/* ============================================
   Cognitive Tools Platform — Design System
   Designed for low cognitive load, calm interaction,
   and maximum readability.
   ============================================ */

/* --- CSS Custom Properties (Light Mode) --- */
:root {
  /* Warm, muted palette */
  --color-bg: #FAF8F5;
  --color-bg-alt: #F0EDE8;
  --color-surface: #FFFFFF;
  --color-surface-hover: #F5F3EF;
  --color-text: #3A3632;
  --color-text-muted: #6B6560;
  --color-text-light: #8A847E;
  --color-heading: #2D2A26;

  /* Accent colors — calm, not alarming */
  --color-primary: #5B8A72;
  --color-primary-light: #7BA896;
  --color-primary-bg: #EDF5F0;
  --color-secondary: #7B71A6;
  --color-secondary-light: #9B93BE;
  --color-secondary-bg: #F0EDF5;
  --color-warm: #C4956A;
  --color-warm-light: #D4AD8A;
  --color-warm-bg: #FBF3EC;

  /* Profile colors */
  --color-adhd: #6B8EC4;
  --color-adhd-bg: #EDF1F8;
  --color-autism: #7BA87B;
  --color-autism-bg: #EDF5ED;
  --color-dyslexia: #C49B6B;
  --color-dyslexia-bg: #FBF3EC;

  /* Feedback colors — gentle, not harsh */
  --color-info: #6B8EC4;
  --color-info-bg: #EDF1F8;
  --color-caution: #C4956A;
  --color-caution-bg: #FBF3EC;

  /* Borders and shadows */
  --color-border: #E5E0DA;
  --color-border-light: #EDE9E3;
  --shadow-sm: 0 1px 3px rgba(58, 54, 50, 0.06);
  --shadow-md: 0 2px 8px rgba(58, 54, 50, 0.08);
  --shadow-lg: 0 4px 16px rgba(58, 54, 50, 0.1);

  /* Spacing scale */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Typography */
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', Menlo, monospace;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.375rem;
  --font-size-2xl: 1.75rem;
  --font-size-3xl: 2.25rem;
  --line-height: 1.7;
  --line-height-tight: 1.3;

  /* Layout */
  --sidebar-width: 280px;
  --content-max-width: 860px;
  --radius: 8px;
  --radius-lg: 12px;

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

/* --- Dark Mode --- */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #1E1C1A;
    --color-bg-alt: #272422;
    --color-surface: #2D2A27;
    --color-surface-hover: #363330;
    --color-text: #E0DCD7;
    --color-text-muted: #A09A94;
    --color-text-light: #7A746E;
    --color-heading: #F0ECE7;

    --color-primary: #7BA896;
    --color-primary-light: #5B8A72;
    --color-primary-bg: #1E2D26;
    --color-secondary: #9B93BE;
    --color-secondary-light: #7B71A6;
    --color-secondary-bg: #252030;
    --color-warm: #D4AD8A;
    --color-warm-light: #C4956A;
    --color-warm-bg: #2D2218;

    --color-adhd: #8AAAD6;
    --color-adhd-bg: #1E2530;
    --color-autism: #8FBE8F;
    --color-autism-bg: #1E2D1E;
    --color-dyslexia: #D4AD8A;
    --color-dyslexia-bg: #2D2218;

    --color-info: #8AAAD6;
    --color-info-bg: #1E2530;
    --color-caution: #D4AD8A;
    --color-caution-bg: #2D2218;

    --color-border: #3D3935;
    --color-border-light: #33302C;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.3);
  }
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 100%;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

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

body {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: var(--line-height);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Focus Indicators (Accessibility) --- */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* --- Skip Link --- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  background: var(--color-primary);
  color: white;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius);
  z-index: 1000;
  font-weight: 500;
  text-decoration: none;
}

.skip-link:focus {
  top: var(--space-md);
}

/* --- Layout --- */
.layout {
  display: flex;
  min-height: 100vh;
}

/* --- Sidebar Navigation --- */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  padding: var(--space-xl) 0;
  z-index: 100;
  transition: transform var(--transition-normal);
}

