/* ============================================
   計算エキスパート — Core Stylesheet
   ============================================ */

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --accent: #f59e0b;
  --accent-dark: #d97706;
  --accent-glow: rgba(245,158,11,.25);
  --bg: #f1f5f9;
  --surface: #ffffff;
  --surface-glass: rgba(255,255,255,.75);
  --text: #1e293b;
  --text-secondary: #64748b;
  --text-light: #94a3b8;
  --border: #e2e8f0;
  --border-glow: rgba(0,0,0,.08);
  --success: #22c55e;
  --danger: #ef4444;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.05);
  --shadow-lg: 0 12px 32px rgba(0,0,0,.1), 0 4px 10px rgba(0,0,0,.05);
  --font: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'SF Mono', 'Cascadia Code', 'Consolas', monospace;
  --transition: 180ms cubic-bezier(.4,0,.2,1);
  --header-h: 60px;
  --container: 1100px;
  --key-bg: rgba(0,0,0,.03);
  --key-hover: rgba(0,0,0,.07);
  --key-active: rgba(0,0,0,.12);
  --display-bg: #0f172a;
  --display-text: #fff;
}

[data-theme="dark"] {
  --primary: #3b82f6;
  --primary-dark: #60a5fa;
  --primary-light: rgba(59,130,246,.15);
  --bg: #0b1120;
  --surface: rgba(22,30,49,.7);
  --surface-glass: rgba(22,30,49,.65);
  --text: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-light: #64748b;
  --border: rgba(255,255,255,.08);
  --border-glow: rgba(255,255,255,.12);
  --shadow: 0 1px 3px rgba(0,0,0,.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,.35);
  --shadow-lg: 0 12px 32px rgba(0,0,0,.45);
  --key-bg: rgba(255,255,255,.06);
  --key-hover: rgba(255,255,255,.12);
  --key-active: rgba(255,255,255,.18);
  --display-bg: rgba(10,15,26,.65);
  --display-text: #f3f4f6;
  --danger: #f87171;
  --success: #4ade80;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  transition: background var(--transition), color var(--transition);
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

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

/* ============================================
   Header
   ============================================ */
.site-header {
  background: var(--surface-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  transition: background var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  white-space: nowrap;
}

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

.logo-icon {
  font-size: 1.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--primary);
  color: #fff;
  border-radius: var(--radius-sm);
}

.main-nav > ul {
  display: flex;
  list-style: none;
  gap: 4px;
  align-items: center;
}

.main-nav a, .nav-more-btn {
  display: block;
  padding: 6px 14px;
  font-size: .875rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-xs);
  transition: all var(--transition);
  white-space: nowrap;
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font);
}

.main-nav a:hover, .main-nav a.active, .nav-more-btn:hover {
  color: var(--primary);
  background: var(--primary-light);
}

.main-nav a.active { font-weight: 700; }

.nav-more { position: relative; }

.nav-dropdown {
  display: none;
  position: absolute;
  right: 0;
  top: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  min-width: 200px;
  padding: 6px;
  flex-direction: column;
  z-index: 50;
}

.nav-more.open .nav-dropdown { display: flex; }
.nav-dropdown a { padding: 10px 14px; border-radius: var(--radius-xs); }

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all var(--transition);
}

.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ============================================
   Main Content
   ============================================ */
.site-main {
  padding: 32px 0;
  min-height: calc(100vh - var(--header-h) - 200px);
}

.page-header {
  text-align: center;
  margin-bottom: 28px;
}

.page-header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}

.page-header p {
  color: var(--text-secondary);
  font-size: .95rem;
  max-width: 600px;
  margin: 0 auto;
}

/* Ad slot placeholders */
.ad-slot {
  background: var(--surface);
  border: 2px dashed var(--border);
  border-radius: var(--radius-sm);
  padding: 16px;
  text-align: center;
  color: var(--text-light);
  font-size: .8rem;
  margin: 24px 0;
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ad-slot-sidebar {
  min-height: 250px;
}

