/* ============================================================
   DESIGN TOKENS — Single source of truth
   ============================================================ */
:root {
  /* Color — strict monochromatic scale */
  --c-black: #000000;
  --c-white: #FFFFFF;
  --c-grey-50:  #F5F5F5;  /* App bg */
  --c-grey-100: #E5E5E5;  /* Lines */
  --c-grey-400: #A3A3A3;  /* Muted */
  --c-grey-600: #525252;  /* Subtext */

  /* Spacing — 8pt base, 4pt subdivision */
  --space-1:  4px;   /* T-1 icon gap */
  --space-2:  8px;   /* T-2 base grid */
  --space-3: 16px;   /* T-3 component padding */
  --space-4: 24px;   /* T-4 card padding */
  --space-5: 32px;   /* T-5 content blocks */
  --space-6: 48px;   /* T-6 section breaks */
  --space-7: 64px;   /* T-7 page sections */

  /* Radius — 6px standard */
  --radius-0: 0px;
  --radius-1: 4px;
  --radius-2: 6px;   /* Standard */
  --radius-3: 8px;
  --radius-4: 12px;
  --radius-pill: 999px;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, Menlo, monospace;

  --fs-heading-xl: 36px;  --lh-heading-xl: 40px;
  --fs-heading-l:  24px;  --lh-heading-l:  32px;
  --fs-heading-m:  18px;  --lh-heading-m:  24px;
  --fs-body:       14px;  --lh-body:       20px;
  --fs-body-sm:    12px;  --lh-body-sm:    16px;

  /* Motion */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --dur-fast: 120ms;
  --dur-med:  200ms;
}

/* ============================================================
   RESET + BASE
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 14px; }

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--c-black);
  background: var(--c-grey-50);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "cv11", "ss01";
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

button { cursor: pointer; background: none; border: none; }

code, pre, .mono { font-family: var(--font-mono); }

/* ============================================================
   LAYOUT — 12 column, 1000px canvas, 24px gutter, 16px margin
   ============================================================ */
.container {
  max-width: 1032px;
  margin: 0 auto;
  padding: 0 var(--space-3);
}

/* ============================================================
   TOP NAV
   ============================================================ */
.topnav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--c-grey-100);
}
.topnav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  max-width: 1032px;
  margin: 0 auto;
  padding: 0 var(--space-3);
}
.brand {
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.01em;
}
.brand span { color: var(--c-grey-400); font-weight: 500; }
.nav-tabs {
  display: flex;
  gap: var(--space-4);
}
.nav-tab {
  font-size: var(--fs-body);
  font-weight: 500;
  color: var(--c-grey-600);
  padding: var(--space-1) 0;
  border-bottom: 1.5px solid transparent;
  transition: color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}
.nav-tab:hover { color: var(--c-black); }
.nav-tab.active { color: var(--c-black); border-bottom-color: var(--c-black); }
.nav-search {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 6px 10px;
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  min-width: 220px;
  color: var(--c-grey-400);
  font-size: var(--fs-body-sm);
}
.nav-search svg { width: 12px; height: 12px; }

/* ============================================================
   PAGE SHELL
   ============================================================ */
.page { display: none; padding: var(--space-6) 0 var(--space-7); }
.page.active { display: block; }

.page-header { margin-bottom: var(--space-6); }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-grey-600);
  padding: 4px 10px;
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  margin-bottom: var(--space-3);
}
.eyebrow::before {
  content: '';
  width: 5px; height: 5px;
  background: var(--c-black);
  border-radius: var(--radius-pill);
}
.page-title {
  font-size: var(--fs-heading-xl);
  line-height: var(--lh-heading-xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-2);
}
.page-lede {
  color: var(--c-grey-600);
  max-width: 580px;
  font-size: var(--fs-body);
}
.version-chip {
  float: right;
  font-size: var(--fs-body-sm);
  color: var(--c-grey-400);
}
.version-chip b { color: var(--c-black); font-weight: 500; margin-left: 6px; }

/* Stat row */
.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
  margin-top: var(--space-4);
}
.stat {
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: var(--space-3);
}
.stat-value {
  font-size: var(--fs-heading-l);
  line-height: var(--lh-heading-l);
  font-weight: 600;
  letter-spacing: -0.01em;
}
.stat-label {
  font-size: 11px;
  color: var(--c-grey-600);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-top: 2px;
}

