/* ============================================
   GUIDE IA — Design Tokens & Styles
   ============================================ */

/* --- Fonts --- */
/* General Sans (body) + Cabinet Grotesk (display) from Fontshare */

/* --- Type Scale --- */
:root {
  --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);
  --text-3xl: clamp(2.5rem, 1rem + 4vw, 5rem);

  /* Spacing */
  --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;
  --space-32: 8rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

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

  /* Font families */
  --font-display: 'Cabinet Grotesk', 'Inter', sans-serif;
  --font-body: 'General Sans', 'Inter', sans-serif;
}

/* --- Color: Tech-Educational Palette (Indigo/Violet) --- */
:root,
[data-theme='light'] {
  --color-bg: #f5f5fa;
  --color-surface: #ffffff;
  --color-surface-2: #fafafc;
  --color-surface-offset: #eeeef5;
  --color-divider: #dddde8;
  --color-border: #cdcdd9;

  --color-text: #1a1a2e;
  --color-text-muted: #6b6b8d;
  --color-text-faint: #a0a0b8;
  --color-text-inverse: #f5f5fa;

  --color-primary: #4f46e5;
  --color-primary-hover: #4338ca;
  --color-primary-active: #3730a3;
  --color-primary-highlight: #e0e7ff;

  --color-accent: #7c3aed;
  --color-accent-hover: #6d28d9;

  --color-success: #059669;
  --color-warning: #d97706;

  --shadow-sm: 0 1px 2px rgba(79, 70, 229, 0.06);
  --shadow-md: 0 4px 12px rgba(79, 70, 229, 0.08);
  --shadow-lg: 0 12px 32px rgba(79, 70, 229, 0.12);
}

[data-theme='dark'] {
  --color-bg: #0f0f1a;
  --color-surface: #1a1a2e;
  --color-surface-2: #1e1e34;
  --color-surface-offset: #16162a;
  --color-divider: #2a2a44;
  --color-border: #3a3a55;

  --color-text: #e0e0ef;
  --color-text-muted: #8888a8;
  --color-text-faint: #5a5a78;
  --color-text-inverse: #0f0f1a;

  --color-primary: #818cf8;
  --color-primary-hover: #6366f1;
  --color-primary-active: #4f46e5;
  --color-primary-highlight: #2a2a55;

  --color-accent: #a78bfa;
  --color-accent-hover: #8b5cf6;

  --color-success: #34d399;
  --color-warning: #fbbf24;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.5);
}

/* --- Layout --- */
.container {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

.container--narrow {
  max-width: var(--content-default);
}

/* --- Header --- */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-divider);
  padding: var(--space-4) 0;
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

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

.header__logo-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.header__nav a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
}

.header__nav a:hover {
  color: var(--color-primary);
}

.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-offset);
  color: var(--color-text);
}

/* Mobile nav */
.mobile-menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  color: var(--color-text);
}

@media (max-width: 768px) {
  .mobile-menu-btn { display: flex; }
  .header__nav { display: none; }
  .header__nav.is-open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-divider);
    padding: var(--space-6);
    gap: var(--space-4);
    box-shadow: var(--shadow-lg);
  }
}

/* --- Hero --- */
.hero {
  padding: clamp(var(--space-16), 10vw, var(--space-32)) 0 clamp(var(--space-12), 8vw, var(--space-24));
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -30%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, color-mix(in srgb, var(--color-primary) 12%, transparent) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-4);
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-6);
}

.hero h1 {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: var(--space-6);
  position: relative;
}

.hero h1 span {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto var(--space-8);
  line-height: 1.6;
}

.hero__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-full);
  text-decoration: none;
  box-shadow: 0 4px 16px color-mix(in srgb, var(--color-primary) 30%, transparent);
}

.hero__cta:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
}

/* --- Section --- */
.section {
  padding: clamp(var(--space-12), 8vw, var(--space-24)) 0;
}

.section--alt {
  background: var(--color-surface);
}

.section__header {
  text-align: center;
  margin-bottom: clamp(var(--space-8), 5vw, var(--space-16));
}

.section__label {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}

.section__title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.section__desc {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* --- Cards Grid --- */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  transition: transform var(--transition-interactive), box-shadow var(--transition-interactive);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card__icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-lg);
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  margin-bottom: var(--space-5);
  font-size: 1.5rem;
}

.card__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.card__text {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* --- Numbered Steps --- */
.steps {
  display: grid;
  gap: var(--space-8);
  counter-reset: step-counter;
}

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-6);
  align-items: start;
  counter-increment: step-counter;
}

