/* ============================================
   calcul-interets-composes.fr — Dark Theme
   Mobile-first, responsive
   ============================================ */

:root {
  --bg-primary: #0f172a;
  --bg-card: #1e293b;
  --bg-input: #334155;
  --accent: #6366f1;
  --accent-hover: #818cf8;
  --accent-glow: rgba(99, 102, 241, 0.3);
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: #334155;
  --success: #22c55e;
  --warning: #f59e0b;
  --error: #ef4444;
  --radius: 12px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

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

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--accent-hover);
}

/* ---- Header / Nav ---- */
.site-header {
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  overflow: visible;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  overflow: visible;
}

.logo {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
}

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

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.25rem;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.main-nav a {
  color: var(--text-secondary);
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  font-size: 0.85rem;
  transition: all 0.2s;
  white-space: nowrap;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--text-primary);
  background: var(--bg-input);
}

/* ---- Nav Dropdown ---- */
.nav-dropdown {
  position: relative;
}

.nav-dropdown-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-family: inherit;
  font-weight: 400;
  line-height: 1;
  transition: all 0.2s;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.nav-dropdown-btn:hover,
.nav-dropdown-btn.active {
  color: var(--text-primary);
  background: var(--bg-input);
}

.nav-dropdown-menu {
  display: none;
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  z-index: 999;
  background: #1e293b;
  border: 1px solid rgba(99,102,241,0.35);
  border-radius: 10px;
  box-shadow: 0 12px 32px rgba(0,0,0,0.5);
  min-width: 210px;
  padding: 0.4rem 0;
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown.open .nav-dropdown-menu {
  display: block;
}

.nav-dropdown-menu a {
  display: flex !important;
  justify-content: space-between;
  align-items: center;
  padding: 0.55rem 1.1rem;
  color: #94a3b8;
  text-decoration: none;
  font-size: 0.85rem;
  gap: 1rem;
  transition: all 0.15s;
  margin: 0.1rem 0.4rem;
  border-radius: 6px;
  width: auto;
}

.nav-dropdown-menu a:hover {
  background: rgba(99,102,241,0.12);
  color: #f1f5f9;
}

.nav-dropdown-menu .rate {
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  background: rgba(99,102,241,0.15);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  flex-shrink: 0;
}




/* ---- Main Layout ---- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
}

.page-hero {
  text-align: center;
  margin-bottom: 2rem;
}

.page-hero h1 {
  font-size: 1.75rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  line-height: 1.2;
}

.page-hero h1 span {
  color: var(--accent);
}

.page-hero p {
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto;
  font-size: 0.95rem;
}

@media (min-width: 768px) {
  .page-hero h1 {
    font-size: 2.25rem;
  }
}

/* ---- Cards ---- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.card + .card {
  margin-top: 1.5rem;
}

.card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* ---- Mode Tabs ---- */
.mode-tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.mode-tab {
  flex: 1;
  min-width: 0;
  padding: 0.75rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
}

.mode-tab:hover {
  border-color: var(--accent);
  color: var(--text-primary);
}

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

/* ---- Form Inputs ---- */
.form-grid {
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 640px) {
  .form-grid {
    grid-template-columns: 1fr 1fr;
  }

  .form-grid .full-width {
    grid-column: 1 / -1;
  }
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.input-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.input-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.input-row input[type="range"] {
  flex: 1;
  min-width: 0;
}

.input-row .num-input {
  width: 110px;
  flex-shrink: 0;
}

input[type="number"],
input[type="text"],
select {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  padding: 0.6rem 0.75rem;
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  transition: border-color 0.2s;
  width: 100%;
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

/* Remove number input spinners */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
input[type="number"] {
  -moz-appearance: textfield;
}

/* ---- Range Slider ---- */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  height: 6px;
  background: var(--bg-input);
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid var(--bg-card);
  box-shadow: 0 0 0 3px var(--accent-glow);
  transition: transform 0.15s;
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid var(--bg-card);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

/* ---- Preset Buttons ---- */
.presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.25rem;
}

.preset-btn {
  padding: 0.35rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.preset-btn:hover,
.preset-btn.active {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(99, 102, 241, 0.1);
}

/* ---- Toggle Switch ---- */
.toggle-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 0;
}

.toggle-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.toggle {
  position: relative;
  width: 44px;
  height: 24px;
  flex-shrink: 0;
}

.toggle input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  inset: 0;
  background: var(--bg-input);
  border-radius: 12px;
  cursor: pointer;
  transition: background 0.2s;
}

.toggle-slider::before {
  content: '';
  position: absolute;
  width: 18px;
  height: 18px;
  left: 3px;
  top: 3px;
  background: var(--text-secondary);
  border-radius: 50%;
  transition: all 0.2s;
}

.toggle input:checked + .toggle-slider {
  background: var(--accent);
}

.toggle input:checked + .toggle-slider::before {
  transform: translateX(20px);
  background: #fff;
}

/* ---- Results ---- */
.results-banner {
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: center;
  margin: 1.5rem 0;
}

.results-banner .result-big {
  font-size: 2rem;
  font-weight: 800;
  color: #fff;
  line-height: 1.2;
}

.results-banner .result-label {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.8);
  margin-top: 0.25rem;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.result-item {
  text-align: center;
  padding: 1rem;
  background: var(--bg-primary);
  border-radius: 8px;
}

.result-item .value {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.result-item .label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

/* ---- Chart ---- */
.chart-container {
  position: relative;
  width: 100%;
  height: 350px;
  margin: 1rem 0;
}

@media (min-width: 768px) {
  .chart-container {
    height: 400px;
  }
}

/* ---- Table ---- */
.table-wrapper {
  overflow-x: auto;
  margin-top: 1rem;
  border-radius: 8px;
  border: 1px solid var(--border);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  white-space: nowrap;
}

