:root {
  --bg-primary: #0f1115;
  --bg-surface: #171a21;
  --bg-surface-elevated: #1e222d;
  --border-color: #272c3b;
  --text-primary: #f0f3f8;
  --text-secondary: #9aa5b8;
  --text-muted: #647087;
  --accent-purple: #a855f7;
  --accent-pink: #ec4899;
  --accent-blue: #3b82f6;
  --accent-cyan: #06b6d4;
  --accent-green: #10b981;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

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

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.5;
  min-height: 100vh;
  padding: 24px 16px 64px;
}

.container {
  max-width: 960px;
  margin: 0 auto;
}

/* Header */
header {
  margin-bottom: 24px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background-color: rgba(168, 85, 247, 0.12);
  color: var(--accent-purple);
  border: 1px solid rgba(168, 85, 247, 0.25);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 9999px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 780px;
}

/* Tabs */
.tabs-nav {
  display: flex;
  gap: 8px;
  margin-bottom: 24px;
  background-color: var(--bg-surface);
  padding: 4px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  flex-wrap: wrap;
}

.tab-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.15s ease;
  display: flex;
  align-items: center;
  gap: 6px;
}

.tab-btn.active {
  background-color: var(--bg-surface-elevated);
  color: var(--text-primary);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

/* Layout */
.calculator-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 32px;
}

@media (max-width: 860px) {
  .calculator-grid {
    grid-template-columns: 1fr;
  }
}

.card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
}

.card-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Form inputs */
.form-group {
  margin-bottom: 18px;
}

label {
  display: block;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

input[type="number"], select {
  width: 100%;
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 1rem;
  font-family: inherit;
  transition: border-color 0.15s ease;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--accent-purple);
}

.gender-selector {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-bottom: 18px;
}

.gender-btn {
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 8px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.85rem;
  transition: all 0.15s ease;
  text-align: center;
}

.gender-btn.active {
  border-color: var(--accent-purple);
  background-color: rgba(168, 85, 247, 0.12);
  color: var(--text-primary);
}

.presets-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}

.btn-preset {
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.75rem;
  padding: 4px 8px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-preset:hover {
  border-color: var(--accent-purple);
  color: var(--text-primary);
}

/* Results panel */
.results-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  display: flex;
  flex-direction: column;
}

.highlight-box {
  background: linear-gradient(135deg, rgba(168, 85, 247, 0.12), rgba(236, 72, 153, 0.08));
  border: 1px solid rgba(168, 85, 247, 0.3);
  border-radius: 10px;
  padding: 18px;
  margin-bottom: 20px;
  text-align: center;
}

.highlight-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent-purple);
  font-weight: 600;
  margin-bottom: 4px;
}

.highlight-value {
  font-family: var(--font-mono);
  font-size: 2.3rem;
  font-weight: 800;
  color: #ffffff;
}

.highlight-subtext {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

.size-grid-badges {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

.size-badge {
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 12px;
  text-align: center;
}

.size-badge-label {
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}

.size-badge-val {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 2px;
}

/* Comparison tables */
.table-section {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 32px;
}

.section-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.table-wrapper {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

th, td {
  padding: 10px 12px;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
}

th {
  background-color: var(--bg-surface-elevated);
  color: var(--text-secondary);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

tr:hover td {
  background-color: rgba(255, 255, 255, 0.02);
}

.selected-row td {
  background-color: rgba(168, 85, 247, 0.15) !important;
  color: #ffffff;
  font-weight: 700;
}

.mono-cell {
  font-family: var(--font-mono);
  font-weight: 600;
}

/* Guide cards */
.guide-section {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 32px;
}

.guide-steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.guide-step {
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 16px;
}

.guide-step-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent-purple);
  margin-bottom: 6px;
}

.guide-step-text {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.45;
}

/* FAQ */
.faq-section {
  margin-bottom: 40px;
}

.faq-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.faq-item {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 18px 20px;
  margin-bottom: 12px;
}

.faq-q {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.faq-a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Footer standard */
footer {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s ease;
}

.footer-links a:hover {
  color: var(--accent-purple);
}

.footer-contact {
  color: var(--text-secondary);
}

.footer-contact a {
  color: var(--accent-purple);
  text-decoration: none;
}

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


/* Related tools section */
.related-tools-section {
  background-color: var(--bg-surface, #171a21);
  border: 1px solid var(--border-color, #272c3b);
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 32px;
}
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  margin-top: 14px;
}
.related-card {
  background-color: var(--bg-surface-elevated, #1e222d);
  border: 1px solid var(--border-color, #272c3b);
  border-radius: 8px;
  padding: 14px 16px;
  text-decoration: none;
  color: inherit;
  transition: all 0.15s ease;
  display: flex;
  flex-direction: column;
}
.related-card:hover {
  border-color: #3b82f6;
  transform: translateY(-2px);
}
.related-emoji {
  font-size: 1.4rem;
  margin-bottom: 6px;
}
.related-name {
  font-size: 0.9rem;
  font-weight: 600;
  color: #f0f3f8;
  margin-bottom: 4px;
}
.related-desc {
  font-size: 0.75rem;
  color: #9aa5b8;
  line-height: 1.4;
}

.btn-print {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  background-color: var(--bg-surface-elevated, #1e222d);
  border: 1px solid var(--border-color, #272c3b);
  color: var(--text-primary, #f0f3f8);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 12px 18px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.15s ease;
  margin-top: 14px;
}
.btn-print:hover {
  border-color: #3b82f6;
  background-color: rgba(59, 130, 246, 0.1);
  color: #3b82f6;
}

/* Print Styles */
@media print {
  body {
    background-color: #ffffff !important;
    color: #111111 !important;
    padding: 0 !important;
  }
  header .badge,
  .btn-print,
  .presets-list,
  .related-tools-section,
  .faq-section,
  footer,
  aside,
  nav {
    display: none !important;
  }
  .card, .results-card, table, .table-wrapper {
    background: #ffffff !important;
    border: 1px solid #cccccc !important;
    color: #111111 !important;
    box-shadow: none !important;
  }
  .breakdown-row {
    border-bottom: 1px solid #eeeeee !important;
  }
  .breakdown-val, th, td {
    color: #111111 !important;
  }
}