/* ============================================
   云能音乐 官网样式
   设计风格匹配 APP: 蓝青渐变主题
   Primary: #3a7bd5, Secondary: #00d2ff
   ============================================ */

:root {
    /* Colors - matching APP theme */
    --primary: #3a7bd5;
    --primary-dark: #2c5fb3;
    --primary-light: #5d9df5;
    --secondary: #00d2ff;
    --secondary-dark: #00a8cc;
    --accent: #ff6b6b;
    --gradient: linear-gradient(135deg, #3a7bd5, #00d2ff);
    --gradient-dark: linear-gradient(135deg, #2c5fb3, #0088aa);

    /* Backgrounds */
    --bg: #f8f9fa;
    --card: #ffffff;
    --surface-variant: #f1f3f5;

    /* Text */
    --text: #2d3436;
    --text-secondary: #636e72;
    --text-light: #b2bec3;

    /* Borders & Shadows */
    --border: #dfe6e9;
    --border-light: #f1f3f5;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(58, 123, 213, 0.15);
    --shadow-xl: 0 12px 48px rgba(58, 123, 213, 0.2);

    /* Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-xxl: 48px;
    --space-xxxl: 80px;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
        'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    overflow-x: hidden;
}

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

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

/* ========== Navigation ========== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 0 var(--space-lg);
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-light);
    transition: background 0.3s, box-shadow 0.3s;
}

.nav.scrolled {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-sm);
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 20px;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-logo .logo-icon {
    width: 36px;
    height: 36px;
    background: var(--gradient);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 18px;
    -webkit-text-fill-color: white;
}

.nav-links {
    display: flex;
    gap: var(--space-xl);
    list-style: none;
}

.nav-links a {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.2s;
}

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text);
    padding: var(--space-xs);
}

/* ========== Hero Section ========== */
.hero {
    padding: 160px var(--space-lg) 120px;
    text-align: center;
    position: relative;
    overflow: hidden;
    background: var(--gradient);
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(
        circle at 30% 50%,
        rgba(255, 255, 255, 0.1) 0%,
        transparent 50%
    );
    animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
    0% { transform: translate(0, 0); }
    100% { transform: translate(5%, -5%); }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 640px;
    margin: 0 auto;
}

.hero-tag {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-xl);
    color: white;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: var(--space-lg);
    backdrop-filter: blur(8px);
}

.hero h1 {
    font-size: 48px;
    font-weight: 800;
    color: white;
    margin-bottom: var(--space-md);
    letter-spacing: -0.5px;
    line-height: 1.2;
}

.hero p {
    font-size: 20px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--space-xl);
    line-height: 1.6;
}

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

.btn-hero-primary {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 14px 32px;
    background: white;
    color: var(--primary);
    font-size: 16px;
    font-weight: 700;
    border-radius: var(--radius-xl);
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.15);
}

.btn-hero-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

.btn-hero-secondary {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 14px 32px;
    background: rgba(255, 255, 255, 0.15);
    color: white;
    font-size: 16px;
    font-weight: 600;
    border: 2px solid rgba(255, 255, 255, 0.4);
    border-radius: var(--radius-xl);
    transition: background 0.2s, border-color 0.2s;
    backdrop-filter: blur(8px);
}

.btn-hero-secondary:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: rgba(255, 255, 255, 0.6);
}

/* Hero wave decoration */
.hero-wave {
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    overflow: hidden;
    line-height: 0;
}

.hero-wave svg {
    width: 100%;
    height: 80px;
}

/* ========== Section Common ========== */
.section {
    padding: var(--space-xxxl) var(--space-lg);
}

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

.section-label {
    display: inline-block;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: var(--space-sm);
}

.section-title {
    font-size: 34px;
    font-weight: 800;
    color: var(--text);
    margin-bottom: var(--space-md);
    letter-spacing: -0.3px;
}

.section-desc {
    font-size: 17px;
    color: var(--text-secondary);
    max-width: 520px;
    margin: 0 auto;
    line-height: 1.7;
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--space-lg);
    max-width: 1080px;
    margin: 0 auto;
}

.feature-card {
    background: var(--card);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    transition: transform 0.25s, box-shadow 0.25s;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-md);
    background: rgba(58, 123, 213, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-md);
    font-size: 28px;
    color: var(--primary);
}

.feature-card h3 {
    font-size: 19px;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    color: var(--text);
}

.feature-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ========== Screenshots Section ========== */
.screenshots {
    background: var(--card);
}

.screenshots-scroll {
    display: flex;
    gap: var(--space-xl);
    overflow-x: auto;
    padding: var(--space-md) 0;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    max-width: 1080px;
    margin: 0 auto;
    scrollbar-width: none;
}

.screenshots-scroll::-webkit-scrollbar {
    display: none;
}

.screenshot-card {
    flex: 0 0 280px;
    scroll-snap-align: start;
    text-align: center;
}

.screenshot-frame {
    width: 280px;
    height: 560px;
    background: var(--gradient);
    border-radius: var(--radius-xl);
    padding: 16px;
    box-shadow: var(--shadow-lg);
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 48px;
}

.screenshot-card span {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* ========== Download Section ========== */
.download {
    background: var(--bg);
}

.download-card {
    max-width: 560px;
    margin: 0 auto;
    background: var(--gradient);
    border-radius: var(--radius-xl);
    padding: var(--space-xxl) var(--space-xl);
    text-align: center;
    color: white;
    box-shadow: var(--shadow-xl);
}

.download-card .download-icon {
    font-size: 48px;
    margin-bottom: var(--space-md);
}

.download-card h2 {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: var(--space-sm);
}

.download-card p {
    font-size: 16px;
    opacity: 0.9;
    margin-bottom: var(--space-lg);
}

.download-info {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
    font-size: 14px;
    opacity: 0.8;
}

.download-info span {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 16px 48px;
    background: white;
    color: var(--primary);
    font-size: 18px;
    font-weight: 700;
    border-radius: var(--radius-xl);
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.2);
    border: none;
    cursor: pointer;
}

.btn-download:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
}

/* ========== Footer ========== */
.footer {
    background: var(--text);
    color: var(--text-light);
    padding: var(--space-xxl) var(--space-lg) var(--space-lg);
}

.footer-content {
    max-width: 1080px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.footer-brand {
    font-size: 20px;
    font-weight: 700;
    color: white;
}

.footer-links {
    display: flex;
    gap: var(--space-xl);
    list-style: none;
    flex-wrap: wrap;
}

.footer-links a {
    font-size: 14px;
    color: var(--text-light);
    transition: color 0.2s;
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    max-width: 1080px;
    margin: 0 auto;
    padding-top: var(--space-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-size: 13px;
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .nav-links.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: white;
        padding: var(--space-md);
        border-bottom: 1px solid var(--border-light);
        box-shadow: var(--shadow-md);
        gap: var(--space-md);
    }

    .nav-toggle {
        display: block;
    }

    .hero {
        padding: 128px var(--space-md) 80px;
    }

    .hero h1 {
        font-size: 34px;
    }

    .hero p {
        font-size: 17px;
    }

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

    .section-title {
        font-size: 28px;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: var(--space-md);
    }

    .screenshot-card {
        flex: 0 0 240px;
    }

    .screenshot-frame {
        width: 240px;
        height: 480px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 400px) {
    .hero h1 {
        font-size: 28px;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .btn-hero-primary,
    .btn-hero-secondary {
        width: 100%;
        justify-content: center;
    }
}