:root {
    --primary-red: #e11d48;
    --primary-red-hover: #be123c;
    --primary-red-glow: rgba(225, 29, 72, 0.5);
    --bg-black: #050505;
    --card-bg: rgba(23, 23, 23, 0.7);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #262626;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    -webkit-tap-highlight-color: transparent;
}

html { scroll-behavior: smooth; }

body {
    background-color: var(--bg-black);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

body::before {
    content: "";
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: var(--bg-black);
    z-index: -10;
}

a { text-decoration: none; color: inherit; transition: 0.3s; }

/* ==================== 全局动画类 ==================== */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
.reveal.active {
    opacity: 1;
    transform: translateY(0);
}
.delay-100 { transition-delay: 0.1s; }
.delay-200 { transition-delay: 0.2s; }
.delay-300 { transition-delay: 0.3s; }
.delay-400 { transition-delay: 0.4s; }
.delay-500 { transition-delay: 0.5s; }

/* ==================== 导航栏 ==================== */
header#navbar {
    position: fixed;
    top: 0; width: 100%; z-index: 1000;
    background: rgba(5, 5, 5, 0.75);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: all 0.3s ease;
}
header#navbar.scrolled { box-shadow: 0 4px 30px rgba(0, 0, 0, 0.8); }

.nav-container {
    max-width: 1200px; margin: 0 auto; padding: 1rem 2rem;
    display: flex; justify-content: space-between; align-items: center;
}

.logo {
    font-size: 1.5rem; font-weight: 800; color: var(--primary-red);
    display: flex; align-items: center; gap: 0.5rem;
    text-shadow: 0 0 15px rgba(225, 29, 72, 0.4);
}
.logo-img {
    width: 32px; height: 32px; border-radius: 8px;
    object-fit: contain; display: block;
}

.nav-links { display: flex; gap: 2rem; align-items: center; font-weight: 500; }
/* 仅在支持真实 hover 的设备（鼠标）上应用悬停色，触控设备不触发 */
@media (hover: hover) {
    .nav-links a:hover { color: var(--primary-red); text-shadow: 0 0 10px rgba(225, 29, 72, 0.5); }
}

/* ==================== 导航下拉菜单 ==================== */
.nav-dropdown {
    position: relative;
    display: flex;
    align-items: center;
}

.nav-dropdown-trigger {
    display: flex;
    align-items: center;
    gap: 5px;
    cursor: pointer;
    font-weight: 500;
}

.nav-dropdown-trigger svg {
    transition: transform 0.25s ease;
    opacity: 0.7;
    flex-shrink: 0;
}

@media (hover: hover) {
    .nav-dropdown:hover .nav-dropdown-trigger svg {
        transform: rotate(180deg);
        opacity: 1;
    }
}

.nav-dropdown-menu {
    position: absolute;
    top: calc(100% + 14px);
    left: 50%;
    transform: translateX(-50%);
    width: 260px;
    background: rgba(15, 15, 15, 0.97);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 0.5rem;
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255,255,255,0.04);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateX(-50%) translateY(-6px);
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
}

@media (hover: hover) {
    .nav-dropdown:hover .nav-dropdown-menu {
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
        transform: translateX(-50%) translateY(0);
    }
}

.nav-dropdown-item {
    display: flex;
    align-items: flex-start;
    gap: 0.8rem;
    padding: 0.75rem 0.9rem;
    border-radius: 10px;
    transition: background 0.2s;
    cursor: pointer;
}

.nav-dropdown-item:hover {
    background: rgba(255, 255, 255, 0.06);
}

.nav-dropdown-icon {
    width: 32px;
    height: 32px;
    flex-shrink: 0;
    border-radius: 8px;
    background: rgba(225, 29, 72, 0.12);
    border: 1px solid rgba(225, 29, 72, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-red);
    margin-top: 1px;
}

.nav-dropdown-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.nav-dropdown-title {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-main);
    display: block;
}

