/* ===================================
   Claude Code Tutorial - EZOAI
   Anthropic-Inspired Design System
   =================================== */

/* CSS Custom Properties */
:root {
    /* Colors - Light Theme */
    --color-bg-primary: #FAFAFA;
    --color-bg-secondary: #FFFFFF;
    --color-bg-tertiary: #F5F5F5;
    --color-bg-elevated: #FFFFFF;

    --color-text-primary: #1A1A1A;
    --color-text-secondary: #666666;
    --color-text-tertiary: #999999;
    --color-text-inverse: #FFFFFF;

    /* Anthropic Brand Colors */
    --color-accent-primary: #D97757;
    --color-accent-secondary: #E8956B;
    --color-accent-tertiary: #F5B89A;
    --color-accent-subtle: rgba(217, 119, 87, 0.1);
    --color-accent-glow: rgba(217, 119, 87, 0.3);

    /* Level Colors */
    --color-intro: #60A5FA;
    --color-basic: #34D399;
    --color-intermediate: #FBBF24;
    --color-advanced: #F87171;

    /* UI Colors */
    --color-border: rgba(0, 0, 0, 0.08);
    --color-border-hover: rgba(0, 0, 0, 0.15);
    --color-shadow: rgba(0, 0, 0, 0.05);
    --color-shadow-hover: rgba(0, 0, 0, 0.1);

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;

    /* Typography */
    --font-sans: 'DM Sans', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', Consolas, monospace;

    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;
    --text-6xl: 3.75rem;
    --text-7xl: 4.5rem;

    /* Border 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-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Z-index */
    --z-base: 1;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-modal: 300;
    --z-tooltip: 400;
    --z-cursor: 500;
}

/* Dark Theme */
[data-theme="dark"] {
    --color-bg-primary: #0A0A0A;
    --color-bg-secondary: #141414;
    --color-bg-tertiary: #1A1A1A;
    --color-bg-elevated: #1F1F1F;

    --color-text-primary: #FAFAFA;
    --color-text-secondary: #A1A1A1;
    --color-text-tertiary: #666666;
    --color-text-inverse: #0A0A0A;

    --color-accent-subtle: rgba(217, 119, 87, 0.15);
    --color-accent-glow: rgba(217, 119, 87, 0.4);

    --color-border: rgba(255, 255, 255, 0.08);
    --color-border-hover: rgba(255, 255, 255, 0.15);
    --color-shadow: rgba(0, 0, 0, 0.3);
    --color-shadow-hover: rgba(0, 0, 0, 0.5);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-base), color var(--transition-base);
}

/* Cursor Glow Effect */
.cursor-glow {
    position: fixed;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    pointer-events: none;
    background: radial-gradient(circle, var(--color-accent-glow) 0%, transparent 70%);
    transform: translate(-50%, -50%);
    z-index: var(--z-cursor);
    opacity: 0;
    transition: opacity var(--transition-slow);
    mix-blend-mode: screen;
}

body:hover .cursor-glow {
    opacity: 0.5;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-sticky);
    padding: var(--space-md) var(--space-xl);
    background: transparent;
    transition: background-color var(--transition-base), backdrop-filter var(--transition-base);
}

.nav.scrolled {
    background: rgba(250, 250, 250, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
}

[data-theme="dark"] .nav.scrolled {
    background: rgba(10, 10, 10, 0.85);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    text-decoration: none;
    color: var(--color-text-primary);
}

.logo-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
    border-radius: var(--radius-md);
    color: white;
}

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

.logo-text {
    font-size: var(--text-lg);
    font-weight: 600;
    letter-spacing: -0.02em;
}

.logo-badge {
    font-size: var(--text-xs);
    font-weight: 500;
    color: var(--color-accent-primary);
    background: var(--color-accent-subtle);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-full);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.nav-link {
    text-decoration: none;
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-text-primary);
    background: var(--color-accent-subtle);
}