.sidebar-header {
  padding: 0 var(--space-lg);
  margin-bottom: var(--space-xl);
}

.sidebar-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-heading);
  line-height: var(--line-height-tight);
  margin-bottom: var(--space-xs);
}

.sidebar-subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: var(--line-height);
}

.sidebar-nav {
  list-style: none;
}

.sidebar-nav li {
  margin: 0;
}

.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
}

.sidebar-nav a:hover {
  color: var(--color-text);
  background: var(--color-surface-hover);
}

.sidebar-nav a.active {
  color: var(--color-primary);
  background: var(--color-primary-bg);
  border-left-color: var(--color-primary);
  font-weight: 500;
}

.sidebar-nav .nav-icon {
  width: 18px;
  text-align: center;
  flex-shrink: 0;
  font-size: var(--font-size-base);
}

.sidebar-nav .nav-section-label {
  padding: var(--space-lg) var(--space-lg) var(--space-xs);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-light);
}

/* Mobile sidebar toggle */
.sidebar-toggle {
  display: none;
  position: fixed;
  top: var(--space-md);
  left: var(--space-md);
  z-index: 200;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-sm) var(--space-md);
  cursor: pointer;
  color: var(--color-text);
  font-size: var(--font-size-base);
  box-shadow: var(--shadow-sm);
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.3);
  z-index: 90;
}

@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-toggle {
    display: block;
  }

  .sidebar-overlay.visible {
    display: block;
  }

  .main-content {
    margin-left: 0 !important;
  }
}

/* --- Main Content --- */
.main-content {
  margin-left: var(--sidebar-width);
  flex: 1;
  padding: var(--space-2xl) var(--space-xl);
  max-width: calc(var(--content-max-width) + var(--space-xl) * 2);
}

@media (max-width: 768px) {
  .main-content {
    padding: var(--space-3xl) var(--space-md) var(--space-xl);
  }
}

/* --- Section containers --- */
.section {
  display: none;
  animation: fadeIn var(--transition-normal);
}

.section.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  .section.active {
    animation: none;
  }
}

/* --- Typography --- */
h1 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-heading);
  line-height: var(--line-height-tight);
  margin-bottom: var(--space-md);
  letter-spacing: -0.01em;
}

h2 {
  font-size: var(--font-size-2xl);
  font-weight: 600;
  color: var(--color-heading);
  line-height: var(--line-height-tight);
  margin-top: var(--space-3xl);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-border-light);
}

h2:first-child {
  margin-top: 0;
}

h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-heading);
  line-height: var(--line-height-tight);
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-sm);
}

h4 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-heading);
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
}

p {
  margin-bottom: var(--space-md);
  max-width: 65ch;
}

.lead {
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  line-height: var(--line-height);
  margin-bottom: var(--space-xl);
  max-width: 60ch;
}

/* --- Lists --- */
ul, ol {
  padding-left: var(--space-lg);
  margin-bottom: var(--space-md);
}

li {
  margin-bottom: var(--space-sm);
  max-width: 65ch;
}

li::marker {
  color: var(--color-primary);
}

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

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

.card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-md);
  margin-bottom: var(--space-sm);
  flex-wrap: wrap;
}

.card-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-heading);
  margin: 0;
}

.card-subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.card-body p {
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-sm);
}

.card-body p:last-child {
  margin-bottom: 0;
}

/* --- Tags / Badges --- */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 500;
  padding: 2px 8px;
  border-radius: 100px;
  white-space: nowrap;
}

.tag-free {
  background: var(--color-primary-bg);
  color: var(--color-primary);
}

.tag-paid {
  background: var(--color-warm-bg);
  color: var(--color-warm);
}

.tag-freemium {
  background: var(--color-secondary-bg);
  color: var(--color-secondary);
}