.nav-dropdown-desc {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: block;
    line-height: 1.4;
}

/* 下拉菜单与菜单之间的桥接区（防止鼠标移动时菜单消失） */
.nav-dropdown::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    width: 120%;
    height: 16px;
}

.lang-switch {
    padding: 0.4rem 0.8rem; border: 1px solid var(--border-color);
    border-radius: 6px; font-size: 0.85rem; cursor: pointer;
    display: flex; align-items: center; gap: 4px;
    background: rgba(255, 255, 255, 0.05);
    position: relative; user-select: none;
}
.lang-switch:hover { background: rgba(255, 255, 255, 0.1); }
.lang-switch-caret { flex-shrink: 0; transition: transform 0.2s; }
.lang-switch.open .lang-switch-caret { transform: rotate(180deg); }
.lang-dropdown-menu {
    position: absolute; top: calc(100% + 8px); right: 0;
    background: #141927; border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 10px; padding: 0.35rem; min-width: 150px;
    display: none; box-shadow: 0 12px 36px rgba(0, 0, 0, 0.5);
    z-index: 1010;
}
.lang-switch.open .lang-dropdown-menu { display: block; }
.lang-dropdown-item {
    display: block; padding: 0.5rem 0.85rem; border-radius: 6px;
    color: var(--text-primary); text-decoration: none;
    font-size: 0.84rem; white-space: nowrap; transition: background 0.15s;
}
.lang-dropdown-item:hover { background: rgba(255, 255, 255, 0.09); color: var(--text-primary); }
.lang-dropdown-item.active { color: var(--primary-red); font-weight: 600; pointer-events: none; }

/* ==================== Hero 3D 特效区域 ==================== */
.hero-section {
    position: relative;
    min-height: 95vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 140px 2rem 60px;
    background-color: var(--bg-black);
}

.cyber-grid-wrapper {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    perspective: 600px;
    z-index: 1;
    overflow: hidden;
}

.cyber-grid {
    position: absolute;
    width: 200%; height: 150%;
    top: 45%; left: -50%;
    background-image:
        linear-gradient(rgba(225, 29, 72, 0.6) 2px, transparent 2px),
        linear-gradient(90deg, rgba(225, 29, 72, 0.6) 2px, transparent 2px);
    background-size: 60px 60px;
    transform: rotateX(80deg);
    transform-origin: top center;
    animation: gridMove 1.5s linear infinite;
    filter: drop-shadow(0 0 10px rgba(225, 29, 72, 0.5));
}

@keyframes gridMove {
    0%   { background-position: 0 0; }
    100% { background-position: 0 60px; }
}

.cyber-horizon {
    position: absolute;
    top: 45%; left: 0; width: 100%; height: 3px;
    background: rgba(225, 29, 72, 1);
    box-shadow: 0 0 40px 15px rgba(225, 29, 72, 0.6);
    z-index: 2;
}

.cyber-grid-wrapper::after {
    content: "";
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: radial-gradient(ellipse at center 45%, transparent 10%, var(--bg-black) 75%);
    z-index: 3;
    pointer-events: none;
}

.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    z-index: 0;
    animation: float-orb 8s ease-in-out infinite alternate;
}
.orb-1 { top: 10%; left: 20%; width: 400px; height: 400px; background: rgba(225, 29, 72, 0.15); }
.orb-2 { top: 30%; right: 10%; width: 300px; height: 300px; background: rgba(225, 29, 72, 0.1); animation-delay: -4s; }

@keyframes float-orb {
    0%   { transform: translate(0, 0) scale(1); }
    100% { transform: translate(40px, -40px) scale(1.1); }
}

/* ==================== Hero 内容区 ==================== */
.hero-content {
    text-align: center;
    max-width: 900px;
    z-index: 10;
    position: relative;
}

