/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-primary: #1a73e8;
  --color-primary-dark: #1557b0;
  --color-primary-light: #e8f0fe;
  --color-bg: #f8f9fa;
  --color-surface: #ffffff;
  --color-text: #202124;
  --color-text-secondary: #5f6368;
  --color-border: #dadce0;
  --color-success: #0d904f;
  --color-error: #d93025;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.08);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.1);
  --max-width: 960px;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* === Layout === */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 16px; }

header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 12px 0;
}

header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.site-logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}

.site-logo:hover { text-decoration: none; }

.site-logo span { color: var(--color-primary); }

header nav { display: flex; gap: 16px; flex-wrap: wrap; }
header nav a { font-size: 14px; color: var(--color-text-secondary); }
header nav a:hover { color: var(--color-primary); }

main { padding: 24px 0 80px; }
main .container { display: flex; flex-direction: column; gap: 24px; }

/* === Converter Widget === */
.converter-widget {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-lg);
}

.converter-widget h1 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--color-text);
}

.converter-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.converter-form input,
.converter-form select {
  width: 100%;
  padding: 14px 12px;
  font-size: 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-surface);
  color: var(--color-text);
  appearance: none;
  -webkit-appearance: none;
}

.converter-form input:focus,
.converter-form select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px var(--color-primary-light);
}

.converter-form select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%235f6368' d='M2 4l4 4 4-4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
}

.swap-btn {
  align-self: center;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: 50%;
  width: 44px;
  height: 44px;
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
  flex-shrink: 0;
}

.swap-btn:hover { background: var(--color-primary-dark); }

/* === Result === */
.converter-result {
  margin-top: 20px;
  padding: 16px;
  background: var(--color-primary-light);
  border-radius: var(--radius);
}

.result-amount {
  display: block;
  font-size: 26px;
  font-weight: 700;
  color: var(--color-text);
  word-break: break-word;
}

.result-meta {
  display: block;
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-top: 4px;
}

.trend-indicator {
  display: inline-block;
  font-weight: 700;
  margin-left: 6px;
  font-size: 14px;
}

.trend-up { color: var(--color-success); }
.trend-down { color: var(--color-error); }
.trend-flat { color: var(--color-text-secondary); }

/* === Rate Chart === */
.rate-chart {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
}

.rate-chart h2 { font-size: 18px; margin-bottom: 4px; }

.chart-subtitle {
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-bottom: 16px;
}

.chart-wrap {
  width: 100%;
  position: relative;
}

.chart-wrap canvas {
  display: block;
  width: 100%;
  cursor: crosshair;
}

.chart-info {
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-top: 12px;
  text-align: center;
}

/* === Conversion Table === */
.conversion-table {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
}

.conversion-table h2 {
  font-size: 18px;
  margin-bottom: 16px;
}

.conversion-table table { width: 100%; border-collapse: collapse; }

.conversion-table th {
  text-align: left;
  padding: 10px 12px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-bottom: 2px solid var(--color-border);
}

.conversion-table td {
  padding: 10px 12px;
  font-size: 15px;
  border-bottom: 1px solid var(--color-border);
}

.conversion-table tr:last-child td { border-bottom: none; }

.conversion-table .table-result { font-weight: 600; }

/* === Explainer === */
.explainer {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
}

.explainer h2 { font-size: 18px; margin-bottom: 12px; }
.explainer p { color: var(--color-text-secondary); font-size: 15px; }

/* === FAQ === */
.faq {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
}

.faq h2 { font-size: 18px; margin-bottom: 16px; }

.faq-item { padding: 16px 0; border-bottom: 1px solid var(--color-border); }
.faq-item:last-child { border-bottom: none; padding-bottom: 0; }
.faq-item:first-of-type { padding-top: 0; }

.faq-item h3 { font-size: 15px; font-weight: 600; margin-bottom: 6px; color: var(--color-text); }
.faq-item p { font-size: 14px; color: var(--color-text-secondary); line-height: 1.7; }

/* === Pairs Grid (Index Page) === */
.pairs-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
}

.pairs-grid a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  background: var(--color-surface);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  font-size: 15px;
  font-weight: 500;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.pairs-grid a:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow);
  text-decoration: none;
}

.pairs-grid a .arrow {
  color: var(--color-text-secondary);
  font-size: 13px;
}

.section-heading {
  font-size: 18px;
  font-weight: 700;
  margin: 24px 0 12px;
}

.section-heading:first-of-type { margin-top: 0; }

/* === Privacy Page === */
.content-page {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
}

.content-page h1 { font-size: 22px; margin-bottom: 16px; }
.content-page h2 { font-size: 17px; margin: 20px 0 8px; }
.content-page p { font-size: 15px; color: var(--color-text-secondary); margin-bottom: 12px; }

/* === Footer === */
footer {
  padding: 24px 0;
  border-top: 1px solid var(--color-border);
  margin-top: 24px;
}

footer .container {
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 13px;
  color: var(--color-text-secondary);
}

footer nav { display: flex; gap: 16px; flex-wrap: wrap; }
footer nav a { color: var(--color-text-secondary); font-size: 13px; }
footer nav a:hover { color: var(--color-primary); }

.footer-copy { font-size: 12px; }

/* === Tablet (>=768px) === */
@media (min-width: 768px) {
  .converter-widget h1 { font-size: 26px; }

  .converter-form {
    flex-direction: row;
    align-items: center;
  }

  .converter-form input,
  .converter-form select {
    width: auto;
    flex: 1;
  }

  .result-amount { font-size: 30px; }

  .pairs-grid { grid-template-columns: repeat(2, 1fr); }

  footer .container { flex-direction: row; justify-content: space-between; align-items: center; }
}

/* === Desktop (>=1024px) === */
@media (min-width: 1024px) {
  .converter-widget { padding: 32px; }
  .pairs-grid { grid-template-columns: repeat(3, 1fr); }
}