.theme-toggle {
    width: 40px;
    height: 40px;
    border: none;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-secondary);
    transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.theme-toggle:hover {
    background: var(--color-accent-subtle);
    transform: scale(1.05);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
}

.sun-icon { display: block; }
.moon-icon { display: none; }

[data-theme="dark"] .sun-icon { display: none; }
[data-theme="dark"] .moon-icon { display: block; }

.nav-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 40px;
    height: 40px;
    border: none;
    background: transparent;
    cursor: pointer;
    padding: 10px;
    justify-content: center;
}

.nav-menu-btn span {
    width: 100%;
    height: 2px;
    background: var(--color-text-primary);
    border-radius: 2px;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.nav-menu-btn.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.nav-menu-btn.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg-primary);
    z-index: calc(var(--z-sticky) - 1);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
}

.mobile-menu.active {
    opacity: 1;
    pointer-events: auto;
}

.mobile-menu-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
    text-align: center;
}

.mobile-link {
    font-size: var(--text-3xl);
    font-weight: 600;
    color: var(--color-text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.mobile-link:hover {
    color: var(--color-accent-primary);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: var(--space-4xl) var(--space-xl);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.hero-gradient {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 50% at 50% -20%, var(--color-accent-subtle) 0%, transparent 50%),
        radial-gradient(ellipse 60% 40% at 80% 60%, rgba(96, 165, 250, 0.1) 0%, transparent 50%);
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(var(--color-border) 1px, transparent 1px),
        linear-gradient(90deg, var(--color-border) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse 50% 50% at 50% 50%, black 40%, transparent 100%);
    -webkit-mask-image: radial-gradient(ellipse 50% 50% at 50% 50%, black 40%, transparent 100%);
}

.floating-shapes {
    position: absolute;
    inset: 0;
}

.shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    animation: float 20s ease-in-out infinite;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: var(--color-accent-primary);
    opacity: 0.1;
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.shape-2 {
    width: 300px;
    height: 300px;
    background: var(--color-intro);
    opacity: 0.08;
    top: 50%;
    right: 15%;
    animation-delay: -7s;
}

.shape-3 {
    width: 250px;
    height: 250px;
    background: var(--color-basic);
    opacity: 0.08;
    bottom: 20%;
    left: 30%;
    animation-delay: -14s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(30px, -30px) scale(1.1); }
    50% { transform: translate(-20px, 20px) scale(0.95); }
    75% { transform: translate(40px, 10px) scale(1.05); }
}

.hero-content {
    position: relative;
    z-index: var(--z-base);
    text-align: center;
    max-width: 900px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
    animation: fadeInUp 0.8s ease-out;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: var(--color-accent-primary);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.2); }
}

.hero-title {
    margin-bottom: var(--space-xl);
}

.title-line {
    display: block;
    font-size: clamp(var(--text-4xl), 8vw, var(--text-7xl));
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
    animation: fadeInUp 0.8s ease-out backwards;
}

.title-line:nth-child(1) { animation-delay: 0.1s; }
.title-line:nth-child(2) { animation-delay: 0.2s; }

.title-accent {
    background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary), var(--color-accent-tertiary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto var(--space-2xl);
    line-height: 1.8;
    animation: fadeInUp 0.8s ease-out 0.3s backwards;
}

.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xl);
    margin-bottom: var(--space-2xl);
    animation: fadeInUp 0.8s ease-out 0.4s backwards;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: var(--text-4xl);
    font-weight: 700;
    color: var(--color-accent-primary);
    font-feature-settings: 'tnum';
}

.stat-label {
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--color-border);
}

.hero-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease-out 0.5s backwards;
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    font-family: var(--font-sans);
    font-size: var(--text-base);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-base);
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
    color: white;
    box-shadow: 0 4px 20px var(--color-accent-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px var(--color-accent-glow);
}

.btn-primary svg {
    width: 18px;
    height: 18px;
    transition: transform var(--transition-fast);
}

.btn-primary:hover svg {
    transform: translateX(4px);
}

.btn-secondary {
    background: var(--color-bg-elevated);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
}

