/* ========================================
   五彩 Wucai - Content Hub Styles
   Light Pastel Theme
   ======================================== */

:root {
    /* Light theme colors - pastel pink to blue */
    --bg-primary: #FFF5F7;       /* Very light pastel pink */
    --bg-secondary: #F0F7FF;     /* Very light pastel blue */
    --bg-card: #FFFFFF;
    --bg-card-hover: #FFF8FA;
    
    /* Text colors */
    --text-primary: #1A202C;
    --text-secondary: #4A5568;
    --text-muted: #A0AEC0;
    
    /* Tone colors - pastel versions */
    --tone-1: #7EB8E8;  /* Pastel Blue - 1st tone */
    --tone-2: #7DD8A3;  /* Pastel Green - 2nd tone */
    --tone-3: #F4A8A0;  /* Pastel Red/Coral - 3rd tone */
    --tone-4: #D4A017;  /* Golden Yellow - 4th tone */
    --tone-5: #CBD5E0;  /* Pastel Gray - neutral */
    
    /* Accent colors - pastel */
    --accent-pink: #FFB5C5;
    --accent-purple: #D4A5E8;
    --accent-blue: #A5C8F7;
    --accent-green: #A5E8C5;
    --accent-yellow: #FFE4A5;
    --accent-orange: #FFCBA5;
    
    /* Gradients - softer pastel */
    --gradient-primary: linear-gradient(135deg, var(--tone-1), var(--tone-2), var(--tone-3), var(--tone-4));
    --gradient-hero: linear-gradient(135deg, #FFB5C5 0%, #D4A5E8 50%, #A5C8F7 100%);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 5rem;
    
    /* Border radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Fonts */
    --font-primary: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'Space Mono', 'SF Mono', monospace;
}

/* ========================================
   Reset & Base
   ======================================== */

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    color: inherit;
    text-decoration: none;
}

/* ========================================
   Navigation
   ======================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nav-logo {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-sub {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

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

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav-links a:hover {
    color: var(--text-primary);
}

.github-link {
    display: flex;
    align-items: center;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    transition: background 0.2s ease;
    border: 1px solid rgba(0, 0, 0, 0.08);
}

.github-link:hover {
    background: var(--bg-card-hover);
    border-color: rgba(0, 0, 0, 0.12);
}

/* ========================================
   Hero Section
   ======================================== */

.hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: calc(80px + var(--spacing-xl)) var(--spacing-lg) var(--spacing-lg);
    max-width: 1400px;
    margin: 0 auto;
    gap: var(--spacing-xl);
}

.hero-content {
    flex: 1;
    max-width: 650px;
}

.hero-badge {
    display: inline-block;
    background: linear-gradient(135deg, rgba(212, 165, 232, 0.2), rgba(165, 200, 247, 0.2));
    border: 1px solid rgba(212, 165, 232, 0.4);
    color: var(--accent-purple);
    font-size: 0.875rem;
    font-weight: 600;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    margin-bottom: var(--spacing-md);
}

.hero h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
}

.gradient-text {
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Hero Wucai with tone colors */
.hero-wucai {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    vertical-align: baseline;
    position: relative;
}

.wucai-chars {
    display: inline-block;
}

.wucai-pinyin {
    display: flex;
    gap: 0.4rem;
    font-size: 0.35em;
    font-weight: 500;
    margin-top: -0.1rem;
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.pinyin-tone {
    display: inline-block;
    font-family: var(--font-primary);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.75rem;
    font-family: var(--font-primary);
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient-hero);
    color: white;
    box-shadow: 0 4px 12px rgba(212, 165, 232, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(212, 165, 232, 0.4);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.btn-secondary:hover {
    background: var(--bg-secondary);
    border-color: rgba(0, 0, 0, 0.15);
}

.hero-stats {
    display: flex;
    gap: var(--spacing-xl);
}

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

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    font-family: var(--font-mono);
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-logo {
    width: 280px;
    height: 280px;
    border-radius: 48px;
    box-shadow: 0 20px 60px rgba(212, 165, 232, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-logo:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 30px 80px rgba(212, 165, 232, 0.4);
}

.tone-demo {
    display: flex;
    gap: var(--spacing-md);
}

.tone-demo .char {
    font-size: 5rem;
    font-weight: 500;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: default;
    border: 1px solid rgba(0, 0, 0, 0.08);
}

