/* ── Design Tokens ─────────────────────────────────── */
: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 (4px base) */
  --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);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);

  /* Shadows */
  --shadow-sm: 0 1px 2px oklch(0.2 0.01 80 / 0.06);
  --shadow-md: 0 4px 12px oklch(0.2 0.01 80 / 0.08);
  --shadow-lg: 0 12px 32px oklch(0.2 0.01 80 / 0.12);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;

  /* Fonts */
  --font-display: 'Cabinet Grotesk', 'Trebuchet MS', sans-serif;
  --font-body: 'Satoshi', 'Helvetica Neue', sans-serif;
}

/* ── Interlink Brand Colors ───────────────────────── */
:root,
[data-theme='light'] {
  --color-bg: #F5F7FA;
  --color-surface: #FFFFFF;
  --color-surface-2: #F0F4F8;
  --color-border: #D1D9E6;
  --color-divider: #E2E8F0;

  --color-text: #1A2B42;
  --color-text-muted: #5A6A80;
  --color-text-faint: #9CAABE;
  --color-text-inverse: #FFFFFF;

  --color-primary: #0C5E6A;
  --color-primary-hover: #094A54;
  --color-primary-light: #E8F4F6;
  --color-primary-glow: oklch(0.50 0.08 192 / 0.08);

  --color-growth: #0C5E6A;
  --color-growth-bg: #E8F4F6;
  --color-growth-border: #B3D9DE;

  --color-scale: #1B3A5C;
  --color-scale-bg: #E8EEF5;
  --color-scale-border: #A8BFDA;

  --color-success: #2A7D3F;
  --color-warning: #964219;
}

[data-theme='dark'] {
  --color-bg: #0F1318;
  --color-surface: #1A1F28;
  --color-surface-2: #232A35;
  --color-border: #2E3848;
  --color-divider: #2A3344;

  --color-text: #D4DAE3;
  --color-text-muted: #8896A8;
  --color-text-faint: #5A6A7E;
  --color-text-inverse: #0F1318;

  --color-primary: #4CA8B8;
  --color-primary-hover: #6BC0CE;
  --color-primary-light: #1A2E33;
  --color-primary-glow: oklch(0.60 0.08 192 / 0.12);

  --color-growth: #4CA8B8;
  --color-growth-bg: #152A2E;
  --color-growth-border: #2A4E55;

  --color-scale: #7BA3CC;
  --color-scale-bg: #16233A;
  --color-scale-border: #2A4060;

  --color-success: #5CB86E;
  --color-warning: #D4874C;

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

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg: #0F1318;
    --color-surface: #1A1F28;
    --color-surface-2: #232A35;
    --color-border: #2E3848;
    --color-divider: #2A3344;
    --color-text: #D4DAE3;
    --color-text-muted: #8896A8;
    --color-text-faint: #5A6A7E;
    --color-text-inverse: #0F1318;
    --color-primary: #4CA8B8;
    --color-primary-hover: #6BC0CE;
    --color-primary-light: #1A2E33;
    --color-primary-glow: oklch(0.60 0.08 192 / 0.12);
    --color-growth: #4CA8B8;
    --color-growth-bg: #152A2E;
    --color-growth-border: #2A4E55;
    --color-scale: #7BA3CC;
    --color-scale-bg: #16233A;
    --color-scale-border: #2A4060;
    --color-success: #5CB86E;
    --color-warning: #D4874C;
    --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.2);
    --shadow-md: 0 4px 12px oklch(0 0 0 / 0.3);
    --shadow-lg: 0 12px 32px oklch(0 0 0 / 0.4);
  }
}

/* ── Page Layout ──────────────────────────────────── */
body {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.page-wrapper {
  width: 100%;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: var(--space-8) var(--space-4);
}

@media (min-width: 768px) {
  .page-wrapper {
    padding: var(--space-12) var(--space-8);
  }
}

/* ── Header ───────────────────────────────────────── */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-12);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
}

.logo svg {
  width: 36px;
  height: 36px;
}

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

.theme-toggle {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
}

.theme-toggle:hover {
  background: var(--color-surface-2);
  color: var(--color-text);
}