.tag-browser {
  background: var(--color-info-bg);
  color: var(--color-info);
}

.tag-local {
  background: var(--color-bg-alt);
  color: var(--color-text-muted);
}

.tag-open-source {
  background: var(--color-primary-bg);
  color: var(--color-primary);
}

.tag-low-distraction {
  background: var(--color-autism-bg);
  color: var(--color-autism);
}

.tag-adhd {
  background: var(--color-adhd-bg);
  color: var(--color-adhd);
}

.tag-autism {
  background: var(--color-autism-bg);
  color: var(--color-autism);
}

.tag-dyslexia {
  background: var(--color-dyslexia-bg);
  color: var(--color-dyslexia);
}

/* --- Info Boxes --- */
.info-box {
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.info-box p:last-child {
  margin-bottom: 0;
}

.info-box-gentle {
  background: var(--color-primary-bg);
  border-left: 4px solid var(--color-primary);
}

.info-box-caution {
  background: var(--color-caution-bg);
  border-left: 4px solid var(--color-caution);
}

.info-box-info {
  background: var(--color-info-bg);
  border-left: 4px solid var(--color-info);
}

.info-box-important {
  background: var(--color-secondary-bg);
  border-left: 4px solid var(--color-secondary);
}

.info-box-title {
  font-weight: 600;
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-sm);
  color: var(--color-heading);
}

/* --- Tool Grid --- */
.tool-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

@media (min-width: 640px) {
  .tool-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* --- Feature blocks --- */
.feature-block {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin-bottom: var(--space-lg);
}

.feature-block h3 {
  margin-top: 0;
}

.feature-icon {
  font-size: 1.5rem;
  margin-bottom: var(--space-sm);
}

/* --- Profile sections --- */
.profile-tabs {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
}

.profile-tab {
  padding: var(--space-sm) var(--space-lg);
  border: 2px solid var(--color-border);
  border-radius: 100px;
  background: var(--color-surface);
  cursor: pointer;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  transition: all var(--transition-fast);
}

.profile-tab:hover {
  border-color: var(--color-text-light);
  color: var(--color-text);
}

.profile-tab.active {
  font-weight: 600;
}

.profile-tab[data-profile="adhd"].active {
  border-color: var(--color-adhd);
  background: var(--color-adhd-bg);
  color: var(--color-adhd);
}

.profile-tab[data-profile="autism"].active {
  border-color: var(--color-autism);
  background: var(--color-autism-bg);
  color: var(--color-autism);
}

.profile-tab[data-profile="dyslexia"].active {
  border-color: var(--color-dyslexia);
  background: var(--color-dyslexia-bg);
  color: var(--color-dyslexia);
}

.profile-content {
  display: none;
}

.profile-content.active {
  display: block;
  animation: fadeIn var(--transition-normal);
}

/* --- Friction point mapping --- */
.friction-point {
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-md);
}

.friction-point h4 {
  margin-top: 0;
  font-size: var(--font-size-base);
  font-weight: 600;
}

.friction-point .friction-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
  font-style: italic;
}

/* --- Criteria checklist --- */
.criteria-list {
  list-style: none;
  padding: 0;
}

.criteria-list li {
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-border-light);
  display: flex;
  gap: var(--space-sm);
  align-items: flex-start;
}

.criteria-list li:last-child {
  border-bottom: none;
}

.criteria-icon {
  flex-shrink: 0;
  width: 20px;
  text-align: center;
  font-size: var(--font-size-sm);
}

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

.criteria-reject .criteria-icon {
  color: var(--color-caution);
}

/* --- Welcome hero --- */
.hero {
  margin-bottom: var(--space-3xl);
}

.hero h1 {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--space-md);
}

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

.principle-box {
  background: var(--color-primary-bg);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin: var(--space-xl) 0;
  border: 1px solid var(--color-primary);
}

.principle-box p {
  font-size: var(--font-size-lg);
  font-weight: 500;
  color: var(--color-heading);
  margin: 0;
  text-align: center;
  font-style: italic;
}

