/* Fizzy-inspired CSS Architecture
 * Layers: reset, base, components, modules, utilities
 * Colors: OKLCH with CSS variables
 * Naming: BEM-like (.component, .component__element, .component--modifier)
 */

@layer reset, base, components, modules, utilities;

@layer reset {
  *, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
  }
}

@layer base {
  :root {
    /* Colors — OKLCH */
    --color-background: oklch(0.985 0 0);
    --color-foreground: oklch(0.145 0 0);
    --color-primary: oklch(0.55 0.15 250);
    --color-primary-foreground: oklch(0.985 0 0);
    --color-secondary: oklch(0.75 0.05 260);
    --color-muted: oklch(0.556 0 0);
    --color-border: oklch(0.85 0 0);
    --color-surface: oklch(1 0 0);
    --color-surface-raised: oklch(0.97 0 0);

    /* Status colors */
    --color-draft: oklch(0.65 0.05 260);
    --color-in-progress: oklch(0.75 0.15 85);
    --color-in-review: oklch(0.6 0.15 250);
    --color-completed: oklch(0.6 0.17 155);
    --color-planned: oklch(0.556 0 0);

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;

    /* Typography */
    --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    --font-mono: ui-monospace, "Cascadia Code", "Fira Code", monospace;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;

    /* Layout */
    --container-max-width: 1200px;
    --border-radius: 0.375rem;
    --border-radius-lg: 0.5rem;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
  }

  html[data-theme="dark"] {
    --color-background: oklch(0.145 0 0);
    --color-foreground: oklch(0.985 0 0);
    --color-border: oklch(0.3 0 0);
    --color-surface: oklch(0.18 0 0);
    --color-surface-raised: oklch(0.22 0 0);
    --color-muted: oklch(0.7 0 0);
  }

  body {
    font-family: var(--font-sans);
    font-size: var(--font-size-md);
    line-height: 1.5;
    color: var(--color-foreground);
    background-color: var(--color-background);
    -webkit-font-smoothing: antialiased;
  }

  a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
  }

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

@layer components {
  /* Flash messages */
  .flash {
    padding: var(--space-sm) var(--space-xl);
    font-size: var(--font-size-sm);
    text-align: center;
  }

  .flash--alert {
    background: oklch(0.94 0.06 25);
    color: oklch(0.45 0.15 25);
  }

  .flash--notice {
    background: oklch(0.92 0.06 155);
    color: oklch(0.45 0.17 155);
  }

  /* Navigation */
  .nav {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-md) var(--space-xl);
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
  }

  .nav__brand {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-foreground);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
  }

  .nav__links {
    display: flex;
    gap: var(--space-xs);
    list-style: none;
    padding: 0;
  }

  .nav__link {
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--border-radius);
    color: var(--color-muted);
    font-size: var(--font-size-sm);
    text-decoration: none;
    transition: background var(--transition-fast), color var(--transition-fast);
  }

  .nav__link:hover {
    background: var(--color-surface-raised);
    color: var(--color-foreground);
    text-decoration: none;
  }

  .nav__link--active {
    background: var(--color-surface-raised);
    color: var(--color-foreground);
    font-weight: 500;
  }

  /* Board */
  .board {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-lg);
    padding: var(--space-xl);
    max-width: var(--container-max-width);
    margin: 0 auto;
  }

  @media (max-width: 1024px) {
    .board { grid-template-columns: repeat(2, 1fr); }
  }

  @media (max-width: 640px) {
    .board { grid-template-columns: 1fr; }
  }

  .board__column {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    min-height: 200px;
  }

  .board__column-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--border-radius);
    font-size: var(--font-size-sm);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }

  .board__column-header--draft {
    background: oklch(0.92 0.02 260);
    color: var(--color-draft);
  }

  .board__column-header--planned {
    background: oklch(0.92 0 0);
    color: var(--color-planned);
  }

  .board__column-header--in-progress {
    background: oklch(0.94 0.06 85);
    color: oklch(0.55 0.15 85);
  }

