/* ==================== 全局变量与首页一致 ==================== */
:root {
    --bg-deep: #050b14;
    --bg-card: rgba(15, 23, 42, 0.7);
    --bg-card-hover: rgba(30, 41, 59, 0.85);
    --border-soft: #334155;
    --border-glow: rgba(56, 189, 248, 0.25);
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --accent-blue: #38bdf8;
    --accent-purple: #a855f7;
    --accent-green: #10b981;
    --gradient-hero: linear-gradient(135deg, #38bdf8, #a855f7);
    --gradient-subtle: linear-gradient(145deg, #0f172a, #020617);
    --radius-xl: 28px;
    --radius-2xl: 48px;
    --shadow-glow: 0 0 20px rgba(56, 189, 248, 0.3);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg-deep);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 32px;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s;
}

/* ==================== 导航栏（与首页完全统一） ==================== */
header {
    background: rgba(5, 11, 20, 0.92);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border-glow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    padding: 16px 0;
}

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

.brand-name {
    font-size: 1.8rem;
    font-weight: 800;
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    letter-spacing: -0.5px;
    line-height: 1.2;
}

.brand-accent {
    color: var(--accent-blue);
    -webkit-text-fill-color: var(--accent-blue);
}

.brand-tagline {
    font-size: 0.7rem;
    color: var(--text-secondary);
    letter-spacing: 0.3px;
    margin-top: 2px;
}

.nav-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
    flex-wrap: wrap;
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: #cbd5e1;
    position: relative;
    padding: 4px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-blue);
    transition: width 0.25s;
    box-shadow: var(--shadow-glow);
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent-blue);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* 移动端菜单按钮 */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 28px;
    height: 20px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
}

.menu-toggle span {
    width: 100%;
    height: 2px;
    background: #cbd5e1;
    border-radius: 2px;
    transition: all 0.3s;
}

.menu-toggle--active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
}

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

.menu-toggle--active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
}

/* ==================== 下载页 Hero 标题区 ==================== */
.hero-download {
    text-align: center;
    padding: 60px 0 30px;
}

.hero-download h1 {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(to right, #f0f9ff, #a5f3fc);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 12px;
}

.hero-download p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto;
}

/* ==================== 平台切换选项卡（三栏） ==================== */
.platform-badge-row {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 36px;
    flex-wrap: wrap;
}

.platform-tab {
    background: rgba(15, 23, 42, 0.65);
    backdrop-filter: blur(4px);
    border: 1px solid var(--border-soft);
    border-radius: 60px;
    padding: 10px 24px;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.25s;
    display: flex;
    align-items: center;
    gap: 8px;
}

.platform-tab:hover {
    border-color: var(--accent-blue);
    color: white;
}

.platform-tab.active {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
    color: #0f172a;
    box-shadow: 0 0 16px rgba(56, 189, 248, 0.4);
}

/* ==================== 下载面板容器 ==================== */
.download-panel {
    position: relative;
    margin-bottom: 40px;
}

.panel-content {
    display: none;
    animation: fadeSlide 0.35s ease;
}

.panel-content.active-panel {
    display: block;
}

@keyframes fadeSlide {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.download-layout {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
    align-items: center;
    background: var(--bg-card);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-soft);
    border-radius: var(--radius-xl);
    padding: 40px;
}

.download-info-area {
    flex: 1;
    min-width: 280px;
}

.version-chip {
    display: inline-block;
    background: rgba(56, 189, 248, 0.12);
    border: 1px solid rgba(56, 189, 248, 0.3);
    border-radius: 40px;
    padding: 4px 18px;
    font-size: 0.8rem;
    color: var(--accent-blue);
    margin-bottom: 24px;
}

.download-btn-large {
    display: inline-block;
    background: var(--gradient-hero);
    padding: 14px 38px;
    border-radius: 40px;
    font-weight: 700;
    color: white;
    font-size: 1.1rem;
    transition: transform 0.2s, box-shadow 0.3s;
    box-shadow: 0 8px 22px rgba(56, 189, 248, 0.3);
    margin-bottom: 28px;
    border: none;
    cursor: pointer;
}

.download-btn-large:hover {
    transform: translateY(-3px);
    box-shadow: 0 14px 30px rgba(56, 189, 248, 0.45);
}

/* 规格表 */
.spec-table {
    margin: 24px 0 20px;
    background: rgba(5, 11, 20, 0.5);
    border-radius: 16px;
    overflow: hidden;
}

.spec-row {
    display: flex;
    justify-content: space-between;
    padding: 12px 20px;
    border-bottom: 1px solid rgba(51, 65, 85, 0.4);
    font-size: 0.9rem;
    color: #cbd5e1;
}

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

.spec-row span:first-child {
    color: var(--accent-blue);
    font-weight: 600;
}

/* 特性标签 */
.features-list {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 16px;
}

.feature-tag {
    background: rgba(56, 189, 248, 0.1);
    border: 1px solid rgba(56, 189, 248, 0.25);
    color: #bae6fd;
    padding: 6px 16px;
    border-radius: 30px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* 右侧视觉装饰 */
.download-visual {
    flex: 0 0 260px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

.os-icon-large {
    font-size: 5rem;
    filter: drop-shadow(0 0 12px rgba(56,189,248,0.4));
}

.terminal-preview {
    background: #0f172a;
    border-radius: 16px;
    padding: 16px;
    font-family: 'Fira Code', monospace;
    font-size: 0.75rem;
    color: #a5f3fc;
    width: 100%;
    box-shadow: 0 12px 24px rgba(0,0,0,0.5);
    border: 1px solid var(--border-soft);
}

