/* ==========================================================================
   OpenClaw Handbook - Apple Style CSS
   Version: 1.0
   ========================================================================== */

/* ==========================================================================
   CSS Variables (Design Tokens)
   ========================================================================== */
:root {
    /* Colors - Apple Style */
    --color-bg: #FFFFFF;
    --color-bg-secondary: #F5F5F7;
    --color-bg-tertiary: #E8E8ED;
    --color-text: #1D1D1F;
    --color-text-secondary: #86868B;
    --color-text-tertiary: #6E6E73;
    --color-accent: #0071E3;
    --color-accent-hover: #0077ED;
    --color-accent-secondary: #5856D6;
    --color-accent-gradient: linear-gradient(135deg, #007AFF 0%, #5856D6 100%);
    --color-border: #D2D2D7;
    --color-border-light: #E5E5EA;
    --color-success: #34C759;
    --color-warning: #FF9500;
    --color-error: #FF3B30;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
    --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.06);
    --shadow-card-hover: 0 8px 30px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-display: 'Inter', 'SF Pro Display', 'PingFang SC', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-text: 'Noto Sans SC', 'SF Pro Text', 'PingFang SC', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'SF Mono', 'Menlo', 'Monaco', 'Fira Code', Consolas, monospace;
    
    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;
    --space-4xl: 96px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Layout */
    --navbar-height: 64px;
    --container-max: 1200px;
    --sidebar-width: 280px;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background-color: #FFFFFF;
}

body {
    font-family: var(--font-text);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    transition: background-color var(--transition-base), color var(--transition-base);
}

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul, ol {
    list-style: none;
}

/* ==========================================================================
   Typography
   ========================================================================== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
}

h1 { font-size: 56px; font-weight: 700; }
h2 { font-size: 36px; }
h3 { font-size: 24px; }
h4 { font-size: 18px; }

.gradient-text {
    background: linear-gradient(135deg, #007AFF 0%, #5856D6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

/* ==========================================================================
   Navigation Bar
   ========================================================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--color-border-light);
}

[data-theme="dark"] .navbar {
    background: rgba(0, 0, 0, 0.8);
}

.navbar-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: var(--navbar-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 600;
    font-size: 18px;
    transition: opacity var(--transition-fast);
}

.navbar-logo:hover {
    opacity: 0.8;
}

.logo-text {
    color: #1A1A1A;
}

.logo-icon {
    width: 32px;
    height: 32px;
}

.navbar-links {
    display: flex;
    gap: var(--space-xl);
}

.nav-link {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-secondary);
    padding: var(--space-sm) 0;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-text);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--color-accent);
    border-radius: 1px;
}

.navbar-actions {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.btn-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text);
}

.btn-icon svg {
    width: 20px;
    height: 20px;
}

/* Progress Bar */
.progress-bar {
    height: 2px;
    background: transparent;
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: var(--color-accent-gradient);
    transition: width 100ms ease;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--navbar-height) + var(--space-3xl)) var(--space-lg) var(--space-3xl);
    position: relative;
    overflow: hidden;
}

.hero-wrapper {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-2xl);
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: -1;
}

.hero-gradient {
    position: absolute;
    top: -50%;
    right: -20%;
    width: 80%;
    height: 100%;
    background: radial-gradient(ellipse at center, rgba(94, 92, 230, 0.15) 0%, transparent 70%);
}

[data-theme="dark"] .hero-gradient {
    background: radial-gradient(ellipse at center, rgba(94, 92, 230, 0.2) 0%, transparent 70%);
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(94, 92, 230, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(94, 92, 230, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
}

.hero-content {
    flex: 1;
    max-width: 580px;
    animation: fadeInUp 0.8s ease;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-full);
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

.badge-icon {
    font-size: 16px;
}

.hero-title {
    font-size: clamp(40px, 8vw, 72px);
    font-weight: 700;
    line-height: 1.05;
    margin-bottom: var(--space-lg);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 20px;
    color: var(--color-text-secondary);
    line-height: 1.5;
    margin-bottom: var(--space-xl);
}

.hero-stats {
    display: flex;
    gap: var(--space-2xl);
    margin-bottom: var(--space-xl);
    padding: var(--space-lg) 0;
    border-top: 1px solid #E9ECEF;
    border-bottom: 1px solid #E9ECEF;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 32px;
    font-weight: 700;
    font-family: var(--font-display);
    background: var(--color-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 13px;
    color: var(--color-text-secondary);
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 14px 28px;
    background: var(--color-accent-gradient);
    color: white;
    font-weight: 600;
    font-size: 16px;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 113, 227, 0.4);
    text-shadow: 0 0 20px rgba(255, 255, 255, 0.8);
}