/* ── Hero ─────────────────────────────────────────── */
.hero {
  text-align: center;
  margin-bottom: var(--space-12);
}

.hero h1 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.03em;
  margin-bottom: var(--space-4);
}

.hero p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 560px;
  margin-inline: auto;
  line-height: 1.65;
}

/* ── Calculator Section ───────────────────────────── */
.calculator-section {
  margin-bottom: var(--space-16);
}

.slider-container {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  margin-bottom: var(--space-8);
  box-shadow: var(--shadow-sm);
}

.slider-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: var(--space-6);
  flex-wrap: wrap;
  gap: var(--space-2);
}

.slider-label span {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--text-lg);
  color: var(--color-text);
}

.doc-count-display {
  font-family: var(--font-body);
  font-weight: 700;
  font-size: var(--text-xl);
  color: var(--color-primary);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}

/* Freeform numeric input */
.input-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

.input-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  white-space: nowrap;
  flex-shrink: 0;
}

.doc-input {
  width: 160px;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-base);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--color-text);
  background: var(--color-surface-2);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  text-align: center;
  letter-spacing: -0.01em;
  transition:
    border-color var(--transition-interactive),
    box-shadow var(--transition-interactive);
}

.doc-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-glow);
}

.doc-input::placeholder {
  color: var(--color-text-faint);
  font-weight: 400;
}

/* Range slider custom styling */
.range-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 8px;
  border-radius: var(--radius-full);
  background: var(--color-surface-2);
  outline: none;
  cursor: pointer;
  margin-bottom: var(--space-4);
}

.range-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
  border: 3px solid var(--color-surface);
  box-shadow: var(--shadow-md), 0 0 0 3px var(--color-primary-glow);
  transition:
    transform var(--transition-interactive),
    box-shadow var(--transition-interactive);
}

.range-slider::-webkit-slider-thumb:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-lg), 0 0 0 6px var(--color-primary-glow);
}

.range-slider::-webkit-slider-thumb:active {
  transform: scale(0.95);
}

.range-slider::-moz-range-thumb {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
  border: 3px solid var(--color-surface);
  box-shadow: var(--shadow-md), 0 0 0 3px var(--color-primary-glow);
}

.tick-marks {
  display: flex;
  justify-content: space-between;
  padding: 0 2px;
}

.tick-marks span {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-variant-numeric: tabular-nums;
}

/* Quick-select buttons */
.quick-select {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  margin-top: var(--space-4);
}

.quick-btn {
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  background: var(--color-surface-2);
  border: 1px solid transparent;
  transition:
    background var(--transition-interactive),
    color var(--transition-interactive),
    border-color var(--transition-interactive);
}

.quick-btn:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

.quick-btn:active {
  transform: scale(0.97);
}

.quick-btn.active {
  color: var(--color-text-inverse);
  background: var(--color-primary);
  border-color: var(--color-primary);
}

/* ── Plan Cards (side by side) ────────────────────── */
.plan-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

@media (min-width: 680px) {
  .plan-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.plan-card {
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  position: relative;
  overflow: hidden;
  transition:
    border-color 300ms var(--ease-out),
    box-shadow 300ms var(--ease-out);
}

.plan-card.recommended {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary), var(--shadow-md);
}

.plan-card.recommended::before {
  content: attr(data-badge);
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  font-size: var(--text-xs);
  font-weight: 600;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  letter-spacing: 0.02em;
}

.plan-card.unavailable {
  opacity: 0.55;
}

.plan-card.unavailable .plan-total {
  text-decoration: line-through;
  text-decoration-color: var(--color-text-faint);
}

/* Plan card header */
.plan-header {
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-divider);
}

.plan-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  margin-bottom: var(--space-1);
}

.plan-card.growth .plan-name {
  color: var(--color-growth);
}

.plan-card.scale .plan-name {
  color: var(--color-scale);
}

.plan-scope {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* Pricing total */
.plan-total-row {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.plan-total {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--text-xl);
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  transition: color 300ms var(--ease-out);
}

