/* ========================================
   OpenClaw Academy — Main Stylesheet
   ======================================== */

/* --- Design Tokens --- */
:root {
  --color-bg: #0f172a;
  --color-surface: #1e293b;
  --color-surface-alt: #162032;
  --color-text: #e2e8f0;
  --color-text-muted: #94a3b8;
  --color-primary: #f97316;
  --color-primary-hover: #ea580c;
  --color-primary-subtle: rgba(249, 115, 22, 0.1);
  --color-accent: #06b6d4;
  --color-accent-hover: #0891b2;
  --color-border: #334155;
  --color-code-bg: #0d1117;
  --color-code-border: #21262d;
  --color-success: #22c55e;
  --color-warning: #eab308;
  --color-danger: #ef4444;

  --font-heading: system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-body: system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', ui-monospace, 'Cascadia Code', monospace;

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

  --radius: 0.5rem;
  --radius-sm: 0.25rem;
  --radius-lg: 0.75rem;
  --max-width: 48rem;
  --header-height: 3.5rem;

  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + var(--space-lg));
}

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

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; margin-top: var(--space-2xl); margin-bottom: var(--space-md); }
h3 { font-size: 1.25rem; margin-top: var(--space-xl); margin-bottom: var(--space-sm); }
h4 { font-size: 1.1rem; margin-top: var(--space-lg); margin-bottom: var(--space-sm); }

p {
  margin-bottom: var(--space-md);
}

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

a:hover {
  color: var(--color-accent-hover);
  text-decoration: underline;
}

strong {
  color: var(--color-text);
  font-weight: 600;
}

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

hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: var(--space-xl) 0;
}

/* --- Layout --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-md);
}

@media (min-width: 768px) {
  .container {
    padding: var(--space-xl);
  }
}

/* --- Site Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
}

.site-header .header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.site-logo {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.site-logo:hover {
  color: var(--color-primary);
  text-decoration: none;
}

/* Desktop nav */
.site-nav {
  display: none;
  align-items: center;
  gap: var(--space-lg);
}

.site-nav a {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.site-nav a:hover {
  color: var(--color-primary);
  text-decoration: none;
}

/* Lessons dropdown */
.nav-dropdown {
  position: relative;
}

.nav-dropdown-toggle {
  background: none;
  border: none;
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  padding: var(--space-xs) 0;
  transition: color var(--transition-fast);
}

.nav-dropdown-toggle:hover {
  color: var(--color-primary);
}

.nav-dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  right: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-sm) 0;
  min-width: 20rem;
  max-height: 70vh;
  overflow-y: auto;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  z-index: 200;
}

.nav-dropdown-menu.open {
  display: block;
}

.nav-dropdown-menu a {
  display: block;
  padding: var(--space-xs) var(--space-md);
  font-size: 0.85rem;
  color: var(--color-text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-dropdown-menu a:hover {
  background: var(--color-primary-subtle);
  color: var(--color-primary);
  text-decoration: none;
}

.nav-dropdown-phase {
  padding: var(--space-xs) var(--space-md);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-xs);
}

.nav-dropdown-phase:first-child {
  border-top: none;
  margin-top: 0;
}

/* Hamburger */
.hamburger {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text-muted);
  border-radius: 1px;
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.hamburger[aria-expanded="true"] span:nth-child(1) {
  transform: rotate(45deg) translate(4px, 4px);
}

.hamburger[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.hamburger[aria-expanded="true"] span:nth-child(3) {
  transform: rotate(-45deg) translate(4px, -4px);
}

/* Mobile menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-surface);
  overflow-y: auto;
  z-index: 99;
  padding: var(--space-md);
}

.mobile-menu.open {
  display: block;
}

.mobile-menu a {
  display: block;
  padding: var(--space-sm) var(--space-md);
  color: var(--color-text-muted);
  font-size: 0.95rem;
  border-radius: var(--radius-sm);
}

.mobile-menu a:hover {
  background: var(--color-primary-subtle);
  color: var(--color-primary);
  text-decoration: none;
}

.mobile-menu-phase {
  padding: var(--space-sm) var(--space-md);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  margin-top: var(--space-md);
}

.mobile-menu-phase:first-child {
  margin-top: 0;
}

@media (min-width: 768px) {
  .site-nav {
    display: flex;
  }
  .hamburger {
    display: none;
  }
}

/* --- Site Footer --- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-xl) var(--space-md);
  margin-top: var(--space-3xl);
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

.site-footer a {
  color: var(--color-text-muted);
}

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

.footer-links {
  display: flex;
  justify-content: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-md);
  flex-wrap: wrap;
}

/* --- Homepage --- */
.hero {
  text-align: center;
  padding: var(--space-3xl) 0 var(--space-2xl);
}

.hero h1 {
  font-size: 2.25rem;
  margin-bottom: var(--space-md);
}

.hero-tagline {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  max-width: 36rem;
  margin: 0 auto var(--space-xl);
  line-height: 1.6;
}

.hero-cta {
  display: inline-block;
  background: var(--color-primary);
  color: var(--color-bg);
  font-weight: 600;
  padding: var(--space-sm) var(--space-xl);
  border-radius: var(--radius);
  font-size: 1.05rem;
  transition: background var(--transition-fast);
}

.hero-cta:hover {
  background: var(--color-primary-hover);
  color: var(--color-bg);
  text-decoration: none;
}

/* Summary cards */
.summary-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  margin-bottom: var(--space-2xl);
}

@media (min-width: 768px) {
  .summary-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

