/* ── Tokens ──────────────────────────────────────────── */
:root {
  --bg:          #f8f7f4;
  --bg-panel:    #ffffff;
  --bg-card:     #f1efe9;
  --bg-card-alt: #e8e5dd;
  --accent:      #2563eb;
  --accent-light:#bfdbfe;
  --accent-b:      #7c3aed;
  --accent-b-light:#ddd6fe;
  --text-1:      #111110;
  --text-2:      #6b6b63;
  --text-3:      #9b9b92;
  --border:      rgba(0,0,0,0.09);
  --border-md:   rgba(0,0,0,0.14);
  --radius:      10px;
  --radius-lg:   16px;
  --shadow:      0 1px 3px rgba(0,0,0,0.07), 0 4px 16px rgba(0,0,0,0.05);
  --font-sans:   'Syne', sans-serif;
  --font-mono:   'DM Mono', monospace;
  --transition:  0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg:          #0f0f0e;
  --bg-panel:    #1a1a18;
  --bg-card:     #222220;
  --bg-card-alt: #2a2a27;
  --accent:      #3b82f6;
  --accent-light:#1e3a5f;
  --accent-b:      #a78bfa;
  --accent-b-light:#2e1065;
  --text-1:      #f0ede8;
  --text-2:      #9b9b92;
  --text-3:      #6b6b63;
  --border:      rgba(255,255,255,0.07);
  --border-md:   rgba(255,255,255,0.12);
  --shadow:      0 1px 3px rgba(0,0,0,0.3), 0 4px 20px rgba(0,0,0,0.2);
}

/* ── Reset ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-font-smoothing: antialiased; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text-1);
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

/* ── Header ──────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 64px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
}

.logo-group {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-1);
  white-space: nowrap;
}

.logo-icon {
  color: var(--accent);
  font-size: 12px;
}

.header-center {
  display: flex;
  justify-content: center;
}

.header-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
}

.btn-icon {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
  background: transparent;
  border: 1px solid var(--border-md);
  border-radius: 8px;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}

.btn-icon:hover {
  background: var(--bg-card);
  color: var(--text-1);
  border-color: var(--border-md);
}

.btn-icon svg { flex-shrink: 0; }

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

.btn-icon.active:hover {
  background: color-mix(in srgb, var(--accent) 90%, black);
}

.btn-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-1);
  text-decoration: none;
  background: var(--bg-card);
  border: 1px solid var(--border-md);
  border-radius: 100px;
  transition: all var(--transition);
}

.btn-link:hover {
  background: var(--bg-card-alt);
  border-color: var(--text-3);
  transform: translateY(-1px);
}

.btn-link svg {
  color: var(--accent);
}

/* Sun/moon toggle */
[data-theme="light"] .icon-moon { display: none; }
[data-theme="dark"]  .icon-sun  { display: none; }

/* ── Main layout ─────────────────────────────────────── */
.main-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.tab-pane {
  display: none;
  animation: fadeIn 0.4s ease-out;
}

.tab-pane.active {
  display: block;
}

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


/* ── Tab Navigation ──────────────────────────────────── */
.tabs-nav {
  position: sticky;
  top: 64px;
  z-index: 90;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.tabs-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 48px;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  overflow-x: auto;
  scrollbar-width: none;
}

.tabs-inner::-webkit-scrollbar { display: none; }

.tab-btn {
  padding: 0 4px;
  height: 48px;
  background: transparent;
  border: none;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
  cursor: pointer;
  position: relative;
  transition: color var(--transition);
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--text-1);
}

.tab-btn.active {
  color: var(--accent);
}

.tab-btn.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 2px 2px 0 0;
}

/* ── Placeholder content ─────────────────────────────── */
.placeholder {
  min-height: 60vh;
  display: none;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.placeholder.active {
  display: flex;
}

.coming-soon {
  padding: 4rem;
  background: var(--bg-card);
  border: 1px solid var(--border-md);
  border-radius: 24px;
  box-shadow: var(--shadow-lg);
}

.coming-soon h2 {
  font-size: 2rem;
  margin-bottom: 1rem;
  color: var(--text-1);
}

.coming-soon p {
  color: var(--text-2);
  font-size: 1.1rem;
}

.hero {
  margin-bottom: 2.5rem;
}

.hero-title-group {
  display: flex;
  align-items: center;
  gap: 2.5rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  color: var(--text-1);
  margin: 0;
}

.hero h1 em {
  font-style: normal;
  color: var(--accent);
}

.hero-sub {
  margin-top: 0;
  font-size: 15px;
  color: var(--text-2);
}

/* ── Toggle Switch ───────────────────────────────────── */
.toggle-container {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-md);
  border-radius: 100px;
  box-shadow: var(--shadow-sm);
}