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

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: var(--space-2xl);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
    color: var(--color-text-tertiary);
    font-size: var(--text-xs);
    animation: fadeInUp 0.8s ease-out 0.7s backwards;
}

.scroll-mouse {
    width: 24px;
    height: 36px;
    border: 2px solid var(--color-text-tertiary);
    border-radius: 12px;
    position: relative;
}

.scroll-wheel {
    width: 4px;
    height: 8px;
    background: var(--color-text-tertiary);
    border-radius: 2px;
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollWheel 1.5s ease-in-out infinite;
}

@keyframes scrollWheel {
    0%, 100% { opacity: 1; transform: translateX(-50%) translateY(0); }
    50% { opacity: 0.3; transform: translateX(-50%) translateY(8px); }
}

/* Sections */
.section {
    min-height: 100vh;
    padding: var(--space-4xl) var(--space-xl);
}

.section-container {
    max-width: 1400px;
    margin: 0 auto;
}

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

.section-tag {
    display: inline-block;
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-accent-primary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-md);
}

.section-title {
    font-size: clamp(var(--text-3xl), 5vw, var(--text-5xl));
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
}

.section-description {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Level Tabs */
.level-tabs {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-2xl);
    flex-wrap: wrap;
}

.level-tab {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    cursor: pointer;
    font-family: var(--font-sans);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
}

.level-tab:hover {
    border-color: var(--color-border-hover);
    color: var(--color-text-primary);
}

.level-tab.active {
    background: var(--color-accent-primary);
    border-color: var(--color-accent-primary);
    color: white;
}

.tab-icon {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 600;
}

/* Tutorial Cards */
.tutorials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: var(--space-lg);
}

.tutorial-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.tutorial-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--card-color), transparent);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.tutorial-card:hover {
    border-color: var(--color-border-hover);
    transform: translateY(-4px);
    box-shadow: 0 20px 40px var(--color-shadow-hover);
}

.tutorial-card:hover::before {
    opacity: 1;
}

.tutorial-card[data-level="intro"] { --card-color: var(--color-intro); }
.tutorial-card[data-level="basic"] { --card-color: var(--color-basic); }
.tutorial-card[data-level="intermediate"] { --card-color: var(--color-intermediate); }
.tutorial-card[data-level="advanced"] { --card-color: var(--color-advanced); }

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

.card-number {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--card-color);
    background: rgba(var(--card-color), 0.1);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
}

.card-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    color: var(--color-text-tertiary);
}

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

.card-title {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: var(--space-sm);
    line-height: 1.4;
}

.card-description {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    margin-top: var(--space-md);
}

.card-tag {
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
    background: var(--color-bg-tertiary);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
}

/* Hands-on Section */
.handson-tabs {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-2xl);
}

.handson-tab {
    padding: var(--space-md) var(--space-xl);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    cursor: pointer;
    font-family: var(--font-sans);
    font-size: var(--text-base);
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
}

.handson-tab:hover {
    border-color: var(--color-border-hover);
}

.handson-tab.active {
    background: var(--color-accent-primary);
    border-color: var(--color-accent-primary);
    color: white;
}

.handson-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--space-lg);
}

.handson-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: all var(--transition-base);
}

.handson-card:hover {
    border-color: var(--color-border-hover);
    transform: translateY(-4px);
    box-shadow: 0 20px 40px var(--color-shadow-hover);
}

.handson-visual {
    height: 160px;
    background: linear-gradient(135deg, var(--color-accent-subtle), var(--color-bg-tertiary));
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.handson-visual::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        repeating-linear-gradient(
            45deg,
            transparent,
            transparent 10px,
            var(--color-border) 10px,
            var(--color-border) 11px
        );
    opacity: 0.3;
}

.handson-number {
    font-size: var(--text-6xl);
    font-weight: 700;
    color: var(--color-accent-primary);
    opacity: 0.3;
    position: relative;
    z-index: 1;
}

