/* ================================
   习惯打卡 - Global Styles
   ================================ */

:root {
    /* Colors */
    --bg-primary: #0D0D0D;
    --bg-secondary: #151515;
    --bg-tertiary: #1A1A1A;
    --bg-card: #1E1E1E;
    --bg-card-hover: #252525;
    
    --text-primary: #FFFFFF;
    --text-secondary: #A0A0A0;
    --text-tertiary: #666666;
    
    --accent-cyan: #50C8C8;
    --accent-yellow: #FFD966;
    --accent-red: #FF6B6B;
    
    --gradient-cyan: linear-gradient(135deg, #50C8C8 0%, #3BA3A3 100%);
    --gradient-yellow: linear-gradient(135deg, #FFD966 0%, #F5C542 100%);
    --gradient-red: linear-gradient(135deg, #FF6B6B 0%, #FF4757 100%);
    
    --border-color: #2A2A2A;
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.4);
    
    /* Typography */
    --font-display: 'SF Pro Display', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-body: 'SF Pro Text', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --container-max: 1200px;
    --section-padding: 100px;
}

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

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ================================
   Typography
   ================================ */

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

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

/* ================================
   Header
   ================================ */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(13, 13, 13, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 36px;
    height: 36px;
}

.logo-text {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
}

.nav {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav a {
    font-size: 14px;
    color: var(--text-secondary);
    transition: color 0.2s;
}

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

.btn-nav {
    padding: 8px 20px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.2s;
}

.btn-nav:hover {
    background: var(--bg-card);
    border-color: var(--accent-cyan);
}

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

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(80, 200, 200, 0.15), transparent),
        radial-gradient(ellipse 60% 40% at 80% 60%, rgba(255, 217, 102, 0.1), transparent);
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 100px;
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.hero-title {
    font-size: clamp(40px, 8vw, 72px);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 24px;
    background: linear-gradient(180deg, #FFFFFF 0%, #A0A0A0 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 48px;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 64px;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    background: var(--accent-cyan);
    color: #000;
    font-weight: 600;
    font-size: 15px;
    border-radius: 12px;
    transition: all 0.2s;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(80, 200, 200, 0.3);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    padding: 14px 28px;
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-weight: 500;
    font-size: 15px;
    border-radius: 12px;
    transition: all 0.2s;
}

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

.btn-large {
    padding: 18px 36px;
    font-size: 16px;
}

.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 40px;
}

.stat {
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary);
    font-family: var(--font-display);
}

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

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

/* ================================
   Features
   ================================ */

.features {
    padding: var(--section-padding) 0;
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-title {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 16px;
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.feature-card {
    padding: 40px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    transition: all 0.3s;
}

.feature-card:hover {
    background: var(--bg-card-hover);
    border-color: rgba(80, 200, 200, 0.3);
    transform: translateY(-4px);
}

.feature-icon {
    width: 64px;
    height: 64px;
    margin-bottom: 24px;
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ================================
   Streak Section
   ================================ */

.streak-section {
    padding: var(--section-padding) 0;
}

.streak-card {
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: 48px;
    padding: 48px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 24px;
}

.streak-fire {
    width: 80px;
    height: 80px;
}

.streak-fire svg {
    width: 100%;
    height: 100%;
}

.streak-content h2 {
    font-size: 28px;
    margin-bottom: 8px;
}

.streak-content p {
    color: var(--text-secondary);
    font-size: 15px;
}

.streak-stats {
    display: flex;
    gap: 32px;
}

.streak-stat {
    text-align: center;
}

.streak-number {
    display: block;
    font-size: 40px;
    font-weight: 700;
    color: var(--accent-yellow);
    font-family: var(--font-display);
}

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

/* ================================
   Testimonials
   ================================ */

.testimonials {
    padding: var(--section-padding) 0;
    background: var(--bg-secondary);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.testimonial-card {
    position: relative;
    padding: 32px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
}

.testimonial-card.featured {
    border-color: var(--accent-cyan);
    background: linear-gradient(180deg, rgba(80, 200, 200, 0.05) 0%, var(--bg-card) 100%);
}

.testimonial-badge {
    position: absolute;
    top: 24px;
    right: 24px;
    padding: 4px 10px;
    background: var(--accent-cyan);
    color: #000;
    font-size: 11px;
    font-weight: 600;
    border-radius: 4px;
}

.testimonial-avatar {
    width: 48px;
    height: 48px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 20px;
}

.testimonial-content {
    margin-bottom: 20px;
}

.testimonial-content p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
    font-style: italic;
}

.testimonial-author strong {
    display: block;
    font-size: 14px;
    margin-bottom: 2px;
}

.testimonial-author span {
    font-size: 12px;
    color: var(--text-tertiary);
}

/* ================================
   CTA
   ================================ */

.cta {
    padding: 120px 0;
}

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

.cta-content h2 {
    font-size: 40px;
    margin-bottom: 16px;
}

.cta-content p {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

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

.footer {
    padding: 60px 0 40px;
    border-top: 1px solid var(--border-color);
}

.footer-inner {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 80px;
    margin-bottom: 40px;
}

.footer-brand p {
    font-size: 14px;
    color: var(--text-tertiary);
    margin-top: 12px;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.footer-col h4 {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-col a {
    display: block;
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    transition: color 0.2s;
}

.footer-col a:hover {
    color: var(--accent-cyan);
}

.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.footer-bottom p {
    font-size: 13px;
    color: var(--text-tertiary);
}

/* ================================
   Animations
   ================================ */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-content > * {
    animation: fadeInUp 0.6s ease-out forwards;
}

.hero-content > *:nth-child(1) { animation-delay: 0.1s; }
.hero-content > *:nth-child(2) { animation-delay: 0.2s; }
.hero-content > *:nth-child(3) { animation-delay: 0.3s; }
.hero-content > *:nth-child(4) { animation-delay: 0.4s; }
.hero-content > *:nth-child(5) { animation-delay: 0.5s; }

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

@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .streak-card {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 32px;
    }
    
    .streak-stats {
        justify-content: center;
    }
    
    .footer-inner {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }
    
    .nav {
        display: none;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 20px;
    }
    
    .stat-divider {
        width: 40px;
        height: 1px;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .streak-stats {
        flex-direction: column;
        gap: 20px;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: 24px;
    }
}