/* Section */
.section { margin-top: var(--space-6); }
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: var(--space-3);
}
.section-title {
  font-size: var(--fs-heading-l);
  line-height: var(--lh-heading-l);
  font-weight: 600;
  letter-spacing: -0.01em;
}
.section-sub {
  font-size: var(--fs-body);
  color: var(--c-grey-600);
  margin-top: 4px;
}
.section-meta {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-600);
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  padding: 4px 8px;
  border-radius: var(--radius-2);
}

/* Card */
.card {
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: var(--space-4);
}
.card + .card { margin-top: var(--space-3); }

/* Subsection label inside card */
.sub-label {
  font-size: 11px;
  font-weight: 500;
  color: var(--c-grey-600);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-left: 2px solid var(--c-black);
  padding-left: var(--space-2);
}
.sub-label .spec {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--c-grey-400);
  letter-spacing: 0;
  text-transform: none;
  margin-left: var(--space-2);
  font-weight: 400;
}
.sub-label .spec b { color: var(--c-grey-600); font-weight: 500; }

.hr-dim {
  border: 0;
  border-top: 1px solid var(--c-grey-100);
  margin: var(--space-4) 0;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-family: var(--font-sans);
  font-weight: 500;
  border-radius: var(--radius-2);
  border: 1px solid transparent;
  transition: all var(--dur-fast) var(--ease);
  white-space: nowrap;
  user-select: none;
}
.btn:focus-visible {
  outline: 2px solid var(--c-black);
  outline-offset: 2px;
}

/* Sizes — padding follows 8pt grid, height 30/36/40/48 */
.btn-xs  { padding: 0 10px; height: 28px; font-size: 12px; }
.btn-sm  { padding: 0 12px; height: 32px; font-size: 13px; }
.btn-def { padding: 0 14px; height: 36px; font-size: 14px; }
.btn-lg  { padding: 0 20px; height: 44px; font-size: 14px; }

/* Variants */
.btn-primary {
  background: var(--c-black);
  color: var(--c-white);
  border-color: var(--c-black);
}
.btn-primary:hover:not(:disabled) { background: #1a1a1a; }
.btn-primary:active:not(:disabled) { background: #2a2a2a; }

.btn-secondary {
  background: var(--c-white);
  color: var(--c-black);
  border-color: var(--c-black);
}
.btn-secondary:hover:not(:disabled) { background: var(--c-grey-50); }

.btn-ghost {
  background: transparent;
  color: var(--c-black);
  border-color: transparent;
}
.btn-ghost:hover:not(:disabled) { background: var(--c-grey-50); }

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}

.button-anatomy {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-4);
  align-items: center;
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: var(--space-3);
}
.anatomy-specs {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-600);
  line-height: 1.7;
}
.anatomy-specs b { color: var(--c-black); font-weight: 500; display: inline-block; width: 56px; }

/* ============================================================
   BADGES & TAGS
   ============================================================ */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: var(--c-grey-50);
  color: var(--c-black);
  border: 1px solid var(--c-grey-100);
  white-space: nowrap;
}
.badge-dot::before {
  content: '';
  width: 6px; height: 6px;
  background: var(--c-grey-400);
  border-radius: var(--radius-pill);
}
.badge-active::before   { background: var(--c-black); }
.badge-inactive::before { background: var(--c-grey-400); }
.badge-pending::before  { background: var(--c-grey-600); }
.badge-live            { background: var(--c-black); color: var(--c-white); border-color: var(--c-black); }
.badge-live::before    { background: var(--c-white); }
.badge-archived        { color: var(--c-grey-400); }
.badge-archived::before { background: var(--c-grey-400); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: var(--radius-2);
  background: var(--c-grey-50);
  color: var(--c-black);
  border: 1px solid var(--c-grey-100);
  transition: all var(--dur-fast) var(--ease);
  cursor: pointer;
}
.tag:hover { background: var(--c-grey-100); }
.tag.selected {
  background: var(--c-black);
  color: var(--c-white);
  border-color: var(--c-black);
}
.tag.disabled {
  color: var(--c-grey-400);
  cursor: not-allowed;
  opacity: 0.6;
}
.tag-dismissible .x {
  width: 14px; height: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-pill);
  margin-left: 2px;
  transition: background var(--dur-fast);
}
.tag-dismissible .x:hover { background: rgba(0,0,0,0.08); }
.tag.selected .x:hover { background: rgba(255,255,255,0.16); }