.btn-primary svg {
    width: 18px;
    height: 18px;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    padding: 14px 28px;
    border: 1px solid var(--color-border);
    color: var(--color-text);
    font-weight: 500;
    font-size: 16px;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.btn-secondary:hover {
    background: var(--color-bg-secondary);
    border-color: var(--color-text-tertiary);
}

/* Hero Visual */
.hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-card {
    width: 100%;
    max-width: 420px;
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    overflow: hidden;
    border: 1px solid var(--color-border-light);
}

.card-header {
    padding: var(--space-md);
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border-light);
}

.card-dots {
    display: flex;
    gap: 6px;
}

.card-dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-border);
}

.card-dots span:nth-child(1) { background: #FF5F57; }
.card-dots span:nth-child(2) { background: #FEBC2E; }
.card-dots span:nth-child(3) { background: #28C840; }

.card-content {
    padding: var(--space-lg);
}

.code-preview {
    font-family: var(--font-mono);
    font-size: 14px;
    line-height: 1.8;
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.code-comment {
    color: var(--color-text-tertiary);
}

.code-function {
    color: #5E5CE6;
}

[data-theme="dark"] .code-function {
    color: #8E8EF9;
}

/* ==========================================================================
   Sections
   ========================================================================== */
section {
    padding: var(--space-4xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.section-title {
    margin-bottom: var(--space-md);
    color: var(--color-text);
    font-weight: 600;
}

.section-subtitle {
    font-size: 18px;
    color: var(--color-text-secondary);
}

/* ==========================================================================
   Features Section
   ========================================================================== */
.features {
    background: var(--color-bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
}

.feature-card {
    padding: var(--space-xl);
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border-light);
    transition: all var(--transition-base);
    box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
    border-color: var(--color-accent);
}

.feature-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-accent-gradient);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-md);
}

.feature-icon svg {
    width: 24px;
    height: 24px;
    color: white;
}

.feature-card h3 {
    font-size: 18px;
    margin-bottom: var(--space-sm);
    color: var(--color-text);
    font-weight: 600;
}

.feature-card p {
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* ==========================================================================
   Chapters Section
   ========================================================================== */
.chapters-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.chapter-item {
    background: var(--color-bg);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-base);
}

.chapter-item:hover {
    border-color: var(--color-accent);
    box-shadow: var(--shadow-card);
}

.chapter-header {
    display: flex;
    align-items: center;
    padding: var(--space-lg);
    gap: var(--space-lg);
    cursor: pointer;
}

.chapter-number {
    font-size: 36px;
    font-weight: 700;
    font-family: var(--font-display);
    background: var(--color-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    min-width: 60px;
}

.chapter-info {
    flex: 1;
}

.chapter-info h3 {
    font-size: 20px;
    margin-bottom: var(--space-xs);
}

.chapter-info p {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-sm);
}

.chapter-meta {
    display: flex;
    gap: var(--space-md);
}

.chapter-badge {
    padding: 4px 10px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-full);
    font-size: 12px;
    font-weight: 500;
    color: var(--color-accent);
}

.chapter-time {
    font-size: 12px;
    color: var(--color-text-tertiary);
    line-height: 24px;
}

.btn-expand {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
}

.btn-expand:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text);
}

.btn-expand svg {
    width: 20px;
    height: 20px;
    transition: transform var(--transition-base);
}

.chapter-item.expanded .btn-expand svg {
    transform: rotate(180deg);
}

.chapter-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.chapter-item.expanded .chapter-content {
    max-height: 2000px;
}

.chapter-list {
    padding: 0 var(--space-lg) var(--space-lg);
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.chapter-article {
    display: flex;
    align-items: center;
    padding: var(--space-md);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.chapter-article:hover {
    background: var(--color-bg-secondary);
}

.article-num {
    font-size: 13px;
    font-weight: 600;
    color: var(--color-accent);
    min-width: 40px;
    font-family: var(--font-mono);
}

.article-title {
    flex: 1;
    font-size: 14px;
}

.chapter-article svg {
    width: 16px;
    height: 16px;
    color: var(--color-text-tertiary);
    opacity: 0;
    transform: translateX(-8px);
    transition: all var(--transition-fast);
}