  .board__column-header--in-review {
    background: oklch(0.92 0.06 250);
    color: oklch(0.45 0.15 250);
  }

  .board__column-header--completed {
    background: oklch(0.92 0.06 155);
    color: oklch(0.45 0.17 155);
  }

  .board__column-body {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    flex: 1;
  }

  /* Card */
  .card {
    --card-padding: var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    padding: var(--card-padding);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  }

  .card:hover {
    border-color: var(--color-primary);
    box-shadow: 0 1px 3px oklch(0 0 0 / 0.08);
  }

  .card__title {
    font-size: var(--font-size-md);
    font-weight: 600;
    color: var(--color-foreground);
    margin-bottom: var(--space-sm);
  }

  .card__title a {
    color: inherit;
    text-decoration: none;
  }

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

  .card__meta {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-wrap: wrap;
    margin-bottom: var(--space-sm);
  }

  .card__footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: var(--font-size-xs);
    color: var(--color-muted);
    margin-top: var(--space-sm);
  }

  /* Badge */
  .badge {
    --badge-background: var(--color-surface-raised);
    --badge-color: var(--color-muted);
    display: inline-flex;
    align-items: center;
    padding: 0.125rem 0.5rem;
    border-radius: 9999px;
    font-size: var(--font-size-xs);
    font-weight: 500;
    background: var(--badge-background);
    color: var(--badge-color);
    white-space: nowrap;
  }

  .badge--draft {
    --badge-background: oklch(0.92 0.02 260);
    --badge-color: var(--color-draft);
  }

  .badge--planned {
    --badge-background: oklch(0.92 0 0);
    --badge-color: var(--color-planned);
  }

  .badge--in-progress {
    --badge-background: oklch(0.94 0.06 85);
    --badge-color: oklch(0.55 0.15 85);
  }

  .badge--in-review {
    --badge-background: oklch(0.92 0.06 250);
    --badge-color: oklch(0.45 0.15 250);
  }

  .badge--completed {
    --badge-background: oklch(0.92 0.06 155);
    --badge-color: oklch(0.45 0.17 155);
  }

  .badge--effort {
    --badge-background: oklch(0.95 0 0);
    --badge-color: oklch(0.4 0 0);
  }

  .badge--count {
    --badge-background: transparent;
    --badge-color: inherit;
    font-weight: 400;
    padding: 0;
  }

  /* Progress bar */
  .progress {
    --progress-height: 4px;
    --progress-background: var(--color-border);
    --progress-fill: var(--color-primary);
    width: 100%;
    height: var(--progress-height);
    background: var(--progress-background);
    border-radius: var(--progress-height);
    overflow: hidden;
  }

  .progress__fill {
    height: 100%;
    background: var(--progress-fill);
    border-radius: var(--progress-height);
    transition: width var(--transition-normal);
  }

  /* Empty state */
  .empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-xl) var(--space-md);
    text-align: center;
    color: var(--color-muted);
    flex: 1;
  }

  .empty-state__title {
    font-size: var(--font-size-sm);
    font-weight: 500;
    margin-bottom: var(--space-xs);
  }

  .empty-state__description {
    font-size: var(--font-size-xs);
  }

  /* Back link */
  .back-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    color: var(--color-muted);
    font-size: var(--font-size-sm);
    text-decoration: none;
    transition: color var(--transition-fast);
  }

  .back-link:hover {
    color: var(--color-foreground);
    text-decoration: none;
  }

  /* Plan header */
  .plan-header {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--space-xl);
    padding-bottom: 0;
  }

  .plan-header__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin-bottom: var(--space-sm);
  }

  .plan-header__meta {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
    margin-bottom: var(--space-md);
  }

  .plan-header__progress {
    margin-bottom: var(--space-sm);
  }

  .plan-header__progress-text {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--color-muted);
    margin-top: var(--space-xs);
  }

  .plan-header__updated {
    font-size: var(--font-size-xs);
    color: var(--color-muted);
  }

