/* ==========================================================================
   Web Apps — Shared Design System
   Warm editorial palette · Inter · 8px grid · OKLCH colors
   ========================================================================== */

/* ---------- 1. CSS Variables / Design Tokens ------------------------------ */
:root {
  color-scheme: light;

  /* --- Warm neutral base (inspired by Sidecar Viewer beige palette) --- */
  --bg: oklch(95.5% 0.025 55); /* warm beige page bg */
  --bg-surface: oklch(98% 0.015 55); /* warm off-white panels */
  --bg-elevated: oklch(99% 0.008 55); /* popovers, modals */
  --ink: oklch(20% 0.02 45); /* dark warm brown */
  --ink-2: oklch(45% 0.02 45); /* secondary text */
  --ink-3: oklch(60% 0.015 45); /* tertiary / muted */
  --line: oklch(88% 0.015 55); /* borders */
  --line-hover: oklch(80% 0.02 55); /* border hover */

  /* --- Per-app accent (apps override these two) --- */
  --accent: oklch(58% 0.18 40); /* default: terracotta */
  --accent-soft: oklch(58% 0.18 40 / 12%);

  /* --- Derived from accent via color-mix --- */
  --accent-hover: color-mix(in oklch, var(--accent) 82%, black);
  --accent-glow: color-mix(in oklch, var(--accent) 10%, transparent);

  /* --- Semantic --- */
  --success: oklch(72% 0.19 145);
  --error: oklch(63% 0.24 27);
  --warning: oklch(72% 0.17 85);

  /* --- Spacing (8px grid) --- */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 20px;
  --sp-6: 24px;
  --sp-8: 32px;
  --sp-10: 40px;
  --sp-12: 48px;
  --sp-16: 64px;

  /* --- Radii --- */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-pill: 999px;

  /* --- Shadows --- */
  --shadow-sm: 0 1px 3px oklch(0% 0 0 / 4%), 0 1px 2px oklch(0% 0 0 / 6%);
  --shadow-md: 0 4px 12px oklch(0% 0 0 / 6%), 0 1px 3px oklch(0% 0 0 / 4%);
  --shadow-lg: 0 12px 32px oklch(0% 0 0 / 8%), 0 4px 8px oklch(0% 0 0 / 4%);

  /* --- Typography --- */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Monaco", "Consolas", monospace;
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

/* Fallback for browsers without OKLCH */
@supports not (color: oklch(50% 0.1 0)) {
  :root {
    --bg: #f0e9df;
    --bg-surface: #f7f2eb;
    --bg-elevated: #faf7f2;
    --ink: #2d2520;
    --ink-2: #6b5e54;
    --ink-3: #9a8f85;
    --line: #ddd6cc;
    --line-hover: #c9bfb3;
    --accent: #c0623a;
    --accent-soft: rgba(192, 98, 58, 0.12);
    --accent-hover: #a0502e;
    --accent-glow: rgba(192, 98, 58, 0.1);
    --success: #22c55e;
    --error: #ef4444;
    --warning: #eab308;
  }
}

/* ---------- 2. Reset + Base ----------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-family: var(--font-sans);
  font-feature-settings:
    "liga" 1,
    "calt" 1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

@supports (font-variation-settings: normal) {
  html {
    font-family:
      "Inter var",
      -apple-system,
      BlinkMacSystemFont,
      "Segoe UI",
      Roboto,
      sans-serif;
  }
}

body {
  margin: 0;
  padding-top: 40px;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  position: relative;
  overflow-x: hidden;
}

/* --- Accent-tinted gradient blooms --- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 10%, var(--accent-glow), transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 90%, color-mix(in oklch, var(--accent) 6%, transparent), transparent 50%);
  pointer-events: none;
  z-index: 0;
}

/* ---------- 3. Compact Header Bar ----------------------------------------- */
.app-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  height: 40px;
  padding: 0 var(--sp-4);
  box-sizing: border-box;
  background: oklch(94% 0.025 55 / 92%);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
  font-size: 0.8125rem;
  font-weight: 500;
}

@supports not (color: oklch(50% 0.1 0)) {
  .app-header {
    background: rgba(233, 226, 216, 0.92);
  }
}

.app-header a {
  color: var(--ink-2);
  text-decoration: none;
  transition: color 0.15s var(--ease);
}
.app-header a:hover {
  color: var(--accent);
}

.app-header .back {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}

.app-header .back::before {
  content: "\2190"; /* ← arrow */
  font-size: 1rem;
}

.app-header .sep {
  color: var(--ink-3);
  user-select: none;
}

.app-header .title {
  color: var(--ink);
  font-weight: 600;
}

/* ---------- 4. Components ------------------------------------------------- */

/* Panel / Card */
.panel,
.card {
  background: var(--bg-surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition:
    box-shadow 0.2s var(--ease),
    border-color 0.2s var(--ease);
}