/* ============================================
   Calculator Card
   ============================================ */
.calc-wrapper {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 24px;
  align-items: start;
}

.calc-card {
  background: var(--surface-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transition: background var(--transition), border var(--transition);
}

.calc-display {
  padding: 20px 24px;
  background: #0f172a;
  color: #fff;
  min-height: 100px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: flex-end;
}

.calc-expression {
  font-size: .9rem;
  color: #94a3b8;
  min-height: 1.5em;
  word-break: break-all;
  text-align: right;
  width: 100%;
}

.calc-result {
  font-family: var(--font-mono);
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1.2;
  word-break: break-all;
  text-align: right;
  width: 100%;
  transition: font-size var(--transition);
}

.calc-result.small { font-size: 1.8rem; }

.calc-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  padding: 1px;
}

.calc-btn {
  background: var(--key-bg);
  border: none;
  font-family: var(--font);
  font-size: 1.2rem;
  font-weight: 500;
  padding: 18px 8px;
  cursor: pointer;
  transition: all var(--transition);
  color: var(--text);
  position: relative;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.calc-btn:hover { background: var(--key-hover); transform: translateY(-1px); }
.calc-btn:active { background: var(--key-active); transform: scale(.96); }

.calc-btn.operator {
  background: rgba(245,158,11,.08);
  color: var(--accent);
  font-weight: 700;
  font-size: 1.3rem;
  border-color: rgba(245,158,11,.15);
}

.calc-btn.operator:hover { background: rgba(245,158,11,.15); }

.calc-btn.function {
  background: var(--key-bg);
  color: var(--text-secondary);
  font-size: 1rem;
  font-weight: 600;
}

.calc-btn.equals {
  background: var(--accent);
  color: #fff;
  font-size: 1.4rem;
  font-weight: 700;
  box-shadow: 0 4px 15px var(--accent-glow);
}

.calc-btn.equals:hover { background: var(--accent-dark); box-shadow: 0 6px 20px var(--accent-glow); transform: translateY(-2px); }

.calc-btn.clear {
  background: rgba(239,68,68,.08);
  color: var(--danger);
  font-weight: 700;
}

.calc-btn.clear:hover { background: rgba(239,68,68,.15); }

.calc-btn.wide { grid-column: span 2; }

.calc-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: -2px;
  z-index: 1;
}

/* Memory buttons */
.calc-memory {
  display: flex;
  gap: 1px;
  background: var(--border);
  padding: 1px;
  padding-top: 0;
}

.mem-btn {
  flex: 1;
  background: #f1f5f9;
  border: none;
  font-family: var(--font);
  font-size: .75rem;
  font-weight: 600;
  padding: 10px 4px;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all var(--transition);
}

.mem-btn:hover { background: var(--primary-light); color: var(--primary); }
.mem-btn.has-memory { color: var(--primary); }

/* History panel */
.calc-history {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
}

.calc-history h3 {
  font-size: .9rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.calc-history h3 button {
  background: none;
  border: none;
  color: var(--text-light);
  font-size: .8rem;
  cursor: pointer;
  font-family: var(--font);
}

.calc-history h3 button:hover { color: var(--danger); }

.history-list {
  list-style: none;
  max-height: 400px;
  overflow-y: auto;
}

.history-item {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background var(--transition);
}

.history-item:last-child { border-bottom: none; }
.history-item:hover { background: #f8fafc; margin: 0 -16px; padding: 10px 16px; }

.history-expr {
  font-size: .8rem;
  color: var(--text-secondary);
}

.history-result {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
}

.history-empty {
  color: var(--text-light);
  font-size: .85rem;
  text-align: center;
  padding: 24px 0;
}

/* Keyboard shortcuts info */
.keyboard-info {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
  margin-top: 16px;
}

.keyboard-info h3 {
  font-size: .9rem;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.key-list { list-style: none; }

.key-list li {
  display: flex;
  justify-content: space-between;
  padding: 4px 0;
  font-size: .8rem;
  color: var(--text-secondary);
}

