/* ===== 全局变量 ===== */
:root {
    --primary-color: #6366f1;
    --primary-light: #818cf8;
    --primary-dark: #4f46e5;
    --accent-color: #06b6d4;
    --bg-dark: #0f0f1a;
    --bg-card: #1a1a2e;
    --bg-card-hover: #252542;
    --text-primary: #ffffff;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --gradient-main: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #d946ef 100%);
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
}

/* 下载页Hero区域 */
.download-hero {
    padding: 180px 0 100px;
    background: var(--bg-dark);
    text-align: center;
    color: var(--text-primary);
    position: relative;
    overflow: hidden;
}

.download-hero::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 600px;
    height: 600px;
    background: var(--gradient-main);
    filter: blur(150px);
    opacity: 0.15;
    border-radius: 50%;
    transform: translate(-50%, -50%);
    animation: heroGlow 8s ease-in-out infinite;
}

@keyframes heroGlow {
    0%, 100% { transform: translate(-50%, -50%) scale(1); opacity: 0.15; }
    50% { transform: translate(-50%, -50%) scale(1.2); opacity: 0.2; }
}

.download-hero h1 {
    font-size: 56px;
    margin-bottom: 20px;
    font-weight: 800;
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    position: relative;
    z-index: 1;
}

.download-subtitle {
    font-size: 22px;
    color: var(--text-secondary);
    margin-bottom: 35px;
    position: relative;
    z-index: 1;
}

.download-badges {
    display: flex;
    justify-content: center;
    gap: 15px;
    position: relative;
    z-index: 1;
}

.badge {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    padding: 10px 24px;
    border-radius: 25px;
    font-size: 14px;
    font-weight: 500;
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s;
}

.badge:hover {
    border-color: var(--primary-light);
    transform: translateY(-2px);
    background: var(--bg-card-hover);
}

/* 主要下载区域 */
.download-main {
    padding: 100px 0;
    background: var(--bg-dark);
    position: relative;
}

.platform-tabs {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 60px;
    flex-wrap: wrap;
}

.tab-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    padding: 16px 45px;
    border-radius: 30px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s;
    color: var(--text-secondary);
    font-weight: 500;
}

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

.tab-btn.active {
    background: var(--gradient-main);
    border-color: transparent;
    color: white;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

.download-platforms {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0;
    max-width: 700px;
    margin: 0 auto;
}

.platform-card {
    display: none;
    padding: 60px 50px;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    text-align: center;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    animation: cardFadeIn 0.4s ease;
    position: relative;
    overflow: hidden;
}

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

.platform-card.active {
    display: block;
}

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

.platform-header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
}

.platform-icon {
    font-size: 64px;
}

.platform-header h2 {
    font-size: 32px;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-weight: 700;
}

.platform-header p {
    color: var(--text-secondary);
    font-size: 17px;
}

.download-info {
    background: var(--bg-card-hover);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 30px;
    margin-bottom: 40px;
}

.info-row {
    display: flex;
    justify-content: space-between;
    padding: 16px 0;
    border-bottom: 1px solid var(--glass-border);
    transition: all 0.3s;
}

.info-row:hover {
    background: rgba(99, 102, 241, 0.05);
    padding-left: 10px;
    padding-right: 10px;
    margin: 0 -10px;
    border-radius: 8px;
}

.info-row:last-child {
    border-bottom: none;
}

.info-row span:first-child {
    color: var(--text-secondary);
    font-weight: 500;
}

.info-row span:last-child {
    font-weight: 600;
    color: var(--primary-light);
    font-size: 15px;
}

.btn-download-large {
    width: 100%;
    background: var(--gradient-main);
    color: white;
    border: none;
    padding: 24px;
    border-radius: 30px;
    font-size: 20px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    transition: all 0.3s;
    margin-bottom: 25px;
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.btn-download-large:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.5);
}

.btn-download-large.apple {
    background: var(--glass-bg);
    border: 2px solid var(--glass-border);
}

.btn-download-large.apple:hover {
    background: var(--bg-card-hover);
    border-color: var(--primary-light);
}

.btn-arrow {
    font-size: 24px;
}

.download-tips {
    text-align: left;
}

.download-tips p {
    color: var(--text-secondary);
    margin-bottom: 12px;
    font-size: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.store-links {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 25px;
    flex-wrap: wrap;
}

.store-link {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--bg-card-hover);
    border: 1px solid var(--glass-border);
    padding: 14px 28px;
    border-radius: 14px;
    text-decoration: none;
    color: var(--text-primary);
    font-size: 15px;
    font-weight: 500;
    transition: all 0.3s;
}