.chapter-article:hover svg {
    opacity: 1;
    transform: translateX(0);
}

/* ==========================================================================
   Appendix Section
   ========================================================================== */
.appendix {
    background: var(--color-bg-secondary);
}

.appendix-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
}

.appendix-card {
    padding: var(--space-xl);
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border-light);
    text-align: center;
    transition: all var(--transition-base);
}

.appendix-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
    border-color: var(--color-accent);
}

.appendix-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-accent-gradient);
    border-radius: var(--radius-md);
    margin: 0 auto var(--space-md);
}

.appendix-icon svg {
    width: 28px;
    height: 28px;
    color: white;
}

.appendix-card h3 {
    font-size: 18px;
    margin-bottom: var(--space-sm);
}

.appendix-card p {
    font-size: 14px;
    color: var(--color-text-secondary);
}

/* ==========================================================================
   About Section
   ========================================================================== */
.about {
    padding: var(--space-3xl) 0;
}

.about-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.about-content h2 {
    margin-bottom: var(--space-lg);
}

.about-content p {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
}

.about-meta {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
    margin-top: var(--space-lg);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border-light);
    font-size: 13px;
    color: var(--color-text-tertiary);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
    padding: var(--space-2xl) 0;
    border-top: 1px solid var(--color-border-light);
}

.footer-content {
    text-align: center;
}

.footer-content p {
    font-size: 14px;
    color: var(--color-text-secondary);
}

.footer-note {
    font-size: 12px !important;
    color: var(--color-text-tertiary) !important;
    margin-top: var(--space-sm) !important;
}

/* ==========================================================================
   Search Modal
   ========================================================================== */
.search-modal {
    position: fixed;
    inset: 0;
    z-index: 2000;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 120px;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
}

.search-modal.active {
    opacity: 1;
    visibility: visible;
}

.search-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.search-container {
    position: relative;
    width: 100%;
    max-width: 600px;
    margin: 0 var(--space-lg);
    background: var(--color-bg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    transform: translateY(-20px) scale(0.95);
    transition: transform var(--transition-base);
}

.search-modal.active .search-container {
    transform: translateY(0) scale(1);
}

.search-input-wrapper {
    display: flex;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--color-border-light);
}

.search-input-wrapper svg {
    width: 20px;
    height: 20px;
    color: var(--color-text-tertiary);
    flex-shrink: 0;
}

.search-input {
    flex: 1;
    padding: var(--space-sm) var(--space-md);
    font-size: 16px;
    border: none;
    background: none;
    color: var(--color-text);
    outline: none;
}

.search-input::placeholder {
    color: var(--color-text-tertiary);
}

.search-kbd {
    padding: 4px 8px;
    background: var(--color-bg-secondary);
    border-radius: 4px;
    font-size: 12px;
    font-family: var(--font-mono);
    color: var(--color-text-tertiary);
}

.search-results {
    max-height: 400px;
    overflow-y: auto;
    padding: var(--space-md);
}

.search-hint {
    text-align: center;
    padding: var(--space-xl);
    color: var(--color-text-tertiary);
    font-size: 14px;
}

/* ==========================================================================
   Back to Top Button
   ========================================================================== */
.back-to-top {
    position: fixed;
    bottom: var(--space-xl);
    right: var(--space-xl);
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-md);
    color: var(--color-text);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-base);
    z-index: 100;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--color-bg-secondary);
    transform: translateY(-2px);
}

.back-to-top svg {
    width: 20px;
    height: 20px;
}

/* ==========================================================================
   Animations
   ========================================================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1024px) {
    .hero-wrapper {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-content {
        max-width: 100%;
        text-align: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-visual {
        margin-top: var(--space-2xl);
        max-width: 100%;
    }
    
    .hero-visual .hero-card {
        max-width: 420px;
        margin: 0 auto;
    }
    
    h1 {
        font-size: 40px;
    }
}

@media (max-width: 768px) {
    .navbar-links {
        display: none;
    }
    
    section {
        padding: var(--space-3xl) 0;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--space-md);
    }
    
    .hero-card {
        max-width: 100%;
        padding: var(--space-md);
    }
    
    .chapter-header {
        flex-wrap: wrap;
    }
    
    .chapter-number {
        font-size: 28px;
    }
    
    .features-grid,
    .appendix-grid {
        grid-template-columns: 1fr;
    }
    
    .back-to-top {
        bottom: var(--space-md);
        right: var(--space-md);
    }
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */
.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;
}