/* =====================================================
   Week Calendar Calculator - Styles
   ===================================================== */

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --bg: #f8fafc;
  --card-bg: #ffffff;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --success: #10b981;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 4px 14px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
}

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

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

/* Header */
header {
  background: linear-gradient(135deg, var(--primary) 0%, #7c3aed 100%);
  color: white;
  padding: 48px 24px;
  text-align: center;
}
header h1 {
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.5px;
}
header p {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* Container */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 20px;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 4px;
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 6px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
  border: 1px solid var(--border);
}
.tab-btn {
  flex: 1;
  padding: 12px 16px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s;
}
.tab-btn:hover { color: var(--primary); background: var(--primary-light); }
.tab-btn.active { background: var(--primary); color: white; }

/* Tab content */
.tab-content { display: none; }
.tab-content.active { display: block; }

/* Calculator card */
.calc-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.form-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: flex-end;
  margin-bottom: 20px;
}
.form-group > div { display: flex; flex-direction: column; gap: 4px; }
.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.form-group input, .form-group select {
  padding: 10px 14px;
  border: 2px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  transition: border-color 0.2s;
}
.form-group input:focus, .form-group select:focus {
  outline: none;
  border-color: var(--primary);
}

.btn {
  padding: 10px 24px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}
.btn:hover { background: var(--primary-dark); }

/* Result */
.result {
  margin-top: 20px;
  padding: 20px 24px;
  background: var(--primary-light);
  border-radius: 10px;
  border-left: 4px solid var(--primary);
}
.result h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--primary-dark);
}
.result .big {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin: 4px 0;
}
.result .detail {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Week table */
.week-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
  font-size: 0.9rem;
}
.week-table th {
  background: var(--primary);
  color: white;
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.8rem;
  letter-spacing: 0.5px;
}
.week-table td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
}
.week-table tr:hover td { background: #f1f5f9; }
.week-table .current-week td {
  background: #fef3c7;
  font-weight: 600;
}
.week-table .week-num { font-weight: 700; color: var(--primary-dark); }

/* Quick links */
.quick-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}
.quick-links a {
  padding: 4px 10px;
  background: var(--primary-light);
  color: var(--primary-dark);
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s;
}
.quick-links a:hover { background: #bfdbfe; }
.quick-links .active {
  padding: 4px 10px;
  background: var(--primary);
  color: white;
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 700;
}

/* Breadcrumb Navigation */
.breadcrumb-nav {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}
.breadcrumb-nav a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}
.breadcrumb-nav a:hover { text-decoration: underline; }
.breadcrumb-nav span[aria-current] {
  color: var(--text);
  font-weight: 600;
}

/* Week / Day Navigation */
.week-nav, .day-nav, .year-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 20px;
  background: var(--card-bg);
  border-radius: 10px;
  margin-bottom: 24px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  justify-content: center;
  flex-wrap: wrap;
}
.nav-arrow {
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  transition: color 0.2s;
}
.nav-arrow:hover { color: var(--primary-dark); }
.nav-arrow.disabled {
  color: var(--text-muted);
  opacity: 0.4;
  cursor: default;
}
.nav-current, .year-current {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
}

/* Week Grid (7-day display) */
.week-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 8px;
  margin-top: 20px;
  margin-bottom: 20px;
}
.day-cell {
  background: #f1f5f9;
  padding: 12px 8px;
  border-radius: 10px;
  text-align: center;
  transition: transform 0.15s;
}
.day-cell:hover { transform: translateY(-2px); }
.day-cell.today {
  background: var(--primary);
  color: white;
  box-shadow: 0 4px 12px rgba(37,99,235,0.3);
}
.day-cell.today .day-date { color: white; }
.day-cell.today .day-name { color: rgba(255,255,255,0.85); }
.day-cell.today .day-num { color: rgba(255,255,255,0.7); }
.day-name {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
}
.day-date {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--primary-dark);
  text-decoration: none;
  display: block;
  transition: color 0.2s;
}
.day-date:hover { color: var(--primary); }
.day-num {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Fact Cards */
.week-facts {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 16px;
}
.fact-card {
  background: #f1f5f9;
  padding: 16px;
  border-radius: 10px;
  text-align: center;
}
.fact-label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}
.fact-value {
  display: block;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
}
.fact-sub {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 2px;
}

/* Month Grid */
.month-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 12px;
}
.month-grid a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  height: 36px;
  padding: 0 8px;
  background: #f1f5f9;
  color: var(--text);
  text-decoration: none;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: all 0.2s;
}
.month-grid a:hover { background: var(--primary-light); color: var(--primary-dark); }
.month-grid a.active {
  background: var(--primary);
  color: white;
}

/* Week Index */
.week-index { gap: 4px; }
.week-index a {
  font-size: 0.75rem;
  padding: 4px 8px;
  min-width: 32px;
  text-align: center;
}
.week-index span {
  color: var(--text-muted);
  font-size: 0.8rem;
  padding: 0 4px;
}

/* Highlight box label-sub */
.label-sub {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* FAQ Section */
.faq-list {
  margin-top: 8px;
}
.faq-list > div {
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.faq-list > div:last-child { border-bottom: none; }
.faq-list h4 {
  font-size: 1rem;
  color: var(--text);
  margin-bottom: 6px;
  font-weight: 600;
}
.faq-list p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0;
}

/* Responsive */
.seo-content {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  margin-bottom: 24px;
}
.seo-content h2 {
  font-size: 1.4rem;
  margin-bottom: 12px;
  color: var(--text);
}
.seo-content p { margin-bottom: 12px; color: var(--text-muted); }
.seo-content .highlight-box {
  background: var(--primary-light);
  border-radius: 10px;
  padding: 24px;
  text-align: center;
  margin: 20px 0;
  border-left: 4px solid var(--primary);
}
.seo-content .highlight-box .big-num {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--primary-dark);
}
.seo-content .highlight-box .label {
  font-size: 0.9rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Info sections */
.info-section {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 24px 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  margin-bottom: 20px;
}
.info-section h3 {
  font-size: 1.1rem;
  margin-bottom: 12px;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}
.info-section p { color: var(--text-muted); margin-bottom: 8px; }

/* Footer */
footer {
  text-align: center;
  padding: 32px 20px;
  color: var(--text-muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}
footer a { color: var(--primary); text-decoration: none; }
footer a:hover { text-decoration: underline; }

/* Responsive */
@media (max-width: 640px) {
  header h1 { font-size: 1.6rem; }
  .form-group { flex-direction: column; align-items: stretch; }
  .calc-card { padding: 20px; }
  .tab-btn { font-size: 0.85rem; padding: 10px 12px; }
}