/* macOS 面板绿色系按钮变体支持（在HTML中通过内联样式已处理） */

/* ==================== 安装流程（简化图解） ==================== */
.install-flow-section {
    margin: 60px 0 40px;
    background: var(--gradient-subtle);
    border-radius: var(--radius-xl);
    padding: 48px 36px;
    border: 1px solid var(--border-soft);
}

.flow-heading {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    color: #f1f5f9;
    margin-bottom: 40px;
    background: linear-gradient(to right, #bae6fd, #c4b5fd);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.flow-steps {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.flow-card {
    flex: 1;
    min-width: 220px;
    background: rgba(5, 11, 20, 0.7);
    border: 1px solid var(--border-soft);
    border-radius: 24px;
    padding: 32px 24px;
    text-align: center;
    transition: border-color 0.3s, transform 0.25s;
    position: relative;
}

.flow-card:hover {
    border-color: var(--accent-blue);
    transform: translateY(-6px);
}

.flow-num {
    position: absolute;
    top: -14px;
    left: 24px;
    background: var(--accent-blue);
    color: #0f172a;
    font-weight: 800;
    font-size: 1.2rem;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.flow-icon {
    font-size: 2.6rem;
    margin: 16px 0 12px;
}

.flow-card h4 {
    font-size: 1.2rem;
    color: white;
    margin-bottom: 10px;
}

.flow-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.flow-arrow {
    font-size: 2rem;
    color: var(--accent-purple);
    display: none;
}

@media (min-width: 769px) {
    .flow-arrow {
        display: block;
    }
}

/* ==================== 内嵌常见问题 ==================== */
.faq-inline-section {
    margin: 40px 0 50px;
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
    margin-top: 28px;
}

.faq-item {
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(4px);
    border: 1px solid var(--border-soft);
    border-radius: 20px;
    padding: 24px;
    transition: border-color 0.3s;
}

.faq-item:hover {
    border-color: var(--accent-blue);
}

.faq-item h4 {
    font-size: 1.1rem;
    color: #f1f5f9;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

/* 安全提示条 */
.alert-note {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    background: rgba(168, 85, 247, 0.08);
    border: 1px solid rgba(168, 85, 247, 0.2);
    border-radius: 20px;
    padding: 24px 28px;
    margin: 30px 0 60px;
}

/* ==================== CTA 号召区域（与首页一致） ==================== */
.cta-banner {
    position: relative;
    background: linear-gradient(135deg, #0b1622 0%, #1a1040 100%);
    border-radius: var(--radius-2xl);
    margin: 40px 0;
    overflow: hidden;
    padding: 60px 0;
}

.cta-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 28px;
    position: relative;
    z-index: 2;
}

.cta-text h2 {
    font-size: 2rem;
    color: white;
    margin-bottom: 12px;
}

.cta-text p {
    color: #cbd5e1;
    max-width: 500px;
}

.cta-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn-glow {
    background: var(--gradient-hero);
    border: none;
    padding: 12px 32px;
    border-radius: 40px;
    font-weight: 700;
    color: white;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.3s;
    display: inline-block;
    text-align: center;
    font-size: 1rem;
    box-shadow: 0 6px 18px rgba(56, 189, 248, 0.3);
}

.btn-glow:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 28px rgba(56, 189, 248, 0.45);
}

.btn-glow-lg {
    padding: 14px 36px;
    font-size: 1.1rem;
}

.btn-ghost-light {
    background: transparent;
    border: 1px solid rgba(255,255,255,0.25);
    color: white;
    padding: 10px 28px;
    border-radius: 40px;
    font-weight: 600;
    transition: background 0.2s;
}

.btn-ghost-light:hover {
    background: rgba(255,255,255,0.1);
}

.cta-decoration {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.cta-dot {
    position: absolute;
    border-radius: 50%;
    background: var(--accent-blue);
    opacity: 0.15;
    filter: blur(30px);
}

.cta-dot-1 {
    width: 200px;
    height: 200px;
    top: -50px;
    right: -40px;
}

.cta-dot-2 {
    width: 150px;
    height: 150px;
    bottom: -30px;
    left: 10%;
    background: var(--accent-purple);
}

.cta-dot-3 {
    width: 100px;
    height: 100px;
    top: 40%;
    left: 55%;
}

/* ==================== 页脚（与首页统一） ==================== */
footer {
    background: #020617;
    border-top: 1px solid #1e293b;
    padding: 56px 0 28px;
    margin-top: 40px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 40px;
}

.footer-col h4 {
    color: #f1f5f9;
    margin-bottom: 18px;
    font-size: 1rem;
    font-weight: 700;
}

.footer-col p {
    color: var(--text-secondary);
    font-size: 0.85rem;
    line-height: 1.6;
}

.footer-col a {
    display: block;
    color: #94a3b8;
    font-size: 0.9rem;
    margin-bottom: 8px;
    transition: color 0.2s;
}

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

.footer-brand {
    font-size: 1.4rem;
    font-weight: 800;
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 8px;
}

.footer-bottom {
    text-align: center;
    padding-top: 40px;
    color: #475569;
    font-size: 0.8rem;
    border-top: 1px solid #1e293b;
    margin-top: 36px;
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }

    .nav-menu {
        display: none;
        flex-direction: column;
        width: 100%;
        background: rgba(5,11,20,0.98);
        backdrop-filter: blur(20px);
        margin-top: 16px;
        padding: 16px 0;
        gap: 12px;
        border-radius: 16px;
    }

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

    .menu-toggle {
        display: flex;
    }

    .hero-download h1 {
        font-size: 2.2rem;
    }

    .download-layout {
        flex-direction: column;
        padding: 28px;
    }

    .download-visual {
        flex: 0 0 auto;
        width: 100%;
    }

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

    .cta-buttons {
        justify-content: center;
    }

    .flow-steps {
        flex-direction: column;
    }

    .flow-arrow {
        display: none;
    }

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