.tone-demo .char:hover {
    transform: translateY(-8px);
}

.tone-demo .tone1 { color: var(--tone-1); box-shadow: 0 8px 30px rgba(126, 184, 232, 0.3); }
.tone-demo .tone2 { color: var(--tone-2); box-shadow: 0 8px 30px rgba(125, 216, 163, 0.3); }
.tone-demo .tone3 { color: var(--tone-3); box-shadow: 0 8px 30px rgba(244, 168, 160, 0.3); }
.tone-demo .tone4 { color: var(--tone-4); box-shadow: 0 8px 30px rgba(201, 160, 220, 0.3); }

/* ========================================
   App Features Section
   ======================================== */

.features-section {
    background: var(--bg-primary);
    padding: var(--spacing-md) var(--spacing-lg) var(--spacing-2xl);
}

.features-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.features-header h2 {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.features-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    text-align: center;
    border: 1px solid rgba(0, 0, 0, 0.06);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

.feature-visual {
    height: 180px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.feature-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Tone Colors Demo */
.tone-colors-demo {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
}

.tone-block {
    width: 70px;
    height: 70px;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: #F0F4F8;
    transition: transform 0.2s ease;
}

.tone-block:hover {
    transform: scale(1.08);
}

/* Tone text colors for feature demo */
.tone-1-bg .tone-char-demo,
.tone-1-bg .tone-label { color: var(--tone-1); }
.tone-2-bg .tone-char-demo,
.tone-2-bg .tone-label { color: var(--tone-2); }
.tone-3-bg .tone-char-demo,
.tone-3-bg .tone-label { color: var(--tone-3); }
.tone-4-bg .tone-char-demo,
.tone-4-bg .tone-label { color: var(--tone-4); }

.tone-char-demo {
    font-size: 1.75rem;
    font-weight: 600;
    line-height: 1;
}

.tone-label {
    font-size: 0.65rem;
    opacity: 1;
    margin-top: 0.25rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

/* Decks Demo */
.decks-demo {
    position: relative;
    width: 160px;
    height: 150px;
    perspective: 600px;
}

.deck-card {
    position: absolute;
    width: 110px;
    padding: 0.75rem 1rem;
    background: white;
    border-radius: 14px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.15rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.deck-char {
    font-size: 2rem;
    font-weight: 600;
    line-height: 1.1;
}

.deck-pinyin {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 500;
}

.deck-meaning {
    font-size: 0.65rem;
    color: var(--text-secondary);
    text-transform: lowercase;
}

.deck-1 {
    bottom: 0;
    left: 0;
    transform: rotate(-8deg) translateZ(0);
    z-index: 1;
    opacity: 0.7;
}

.deck-2 {
    bottom: 20px;
    left: 20px;
    transform: rotate(-3deg) translateZ(0);
    z-index: 2;
    opacity: 0.85;
}

.deck-3 {
    bottom: 40px;
    left: 40px;
    transform: rotate(2deg) translateZ(0);
    z-index: 3;
    box-shadow: 0 8px 28px rgba(0, 0, 0, 0.15);
}

.decks-demo:hover .deck-1 {
    transform: rotate(-12deg) translate(-8px, 4px);
}

.decks-demo:hover .deck-2 {
    transform: rotate(-6deg) translate(-4px, 2px);
}

.decks-demo:hover .deck-3 {
    transform: rotate(4deg) translateY(-6px);
    box-shadow: 0 14px 36px rgba(0, 0, 0, 0.18);
}

/* Reading Demo */
.reading-demo {
    position: relative;
    padding: 1rem;
}

.reading-text {
    font-size: 1.6rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-align: center;
}

.char-tapped {
    position: relative;
    background: rgba(244, 168, 160, 0.2);
    border-radius: 4px;
    padding: 0 2px;
}

.char-popup {
    position: absolute;
    top: -8px;
    left: 50%;
    transform: translateX(-50%);
    background: white;
    border-radius: 10px;
    padding: 0.5rem 0.75rem;
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.15);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.1rem;
    z-index: 10;
    animation: popup-appear 0.3s ease-out;
}

.char-popup::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 50%;
    transform: translateX(-50%);
    border-left: 6px solid transparent;
    border-right: 6px solid transparent;
    border-top: 6px solid white;
}

.popup-char {
    font-size: 1.5rem;
    font-weight: 600;
    line-height: 1;
}

.popup-pinyin {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.popup-meaning {
    font-size: 0.65rem;
    color: var(--text-muted);
}

@keyframes popup-appear {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

@media (max-width: 900px) {
    .features-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
    }
}

/* ========================================
   Sections
   ======================================== */

.section {
    padding: var(--spacing-2xl) var(--spacing-lg);
    max-width: 1400px;
    margin: 0 auto;
}

.section-alt {
    background: var(--bg-secondary);
    max-width: 100%;
    padding-left: var(--spacing-lg);
    padding-right: var(--spacing-lg);
}