.handson-content {
    padding: var(--space-xl);
}

.handson-badge {
    display: inline-block;
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--color-accent-primary);
    background: var(--color-accent-subtle);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-sm);
}

.handson-badge.dev {
    color: var(--color-basic);
    background: rgba(52, 211, 153, 0.1);
}

.handson-title {
    font-size: var(--text-xl);
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.handson-description {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* Best Practices Grid */
.practices-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    gap: var(--space-lg);
}

.practice-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    transition: all var(--transition-base);
    display: flex;
    gap: var(--space-lg);
}

.practice-card:hover {
    border-color: var(--color-border-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--color-shadow);
}

.practice-number {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
    color: white;
    font-size: var(--text-xl);
    font-weight: 700;
    border-radius: var(--radius-lg);
}

.practice-content {
    flex: 1;
}

.practice-title {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.practice-description {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* Modal */
.modal {
    position: fixed;
    inset: 0;
    z-index: var(--z-modal);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-xl);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
}

.modal.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    max-width: 800px;
    max-height: 90vh;
    width: 100%;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-2xl);
    overflow: hidden;
    transform: translateY(20px) scale(0.95);
    transition: transform var(--transition-base);
}

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

.modal-close {
    position: absolute;
    top: var(--space-lg);
    right: var(--space-lg);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-tertiary);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    color: var(--color-text-secondary);
    z-index: 1;
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background: var(--color-accent-subtle);
    color: var(--color-accent-primary);
}

.modal-close svg {
    width: 20px;
    height: 20px;
}

.modal-body {
    padding: var(--space-2xl);
    overflow-y: auto;
    max-height: 90vh;
}

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

.modal-level {
    display: inline-block;
    font-size: var(--text-xs);
    font-weight: 600;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-md);
}

.modal-level.intro { background: rgba(96, 165, 250, 0.1); color: var(--color-intro); }
.modal-level.basic { background: rgba(52, 211, 153, 0.1); color: var(--color-basic); }
.modal-level.intermediate { background: rgba(251, 191, 36, 0.1); color: var(--color-intermediate); }
.modal-level.advanced { background: rgba(248, 113, 113, 0.1); color: var(--color-advanced); }

.modal-title {
    font-size: var(--text-2xl);
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.modal-description {
    font-size: var(--text-base);
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.modal-section {
    margin-top: var(--space-xl);
}

.modal-section h3 {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.modal-section h3::before {
    content: '';
    width: 4px;
    height: 20px;
    background: var(--color-accent-primary);
    border-radius: 2px;
}

.modal-section p, .modal-section ul {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.modal-section ul {
    list-style: none;
    padding-left: var(--space-md);
}

.modal-section li {
    position: relative;
    padding-left: var(--space-md);
    margin-bottom: var(--space-sm);
}

.modal-section li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    background: var(--color-accent-primary);
    border-radius: 50%;
}

.modal-code {
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin-top: var(--space-md);
    overflow-x: auto;
}

.modal-code pre {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    line-height: 1.6;
    color: var(--color-text-primary);
    margin: 0;
}

/* Footer */
.footer {
    background: var(--color-bg-tertiary);
    border-top: 1px solid var(--color-border);
    padding: var(--space-4xl) var(--space-xl);
}

.footer-container {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--space-3xl);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
}

.footer-logo {
    font-size: var(--text-xl);
    font-weight: 700;
}

.footer-badge {
    font-size: var(--text-xs);
    color: var(--color-accent-primary);
    background: var(--color-accent-subtle);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-full);
}

.footer-description {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    max-width: 400px;
}

.footer-column h4 {
    font-size: var(--text-sm);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-lg);
    color: var(--color-text-tertiary);
}

.footer-column a {
    display: block;
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    text-decoration: none;
    margin-bottom: var(--space-sm);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    max-width: 1400px;
    margin: var(--space-2xl) auto 0;
    padding-top: var(--space-xl);
    border-top: 1px solid var(--color-border);
    text-align: center;
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .footer-container {
        grid-template-columns: 1fr 1fr;
    }