.key-list kbd {
  background: #f1f5f9;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  font-family: var(--font-mono);
  font-size: .75rem;
}

/* ============================================
   Form-based calculators (Tax, BMI, Loan, etc.)
   ============================================ */
.form-calc {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  padding: 32px;
  max-width: 600px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: .9rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text);
}

.form-group .hint {
  font-size: .8rem;
  color: var(--text-light);
  margin-top: 4px;
}

.form-input {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 1.1rem;
  color: var(--text);
  transition: border-color var(--transition);
  background: var(--surface);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, .1);
}

.form-input::placeholder { color: var(--text-light); }

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-select {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 1rem;
  color: var(--text);
  background: var(--surface);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' fill='%2364748b'%3E%3Cpath d='M1 1l5 5 5-5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
}

.form-select:focus {
  outline: none;
  border-color: var(--primary);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition);
  width: 100%;
}

.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-primary:active { transform: translateY(0); }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  background: var(--surface);
  color: var(--text-secondary);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: .9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-secondary:hover { border-color: var(--primary); color: var(--primary); }

.btn-group {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
}

.btn-group .btn-tab {
  flex: 1;
  padding: 10px 16px;
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  font-family: var(--font);
  font-size: .9rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
  text-align: center;
}

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

.btn-tab:hover:not(.active) {
  border-color: var(--primary);
  color: var(--primary);
}

/* Results display */
.result-card {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  border-radius: var(--radius);
  padding: 28px;
  color: #fff;
  margin-top: 24px;
  display: none;
}

.result-card.visible { display: block; animation: fadeInUp .3s ease; }

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.result-label {
  font-size: .85rem;
  color: #94a3b8;
  margin-bottom: 4px;
}

.result-value {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 16px;
  word-break: break-all;
}

.result-value.accent { color: var(--accent); }

.result-details {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 12px;
  padding-top: 16px;
  border-top: 1px solid rgba(255,255,255,.1);
}

.result-detail-item .detail-label {
  font-size: .75rem;
  color: #94a3b8;
}

.result-detail-item .detail-value {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 600;
}

/* Copy button */
.copy-btn {
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.2);
  color: #fff;
  padding: 6px 14px;
  border-radius: var(--radius-xs);
  font-family: var(--font);
  font-size: .8rem;
  cursor: pointer;
  transition: all var(--transition);
  margin-top: 8px;
}

.copy-btn:hover { background: rgba(255,255,255,.2); }
.copy-btn.copied { background: var(--success); border-color: var(--success); }

/* ============================================
   BMI Gauge
   ============================================ */
.bmi-gauge {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid rgba(255,255,255,.1);
}

.bmi-bar {
  height: 8px;
  border-radius: 4px;
  background: linear-gradient(90deg, #22c55e 0%, #22c55e 25%, #eab308 25%, #eab308 50%, #f97316 50%, #f97316 75%, #ef4444 75%);
  position: relative;
  margin: 12px 0 8px;
}

.bmi-marker {
  position: absolute;
  top: -6px;
  width: 20px;
  height: 20px;
  background: #fff;
  border-radius: 50%;
  transform: translateX(-50%);
  box-shadow: 0 2px 6px rgba(0,0,0,.3);
  transition: left .5s ease;
}

.bmi-labels {
  display: flex;
  justify-content: space-between;
  font-size: .7rem;
  color: #94a3b8;
}

/* ============================================
   SEO Content Section
   ============================================ */
.seo-content {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;
  margin-top: 32px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.seo-content h2 {
  font-size: 1.3rem;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--primary-light);
}

.seo-content h3 {
  font-size: 1.05rem;
  margin: 20px 0 8px;
  color: var(--text);
}

.seo-content p {
  color: var(--text-secondary);
  margin-bottom: 12px;
  font-size: .95rem;
}

.seo-content ul {
  color: var(--text-secondary);
  margin: 8px 0 16px 20px;
  font-size: .95rem;
}