.count-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--c-black);
}
.count-badge .num {
  min-width: 22px;
  height: 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 6px;
  font-size: 11px;
  font-weight: 600;
  background: var(--c-black);
  color: var(--c-white);
  border-radius: var(--radius-pill);
}
.count-badge .num.muted {
  background: var(--c-grey-100);
  color: var(--c-grey-600);
}
.count-badge .num.empty {
  background: transparent;
  border: 1px dashed var(--c-grey-100);
  color: var(--c-grey-400);
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
}

/* ============================================================
   FORM INPUTS
   ============================================================ */
.field { display: flex; flex-direction: column; gap: 6px; }
.field-label {
  font-size: 11px;
  font-weight: 500;
  color: var(--c-grey-600);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.field-label .req { color: var(--c-black); margin-left: 2px; }

.input {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  padding: 0 12px;
  height: 36px;
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  background: var(--c-white);
  color: var(--c-black);
  transition: border-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
  width: 100%;
}
.input::placeholder { color: var(--c-grey-400); }
.input:hover { border-color: var(--c-grey-400); }
.input:focus {
  outline: none;
  border-color: var(--c-black);
  box-shadow: 0 0 0 3px rgba(0,0,0,0.06);
}
.input:disabled {
  background: var(--c-grey-50);
  color: var(--c-grey-400);
  cursor: not-allowed;
}
.input.error {
  border-color: var(--c-black);
  background: var(--c-white);
}
.input.success {
  border-color: var(--c-black);
}

.field-help {
  font-size: 11px;
  color: var(--c-grey-600);
}
.field-help.is-error { color: var(--c-black); font-weight: 500; }
.field-help.is-success { color: var(--c-grey-600); }

.input-group {
  position: relative;
  display: flex;
  align-items: center;
  width: 100%;
}
.input-group .input { padding-left: 36px; }
.input-group.trailing .input { padding-left: 12px; padding-right: 36px; }
.input-group .icon {
  position: absolute;
  left: 12px;
  width: 14px; height: 14px;
  color: var(--c-grey-400);
  pointer-events: none;
}
.input-group.trailing .icon { left: auto; right: 12px; }
.input-group .end-icon {
  position: absolute;
  right: 12px;
  width: 16px; height: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--c-black);
}

.input-affix {
  display: flex;
  align-items: stretch;
  width: 100%;
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  background: var(--c-white);
  overflow: hidden;
  transition: border-color var(--dur-fast) var(--ease);
}
.input-affix:focus-within { border-color: var(--c-black); box-shadow: 0 0 0 3px rgba(0,0,0,0.06); }
.input-affix .prefix,
.input-affix .suffix {
  display: inline-flex;
  align-items: center;
  padding: 0 12px;
  background: var(--c-grey-50);
  color: var(--c-grey-600);
  font-family: var(--font-mono);
  font-size: 12px;
  border-right: 1px solid var(--c-grey-100);
}
.input-affix .suffix { border-right: 0; border-left: 1px solid var(--c-grey-100); }
.input-affix input {
  flex: 1;
  border: 0;
  outline: none;
  padding: 0 12px;
  height: 34px;
  background: transparent;
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  color: var(--c-black);
}
.input-affix input::placeholder { color: var(--c-grey-400); }

.select {
  position: relative;
  width: 100%;
}
.select select {
  appearance: none;
  -webkit-appearance: none;
  width: 100%;
  padding: 0 36px 0 12px;
  height: 36px;
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  background: var(--c-white);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  color: var(--c-black);
  cursor: pointer;
  transition: border-color var(--dur-fast);
}
.select select:hover { border-color: var(--c-grey-400); }
.select select:focus { outline: none; border-color: var(--c-black); box-shadow: 0 0 0 3px rgba(0,0,0,0.06); }
.select::after {
  content: '';
  position: absolute;
  right: 14px;
  top: 50%;
  width: 8px; height: 8px;
  border-right: 1.5px solid var(--c-black);
  border-bottom: 1.5px solid var(--c-black);
  transform: translateY(-75%) rotate(45deg);
  pointer-events: none;
}

textarea.input {
  min-height: 88px;
  height: auto;
  padding: 10px 12px;
  resize: vertical;
  line-height: 1.5;
}

/* Grid for input examples */
.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4) var(--space-3);
}
.input-grid-full { grid-column: 1 / -1; }

/* Composed form */
.form-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
}