    .footer-main {
        grid-column: 1 / -1;
    }
}

@media (max-width: 768px) {
    :root {
        --space-xl: 1.5rem;
        --space-2xl: 2rem;
        --space-3xl: 3rem;
        --space-4xl: 4rem;
    }

    .nav-links {
        display: none;
    }

    .nav-menu-btn {
        display: flex;
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--space-lg);
    }

    .stat-divider {
        width: 40px;
        height: 1px;
    }

    .tutorials-grid,
    .handson-grid,
    .practices-grid {
        grid-template-columns: 1fr;
    }

    .practice-card {
        flex-direction: column;
    }

    .footer-container {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }

    .footer-links {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: var(--space-xl);
    }
}

@media (max-width: 480px) {
    .hero-actions {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .level-tabs {
        flex-direction: column;
        align-items: stretch;
    }

    .level-tab {
        justify-content: center;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border-hover);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-tertiary);
}

/* Selection */
::selection {
    background: var(--color-accent-subtle);
    color: var(--color-accent-primary);
}

/* Focus Styles */
:focus-visible {
    outline: 2px solid var(--color-accent-primary);
    outline-offset: 2px;
}

/* Loading Animation */
.loading {
    display: flex;
    justify-content: center;
    padding: var(--space-3xl);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===================================
   Enhanced Hands-on & Modal Styles
   =================================== */

/* Hands-on Skills Tags */
.handson-skills {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    margin-top: var(--space-md);
}

.skill-tag {
    font-size: var(--text-xs);
    color: var(--color-accent-primary);
    background: var(--color-accent-subtle);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
}

/* Modal Quote */
.modal-quote {
    border-left: 4px solid var(--color-accent-primary);
    padding: var(--space-md) var(--space-lg);
    background: var(--color-accent-subtle);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-style: italic;
    color: var(--color-text-secondary);
    margin: var(--space-md) 0;
}

/* Commands List */
.commands-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.command-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
}

.command-name {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-accent-primary);
    background: var(--color-bg-secondary);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    min-width: 100px;
}

.command-desc {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

/* Hands-on Detail Section */
.handson-detail {
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-top: var(--space-xl);
}

.handson-goal {
    background: var(--color-accent-subtle);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-lg);
}

.handson-prereq {
    margin-bottom: var(--space-lg);
}

.handson-prereq ul {
    list-style: none;
    padding-left: 0;
    margin-top: var(--space-sm);
}

.handson-prereq li {
    padding-left: var(--space-lg);
    position: relative;
    margin-bottom: var(--space-xs);
}

.handson-prereq li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-basic);
}

/* Hands-on Steps */
.handson-steps h4 {
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: var(--color-text-primary);
}

.step-item {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
}

.step-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.step-number {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
    color: white;
    font-weight: 700;
    border-radius: 50%;
    font-size: var(--text-sm);
}

.step-content {
    flex: 1;
}

.step-action, .step-title {
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--space-sm);
}

.step-prompt {
    margin: var(--space-sm) 0;
}

.prompt-label {
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-xs);
}

.prompt-box {
    display: flex;
    align-items: stretch;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.prompt-box code {
    flex: 1;
    padding: var(--space-md);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--color-accent-primary);
    background: transparent;
    white-space: pre-wrap;
    word-break: break-word;
}

.copy-btn-small {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    border: none;
    background: var(--color-bg-tertiary);
    color: var(--color-text-tertiary);
    cursor: pointer;
    transition: all var(--transition-fast);
    border-left: 1px solid var(--color-border);
}

.copy-btn-small:hover {
    background: var(--color-accent-subtle);
    color: var(--color-accent-primary);
}

.copy-btn-small svg {
    width: 16px;
    height: 16px;
}

.step-expected {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-top: var(--space-sm);
    padding: var(--space-sm);
    background: rgba(52, 211, 153, 0.1);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--color-basic);
}