.section-alt > * {
    max-width: 1400px;
    margin-left: auto;
    margin-right: auto;
}

/* ========================================
   Concept Section
   ======================================== */

.concept-section {
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    padding: var(--spacing-xl) var(--spacing-lg);
}

.concept-container {
    max-width: 1100px;
    margin: 0 auto;
}

.concept-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.concept-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.concept-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Cards Layout */
.concept-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.concept-cards-two {
    grid-template-columns: repeat(2, 1fr);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.concept-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    border: 1px solid rgba(0, 0, 0, 0.06);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.concept-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.card-icon {
    width: 64px;
    height: 64px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    margin: 0 auto var(--spacing-md);
}

.concept-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.concept-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Smart Learning Section */
.smart-learning {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    border: 1px solid rgba(0, 0, 0, 0.06);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
}

.smart-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    margin-bottom: var(--spacing-sm);
}

.smart-learning-content h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.smart-learning-content p {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

.smart-learning-content strong {
    color: var(--text-primary);
}

.smart-learning-content em {
    color: var(--accent-purple);
    font-style: normal;
    font-weight: 500;
}

.smart-features {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.smart-feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--bg-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.feature-icon {
    font-size: 1rem;
}

/* Visual Graph Animation */
.smart-learning-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.visual-graph {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
    max-width: 200px;
}

.graph-word {
    --size: 1;
    width: calc(40px + 20px * var(--size));
    height: calc(40px + 20px * var(--size));
    background: linear-gradient(135deg, var(--tone-1), var(--accent-purple));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: calc(1rem + 0.5rem * var(--size));
    font-weight: 600;
    color: white;
    box-shadow: 0 4px 12px rgba(126, 184, 232, 0.3);
    animation: pulse 2s ease-in-out infinite;
    animation-delay: calc(var(--size) * -0.5s);
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

/* ========================================
   How It Works Section
   ======================================== */

.how-it-works-section {
    background: var(--bg-secondary);
    max-width: 100%;
    padding: var(--spacing-xl) var(--spacing-lg);
}

.steps-container {
    display: flex;
    align-items: stretch;
    justify-content: center;
    gap: var(--spacing-md);
    max-width: 1000px;
    margin: 0 auto;
}

.step {
    flex: 1;
    max-width: 280px;
    text-align: center;
    padding: var(--spacing-md);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(0, 0, 0, 0.06);
    display: flex;
    flex-direction: column;
}

.step-number {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    color: white;
    margin: 0 auto var(--spacing-sm);
    box-shadow: 0 4px 16px rgba(212, 165, 232, 0.3);
}

.step h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.step p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.step-arrow {
    font-size: 1.5rem;
    color: var(--text-muted);
    margin-top: 1.5rem;
    flex-shrink: 0;
}

@media (max-width: 768px) {
    .steps-container {
        flex-direction: column;
        align-items: center;
    }
    
    .step-arrow {
        transform: rotate(90deg);
        margin: 0;
    }
}

@media (max-width: 900px) {
    .concept-cards {
        grid-template-columns: 1fr;
    }
    
    .smart-learning {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .smart-features {
        justify-content: center;
    }
    
    .smart-learning-visual {
        order: -1;
        margin-bottom: var(--spacing-md);
    }
}

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

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

/* ========================================
   Filter Bar
   ======================================== */

.filter-bar {
    display: flex;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    justify-content: center;
}

.filter-btn {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-card);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-family: var(--font-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.filter-btn:hover {
    background: var(--bg-card-hover);
    color: var(--text-primary);
    border-color: rgba(0, 0, 0, 0.12);
}

.filter-btn.active {
    background: var(--accent-purple);
    color: white;
}

/* ========================================
   Cards Grid
   ======================================== */

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-md);
}

.card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-hero);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.card:hover {
    transform: translateY(-4px);
    border-color: rgba(0, 0, 0, 0.12);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.12);
}

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

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

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.card-title-cn {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
}

.card-level {
    padding: 4px 10px;
    background: var(--accent-purple);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.card-level.hsk1 { background: var(--tone-2); }
.card-level.hsk2 { background: var(--tone-1); }
.card-level.hsk3 { background: var(--accent-orange); }
.card-level.hsk4 { background: var(--tone-4); }

.card-preview {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.5;
}

.card-meta {
    display: flex;
    gap: var(--spacing-md);
    color: var(--text-muted);
    font-size: 0.875rem;
    font-family: var(--font-mono);
}

.card-actions {
    display: flex;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-md);
}

.btn {
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    font-family: var(--font-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
}