/* ============================================================
   CHECKBOXES, RADIOS, TOGGLES
   ============================================================ */
.control {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  user-select: none;
}
.control input { position: absolute; opacity: 0; pointer-events: none; }
.control-label {
  display: flex;
  flex-direction: column;
  gap: 1px;
}
.control-label .primary { font-size: var(--fs-body); color: var(--c-black); }
.control-label .secondary { font-size: 11px; color: var(--c-grey-600); }
.control.disabled { cursor: not-allowed; opacity: 0.45; }

/* Checkbox */
.cbox {
  width: 16px; height: 16px;
  border: 1.5px solid var(--c-grey-400);
  border-radius: var(--radius-1);
  background: var(--c-white);
  position: relative;
  flex-shrink: 0;
  transition: all var(--dur-fast) var(--ease);
}
.control:hover .cbox:not(.disabled) { border-color: var(--c-black); }
.control input:checked ~ .cbox {
  background: var(--c-black);
  border-color: var(--c-black);
}
.control input:checked ~ .cbox::after {
  content: '';
  position: absolute;
  left: 4px; top: 1px;
  width: 4px; height: 8px;
  border-right: 1.5px solid var(--c-white);
  border-bottom: 1.5px solid var(--c-white);
  transform: rotate(45deg);
}
.control input:indeterminate ~ .cbox,
.cbox.indeterminate {
  background: var(--c-black);
  border-color: var(--c-black);
}
.control input:indeterminate ~ .cbox::after,
.cbox.indeterminate::after {
  content: '';
  position: absolute;
  left: 3px; right: 3px; top: 50%;
  height: 1.5px;
  background: var(--c-white);
  transform: translateY(-50%);
  border: 0;
}

/* Radio */
.radio {
  width: 16px; height: 16px;
  border: 1.5px solid var(--c-grey-400);
  border-radius: var(--radius-pill);
  background: var(--c-white);
  position: relative;
  flex-shrink: 0;
  transition: all var(--dur-fast) var(--ease);
}
.control:hover .radio:not(.disabled) { border-color: var(--c-black); }
.control input:checked ~ .radio {
  border-color: var(--c-black);
}
.control input:checked ~ .radio::after {
  content: '';
  position: absolute;
  inset: 3px;
  background: var(--c-black);
  border-radius: var(--radius-pill);
}

/* Toggle */
.toggle {
  width: 32px; height: 18px;
  border-radius: var(--radius-pill);
  background: var(--c-grey-100);
  position: relative;
  flex-shrink: 0;
  transition: background var(--dur-med) var(--ease);
}
.toggle::after {
  content: '';
  position: absolute;
  left: 2px; top: 2px;
  width: 14px; height: 14px;
  background: var(--c-white);
  border-radius: var(--radius-pill);
  transition: transform var(--dur-med) var(--ease);
  box-shadow: 0 1px 2px rgba(0,0,0,0.15);
}
.control input:checked ~ .toggle { background: var(--c-black); }
.control input:checked ~ .toggle::after { transform: translateX(14px); }

.control-stack { display: flex; flex-direction: column; gap: var(--space-2); }
.control-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
}

/* Applied example — notification prefs */
.settings-card {
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: var(--space-3);
}
.settings-head {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  font-size: var(--fs-body);
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--c-grey-100);
}
.settings-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
}
.settings-row + .settings-row { border-top: 1px solid var(--c-grey-100); }
.settings-row .label { font-size: var(--fs-body); }
.settings-row .state {
  font-size: 11px;
  color: var(--c-grey-600);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.settings-freq {
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--c-grey-100);
}
.settings-freq .freq-title {
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-grey-600);
  margin-bottom: var(--space-2);
}
.settings-actions {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-2);
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--c-grey-100);
}

/* ============================================================
   FOUNDATIONS PAGE — color swatches, type scale, radius
   ============================================================ */
.swatch-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
}
.swatch-card {
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: var(--space-3);
}
.swatch-card .group-label {
  font-size: 10px;
  font-weight: 500;
  color: var(--c-grey-600);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--c-grey-100);
}
.swatch {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.swatch + .swatch { margin-top: var(--space-2); }
.swatch .chip {
  width: 32px; height: 32px;
  border-radius: var(--radius-2);
  border: 1px solid var(--c-grey-100);
  flex-shrink: 0;
}
.swatch .meta .name {
  font-size: 13px;
  font-weight: 500;
  color: var(--c-black);
}
.swatch .meta .hex {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-600);
}