.plan-total-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* Savings badge */
.savings-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  background: oklch(0.45 0.12 145 / 0.12);
  color: var(--color-success);
  font-size: var(--text-xs);
  font-weight: 600;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-6);
  font-variant-numeric: tabular-nums;
  opacity: 0;
  transform: translateY(4px);
  transition:
    opacity 300ms var(--ease-out),
    transform 300ms var(--ease-out);
}

.savings-badge.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Cost breakdown rows */
.breakdown {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.breakdown-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-2) 0;
  font-size: var(--text-sm);
}

.breakdown-row:not(:last-child) {
  border-bottom: 1px solid var(--color-divider);
}

.breakdown-label {
  color: var(--color-text-muted);
}

.breakdown-value {
  font-weight: 600;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}

/* Cap notice */
.cap-notice {
  margin-top: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: oklch(0.55 0.10 55 / 0.08);
  border-radius: var(--radius-md);
  font-size: var(--text-xs);
  color: var(--color-warning);
  font-weight: 500;
  display: none;
  line-height: 1.5;
}

.cap-notice.visible {
  display: block;
}

/* CTA button */
.plan-cta {
  display: block;
  width: 100%;
  text-align: center;
  padding: var(--space-3) var(--space-4);
  margin-top: var(--space-6);
  border-radius: var(--radius-lg);
  font-weight: 600;
  font-size: var(--text-sm);
  text-decoration: none;
  transition:
    background var(--transition-interactive),
    transform var(--transition-interactive),
    box-shadow var(--transition-interactive);
}

.plan-cta:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.plan-cta:active {
  transform: translateY(0);
  box-shadow: var(--shadow-sm);
}

.plan-card.growth .plan-cta {
  background: var(--color-growth);
  color: var(--color-text-inverse);
}

.plan-card.growth .plan-cta:hover {
  background: var(--color-primary-hover);
}

.plan-card.scale .plan-cta {
  background: var(--color-scale);
  color: var(--color-text-inverse);
}

.plan-card.scale .plan-cta:hover {
  background: #14304E;
}

/* ── Tier Details ─────────────────────────────────── */
.tier-details {
  margin-top: var(--space-12);
}

.tier-details h2 {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  text-align: center;
  margin-bottom: var(--space-8);
  letter-spacing: -0.02em;
}

.tier-table-wrapper {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
}

.tier-table {
  min-width: 560px;
}

.tier-table th,
.tier-table td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  font-size: var(--text-sm);
}

.tier-table thead th {
  background: var(--color-surface-2);
  font-weight: 600;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

.tier-table tbody td {
  color: var(--color-text-muted);
  border-bottom: 1px solid var(--color-divider);
  font-variant-numeric: tabular-nums;
}

.tier-table tbody tr:last-child td {
  border-bottom: none;
}

.tier-table .highlight-row td {
  background: var(--color-primary-light);
  color: var(--color-text);
  font-weight: 500;
}

/* ── Enterprise CTA ───────────────────────────────── */
.enterprise-cta {
  margin-top: var(--space-12);
  text-align: center;
  padding: var(--space-8);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
}

.enterprise-cta h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.enterprise-cta p {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  margin-inline: auto;
  margin-bottom: var(--space-6);
}

.enterprise-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  background: var(--color-text);
  color: var(--color-bg);
  border-radius: var(--radius-lg);
  font-weight: 600;
  font-size: var(--text-sm);
  text-decoration: none;
  transition:
    background var(--transition-interactive),
    transform var(--transition-interactive),
    box-shadow var(--transition-interactive);
}

.enterprise-btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
  opacity: 0.9;
}

.enterprise-btn:active {
  transform: translateY(0);
}

/* ── Footer ───────────────────────────────────────── */
.site-footer {
  margin-top: var(--space-16);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-divider);
  text-align: center;
  color: var(--color-text-faint);
  font-size: var(--text-xs);
  padding-bottom: var(--space-8);
}

/* ── Scroll reveal ────────────────────────────────── */
.fade-in {
  opacity: 1;
}

@supports (animation-timeline: scroll()) {
  .fade-in {
    opacity: 0;
    animation: reveal-fade linear both;
    animation-timeline: view();
    animation-range: entry 0% entry 80%;
  }
}

@keyframes reveal-fade {
  to { opacity: 1; }
}