/* ========================================
   DESIGN TOKENS — Finance / Debt Simulator
   Dark-first with alert red accents
   ======================================== */

:root {
  /* Type scale */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Fonts */
  --font-body: 'DM Sans', 'Helvetica Neue', sans-serif;
  --font-mono: 'JetBrains Mono', 'Consolas', monospace;
}

/* LIGHT MODE */
:root, [data-theme="light"] {
  --color-bg:             #f5f4f0;
  --color-surface:        #ffffff;
  --color-surface-2:      #fafaf8;
  --color-border:         #ddd9d2;
  --color-text:           #1a1816;
  --color-text-muted:     #6b6862;
  --color-text-faint:     #a5a29c;

  --color-primary:        #0e6b6e;
  --color-primary-hover:  #0a5254;

  --color-danger:         #c4233b;
  --color-danger-bg:      #fef2f2;
  --color-danger-border:  #f5c6cb;
  --color-danger-text:    #8b1525;

  --color-safe:           #16794a;
  --color-safe-bg:        #f0fdf4;
  --color-safe-border:    #bbf7d0;
  --color-safe-text:      #0d5c35;

  --color-savings:        #0e6b6e;
  --color-savings-bg:     #f0fdfa;
  --color-savings-border: #99f6e4;

  --color-accent:         #c4233b;
  --color-accent-soft:    rgba(196, 35, 59, 0.08);

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.1);
}

/* DARK MODE */
[data-theme="dark"] {
  --color-bg:             #0f0e0d;
  --color-surface:        #1a1918;
  --color-surface-2:      #222120;
  --color-border:         #333230;
  --color-text:           #e8e6e3;
  --color-text-muted:     #8a8885;
  --color-text-faint:     #5a5856;

  --color-primary:        #5cb8bc;
  --color-primary-hover:  #3da0a4;

  --color-danger:         #f06070;
  --color-danger-bg:      rgba(240, 96, 112, 0.1);
  --color-danger-border:  rgba(240, 96, 112, 0.25);
  --color-danger-text:    #f8a0aa;

  --color-safe:           #4ade80;
  --color-safe-bg:        rgba(74, 222, 128, 0.08);
  --color-safe-border:    rgba(74, 222, 128, 0.2);
  --color-safe-text:      #86efac;

  --color-savings:        #5cb8bc;
  --color-savings-bg:     rgba(92, 184, 188, 0.08);
  --color-savings-border: rgba(92, 184, 188, 0.2);

  --color-accent:         #f06070;
  --color-accent-soft:    rgba(240, 96, 112, 0.1);

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.4);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg:             #0f0e0d;
    --color-surface:        #1a1918;
    --color-surface-2:      #222120;
    --color-border:         #333230;
    --color-text:           #e8e6e3;
    --color-text-muted:     #8a8885;
    --color-text-faint:     #5a5856;
    --color-primary:        #5cb8bc;
    --color-primary-hover:  #3da0a4;
    --color-danger:         #f06070;
    --color-danger-bg:      rgba(240, 96, 112, 0.1);
    --color-danger-border:  rgba(240, 96, 112, 0.25);
    --color-danger-text:    #f8a0aa;
    --color-safe:           #4ade80;
    --color-safe-bg:        rgba(74, 222, 128, 0.08);
    --color-safe-border:    rgba(74, 222, 128, 0.2);
    --color-safe-text:      #86efac;
    --color-savings:        #5cb8bc;
    --color-savings-bg:     rgba(92, 184, 188, 0.08);
    --color-savings-border: rgba(92, 184, 188, 0.2);
    --color-accent:         #f06070;
    --color-accent-soft:    rgba(240, 96, 112, 0.1);
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
    --shadow-lg: 0 12px 32px rgba(0,0,0,0.4);
  }
}

/* ========================================
   LAYOUT
   ======================================== */

.container {
  max-width: 960px;
  margin: 0 auto;
  padding-inline: var(--space-6);
}

/* ========================================
   HEADER
   ======================================== */

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

.header-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.logo-icon { color: var(--color-primary); }

.logo-text {
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: -0.02em;
}

[data-theme-toggle] {
  padding: var(--space-2);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
}

[data-theme-toggle]:hover {
  background: var(--color-accent-soft);
  color: var(--color-text);
}

/* ========================================
   HERO
   ======================================== */

.hero {
  padding: clamp(var(--space-12), 6vw, var(--space-24)) 0 clamp(var(--space-8), 4vw, var(--space-16));
}

.hero h1 {
  font-size: var(--text-2xl);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  max-width: 18ch;
}

.accent-text {
  color: var(--color-accent);
}

.hero-sub {
  margin-top: var(--space-4);
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 52ch;
}

.hero-sub strong {
  color: var(--color-text);
}

/* ========================================
   KPI / EXAMPLES
   ======================================== */

.examples-section {
  padding-bottom: clamp(var(--space-12), 6vw, var(--space-20));
}

.examples-section h2,
.simulator-section h2,
.info-section h2 {
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-2);
}

.section-desc {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  margin-bottom: var(--space-8);
}

.kpi-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.kpi-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.kpi-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.kpi-value {
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  font-weight: 600;
  font-variant-numeric: tabular-nums lining-nums;
}

.kpi-delta {
  font-size: var(--text-xs);
  font-weight: 600;
  font-family: var(--font-mono);
}

.kpi-delta.negative { color: var(--color-danger); }
.kpi-delta.positive { color: var(--color-safe); }