.store-link:hover {
    background: var(--gradient-main);
    border-color: transparent;
    color: white;
    transform: translateY(-2px);
}

.qr-code {
    margin-top: 25px;
}

.qr-placeholder {
    width: 180px;
    height: 180px;
    background: var(--bg-card-hover);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 14px;
}

/* 历史版本 */
.version-history {
    padding: 100px 0;
    background: var(--bg-card);
    position: relative;
    overflow: hidden;
}

.version-history .section-title {
    text-align: center;
    margin-bottom: 50px;
}

.version-list {
    max-width: 900px;
    margin: 0 auto;
}

.version-item {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    padding: 30px;
    border-radius: 16px;
    margin-bottom: 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 25px;
    transition: all 0.3s;
}

.version-item:hover {
    transform: translateX(8px);
    border-color: var(--primary-light);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.15);
}

.version-info {
    display: flex;
    align-items: center;
    gap: 18px;
}

.version-number {
    background: var(--gradient-main);
    color: white;
    padding: 8px 20px;
    border-radius: 8px;
    font-weight: 700;
    font-size: 14px;
}

.version-date {
    color: var(--text-secondary);
    font-size: 15px;
}

.version-desc {
    flex: 1;
    color: var(--text-secondary);
    font-size: 16px;
}

.btn-small-download {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    padding: 12px 28px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 500;
    transition: all 0.3s;
}

.btn-small-download:hover {
    background: var(--gradient-main);
    border-color: transparent;
    color: white;
}

.btn-show-more {
    display: block;
    margin: 40px auto 0;
    background: transparent;
    color: var(--primary-light);
    border: 2px solid var(--glass-border);
    padding: 14px 36px;
    border-radius: 30px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.3s;
}

.btn-show-more:hover {
    background: var(--gradient-main);
    border-color: transparent;
    color: white;
}

/* 安装教程 */
.install-guide {
    padding: 100px 0;
    background: var(--bg-dark);
}

.install-guide .section-title {
    text-align: center;
    margin-bottom: 60px;
}

.guide-steps {
    max-width: 950px;
    margin: 0 auto;
}

.step {
    display: flex;
    align-items: flex-start;
    gap: 35px;
    margin-bottom: 50px;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--gradient-main);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 800;
    flex-shrink: 0;
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
}

.step-content h3 {
    font-size: 22px;
    margin-bottom: 12px;
    color: var(--text-primary);
    font-weight: 700;
}

.step-content p {
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 16px;
}

/* 下载问题FAQ */
.download-faq {
    padding: 100px 0;
    background: var(--bg-card);
}

.download-faq .section-title {
    text-align: center;
    margin-bottom: 50px;
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    max-width: 1100px;
    margin: 0 auto;
}

.faq-item-download {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    padding: 35px;
    border-radius: 16px;
    transition: all 0.4s;
    position: relative;
    overflow: hidden;
}

.faq-item-download::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 0;
    background: var(--gradient-main);
    transition: height 0.3s;
}

.faq-item-download:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(99, 102, 241, 0.2);
    border-color: var(--primary-light);
}

.faq-item-download:hover::before {
    height: 100%;
}

.faq-item-download h3 {
    font-size: 20px;
    margin-bottom: 18px;
    color: var(--text-primary);
    font-weight: 700;
}

.faq-item-download p {
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 15px;
}

/* 响应式 */
@media (max-width: 768px) {
    .download-hero {
        padding: 140px 0 70px;
    }

    .download-hero h1 {
        font-size: 36px;
    }

    .download-subtitle {
        font-size: 17px;
    }

    .download-badges {
        flex-wrap: wrap;
    }

    .platform-tabs {
        gap: 8px;
    }

    .tab-btn {
        padding: 12px 28px;
        font-size: 14px;
    }

    .platform-card {
        padding: 40px 30px;
    }

    .platform-icon {
        font-size: 48px;
    }

    .platform-header h2 {
        font-size: 24px;
    }

    .version-item {
        flex-direction: column;
        align-items: flex-start;
        padding: 24px;
    }

    .version-info {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .btn-small-download {
        align-self: flex-start;
    }

    .step {
        gap: 20px;
    }

    .step-number {
        width: 50px;
        height: 50px;
        font-size: 20px;
    }

    .step-content h3 {
        font-size: 18px;
    }

    .faq-grid {
        grid-template-columns: 1fr;
    }
}