.expected-label {
    font-weight: 600;
    color: var(--color-basic);
}

/* Checkpoints */
.handson-checkpoints {
    margin-top: var(--space-lg);
}

.handson-checkpoints ul {
    list-style: none;
    padding-left: 0;
}

.handson-checkpoints li {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) 0;
    color: var(--color-text-secondary);
}

.handson-checkpoints li svg {
    width: 18px;
    height: 18px;
    color: var(--color-basic);
    flex-shrink: 0;
}

/* Files List */
.handson-files {
    margin-top: var(--space-lg);
}

.files-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-top: var(--space-sm);
}

.file-tag {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
}

.file-tag.created {
    background: rgba(52, 211, 153, 0.1);
    color: var(--color-basic);
    border: 1px solid rgba(52, 211, 153, 0.3);
}

.file-tag.modified {
    background: rgba(251, 191, 36, 0.1);
    color: var(--color-intermediate);
    border: 1px solid rgba(251, 191, 36, 0.3);
}

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

.checklist li {
    margin-bottom: var(--space-sm);
}

.checklist label {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    cursor: pointer;
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.checklist input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--color-accent-primary);
    cursor: pointer;
}

.checklist input[type="checkbox"]:checked + span,
.checklist label:has(input:checked) {
    text-decoration: line-through;
    color: var(--color-text-tertiary);
}

/* Skills List */
.skills-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

/* Copy Button in Code Block */
.modal-code {
    position: relative;
}

.copy-btn {
    position: absolute;
    top: var(--space-sm);
    right: var(--space-sm);
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-family: var(--font-sans);
    font-size: var(--text-xs);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.copy-btn svg {
    width: 14px;
    height: 14px;
}

/* Copy Notification */
.copy-notification {
    position: fixed;
    bottom: var(--space-xl);
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-text-primary);
    color: var(--color-bg-primary);
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: 500;
    z-index: 1000;
    animation: slideUp 0.3s ease, fadeOut 0.3s ease 1.2s forwards;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

@keyframes fadeOut {
    to {
        opacity: 0;
    }
}

/* Best Practices Enhanced */
.practice-example {
    margin-top: var(--space-md);
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.example-bad, .example-good {
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
    padding: var(--space-sm);
    border-radius: var(--radius-sm);
}

.example-bad {
    background: rgba(248, 113, 113, 0.1);
}

.example-good {
    background: rgba(52, 211, 153, 0.1);
}

.example-label {
    flex-shrink: 0;
    font-size: var(--text-xs);
    font-weight: 700;
    padding: 2px 6px;
    border-radius: 4px;
}

.example-bad .example-label {
    background: var(--color-advanced);
    color: white;
}

.example-good .example-label {
    background: var(--color-basic);
    color: white;
}

.example-bad code, .example-good code {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--color-text-secondary);
    word-break: break-word;
}

.practice-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    margin-top: var(--space-md);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-accent-primary);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.practice-link:hover {
    text-decoration: underline;
}

.practice-link svg {
    width: 14px;
    height: 14px;
}

/* Official Resources Banner */
.official-resources-banner {
    background: linear-gradient(135deg, var(--color-accent-subtle), var(--color-bg-tertiary));
    border: 1px solid var(--color-border);
    border-radius: var(--radius-2xl);
    padding: var(--space-2xl);
    margin-bottom: var(--space-3xl);
}

.official-resources-banner h3 {
    font-size: var(--text-xl);
    font-weight: 600;
    margin-bottom: var(--space-lg);
    text-align: center;
}

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

.resource-card {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-lg);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    text-decoration: none;
    transition: all var(--transition-base);
}

.resource-card:hover {
    border-color: var(--color-accent-primary);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--color-shadow);
}

.resource-card.primary {
    background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
    border-color: transparent;
}

.resource-card.primary .resource-icon,
.resource-card.primary .resource-title,
.resource-card.primary .resource-desc,
.resource-card.primary .external-icon {
    color: white;
}

.resource-card.primary:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 40px var(--color-accent-glow);
}

.resource-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-accent-subtle);
    border-radius: var(--radius-lg);
    color: var(--color-accent-primary);
}