.seo-content li { margin-bottom: 4px; }

/* FAQ Section */
.faq-section { margin-top: 24px; }

.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
}

.faq-item:last-child { border-bottom: none; }

.faq-q {
  font-weight: 700;
  font-size: .95rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-q::after {
  content: '+';
  font-size: 1.2rem;
  color: var(--primary);
  transition: transform var(--transition);
}

.faq-item.open .faq-q::after { content: '−'; }

.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height .3s ease;
  color: var(--text-secondary);
  font-size: .9rem;
}

.faq-item.open .faq-a {
  max-height: 500px;
  padding-top: 10px;
}

/* ============================================
   Tools Grid
   ============================================ */
.tools-grid-section {
  padding: 48px 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
}

.section-title {
  font-size: 1.3rem;
  text-align: center;
  margin-bottom: 28px;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}

.tool-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 24px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all var(--transition);
  color: var(--text);
}

.tool-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  color: var(--text);
}

.tool-icon { font-size: 2rem; margin-bottom: 8px; }
.tool-name { font-weight: 700; font-size: .95rem; margin-bottom: 4px; }
.tool-desc { font-size: .8rem; color: var(--text-secondary); }

/* ============================================
   Footer
   ============================================ */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding-top: 48px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  padding-bottom: 40px;
}

.footer-logo {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 10px;
}

.footer-about p {
  font-size: .85rem;
  line-height: 1.8;
}

.footer-links h4 {
  color: #fff;
  font-size: .9rem;
  margin-bottom: 12px;
}

.footer-links ul { list-style: none; }

.footer-links li { margin-bottom: 8px; }

.footer-links a {
  color: #94a3b8;
  font-size: .85rem;
  transition: color var(--transition);
}

.footer-links a:hover { color: #fff; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1);
  padding: 16px 0;
  text-align: center;
  font-size: .8rem;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 900px) {
  .calc-wrapper {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }
}

@media (max-width: 768px) {
  .menu-toggle { display: flex; }

  .main-nav {
    display: none;
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
    padding: 12px;
  }

  .main-nav.open { display: block; }

  .main-nav ul {
    flex-direction: column;
    gap: 2px;
  }

  .main-nav a, .nav-more-btn {
    padding: 12px 16px;
    font-size: 1rem;
    width: 100%;
    text-align: left;
  }

  .nav-dropdown {
    position: static;
    box-shadow: none;
    border: none;
    padding-left: 20px;
  }

  .nav-more.open .nav-dropdown { display: flex; }

  .page-header h1 { font-size: 1.4rem; }

  .calc-result { font-size: 2rem; }
  .calc-btn { padding: 16px 6px; font-size: 1.1rem; }

  .form-calc { padding: 20px; }
  .form-row { grid-template-columns: 1fr; }

  .result-value { font-size: 1.5rem; }
  .result-details { grid-template-columns: 1fr; }

  .seo-content { padding: 20px; }

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

  .footer-inner { grid-template-columns: 1fr; }

  .btn-group { flex-wrap: wrap; }
  .btn-tab { font-size: .8rem; padding: 8px 10px; }
}

@media (max-width: 380px) {
  .calc-btn { padding: 14px 4px; font-size: 1rem; }
  .calc-result { font-size: 1.6rem; }
  .tools-grid { grid-template-columns: 1fr; }
}

/* ============================================
   Utility
   ============================================ */
.text-center { text-align: center; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mb-16 { margin-bottom: 16px; }
.hidden { display: none !important; }

/* Loan table */
.loan-table-wrap {
  overflow-x: auto;
  margin-top: 24px;
}

.loan-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .85rem;
}

.loan-table th {
  background: var(--key-bg);
  padding: 10px 12px;
  text-align: right;
  font-weight: 600;
  border-bottom: 2px solid var(--border);
  white-space: nowrap;
}

.loan-table th:first-child { text-align: center; }

.loan-table td {
  padding: 8px 12px;
  text-align: right;
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: .82rem;
}