/* --- Quick links grid --- */
.quick-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-md);
  margin: var(--space-xl) 0;
}

.quick-link {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  text-decoration: none;
  color: var(--color-text);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.quick-link:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

@media (prefers-reduced-motion: reduce) {
  .quick-link:hover {
    transform: none;
  }
}

.quick-link-icon {
  font-size: 1.5rem;
  margin-bottom: var(--space-sm);
}

.quick-link-title {
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: var(--space-xs);
}

.quick-link-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* --- Ethics section --- */
.ethics-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

@media (min-width: 640px) {
  .ethics-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

.ethics-card h4 {
  margin-top: 0;
}

/* --- Energy level indicator --- */
.energy-levels {
  display: flex;
  gap: var(--space-sm);
  margin: var(--space-md) 0;
  flex-wrap: wrap;
}

.energy-level {
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius);
  font-size: var(--font-size-sm);
  font-weight: 500;
}

.energy-low {
  background: #EDF5F0;
  color: #5B8A72;
}

.energy-medium {
  background: #FBF3EC;
  color: #C4956A;
}

.energy-high {
  background: #F0EDF5;
  color: #7B71A6;
}

@media (prefers-color-scheme: dark) {
  .energy-low {
    background: #1E2D26;
    color: #7BA896;
  }
  .energy-medium {
    background: #2D2218;
    color: #D4AD8A;
  }
  .energy-high {
    background: #252030;
    color: #9B93BE;
  }
}

/* --- Interactive tool demo --- */
.tool-demo {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin: var(--space-lg) 0;
}

.tool-demo h3 {
  margin-top: 0;
}

.tool-demo-input {
  width: 100%;
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: var(--line-height);
  color: var(--color-text);
  background: var(--color-bg);
  resize: vertical;
  min-height: 60px;
  transition: border-color var(--transition-fast);
}

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

.tool-demo-input::placeholder {
  color: var(--color-text-light);
}

.tool-demo-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  font-weight: 500;
  cursor: pointer;
  margin-top: var(--space-sm);
  transition: background var(--transition-fast);
}

.tool-demo-btn:hover {
  background: var(--color-primary-light);
}

.tool-demo-output {
  margin-top: var(--space-md);
  padding: var(--space-md);
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  font-size: var(--font-size-sm);
  min-height: 40px;
}

.tool-demo-output ul {
  margin: 0;
}

.tool-demo-controls {
  display: flex;
  gap: var(--space-sm);
  align-items: center;
  flex-wrap: wrap;
  margin-top: var(--space-sm);
}

.detail-slider {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.detail-slider input[type="range"] {
  width: 120px;
  accent-color: var(--color-primary);
}

/* --- Multi-column layout for fields --- */
.field-columns {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  margin-top: var(--space-lg);
}

@media (min-width: 768px) {
  .field-columns {
    grid-template-columns: 1fr 1fr;
  }
}

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

.field-column h4 {
  margin-top: 0;
}

/* --- Cross-reference badge --- */
.cross-ref {
  font-size: 0.7rem;
  padding: 1px 6px;
  border-radius: 100px;
  background: var(--color-bg-alt);
  color: var(--color-text-muted);
  vertical-align: middle;
  margin-left: var(--space-xs);
  font-weight: 500;
}

/* --- Footer --- */
.footer {
  margin-top: var(--space-3xl);
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--color-border);
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
}

.footer p {
  max-width: none;
}

/* --- Utility classes --- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.mt-md { margin-top: var(--space-md); }
.mb-md { margin-bottom: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mb-lg { margin-bottom: var(--space-lg); }

/* --- Print styles --- */
@media print {
  .sidebar,
  .sidebar-toggle {
    display: none !important;
  }

  .main-content {
    margin-left: 0 !important;
  }

  .section {
    display: block !important;
    page-break-after: always;
  }

  .card,
  .info-box,
  .tool-demo {
    break-inside: avoid;
  }
}