.data-table th {
  background: var(--bg-input);
  color: var(--text-secondary);
  font-weight: 600;
  text-align: right;
  padding: 0.75rem;
  position: sticky;
  top: 0;
}

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

.data-table td {
  padding: 0.6rem 0.75rem;
  text-align: right;
  border-top: 1px solid var(--border);
}

.data-table td:first-child {
  text-align: center;
  font-weight: 600;
  color: var(--accent);
}

.data-table tbody tr:hover {
  background: rgba(99, 102, 241, 0.05);
}

/* ---- Table toggle (annual/monthly) ---- */
.table-toggle { display: flex; gap: 0.5rem; margin-bottom: 1rem; }
.table-view-btn { padding: 0.4rem 1rem; border-radius: 6px; border: 1px solid var(--border); background: transparent; color: var(--text-muted); cursor: pointer; font-size: 0.9rem; transition: all 0.2s; }
.table-view-btn:hover { border-color: var(--accent); color: var(--text); }
.table-view-btn.active { background: var(--accent); color: white; border-color: var(--accent); }

/* ---- Action Buttons ---- */
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg-input);
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.2s;
}

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

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

.btn-primary:hover {
  background: var(--accent-hover);
}

/* ---- Content Sections ---- */
.content-section {
  margin-top: 2.5rem;
}

.content-section h2 {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.content-section h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 1.5rem 0 0.25rem 0;
  color: var(--text-primary);
  border-left: 3px solid var(--accent);
  background: rgba(99, 102, 241, 0.05);
  padding: 0.75rem 1rem;
  border-radius: 0 6px 6px 0;
}

.content-section h3 + p {
  padding: 0.25rem 1rem 1rem;
  margin-top: 0;
  color: var(--text-muted);
  line-height: 1.7;
}

.content-section p {
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  line-height: 1.7;
}

.content-section ul,
.content-section ol {
  color: var(--text-secondary);
  padding-left: 1.5rem;
  margin-bottom: 0.75rem;
}

.content-section li {
  margin-bottom: 0.35rem;
}

.formula-box {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
  color: var(--accent);
  overflow-x: auto;
  margin: 1rem 0;
  text-align: center;
}

.highlight-box {
  background: rgba(99, 102, 241, 0.1);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 1rem 1.25rem;
  margin: 1rem 0;
}

.highlight-box p {
  color: var(--text-primary);
  margin: 0;
}

/* ---- Internal Links Section ---- */
.internal-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.internal-link-card {
  display: block;
  padding: 1rem 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all 0.2s;
}

.internal-link-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.internal-link-card .link-title {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.internal-link-card .link-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* ---- Footer ---- */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 3rem;
  padding: 2rem 1rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
}

.site-footer p {
  margin-bottom: 0.5rem;
}

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

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

/* ---- Rule of 72 specific ---- */
.rule72-result {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 2rem 1rem;
}

.rule72-formula {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
}

.rule72-formula .num72 {
  color: var(--accent);
}

.rule72-formula .divider {
  color: var(--text-muted);
}

.rule72-formula .rate-val {
  color: var(--warning);
}

.rule72-formula .equals {
  color: var(--text-muted);
}

.rule72-formula .years-val {
  color: var(--success);
  font-size: 2rem;
}

.rule72-formula .unit {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 400;
}

/* ---- Comparison specific ---- */
.comparison-grid {
  display: grid;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .comparison-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.comparison-card {
  padding: 1.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.comparison-card.compound {
  background: rgba(99, 102, 241, 0.08);
  border-color: var(--accent);
}

.comparison-card.simple {
  background: rgba(245, 158, 11, 0.08);
  border-color: var(--warning);
}

.comparison-card h3 {
  margin-top: 0;
}

.comparison-card .big-num {
  font-size: 1.75rem;
  font-weight: 800;
}

.comparison-card.compound .big-num {
  color: var(--accent);
}

.comparison-card.simple .big-num {
  color: var(--warning);
}

.diff-banner {
  text-align: center;
  padding: 1rem;
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid var(--success);
  border-radius: var(--radius);
  margin-top: 1rem;
}

.diff-banner .big-num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--success);
}

/* ---- Portfolio Envelopes ---- */
.pf-envelope {
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-top: 1rem;
  position: relative;
  transition: border-color 0.2s;
}

.pf-envelope-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.pf-envelope-color {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  flex-shrink: 0;
}

.pf-envelope-name {
  flex: 1;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  padding: 0.5rem 0.75rem;
  font-size: 0.95rem;
  font-family: inherit;
  font-weight: 600;
  outline: none;
  transition: border-color 0.2s;
}

.pf-envelope-name:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.pf-remove-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 1.1rem;
  cursor: pointer;
  padding: 0.35rem 0.6rem;
  transition: all 0.2s;
  flex-shrink: 0;
  line-height: 1;
}

.pf-remove-btn:hover {
  border-color: var(--error);
  color: var(--error);
  background: rgba(239, 68, 68, 0.1);
}

.pf-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1rem;
}

.pf-fields {
  display: grid;
  gap: 1rem;
}

@media (min-width: 640px) {
  .pf-fields {
    grid-template-columns: 1fr 1fr 1fr;
  }
}

.pf-summary-foot td {
  font-weight: 700;
  color: var(--text-primary);
  border-top: 2px solid var(--accent);
}

/* ---- Utility ---- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.hidden {
  display: none !important;
}

/* ---- Print ---- */
@media print {
  .site-header,
  .site-footer,
  .actions,
  .chart-container,
  input[type="range"] {
    display: none;
  }

  body {
    background: #fff;
    color: #000;
  }

  .card {
    border: 1px solid #ccc;
    box-shadow: none;
  }
}