.loan-table td:first-child { text-align: center; font-family: var(--font); }
.loan-table tr:hover td { background: var(--key-bg); }

/* Unit converter two-column */
.unit-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 16px;
  align-items: end;
}

.unit-swap {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 2px solid var(--border);
  background: var(--surface);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.2rem;
  transition: all var(--transition);
  margin-bottom: 8px;
}

.unit-swap:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: rotate(180deg);
}

/* ============================================
   Scrollbar
   ============================================ */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #94a3b8; }

/* Print */
@media print {
  .site-header, .site-footer, .tools-grid-section, .ad-slot, .menu-toggle { display: none; }
  .site-main { padding: 0; }
  .calc-card, .form-calc { box-shadow: none; border: 1px solid #ccc; }
}

/* ============================================
   Theme Toggle
   ============================================ */
.theme-toggle {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--key-bg);
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: all var(--transition);
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--key-hover);
  transform: rotate(15deg);
}

/* ============================================
   Toast Notification
   ============================================ */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: var(--display-bg);
  color: var(--display-text);
  border: 1px solid var(--accent);
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  font-size: .9rem;
  font-weight: 500;
  z-index: 9999;
  opacity: 0;
  pointer-events: none;
  transition: all .35s cubic-bezier(.175,.885,.32,1.275);
  backdrop-filter: blur(8px);
  white-space: nowrap;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* ============================================
   History Actions Bar
   ============================================ */
.history-actions {
  display: flex;
  gap: 6px;
  margin-top: 8px;
}

.history-action-btn {
  flex: 1;
  padding: 6px 8px;
  background: var(--key-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  color: var(--text-secondary);
  font-family: var(--font);
  font-size: .72rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  text-align: center;
}

.history-action-btn:hover {
  background: var(--key-hover);
  color: var(--text);
}

/* ============================================
   Quick Shortcuts Panel
   ============================================ */
.shortcuts-panel {
  background: var(--surface-glass);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 14px;
  border: 1px solid var(--border);
}

.shortcuts-panel h3 {
  font-size: .85rem;
  color: var(--text-secondary);
  margin-bottom: 10px;
  font-weight: 600;
}

.shortcut-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
}

.shortcut-btn {
  background: var(--key-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  padding: 8px 4px;
  font-family: var(--font);
  font-size: .72rem;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  text-align: center;
  transition: all var(--transition);
}

.shortcut-btn:hover {
  background: var(--key-hover);
  border-color: var(--border-glow);
  transform: translateY(-2px);
}

/* ============================================
   Quick Tax Buttons (on standard calc)
   ============================================ */
.quick-actions {
  display: flex;
  gap: 1px;
  background: var(--border);
  padding: 1px;
  padding-top: 0;
}

.quick-btn {
  flex: 1;
  background: var(--key-bg);
  border: none;
  padding: 9px 4px;
  font-family: var(--font);
  font-size: .75rem;
  font-weight: 600;
  color: var(--accent);
  cursor: pointer;
  transition: all var(--transition);
}

.quick-btn:hover { background: rgba(245,158,11,.1); }

/* ============================================
   Form Calc Dark Mode Fixes
   ============================================ */
.form-calc {
  background: var(--surface-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border);
}

.form-input {
  background: var(--bg);
  color: var(--text);
  border-color: var(--border);
}

.form-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,.15);
}

.form-select {
  background: var(--bg);
  color: var(--text);
  border-color: var(--border);
}

/* ============================================
   SEO / Tool Card Dark Mode
   ============================================ */
.seo-content {
  background: var(--surface-glass);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border);
}

.tool-card {
  background: var(--surface-glass);
  border: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.tools-grid-section {
  background: var(--bg);
}

.calc-history {
  background: var(--surface-glass);
  border: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.keyboard-info {
  background: var(--surface-glass);
  border: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.key-list kbd {
  background: var(--key-bg);
  border-color: var(--border);
}