.resource-card.primary .resource-icon {
    background: rgba(255, 255, 255, 0.2);
}

.resource-icon svg {
    width: 24px;
    height: 24px;
}

.resource-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.resource-title {
    font-weight: 600;
    color: var(--color-text-primary);
    font-size: var(--text-sm);
}

.resource-desc {
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
}

.external-icon {
    flex-shrink: 0;
    width: 18px;
    height: 18px;
    color: var(--color-text-tertiary);
}

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

/* ===================================
   Prompt Tips Section
   =================================== */
.prompt-tips-section {
    margin-top: var(--space-2xl);
    padding-top: var(--space-xl);
    border-top: 1px solid var(--color-border);
}

.source-link {
    color: var(--color-accent-primary);
    text-decoration: none;
    font-size: var(--text-sm);
    transition: color var(--transition-fast);
}

.source-link:hover {
    color: var(--color-accent-secondary);
    text-decoration: underline;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: var(--space-lg);
    margin-top: var(--space-xl);
}

.tip-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-lg);
    transition: all var(--transition-base);
    animation: fadeInUp 0.5s ease forwards;
    opacity: 0;
}

.tip-card:hover {
    border-color: var(--color-accent-primary);
    transform: translateY(-4px);
    box-shadow: 0 12px 40px var(--color-shadow);
}

.tip-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-md);
}

.tip-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--color-accent-subtle);
    color: var(--color-accent-primary);
    font-weight: 700;
    font-size: var(--text-sm);
    border-radius: var(--radius-full);
}

.tip-category {
    font-size: var(--text-xs);
    font-weight: 500;
    color: var(--color-text-tertiary);
    background: var(--color-bg-tertiary);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-full);
}

.tip-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.tip-title {
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-text-primary);
    margin: 0;
}

.tip-description {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin: 0;
}

.tip-example {
    margin-top: var(--space-sm);
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.tip-example .example-bad,
.tip-example .example-good {
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
    padding: var(--space-sm);
    background: var(--color-bg-primary);
    border-radius: var(--radius-md);
    font-size: var(--text-xs);
}

.tip-example code {
    flex: 1;
    font-family: var(--font-mono);
    color: var(--color-text-secondary);
    word-break: break-word;
}

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

/* ===================================
   Enhanced Hands-on Modal Styles
   =================================== */

/* Modal Badges */
.modal-badges {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-wrap: wrap;
    margin-bottom: var(--space-md);
}

.difficulty-badge {
    font-size: var(--text-xs);
    font-weight: 600;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    text-transform: capitalize;
}

.difficulty-badge.初級 {
    background: rgba(52, 211, 153, 0.1);
    color: var(--color-basic);
}

.difficulty-badge.中級 {
    background: rgba(251, 191, 36, 0.1);
    color: var(--color-intermediate);
}

.difficulty-badge.上級 {
    background: rgba(248, 113, 113, 0.1);
    color: var(--color-advanced);
}

.time-badge {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
    background: var(--color-bg-tertiary);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
}

.time-badge svg {
    width: 12px;
    height: 12px;
}

/* Section Headers with Icons */
.modal-section h3 {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.modal-section h3 svg {
    width: 20px;
    height: 20px;
    color: var(--color-accent-primary);
}

.section-hint {
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-lg);
}

/* Related Tutorials Section */
.related-tutorials-section {
    background: var(--color-accent-subtle);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    border: 1px solid var(--color-border);
}

.related-tutorials-grid {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.related-tutorial-card {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.related-tutorial-card:hover {
    border-color: var(--color-accent-primary);
    transform: translateX(4px);
}

.tutorial-id {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--color-accent-primary);
    background: var(--color-bg-tertiary);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    min-width: 50px;
    text-align: center;
}

.tutorial-info {
    flex: 1;
}

.tutorial-title {
    font-weight: 600;
    font-size: var(--text-sm);
    color: var(--color-text-primary);
}

.tutorial-reason {
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
    margin-top: 2px;
}