.btn-primary {
    background: var(--gradient-hero);
    color: white;
}

.btn-primary:hover {
    opacity: 0.9;
    transform: scale(1.02);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.btn-secondary:hover {
    background: var(--bg-card-hover);
    border-color: rgba(0, 0, 0, 0.15);
}

/* ========================================
   Packages Grid
   ======================================== */

.packages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
    gap: var(--spacing-lg);
}

.package-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    border: 1px solid rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.package-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-hero);
}

.package-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(212, 165, 232, 0.25);
}

.package-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.package-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.package-author {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-sm);
}

.package-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.package-stats {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-sm) 0;
    border-top: 1px solid rgba(0, 0, 0, 0.06);
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

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

.package-stat-value {
    font-size: 1.25rem;
    font-weight: 700;
    font-family: var(--font-mono);
    color: var(--accent-purple);
}

.package-stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

/* ========================================
   Create Tools
   ======================================== */

.create-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-yellow), var(--accent-orange));
    color: #92400E;
    font-size: 0.875rem;
    font-weight: 600;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    margin-bottom: var(--spacing-sm);
}

.create-tools {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.tool-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border: 1px solid rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    display: block;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.tool-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-purple);
    box-shadow: 0 12px 32px rgba(212, 165, 232, 0.2);
}

.tool-card-featured {
    background: linear-gradient(135deg, rgba(255, 228, 165, 0.1), rgba(212, 165, 232, 0.1));
    border: 2px solid var(--accent-purple);
    position: relative;
}

.tool-card-featured::before {
    content: '⭐ Recommended';
    position: absolute;
    top: -12px;
    right: 20px;
    background: var(--gradient-hero);
    color: white;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: 12px;
}

.tool-card-coming {
    opacity: 0.5;
    pointer-events: none;
}

.tool-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.tool-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.tool-card p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.tool-tags {
    display: flex;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
}

.tag {
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

.tag-green { background: rgba(165, 232, 197, 0.5); color: #059669; }
.tag-blue { background: rgba(165, 200, 247, 0.5); color: #2563EB; }
.tag-yellow { background: rgba(255, 228, 165, 0.5); color: #D97706; }
.tag-purple { background: rgba(212, 165, 232, 0.5); color: #7C3AED; }
.tag-gray { background: rgba(0, 0, 0, 0.05); color: var(--text-muted); }

/* ========================================
   Steps
   ======================================== */

.steps {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.step {
    text-align: center;
    padding: var(--spacing-lg);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    min-width: 180px;
}

.step-number {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-hero);
    border-radius: 50%;
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0 auto var(--spacing-sm);
}

.step h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.step p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.step-arrow {
    font-size: 2rem;
    color: var(--text-muted);
}

/* ========================================
   Footer
   ======================================== */

.footer {
    background: var(--bg-secondary);
    border-top: 1px solid rgba(0, 0, 0, 0.06);
    padding: var(--spacing-2xl) var(--spacing-lg) var(--spacing-lg);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-xl);
}

.footer-brand .logo {
    font-size: 2.5rem;
    display: block;
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    color: var(--text-secondary);
}

.footer-links {
    display: flex;
    gap: var(--spacing-2xl);
}

.footer-col h4 {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: var(--spacing-sm);
}

.footer-col a {
    display: block;
    color: var(--text-secondary);
    padding: var(--spacing-xs) 0;
    transition: color 0.2s ease;
}

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

.footer-bottom {
    max-width: 1400px;
    margin: 0 auto;
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(0, 0, 0, 0.06);
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-tagline {
    font-family: var(--font-mono);
    color: var(--text-muted);
    margin-top: var(--spacing-sm);
    opacity: 0.5;
}

/* ========================================
   Modal
   ======================================== */

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(8px);
    z-index: 200;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    max-width: 800px;
    width: 100%;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
    border: 1px solid rgba(0, 0, 0, 0.1);
    box-shadow: 0 25px 60px rgba(0, 0, 0, 0.15);
}

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
    transition: color 0.2s ease;
}

.modal-close:hover {
    color: var(--text-primary);
}

/* ========================================
   Responsive
   ======================================== */

@media (max-width: 768px) {
    .hero {
        flex-direction: column;
        text-align: center;
        padding-top: calc(60px + var(--spacing-xl));
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-visual {
        order: -1;
    }
    
    .tone-demo .char {
        font-size: 3rem;
        padding: var(--spacing-sm) var(--spacing-md);
    }
    
    .nav-links a:not(.github-link) {
        display: none;
    }
    
    .packages-grid {
        grid-template-columns: 1fr;
    }
    
    .steps {
        flex-direction: column;
    }
    
    .step-arrow {
        transform: rotate(90deg);
    }
    
    .footer-content {
        flex-direction: column;
    }
    
    .footer-links {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
}