.step__number {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: white;
  border-radius: var(--radius-full);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--text-lg);
  flex-shrink: 0;
}

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

.step__content p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* --- Tools Grid --- */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-6);
}

.tool-card {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  transition: transform var(--transition-interactive), box-shadow var(--transition-interactive), border-color var(--transition-interactive);
}

.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.tool-card__badge {
  display: inline-flex;
  align-self: flex-start;
  padding: var(--space-1) var(--space-3);
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
}

.tool-card__name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
}

.tool-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* --- Use Cases / Accordion --- */
.accordion {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.accordion__item {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.accordion__trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-5) var(--space-6);
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  text-align: left;
}

.accordion__trigger:hover {
  background: var(--color-surface-offset);
}

.accordion__icon {
  width: 24px;
  height: 24px;
  transition: transform 300ms cubic-bezier(0.16, 1, 0.3, 1);
  flex-shrink: 0;
  color: var(--color-text-muted);
}

.accordion__item.is-open .accordion__icon {
  transform: rotate(180deg);
}

.accordion__body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 400ms cubic-bezier(0.16, 1, 0.3, 1);
}

.accordion__body-inner {
  padding: 0 var(--space-6) var(--space-6);
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
}

.accordion__body-inner ul {
  margin-top: var(--space-3);
  padding-left: var(--space-5);
}

.accordion__body-inner li {
  margin-bottom: var(--space-2);
}

/* --- Tips Section --- */
.tips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-6);
}

.tip {
  background: var(--color-surface);
  border-left: 4px solid var(--color-primary);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  padding: var(--space-6);
}

.tip__title {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.tip__text {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* --- Glossary --- */
.glossary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-4);
}

.glossary-item {
  padding: var(--space-5);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
}

.glossary-item dt {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}

.glossary-item dd {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* --- CTA Banner --- */
.cta-banner {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-2xl);
  padding: clamp(var(--space-10), 6vw, var(--space-16));
  text-align: center;
  color: white;
}

.cta-banner h2 {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 800;
  margin-bottom: var(--space-4);
}

.cta-banner p {
  font-size: var(--text-base);
  opacity: 0.9;
  max-width: 500px;
  margin: 0 auto var(--space-8);
}

.cta-banner__btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-8);
  background: white;
  color: var(--color-primary);
  font-weight: 700;
  font-size: var(--text-sm);
  border-radius: var(--radius-full);
  text-decoration: none;
}

.cta-banner__btn:hover {
  background: var(--color-primary-highlight);
  transform: translateY(-1px);
}

/* --- Footer --- */
.footer {
  padding: var(--space-12) 0 var(--space-8);
  border-top: 1px solid var(--color-divider);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  text-align: center;
}

.footer__text {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* --- Scroll Reveal --- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms cubic-bezier(0.16, 1, 0.3, 1), transform 600ms cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Table of Contents (sidebar on desktop) --- */
.content-with-toc {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}

@media (min-width: 1024px) {
  .content-with-toc {
    grid-template-columns: 220px 1fr;
    gap: var(--space-12);
  }
}

.toc {
  display: none;
}

@media (min-width: 1024px) {
  .toc {
    display: block;
    position: sticky;
    top: calc(80px + var(--space-8));
    align-self: start;
  }
}

.toc__title {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-faint);
  margin-bottom: var(--space-4);
}

.toc__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.toc__list a {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-1) var(--space-3);
  border-left: 2px solid transparent;
  display: block;
  transition: color var(--transition-interactive), border-color var(--transition-interactive);
}

.toc__list a:hover,
.toc__list a.is-active {
  color: var(--color-primary);
  border-left-color: var(--color-primary);
}

/* --- Prompt Examples --- */
.prompt-examples {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-4);
}

.prompt-example {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}

.prompt-example__category {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.prompt-example__text {
  font-size: var(--text-sm);
  color: var(--color-text);
  font-style: italic;
  line-height: 1.6;
  padding: var(--space-3);
  background: var(--color-surface-offset);
  border-radius: var(--radius-md);
}

/* --- Comparison Table --- */
.comparison-table {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-divider);
}

.comparison-table table {
  min-width: 600px;
}

.comparison-table th,
.comparison-table td {
  padding: var(--space-4) var(--space-5);
  text-align: left;
  font-size: var(--text-sm);
  border-bottom: 1px solid var(--color-divider);
}

.comparison-table th {
  background: var(--color-surface-offset);
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-text);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.comparison-table td {
  color: var(--color-text-muted);
}

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

/* Section alt for dark mode */
.section--alt {
  background: var(--color-surface-2, var(--color-surface));
}