.tutorial-arrow {
    color: var(--color-text-tertiary);
}

.tutorial-arrow svg {
    width: 16px;
    height: 16px;
    transition: transform var(--transition-fast);
}

.related-tutorial-card:hover .tutorial-arrow svg {
    transform: translateX(4px);
}

/* Goal Section */
.goal-section {
    background: linear-gradient(135deg, var(--color-accent-subtle), transparent);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    border-left: 4px solid var(--color-accent-primary);
}

.goal-text {
    font-size: var(--text-base);
    color: var(--color-text-primary);
    font-weight: 500;
    margin: 0;
}

/* Preparation Section */
.preparation-section {
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    border: 2px dashed var(--color-border);
}

.folder-structure {
    margin-bottom: var(--space-lg);
}

.folder-structure-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-sm);
}

.folder-structure-header .label {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text-secondary);
}

.folder-tree {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    background: var(--color-bg-secondary);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    overflow-x: auto;
    white-space: pre;
    margin: 0;
}

/* Prep Files */
.prep-files h4 {
    font-size: var(--text-base);
    margin-bottom: var(--space-md);
}

.prep-file-item {
    margin-bottom: var(--space-sm);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.prep-file-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--color-bg-secondary);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.prep-file-header:hover {
    background: var(--color-accent-subtle);
}

.prep-file-header.open {
    border-bottom: 1px solid var(--color-border);
}

.file-path {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-accent-primary);
}

.file-path svg {
    width: 16px;
    height: 16px;
}

.file-desc {
    flex: 1;
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
}

.toggle-icon {
    color: var(--color-text-tertiary);
    transition: transform var(--transition-fast);
}

.toggle-icon svg {
    width: 16px;
    height: 16px;
}

.prep-file-header.open .toggle-icon {
    transform: rotate(90deg);
}

.prep-file-content {
    display: none;
    padding: var(--space-md);
    background: var(--color-bg-primary);
}

.prep-file-content.open {
    display: block;
}

.prep-file-content .prompt-box {
    max-height: 300px;
    overflow-y: auto;
}

.prep-file-content pre {
    margin: 0;
    white-space: pre-wrap;
    word-break: break-word;
}

/* Setup Steps */
.setup-steps {
    margin-top: var(--space-lg);
}

.setup-steps h4 {
    font-size: var(--text-base);
    margin-bottom: var(--space-md);
}

.setup-steps-list {
    padding-left: var(--space-lg);
    margin: 0;
}

.setup-steps-list li {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-sm);
    line-height: 1.6;
}

/* Execution Section */
.execution-section {
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

/* Step Description */
.step-description {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-sm);
}

/* Step Tips */
.step-tips {
    margin-top: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: rgba(99, 102, 241, 0.1);
    border-radius: var(--radius-sm);
    font-size: var(--text-xs);
    color: var(--color-text-secondary);
}

.tips-label {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    font-weight: 600;
    color: var(--color-accent-primary);
}

.tips-label svg {
    width: 14px;
    height: 14px;
}

/* Outputs Section */
.outputs-grid {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.output-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.output-desc {
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
}

/* Learning Section */
.learning-section {
    background: linear-gradient(135deg, rgba(251, 191, 36, 0.1), transparent);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    border-left: 4px solid var(--color-intermediate);
}

.learning-points {
    list-style: none;
    padding-left: 0;
    margin: 0;
}

.learning-points li {
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-sm);
    padding-left: var(--space-lg);
    position: relative;
}

.learning-points li::before {
    content: '💡';
    position: absolute;
    left: 0;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .modal-badges {
        flex-direction: row;
    }

    .related-tutorial-card {
        flex-direction: column;
        align-items: flex-start;
    }

    .tutorial-arrow {
        display: none;
    }

    .preparation-section {
        padding: var(--space-md);
    }

    .prep-file-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--space-xs);
    }

    .step-item {
        flex-direction: column;
    }

    .step-number {
        align-self: flex-start;
    }
}