.type-card { background: var(--c-white); }
.type-row {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: var(--space-3);
  align-items: baseline;
  padding: var(--space-3) 0;
}
.type-row + .type-row { border-top: 1px solid var(--c-grey-100); }
.type-meta {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-600);
  line-height: 1.6;
}
.type-meta .name { color: var(--c-black); font-size: 12px; margin-bottom: 2px; }

.type-xl { font-size: 36px; line-height: 40px; font-weight: 700; letter-spacing: -0.02em; }
.type-l  { font-size: 24px; line-height: 32px; font-weight: 600; letter-spacing: -0.01em; }
.type-m  { font-size: 18px; line-height: 24px; font-weight: 500; letter-spacing: -0.005em; }
.type-body { font-size: 14px; line-height: 20px; color: var(--c-grey-600); }
.type-small { font-size: 12px; line-height: 16px; color: var(--c-grey-600); }

/* Radius demo */
.radius-demo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
}
.radius-visual {
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  position: relative;
}
.radius-square {
  width: 160px; height: 160px;
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  position: relative;
}
.radius-square .pill {
  position: absolute;
  top: -8px; right: -8px;
  background: var(--c-black);
  color: var(--c-white);
  font-family: var(--font-mono);
  font-size: 10px;
  padding: 3px 8px;
  border-radius: var(--radius-2);
}
.radius-visual .desc {
  font-size: 12px;
  color: var(--c-grey-600);
  text-align: center;
  max-width: 240px;
}
.applied-example {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.applied-example .title { font-weight: 600; font-size: 15px; margin-bottom: 2px; }
.applied-example .subtitle { font-size: 12px; color: var(--c-grey-600); margin-bottom: var(--space-2); }

/* ============================================================
   LAYOUT & SPACING PAGE
   ============================================================ */
.grid-preview {
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: var(--space-3);
  margin-bottom: var(--space-3);
}
.grid-preview-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--c-grey-100);
}
.grid-preview-head .name {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  font-size: 13px;
}
.grid-preview-head .name::before {
  content: '';
  width: 3px; height: 14px;
  background: var(--c-black);
  border-radius: 1px;
}
.grid-preview-head .name span {
  color: var(--c-grey-400);
  font-weight: 400;
  margin-left: var(--space-2);
}
.grid-preview-head .badge-spec {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--c-grey-600);
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  padding: 3px 8px;
  border-radius: var(--radius-2);
}

/* 8pt grid visualization */
.grid-8pt {
  display: flex;
  align-items: flex-end;
  gap: 2px;
  padding: var(--space-3);
  background: var(--c-grey-50);
  border-radius: var(--radius-2);
  height: 140px;
}
.grid-bar {
  background: var(--c-grey-100);
  border-radius: 2px 2px 0 0;
  position: relative;
  flex: 0 0 auto;
  transition: background var(--dur-fast);
}
.grid-bar:hover { background: var(--c-grey-400); }
.grid-bar-label {
  position: absolute;
  left: 100%;
  bottom: 0;
  padding-left: 8px;
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--c-grey-600);
  white-space: nowrap;
  line-height: 1;
}

/* 12-column grid */
.col-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 8px;
  background: var(--c-grey-50);
  padding: 12px;
  border-radius: var(--radius-2);
}
.col {
  height: 56px;
  background: var(--c-grey-100);
  border-radius: var(--radius-1);
}
.col-grid-legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
}
.col-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-600);
  padding: 4px 10px;
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
}
.col-pill::before {
  content: '';
  width: 10px; height: 10px;
  background: var(--c-grey-100);
  border-radius: 2px;
}
.col-pill.filled::before { background: var(--c-black); }
.col-pill.filled { color: var(--c-black); }

/* Spacing scale visual */
.scale-row {
  display: grid;
  grid-template-columns: 28px 56px 1fr 80px;
  gap: var(--space-3);
  align-items: center;
  padding: 10px 0;
}
.scale-row + .scale-row { border-top: 1px solid var(--c-grey-100); }
.scale-token {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-400);
}
.scale-value {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  color: var(--c-black);
}
.scale-bar {
  height: 14px;
  background: var(--c-black);
  border-radius: var(--radius-pill);
  max-width: 100%;
}
.scale-use {
  font-size: 11px;
  color: var(--c-grey-600);
  font-family: var(--font-mono);
}
.scale-chip {
  font-family: var(--font-mono);
  font-size: 10px;
  padding: 2px 8px;
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  color: var(--c-grey-600);
  justify-self: end;
}

