/* ============================================================
   Retirement Simulator – Stylesheet
   ============================================================ */

/* --- Variables / Reset --- */
:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-danger: #dc2626;
  --color-danger-dark: #b91c1c;
  --color-secondary: #64748b;
  --color-secondary-dark: #475569;
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-border: #e2e8f0;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-success: #16a34a;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,.12), 0 1px 2px rgba(0,0,0,.08);
  --shadow-lg: 0 4px 12px rgba(0,0,0,.12);
  --font: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

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

html { font-size: 16px; scroll-behavior: smooth; }

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

/* --- Header --- */
header {
  background: var(--color-primary);
  color: #fff;
  padding: 0.75rem 1rem;
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

header h1 { font-size: 1.25rem; font-weight: 700; flex: 1; }

.profile-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.profile-bar select {
  padding: 0.3rem 0.5rem;
  border-radius: var(--radius);
  border: 1px solid rgba(255,255,255,.4);
  background: rgba(255,255,255,.15);
  color: #fff;
  font-size: 0.875rem;
  min-width: 160px;
}

.profile-bar select option { background: var(--color-primary); }

/* --- Main --- */
main {
  flex: 1;
  max-width: 1200px;
  margin: 1.5rem auto;
  padding: 0 1rem;
  width: 100%;
}

/* --- Card --- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
}

.card h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-primary);
  color: var(--color-primary);
}

/* --- Form --- */
fieldset {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem;
  margin-bottom: 1rem;
}

legend {
  font-weight: 600;
  padding: 0 0.5rem;
  color: var(--color-text);
}

.form-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.6rem;
}

.form-row label {
  min-width: 200px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.form-row.indent { margin-left: 1.5rem; }

.form-row input[type="number"],
.form-row input[type="text"],
.form-row select {
  flex: 1;
  max-width: 200px;
  padding: 0.35rem 0.6rem;
  border: 1px solid var(--color-border);
  border-radius: calc(var(--radius) / 2);
  font-size: 0.9rem;
  transition: border-color .15s;
}

.form-row input:focus,
.form-row select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,.15);
}

.form-row input[aria-invalid="true"],
.form-row select[aria-invalid="true"] {
  border-color: var(--color-danger);
  box-shadow: 0 0 0 3px rgba(220,38,38,.12);
}

.form-row input[type="checkbox"] { width: auto; }

.spending-model-group {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin-bottom: 0.75rem;
}

.spending-model-group > label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
  cursor: pointer;
}

.hint { font-size: 0.85rem; color: var(--color-text-muted); margin-bottom: 0.75rem; }
.hint.indent { margin-left: 1.5rem; }
.assumption-help { margin-left: calc(200px + 0.75rem); }

/* Advanced collapsible section */
#advanced-section {
  margin-top: 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.5rem 1rem;
  background: var(--color-bg);
}

#advanced-section > summary {
  cursor: pointer;
  padding: 0.5rem 0;
  color: var(--color-primary);
  font-size: 0.95rem;
  user-select: none;
}

#advanced-section > summary::-webkit-details-marker { color: var(--color-primary); }

#advanced-section[open] > summary { margin-bottom: 0.5rem; }

.form-actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 1rem;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius);
  border: none;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: background .15s, transform .1s;
  text-decoration: none;
}

.btn:active { transform: scale(.97); }

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

.btn-secondary { background: var(--color-secondary); color: #fff; }
.btn-secondary:hover { background: var(--color-secondary-dark); }

.btn-danger { background: var(--color-danger); color: #fff; }
.btn-danger:hover { background: var(--color-danger-dark); }

/* --- Results / Tabs --- */
.results-summary {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.results-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.results-controls label {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.results-controls select {
  padding: 0.35rem 0.6rem;
  border: 1px solid var(--color-border);
  border-radius: calc(var(--radius) / 2);
  font-size: 0.9rem;
}

.stat-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  min-width: 140px;
  text-align: center;
}

.stat-card .stat-label { font-size: 0.78rem; color: var(--color-text-muted); }
.stat-card .stat-value { font-size: 1.15rem; font-weight: 700; }
.stat-card.success .stat-value { color: var(--color-success); }
.stat-card.danger .stat-value { color: var(--color-danger); }

.tabs {
  display: flex;
  gap: 0.25rem;
  border-bottom: 2px solid var(--color-border);
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}

.tab-btn {
  padding: 0.5rem 1rem;
  border: none;
  background: none;
  cursor: pointer;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: color .15s, border-color .15s;
  font-weight: 600;
}

.tab-btn:hover { color: var(--color-primary); }
.tab-btn.active { color: var(--color-primary); border-bottom-color: var(--color-primary); }

.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* Percentile chart area */
.chart-area {
  position: relative;
  height: 400px;
  margin-bottom: 1rem;
}

.percentile-legend {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
  font-size: 0.82rem;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  cursor: pointer;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  transition: background .1s;
}

.legend-item:hover { background: var(--color-bg); }

.legend-swatch {
  width: 16px;
  height: 4px;
  border-radius: 2px;
}

.percentile-stats {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.5rem;
  margin-top: 0.75rem;
}

.view-detail-btn {
  margin-top: 0.75rem;
}

/* --- Detail View --- */
#detail-chart-container {
  position: relative;
  height: 400px;
}

.detail-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.detail-controls label { font-size: 0.9rem; color: var(--color-text-muted); }

.detail-controls select {
  padding: 0.35rem 0.6rem;
  border: 1px solid var(--color-border);
  border-radius: calc(var(--radius) / 2);
  font-size: 0.9rem;
}

/* --- Table --- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.data-table th, .data-table td {
  text-align: right;
  padding: 0.4rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
}

.data-table th {
  background: var(--color-bg);
  font-weight: 600;
  text-align: right;
  position: sticky;
  top: 0;
}

.data-table td:first-child, .data-table th:first-child { text-align: left; }

.data-table tbody tr:hover { background: var(--color-bg); }

/* Table wrapper for scroll */
#detail-table-container { overflow-x: auto; max-height: 500px; overflow-y: auto; }

/* --- Loading --- */
#loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(248,250,252,.85);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 200;
  font-size: 1rem;
  color: var(--color-text-muted);
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin .8s linear infinite;
  margin-bottom: 1rem;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* --- Error --- */
.error-box {
  background: #fef2f2;
  border: 1px solid #fca5a5;
  color: var(--color-danger);
  border-radius: var(--radius);
  padding: 1rem;
  margin-bottom: 1rem;
}

/* --- Footer --- */
footer {
  text-align: center;
  padding: 1rem;
  font-size: 0.82rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
}

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

/* --- Responsive --- */
@media (max-width: 640px) {
  .form-row { flex-direction: column; align-items: flex-start; }
  .form-row label { min-width: unset; }
  .form-row input[type="number"], .form-row select { max-width: 100%; width: 100%; }
  .header-inner { flex-direction: column; align-items: flex-start; }
  .profile-bar { width: 100%; }
  .assumption-help { margin-left: 0; }
}