.kpi-danger {
  border-color: var(--color-danger-border);
  background: var(--color-danger-bg);
}
.kpi-danger .kpi-value { color: var(--color-danger); }

.kpi-safe {
  border-color: var(--color-safe-border);
  background: var(--color-safe-bg);
}
.kpi-safe .kpi-value { color: var(--color-safe); }

.savings-callout {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-6);
  background: var(--color-savings-bg);
  border: 1px solid var(--color-savings-border);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  color: var(--color-text);
  margin-top: var(--space-4);
}

.savings-callout strong {
  color: var(--color-savings);
}

.savings-icon {
  color: var(--color-savings);
  flex-shrink: 0;
}

/* ========================================
   SIMULATOR
   ======================================== */

.simulator-section {
  padding: clamp(var(--space-12), 6vw, var(--space-20)) 0;
  border-top: 1px solid var(--color-border);
}

.sim-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-10);
}

.sim-controls {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.control-group label {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
}

.control-group input[type="number"] {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-base);
  font-variant-numeric: tabular-nums;
  width: 100%;
}

.control-group input[type="number"]:focus {
  border-color: var(--color-primary);
  outline: none;
  box-shadow: 0 0 0 3px rgba(14, 107, 110, 0.15);
}

.control-group input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--color-border);
  border-radius: var(--radius-full);
  outline: none;
  cursor: pointer;
}

.control-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
  border: 2px solid var(--color-bg);
  box-shadow: var(--shadow-sm);
}

.control-group input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
  border: 2px solid var(--color-bg);
  box-shadow: var(--shadow-sm);
}

.helper-text {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.helper-text a {
  color: var(--color-primary);
  text-decoration: none;
}

.helper-text a:hover {
  text-decoration: underline;
}

.preset-buttons {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  margin-top: var(--space-2);
}

.preset-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
}

.preset-btn {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  font-weight: 500;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  background: var(--color-surface);
}

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

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

/* Results */

.sim-results {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.result-cards {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.result-card {
  padding: var(--space-5) var(--space-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.result-label {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.result-value {
  font-family: var(--font-mono);
  font-size: var(--text-xl);
  font-weight: 700;
  font-variant-numeric: tabular-nums lining-nums;
}

.result-interest {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
}

.result-danger {
  background: var(--color-danger-bg);
  border-color: var(--color-danger-border);
}
.result-danger .result-label { color: var(--color-danger); }
.result-danger .result-value { color: var(--color-danger); }
.result-danger .result-interest { color: var(--color-danger-text); }

.result-legal {
  background: var(--color-safe-bg);
  border-color: var(--color-safe-border);
}
.result-legal .result-label { color: var(--color-safe); }
.result-legal .result-value { color: var(--color-safe); }
.result-legal .result-interest { color: var(--color-safe-text); }

.result-savings {
  background: var(--color-savings-bg);
  border-color: var(--color-savings-border);
}
.result-savings .result-label { color: var(--color-savings); }
.result-savings .result-value { color: var(--color-savings); font-size: var(--text-lg); }
.result-savings .result-interest { color: var(--color-text-muted); }

/* ========================================
   CHART
   ======================================== */

.chart-container {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-bottom: var(--space-10);
  position: relative;
  height: 360px;
}

.chart-container canvas {
  width: 100% !important;
  height: 100% !important;
}

/* ========================================
   TABLE
   ======================================== */

.table-wrapper h3 {
  font-size: var(--text-lg);
  font-weight: 600;
  margin-bottom: var(--space-4);
}

.table-scroll {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

#monthly-table th,
#monthly-table td {
  padding: var(--space-3) var(--space-4);
  text-align: right;
  font-size: var(--text-sm);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums lining-nums;
  white-space: nowrap;
}

#monthly-table th {
  background: var(--color-surface-2);
  font-weight: 600;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  position: sticky;
  top: 0;
}

#monthly-table th:first-child,
#monthly-table td:first-child {
  text-align: left;
}

#monthly-table tbody tr {
  border-top: 1px solid var(--color-border);
}

#monthly-table tbody tr:hover {
  background: var(--color-accent-soft);
}

#monthly-table td:nth-child(2) { color: var(--color-danger); }
#monthly-table td:nth-child(4) { color: var(--color-safe); font-weight: 600; }

/* ========================================
   INFO SECTION
   ======================================== */

.info-section {
  padding: clamp(var(--space-12), 6vw, var(--space-20)) 0;
  border-top: 1px solid var(--color-border);
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-8);
}

.info-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
}

.info-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-soft);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.info-card h3 {
  font-size: var(--text-base);
  font-weight: 600;
  margin-bottom: var(--space-2);
}

.info-card p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

.source-note {
  margin-top: var(--space-8);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.source-note p {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.source-note a {
  color: var(--color-primary);
  text-decoration: none;
}

.source-note a:hover {
  text-decoration: underline;
}

/* ========================================
   FOOTER
   ======================================== */

footer {
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-border);
}

footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-note {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  max-width: 50ch;
}

.footer-attribution {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-decoration: none;
}

.footer-attribution:hover {
  color: var(--color-text-muted);
}

/* ========================================
   RESPONSIVE
   ======================================== */

@media (max-width: 768px) {
  .kpi-row {
    grid-template-columns: 1fr;
  }

  .sim-layout {
    grid-template-columns: 1fr;
  }

  .info-grid {
    grid-template-columns: 1fr;
  }

  .hero h1 {
    font-size: var(--text-xl);
  }

  .chart-container {
    height: 280px;
  }

  footer .container {
    flex-direction: column;
    align-items: flex-start;
  }
}