.squares-row {
  display: flex;
  align-items: flex-end;
  gap: var(--space-3);
  padding: var(--space-3);
  background: var(--c-grey-50);
  border-radius: var(--radius-2);
}
.sq {
  background: var(--c-black);
  border-radius: 2px;
}
.sq-note {
  font-size: 12px;
  color: var(--c-grey-600);
  max-width: 240px;
}

/* Annotated card */
.annotated-demo {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: var(--space-4);
  align-items: start;
}
.demo-card {
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: var(--space-3);
}
.demo-card .qa {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}
.qa-icon {
  width: 28px; height: 28px;
  background: var(--c-black);
  border-radius: var(--radius-2);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--c-white);
}
.qa-text .t { font-weight: 600; font-size: 13px; }
.qa-text .s { font-size: 11px; color: var(--c-grey-600); }
.demo-card .line {
  height: 8px;
  background: var(--c-grey-100);
  border-radius: var(--radius-pill);
  margin: 6px 0;
}
.demo-card .line.w70 { width: 70%; }
.demo-card .line.w50 { width: 50%; }

.spec-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.spec-item {
  display: grid;
  grid-template-columns: 20px 1fr;
  gap: 10px;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-600);
}
.spec-item .dot {
  width: 10px; height: 10px;
  background: var(--c-black);
  border-radius: var(--radius-1);
}

/* Radius scale reference */
.radius-scale {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: var(--space-3);
}
.radius-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  position: relative;
}
.radius-chip {
  width: 64px; height: 64px;
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
}
.radius-chip.standard { background: var(--c-black); border-color: var(--c-black); }
.radius-item .num { font-family: var(--font-mono); font-weight: 600; font-size: 13px; }
.radius-item .sub { font-size: 11px; color: var(--c-grey-600); }
.radius-item.is-standard::after {
  content: '✓ System';
  position: absolute;
  top: -10px;
  background: var(--c-black);
  color: var(--c-white);
  font-size: 10px;
  padding: 2px 8px;
  border-radius: var(--radius-2);
  font-family: var(--font-sans);
}

/* Card surface variants */
.surface-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
}
.surface {
  padding: var(--space-3);
  border-radius: var(--radius-2);
  border: 1px solid var(--c-grey-100);
  position: relative;
}
.surface-white { background: var(--c-white); }
.surface-grey  { background: var(--c-grey-50); }
.surface-black { background: var(--c-black); color: var(--c-white); border-color: var(--c-black); }
.surface .label-pill {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10px;
  padding: 2px 8px;
  background: rgba(0,0,0,0.06);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  color: var(--c-grey-600);
}
.surface-black .label-pill {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.15);
  color: rgba(255,255,255,0.6);
}
.surface .big {
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: var(--space-3) 0 2px;
}
.surface .caption { font-size: 12px; color: var(--c-grey-600); }
.surface-black .caption { color: rgba(255,255,255,0.6); }
.surface .trend {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  margin-top: 10px;
  color: var(--c-black);
}
.surface-black .trend { color: var(--c-white); }
.surface-black .trend::before { background: var(--c-white); }
.surface .trend::before {
  content: '';
  width: 6px; height: 6px;
  background: var(--c-black);
  border-radius: var(--radius-pill);
}
.surface .overflow {
  position: absolute; top: 10px; right: 10px;
  color: var(--c-grey-400);
  letter-spacing: 2px;
  font-size: 14px;
}
.surface-black .overflow { color: rgba(255,255,255,0.4); }

/* Container hierarchy */
.hierarchy {
  background: var(--c-grey-50);
  border: 1px dashed var(--c-grey-100);
  border-radius: 0;
  padding: var(--space-3);
}
.hierarchy-label {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--c-grey-600);
  margin-bottom: var(--space-2);
}
.hierarchy-section {
  background: var(--c-white);
  border-radius: var(--radius-2);
  padding: var(--space-3);
  box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}
.hierarchy-section .hierarchy-label { margin-bottom: var(--space-2); }
.hierarchy-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-2);
}
.h-card {
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  padding: 10px;
  min-height: 60px;
}
.h-card .line {
  height: 6px;
  background: var(--c-grey-100);
  border-radius: var(--radius-pill);
  margin: 4px 0;
}