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

.summary-card h3 {
  color: var(--color-primary);
  font-size: 1rem;
  margin-top: 0;
  margin-bottom: var(--space-sm);
}

.summary-card p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-bottom: 0;
}

/* Phase sections */
.phase-section {
  margin-bottom: var(--space-2xl);
}

.phase-title {
  font-size: 1.1rem;
  color: var(--color-primary);
  margin-bottom: var(--space-md);
  margin-top: 0;
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border);
}

/* Lesson list */
.lesson-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.lesson-list-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color var(--transition-fast);
}

.lesson-list-item:hover {
  border-color: var(--color-primary);
}

.lesson-list-item a {
  color: var(--color-text);
  flex: 1;
  font-weight: 500;
}

.lesson-list-item a:hover {
  text-decoration: none;
}

.lesson-list-number {
  color: var(--color-primary);
  font-weight: 700;
  font-size: 0.85rem;
  min-width: 1.5rem;
}

.lesson-list-cost {
  color: var(--color-text-muted);
  font-size: 0.8rem;
  white-space: nowrap;
}

/* --- Lesson Page --- */
.lesson {
  padding-top: var(--space-xl);
  padding-bottom: var(--space-2xl);
}

.lesson-header {
  margin-bottom: var(--space-2xl);
}

.lesson-number {
  display: inline-block;
  font-size: 0.85rem;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: var(--space-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.lesson-header h1 {
  margin-bottom: var(--space-sm);
}

.lesson-cost {
  display: inline-block;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.lesson-time {
  display: inline-block;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-left: var(--space-md);
}

/* Lesson content */
.lesson-content h2 {
  border-bottom: 1px solid var(--color-border);
  padding-bottom: var(--space-sm);
}

.lesson-content h2:first-child {
  margin-top: var(--space-lg);
}

.lesson-content ul,
.lesson-content ol {
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
}

.lesson-content li {
  margin-bottom: var(--space-xs);
}

.lesson-content li + li {
  margin-top: var(--space-xs);
}

/* Inline code */
.lesson-content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-code-bg);
  border: 1px solid var(--color-code-border);
  border-radius: var(--radius-sm);
  padding: 0.15em 0.4em;
}

/* Code blocks */
.lesson-content pre {
  position: relative;
  background: var(--color-code-bg);
  border: 1px solid var(--color-code-border);
  border-radius: var(--radius);
  padding: var(--space-md);
  margin-bottom: var(--space-md);
  overflow-x: auto;
  line-height: 1.5;
}

.lesson-content pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 0.875rem;
  color: var(--color-text);
}

/* Copy button */
.copy-btn {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  background: var(--color-surface);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: var(--space-xs) var(--space-sm);
  font-family: var(--font-body);
  font-size: 0.75rem;
  cursor: pointer;
  transition: color var(--transition-fast), border-color var(--transition-fast);
  z-index: 1;
}

.copy-btn:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

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

/* Checklists */
.checklist {
  list-style: none;
  padding-left: 0;
}

.checklist li {
  position: relative;
  padding-left: var(--space-lg);
  margin-bottom: var(--space-sm);
}

.checklist li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.45em;
  width: 1em;
  height: 1em;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
}

/* Callouts */
.callout-tip,
.callout-warning,
.callout-important,
.callout-note {
  border-left: 4px solid;
  border-radius: var(--radius-sm);
  padding: var(--space-md);
  margin-bottom: var(--space-md);
  font-size: 0.95rem;
}

.callout-tip {
  border-color: var(--color-success);
  background: rgba(34, 197, 94, 0.08);
}

.callout-warning {
  border-color: var(--color-warning);
  background: rgba(234, 179, 8, 0.08);
}

.callout-important {
  border-color: var(--color-danger);
  background: rgba(239, 68, 68, 0.08);
}

.callout-note {
  border-color: var(--color-accent);
  background: rgba(6, 182, 212, 0.08);
}

/* Tables */
.lesson-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: var(--space-md);
  font-size: 0.9rem;
}

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

.lesson-content th {
  background: var(--color-surface);
  font-weight: 600;
  color: var(--color-text);
}

.lesson-content td {
  color: var(--color-text-muted);
}

/* Blockquotes */
.lesson-content blockquote {
  border-left: 4px solid var(--color-border);
  padding-left: var(--space-md);
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
  font-style: italic;
}

/* Further Reading */
.lesson-further-reading {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
}

.lesson-further-reading h2 {
  margin-top: 0;
  border-bottom: none;
}

.lesson-further-reading ul {
  list-style: none;
  padding-left: 0;
}

.lesson-further-reading li {
  margin-bottom: var(--space-sm);
  padding-left: var(--space-md);
  position: relative;
}

.lesson-further-reading li::before {
  content: '\2192';
  position: absolute;
  left: 0;
  color: var(--color-primary);
}

/* Lesson navigation */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: var(--space-md);
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
}

.nav-btn {
  display: inline-block;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text-muted);
  font-weight: 500;
  font-size: 0.9rem;
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.nav-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  text-decoration: none;
}

.nav-btn.prev {
  margin-right: auto;
}

.nav-btn.next {
  margin-left: auto;
}

/* Cost badge */
.cost-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: var(--space-md);
}

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

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

.cost-total td {
  font-weight: 600;
  color: var(--color-primary);
}

/* --- About Page --- */
.about-content {
  padding-top: var(--space-xl);
  padding-bottom: var(--space-2xl);
}

.about-content h1 {
  margin-bottom: var(--space-lg);
}

.about-content h2 {
  margin-top: var(--space-2xl);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: var(--space-sm);
}

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