.toggle-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
  transition: color var(--transition);
}

.switch {
  position: relative;
  display: inline-block;
  width: 44px;
  height: 24px;
}

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

.toggle-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--border-md);
  transition: .4s;
  border-radius: 34px;
}

.toggle-slider:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: .4s;
  border-radius: 50%;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

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

/* Dynamic Label Highlighting */
body[data-mode="dual"] .toggle-label:last-child { color: var(--text-1); }
body:not([data-mode="dual"]) .toggle-label:first-child { color: var(--text-1); }

.layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 1.5rem;
  align-items: start;
  transition: grid-template-columns var(--transition);
}

body[data-mode="dual"] .layout {
  grid-template-columns: 600px 1fr;
}

@media (max-width: 1100px) {
  body[data-mode="dual"] .layout { grid-template-columns: 1fr; }
}

@media (max-width: 820px) {
  .layout { grid-template-columns: 1fr; }
  .btn-icon span { display: none; }
  .btn-icon { padding: 6px 8px; }
}

.controls-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

body[data-mode="dual"] .controls-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

@media (max-width: 1100px) {
  body[data-mode="dual"] .controls-container { grid-template-columns: 1fr; }
}

/* ── Controls panel ──────────────────────────────────── */
.controls-panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0;
  box-shadow: var(--shadow);
  transition: border-color var(--transition);
}

#panel-a { border: 2px solid var(--accent) !important; }
#panel-b { border: 2px solid var(--accent-b) !important; }

.control-section {
  padding: 0 0 1.25rem;
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
}

#mortgage-panel .control-section {
  border-bottom: 1px solid var(--accent);
  opacity: 1;
}

#mortgage-panel .control-section:last-child {
  border-bottom: none;
}

.control-section:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: none;
}

.section-title {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 1rem;
}

/* ── Fields ──────────────────────────────────────────── */
.field {
  margin-bottom: 1rem;
}

.field:last-child { margin-bottom: 0; }

.field label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
  margin-bottom: 5px;
}

.input-row { display: flex; gap: 8px; }

.input-wrap {
  display: flex;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-md);
  border-radius: 8px;
  overflow: hidden;
  transition: border-color var(--transition);
  flex: 1;
}

.input-wrap:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 15%, transparent);
}

.affix {
  padding: 0 8px;
  font-size: 13px;
  color: var(--text-3);
  font-family: var(--font-mono);
  user-select: none;
  background: var(--bg-card-alt);
  align-self: stretch;
  display: flex;
  align-items: center;
}

.input-wrap input[type="number"] {
  flex: 1;
  border: none;
  background: transparent;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-1);
  padding: 7px 10px;
  outline: none;
  width: 100%;
  -moz-appearance: textfield;
  appearance: textfield;
}

.input-wrap input[type="number"]::-webkit-outer-spin-button,
.input-wrap input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  appearance: none;
}

select {
  width: 100%;
  padding: 7px 10px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-1);
  background: var(--bg-card);
  border: 1px solid var(--border-md);
  border-radius: 8px;
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition);
  -webkit-appearance: none;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%239b9b92' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 30px;
}

select:focus { border-color: var(--accent); }

/* ── Sliders ─────────────────────────────────────────── */
.slider {
  width: 100%;
  margin-top: 8px;
  -webkit-appearance: none;
  appearance: none;
  height: 4px;
  border-radius: 2px;
  background: var(--bg-card-alt);
  outline: none;
  cursor: pointer;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-panel);
  box-shadow: 0 0 0 1px var(--accent);
  cursor: pointer;
  transition: transform 0.1s ease;
}

#panel-b .slider::-webkit-slider-thumb {
  background: var(--accent-b) !important;
  border-color: var(--accent-b) !important;
  box-shadow: 0 0 0 1px var(--accent-b) !important;
}

#panel-b .slider::-moz-range-thumb {
  background: var(--accent-b) !important;
  border-color: var(--accent-b) !important;
}

#panel-b .slider {
  background: var(--accent-b-light);
  accent-color: var(--accent-b);
}

/* ── Results panel ───────────────────────────────────── */
.results-panel {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.stats-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 0;
  position: relative;
  z-index: 10;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

@media (max-width: 600px) {
  .stat-grid { grid-template-columns: 1fr 1fr; }
}

.stat-card {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1rem 1.1rem;
  box-shadow: var(--shadow);
  transition: background var(--transition);
  display: flex;
  flex-direction: column;
  justify-content: flex-start; /* Ensure labels stay at top */
  min-height: 110px;
}

.stat-card .stat-value {
  margin-top: auto; /* Push value to bottom to align levels */
}

.stat-card.stat-primary {
  background: var(--accent);
  border-color: var(--accent);
}

.stat-card.stat-secondary {
  background: var(--accent-b);
  border-color: var(--accent-b);
}