  /* Plan summary */
  .plan-summary {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--space-xl);
    border-bottom: 1px solid var(--color-border);
  }

  .plan-summary__heading {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--space-md);
  }

  .plan-summary__subheading {
    font-size: var(--font-size-md);
    font-weight: 600;
    margin-top: var(--space-lg);
    margin-bottom: var(--space-sm);
  }

  .plan-summary__text {
    color: var(--color-foreground);
    line-height: 1.6;
    margin-bottom: var(--space-md);
  }

  .plan-summary__list {
    padding-left: var(--space-lg);
    line-height: 1.8;
  }

  .plan-summary__list--check li::marker { content: "✓ "; color: var(--color-completed); }
  .plan-summary__list--cross li::marker { content: "✗ "; color: oklch(0.6 0.2 25); }

  .plan-summary__list--checklist {
    list-style: none;
    padding-left: 0;
  }

  .plan-summary__checkbox {
    margin-right: var(--space-xs);
  }

  .plan-summary__done {
    color: var(--color-muted);
    text-decoration: line-through;
  }

  /* Plan content */
  .plan-content {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--space-xl);
  }

  .plan-content__heading {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--space-lg);
  }
}

@layer modules {
  /* Prose — rendered markdown container */
  .prose {
    line-height: 1.7;
    color: var(--color-foreground);
  }

  .prose h1, .prose h2, .prose h3, .prose h4 {
    font-weight: 600;
    margin-top: 1.5em;
    margin-bottom: 0.5em;
    line-height: 1.3;
  }

  .prose h1 { font-size: var(--font-size-2xl); }
  .prose h2 { font-size: var(--font-size-xl); border-bottom: 1px solid var(--color-border); padding-bottom: 0.3em; }
  .prose h3 { font-size: var(--font-size-lg); }
  .prose h4 { font-size: var(--font-size-md); }

  .prose p { margin-bottom: 1em; }

  .prose ul, .prose ol {
    padding-left: 1.5em;
    margin-bottom: 1em;
  }

  .prose li { margin-bottom: 0.25em; }

  .prose a {
    color: var(--color-primary);
    text-decoration: underline;
  }

  .prose blockquote {
    border-left: 3px solid var(--color-border);
    padding-left: var(--space-md);
    color: var(--color-muted);
    margin: 1em 0;
  }

  .prose pre {
    background: oklch(0.15 0 0);
    color: oklch(0.9 0 0);
    padding: var(--space-md);
    border-radius: var(--border-radius);
    overflow-x: auto;
    margin: 1em 0;
    font-family: var(--font-mono);
    font-size: var(--font-size-sm);
    line-height: 1.5;
  }

  .prose code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    background: var(--color-surface-raised);
    padding: 0.15em 0.35em;
    border-radius: 3px;
  }

  .prose pre code {
    background: none;
    padding: 0;
    font-size: inherit;
  }

  .prose table {
    width: 100%;
    border-collapse: collapse;
    margin: 1em 0;
    font-size: var(--font-size-sm);
  }

  .prose th, .prose td {
    padding: var(--space-sm) var(--space-md);
    border: 1px solid var(--color-border);
    text-align: left;
  }

  .prose th {
    background: var(--color-surface-raised);
    font-weight: 600;
  }

  .prose hr {
    border: none;
    border-top: 1px solid var(--color-border);
    margin: 2em 0;
  }

  .prose img { max-width: 100%; height: auto; border-radius: var(--border-radius); }

  /* GFM task list checkboxes */
  .prose ul:has(input[type="checkbox"]) {
    list-style: none;
    padding-left: 0;
  }

  .prose input[type="checkbox"] {
    margin-right: var(--space-xs);
    pointer-events: none;
  }

  /* Strong/emphasis */
  .prose strong { font-weight: 600; }
  .prose em { font-style: italic; }
}

@layer utilities {
  .font-mono { font-family: var(--font-mono); }
  .visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
  }
}