.panel {
  padding: var(--sp-6);
}
.card {
  padding: var(--sp-4) var(--sp-5);
}

.card:hover {
  border-color: var(--line-hover);
  box-shadow: var(--shadow-md);
}

/* Section (form panels, output panels) */
.section {
  background: var(--bg-surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: var(--sp-5);
  box-shadow: var(--shadow-sm);
}

/* Tabs */
.tabs {
  display: flex;
  gap: var(--sp-2);
  flex-wrap: wrap;
}

.tab {
  padding: var(--sp-2) var(--sp-4);
  border: 1px solid var(--line);
  background: var(--bg-surface);
  border-radius: var(--radius-pill);
  font-size: 0.8125rem;
  font-weight: 500;
  font-family: inherit;
  color: var(--ink-2);
  cursor: pointer;
  transition: all 0.15s var(--ease);
  outline: none;
}

.tab:hover {
  background: var(--bg-elevated);
  border-color: var(--line-hover);
  color: var(--ink);
}

.tab.active,
.tab[aria-selected="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.tab.active:hover,
.tab[aria-selected="true"]:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-4);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  color: var(--ink);
  cursor: pointer;
  transition: all 0.15s var(--ease);
  outline: none;
}

.btn:hover {
  background: var(--bg-elevated);
  border-color: var(--line-hover);
}

.btn:active {
  transform: scale(0.98);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
}

.btn-pill {
  border-radius: var(--radius-pill);
}

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

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

.btn-accent.copied {
  background: var(--success);
  border-color: var(--success);
}

/* Badge */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--sp-1) var(--sp-3);
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-pill);
  background: var(--accent-soft);
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

/* Form inputs */
input[type="text"],
input[type="email"],
input[type="number"],
input[type="url"],
select,
textarea {
  font-family: inherit;
  font-size: 0.9rem;
  padding: var(--sp-2) var(--sp-3);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  color: var(--ink);
  outline: none;
  transition:
    border-color 0.2s var(--ease),
    box-shadow 0.2s var(--ease);
}

input::placeholder,
textarea::placeholder {
  color: var(--ink-3);
}

input:hover,
select:hover,
textarea:hover {
  border-color: var(--line-hover);
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

textarea {
  resize: vertical;
  min-height: 100px;
}

/* Code block */
.code-block {
  background: oklch(15% 0.01 55);
  color: oklch(85% 0.01 55);
  padding: var(--sp-4);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.7;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

@supports not (color: oklch(50% 0.1 0)) {
  .code-block {
    background: #1e1e1e;
    color: #d4d4d4;
  }
}

/* ---------- 5. Utilities -------------------------------------------------- */

/* Text */
.text-muted {
  color: var(--ink-2);
}
.text-faint {
  color: var(--ink-3);
}
.text-accent {
  color: var(--accent);
}
.text-sm {
  font-size: 0.875rem;
}
.text-xs {
  font-size: 0.8125rem;
}
.text-center {
  text-align: center;
}

/* Spacing */
.mt-0 {
  margin-top: 0;
}
.mt-2 {
  margin-top: var(--sp-2);
}
.mt-4 {
  margin-top: var(--sp-4);
}
.mt-6 {
  margin-top: var(--sp-6);
}
.mt-8 {
  margin-top: var(--sp-8);
}
.mb-2 {
  margin-bottom: var(--sp-2);
}
.mb-4 {
  margin-bottom: var(--sp-4);
}
.mb-6 {
  margin-bottom: var(--sp-6);
}
.mb-8 {
  margin-bottom: var(--sp-8);
}
.gap-2 {
  gap: var(--sp-2);
}
.gap-3 {
  gap: var(--sp-3);
}
.gap-4 {
  gap: var(--sp-4);
}

/* Flex / Grid */
.flex {
  display: flex;
}
.flex-col {
  flex-direction: column;
}
.flex-wrap {
  flex-wrap: wrap;
}
.items-center {
  align-items: center;
}
.justify-between {
  justify-content: space-between;
}

/* ---------- 6. Responsive ------------------------------------------------- */
@media (max-width: 640px) {
  .app-header {
    padding: 0 var(--sp-3);
    font-size: 0.75rem;
  }
  .panel {
    padding: var(--sp-4);
  }
  .section {
    padding: var(--sp-4);
  }
}

/* ---------- 7. Accessibility ---------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- 8. View Transitions ------------------------------------------- */
@view-transition {
  navigation: auto;
}
::view-transition-old(root),
::view-transition-new(root) {
  animation-duration: 0.2s;
}