.stat-card.stat-primary .stat-label,
.stat-card.stat-secondary .stat-label { color: rgba(255,255,255,0.7); }

.stat-card.stat-primary .stat-value,
.stat-card.stat-secondary .stat-value { color: #fff; }

.stat-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 4px;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--text-1);
  letter-spacing: -0.02em;
  line-height: 1.1;
  display: flex;
  flex-direction: column;
}

.stat-value .sub-val {
  font-size: 0.85rem;
  opacity: 0.8;
  font-weight: 500;
  margin-bottom: 2px;
}

.stat-value .main-val {
  font-size: 1.75rem;
  font-weight: 600;
}

/* ── Chart ───────────────────────────────────────────── */
.chart-container {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  box-shadow: var(--shadow);
}

.chart-legend {
  display: flex;
  gap: 2rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.legend-group {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-2);
  font-weight: 500;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  flex-shrink: 0;
}

.dot-a-1 { background: #2563eb; }
.dot-a-2 { background: #60a5fa; }
.dot-a-3 { background: #bfdbfe; }

.dot-b-1 { background: #7c3aed; }
.dot-b-2 { background: #a78bfa; }
.dot-b-3 { background: #ddd6fe; }

[data-theme="dark"] .dot-a-1 { background: #3b82f6; }
[data-theme="dark"] .dot-a-2 { background: #93c5fd; }
[data-theme="dark"] .dot-a-3 { background: #1e3a5f; }

[data-theme="dark"] .dot-b-1 { background: #a78bfa; }
[data-theme="dark"] .dot-b-2 { background: #c4b5fd; }
[data-theme="dark"] .dot-b-3 { background: #2e1065; }

.chart-wrap {
  position: relative;
  width: 100%;
  height: 300px;
}

/* ── Formula bar ─────────────────────────────────────── */
.formulas-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.formula-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0.75rem 1rem;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  border-left: 3px solid var(--accent);
}

#formula-bar-b {
  border-left-color: var(--accent-b);
}

.formula-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-3);
  white-space: nowrap;
}

.formula-bar code {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-1);
  word-break: break-all;
}

/* ── Utilities ───────────────────────────────────────── */
.hidden { display: none !important; }

/* ── Toast ───────────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  background: var(--text-1);
  color: var(--bg);
  font-size: 13px;
  font-weight: 500;
  padding: 9px 18px;
  border-radius: 100px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  white-space: nowrap;
  z-index: 999;
}

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

/* ── Print styles ────────────────────────────────────── */
@media print {
  .site-header, .slider, .header-actions { display: none !important; }
  body { background: white; color: black; }
  .controls-panel, .stat-card, .chart-container, .formula-bar {
    border: 1px solid #ddd !important;
    box-shadow: none !important;
    background: white !important;
  }
  .stat-card.stat-primary { background: #2563eb !important; -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  .layout { grid-template-columns: 280px 1fr; gap: 1rem; }
  .main { padding: 1rem; }
  .hero h1 { font-size: 2rem; }
}

/* ── Mortgage Specific ───────────────────────────────── */
.amort-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  color: var(--text-2);
}

.amort-table th {
  text-align: left;
  padding: 12px;
  background: var(--bg-card);
  color: var(--text-1);
  font-weight: 600;
  border-bottom: 2px solid var(--border-md);
}

.amort-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono);
}

.amort-table tr:hover {
  background: var(--bg-card);
}

.table-scroll {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-panel);
}

.mortgage-amort-wrap {
  margin-top: 2rem;
}

/* ── Tooltips ────────────────────────────────────────── */
.info-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--text-3);
  color: var(--bg-panel);
  font-size: 10px;
  font-weight: 700;
  cursor: help;
  margin-left: 6px;
  position: relative;
  vertical-align: middle;
}

.info-btn:hover::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  padding: 8px 12px;
  background: var(--text-1);
  color: var(--bg-panel);
  font-size: 11px;
  font-weight: 500;
  line-height: 1.4;
  border-radius: 6px;
  width: 220px;
  z-index: 200;
  pointer-events: none;
  box-shadow: var(--shadow);
  text-align: center;
}

/* ── Toggle Groups ───────────────────────────────────── */
.toggle-group {
  display: flex;
  background: var(--bg-card);
  padding: 2px;
  border-radius: 6px;
  border: 1px solid var(--border-md);
}

.toggle-group button {
  flex: 1;
  padding: 4px 8px;
  border: none;
  background: transparent;
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 600;
  color: var(--text-2);
  cursor: pointer;
  border-radius: 4px;
  transition: all var(--transition);
}

.toggle-group button.active {
  background: var(--bg-panel);
  color: var(--accent);
  box-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.field-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}

.field-header label { margin-bottom: 0; }