}

.chip-cyan {
  background: rgba(6, 182, 212, 0.15);
  color: var(--accent-cyan);
}

.chip-amber {
  background: rgba(245, 158, 11, 0.15);
  color: var(--accent-amber);
}

.stat-value {
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
  color: var(--text-main);
}

.stat-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Calculator Card */
.calculator-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: var(--card-shadow);
  margin-bottom: 2.5rem;
}

.card-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.card-subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

.calc-inputs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-bottom: 1.25rem;
}

.input-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.currency-prefix {
  position: absolute;
  left: 1rem;
  font-weight: 700;
  color: var(--text-muted);
  pointer-events: none;
}

.input-wrapper input {
  padding-left: 2rem;
}

input, select {
  width: 100%;
  padding: 0.85rem 1rem;
  font-size: 1.05rem;
  font-family: inherit;
  background: var(--bg-color);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

input:focus, select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

/* Presets */
.presets-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-color);
}

.presets-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-right: 0.25rem;
}

.preset-btn {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.35rem 0.85rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.preset-btn:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* Results */
.calc-results {
  background: rgba(0, 0, 0, 0.15);
  border-radius: 16px;
  padding: 1.75rem;
  border: 1px solid var(--border-color);
}

.result-hero {
  text-align: center;
  margin-bottom: 1.75rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px dashed var(--border-color);
}

.result-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.4rem;
}

.result-hero-value {
  font-size: 3rem;
  font-weight: 800;
  color: var(--accent-green);
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 0.4rem;
}

.result-subtext {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}

.result-box {
  background: var(--bg-card);
  padding: 1.25rem;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  text-align: center;
}

.result-box-title {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.result-box-value {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 0.2rem;
}

.result-box-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.text-red {
  color: var(--accent-red);
}

.text-amber {
  color: var(--accent-amber);
}

/* History Table */
.history-section {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: var(--card-shadow);
  margin-bottom: 2.5rem;
}

.table-container {
  overflow-x: auto;
  border-radius: 12px;
  border: 1px solid var(--border-color);
}

.history-table {
  width: 100%;
  border-collapse: collapse;
  text-align: center;
  font-size: 0.9rem;
}

.history-table th {
  background: rgba(0, 0, 0, 0.2);
  padding: 0.85rem 0.6rem;
  font-weight: 600;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-color);
}

.history-table td {
  padding: 0.85rem 0.6rem;
  border-bottom: 1px solid var(--border-color);
}

.year-cell {
  font-weight: 700;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.02);
}

.val-cell {
  font-weight: 600;
}

.total-cell {
  color: var(--accent-red);
  background: rgba(239, 68, 68, 0.08);
}

.empty-cell {
  color: var(--text-muted);
  opacity: 0.5;
}

/* FAQ */
.faq-section {
  margin-bottom: 2.5rem;
}

.faq-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.25rem;
}

.faq-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem;
}

.faq-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  color: var(--text-main);
}

.faq-card p {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.faq-card code {
  background: rgba(255, 255, 255, 0.08);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.85rem;
}

/* Cross Promo */
.cross-promo-card {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(16, 185, 129, 0.05));
  border: 1px solid rgba(59, 130, 246, 0.3);
  border-radius: 20px;
  padding: 2rem;
  margin-bottom: 3rem;
  text-align: center;
}

.cross-promo-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.cross-promo-content h3 {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 0.4rem;
}

.cross-promo-content p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.25rem;
}

.promo-links {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

.promo-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 0.6rem 1.1rem;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
  text-decoration: none;
  transition: all 0.2s;
}

.promo-pill:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
  transform: translateY(-2px);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border-color);
  background: var(--bg-card);
  padding: 2rem 0;
  margin-top: auto;
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.site-footer a {
  color: var(--primary);
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

.footer-note {
  font-size: 0.8rem;
  margin-top: 0.4rem;
  opacity: 0.8;
}

/* Responsive */
@media (max-width: 640px) {
  .hero-section h1 {
    font-size: 1.8rem;
  }
  .result-hero-value {
    font-size: 2.2rem;
  }
  .calculator-card, .history-section {
    padding: 1.25rem;
  }
}