/* Composed hero */
.hero {
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
  overflow: hidden;
}
.hero-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--c-grey-100);
}
.hero-brand { font-weight: 700; letter-spacing: -0.01em; }
.hero-brand span { color: var(--c-grey-400); font-weight: 500; }
.hero-nav-links {
  display: flex;
  gap: var(--space-3);
  font-size: 13px;
  color: var(--c-grey-600);
}
.hero-nav-actions { display: flex; gap: var(--space-2); }
.hero-body {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: var(--space-4);
  padding: var(--space-5) var(--space-4);
}
.hero-content .beta-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  color: var(--c-grey-600);
  padding: 4px 10px;
  background: var(--c-grey-50);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-pill);
  margin-bottom: var(--space-3);
}
.hero-content .beta-chip::before {
  content: '';
  width: 6px; height: 6px;
  background: var(--c-black);
  border-radius: var(--radius-pill);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}
.hero-h {
  font-size: 40px;
  line-height: 44px;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-3);
}
.hero-p {
  color: var(--c-grey-600);
  font-size: var(--fs-body);
  max-width: 420px;
  margin-bottom: var(--space-4);
}
.hero-ctas { display: flex; gap: var(--space-2); margin-bottom: var(--space-4); }
.hero-trust {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.avatar-stack { display: flex; }
.avatar {
  width: 28px; height: 28px;
  border-radius: var(--radius-pill);
  background: var(--c-grey-100);
  border: 2px solid var(--c-white);
  margin-left: -6px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  font-weight: 600;
  color: var(--c-grey-600);
}
.avatar:first-child { margin-left: 0; }
.avatar-a { background: var(--c-black); color: var(--c-white); }
.avatar-b { background: var(--c-grey-600); color: var(--c-white); }
.avatar-c { background: var(--c-grey-400); color: var(--c-white); }
.avatar-d { background: var(--c-grey-100); color: var(--c-grey-600); }
.trust-meta { font-size: 12px; color: var(--c-grey-600); }
.trust-meta b { color: var(--c-black); font-weight: 500; }
.trust-meta .stars { color: var(--c-black); letter-spacing: -1px; }

.hero-side {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.feat-card {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 12px;
  background: var(--c-white);
  border: 1px solid var(--c-grey-100);
  border-radius: var(--radius-2);
}
.feat-icon {
  width: 28px; height: 28px;
  background: var(--c-grey-50);
  border-radius: var(--radius-2);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.feat-card .t { font-size: 13px; font-weight: 600; margin-bottom: 2px; }
.feat-card .s { font-size: 11px; color: var(--c-grey-600); line-height: 1.5; }
.feat-metric {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px;
  background: var(--c-black);
  color: var(--c-white);
  border-radius: var(--radius-2);
}
.feat-metric .m { font-size: 24px; font-weight: 600; letter-spacing: -0.01em; }
.feat-metric .c { font-size: 11px; color: rgba(255,255,255,0.6); }

/* Footer */
.footer {
  border-top: 1px solid var(--c-grey-100);
  background: var(--c-white);
  margin-top: var(--space-7);
}
.footer-inner {
  max-width: 1032px;
  margin: 0 auto;
  padding: var(--space-3);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  color: var(--c-grey-600);
}
.footer-meta { display: flex; gap: var(--space-3); align-items: center; }
.footer-meta .dot {
  width: 5px; height: 5px;
  background: var(--c-black);
  border-radius: var(--radius-pill);
  display: inline-block;
  margin-right: 6px;
}

/* Utility */
.spacer-sm { height: var(--space-2); }
.spacer-md { height: var(--space-3); }
.spacer-lg { height: var(--space-4); }

/* Responsive — collapse grids on narrow */
@media (max-width: 860px) {
  .stat-row, .swatch-grid, .surface-grid, .hierarchy-cards { grid-template-columns: 1fr 1fr; }
  .radius-scale { grid-template-columns: repeat(3, 1fr); }
  .input-grid, .control-grid, .form-split, .hero-body, .annotated-demo, .radius-demo { grid-template-columns: 1fr; }
  .hero-h { font-size: 32px; line-height: 36px; }
  .nav-search { display: none; }
  .nav-tabs { gap: var(--space-3); overflow-x: auto; }
}
@media (max-width: 540px) {
  .stat-row, .swatch-grid, .surface-grid, .hierarchy-cards { grid-template-columns: 1fr; }
  .radius-scale { grid-template-columns: repeat(2, 1fr); }
}