.hero-tag {
    display: inline-block;
    padding: 0.4rem 1rem; background: rgba(225, 29, 72, 0.1);
    border: 1px solid rgba(225, 29, 72, 0.3); color: var(--primary-red);
    border-radius: 50px; font-size: 0.85rem; font-weight: 600;
    margin-bottom: 1.5rem; letter-spacing: 1px;
    box-shadow: 0 0 20px rgba(225, 29, 72, 0.2);
}

.hero-content h1 {
    font-size: clamp(2.5rem, 7vw, 4.8rem); font-weight: 900;
    letter-spacing: -2px; margin-bottom: 1.5rem; color: white;
    line-height: 1.1; text-shadow: 0 0 40px rgba(225, 29, 72, 0.2);
}

.hero-content h1 span {
    background: linear-gradient(135deg, #fff 0%, var(--primary-red) 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}

.hero-content p {
    font-size: 1.25rem; color: var(--text-muted); margin-bottom: 3rem;
    max-width: 750px; margin-left: auto; margin-right: auto; line-height: 1.8;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.8);
}

.cta-group {
    display: flex; gap: 1.5rem; justify-content: center; flex-wrap: wrap;
}

/* ==================== 按钮 ==================== */
.btn {
    padding: 1rem 2.5rem; border-radius: 12px; font-weight: 600;
    cursor: pointer; transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: inline-flex; align-items: center; gap: 10px; font-size: 1.05rem;
    position: relative; overflow: hidden;
}

.btn-primary,
.btn.btn-primary {
    background-color: var(--primary-red); color: white;
    box-shadow: 0 0 20px var(--primary-red-glow);
}

.btn-primary::before {
    content: ''; position: absolute; top: 0; left: -100%; width: 50%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transform: skewX(-20deg); animation: btn-shine 3s infinite;
}
@keyframes btn-shine {
    0%   { left: -100%; }
    20%  { left: 200%; }
    100% { left: 200%; }
}

.btn-primary:hover {
    background-color: var(--primary-red-hover); transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(225, 29, 72, 0.6);
}

.btn-secondary,
.btn.btn-secondary {
    background-color: rgba(255, 255, 255, 0.03); border: 1px solid var(--border-color);
    color: white; backdrop-filter: blur(10px);
}
.btn-secondary:hover,
.btn.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.1); border-color: #666; transform: translateY(-4px);
}

/* ==================== 数据指标 ==================== */
.trust-metrics {
    display: flex; justify-content: center; gap: 5rem; margin-top: 5rem;
    padding-top: 3rem; border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.metric-item { text-align: center; }
.metric-value {
    display: block; font-size: 2rem; font-weight: 900; color: white;
    margin-bottom: 0.3rem; text-shadow: 0 0 10px rgba(255, 255, 255, 0.2);
}
.metric-label {
    color: var(--text-muted); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 1.5px;
}

/* ==================== 特性板块 ==================== */
.features-wrapper { max-width: 1200px; margin: 120px auto; padding: 0 2rem; }
.section-header { text-align: center; margin-bottom: 4rem; }
.section-header h2 { font-size: 2.5rem; margin-bottom: 1rem; font-weight: 800; }
.section-header p { color: var(--text-muted); font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

.features-layout {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem; align-items: stretch;
}

.feature-box {
    background: var(--card-bg); backdrop-filter: blur(10px);
    padding: 2.5rem; border-radius: 20px; border: 1px solid var(--border-color);
    position: relative; overflow: hidden; transition: all 0.4s ease;
}
.feature-box::before {
    content: ""; position: absolute; top: 0; left: 0; width: 4px; height: 100%;
    background: linear-gradient(to bottom, var(--primary-red), transparent);
    opacity: 0; transition: 0.4s;
}
.feature-box:hover {
    transform: translateY(-10px); border-color: rgba(225, 29, 72, 0.4);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5);
}
.feature-box:hover::before { opacity: 1; }

.feature-icon {
    color: var(--primary-red); margin-bottom: 1.2rem;
    background: rgba(225, 29, 72, 0.1); width: 50px; height: 50px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 12px; transition: 0.3s;
}
.feature-box:hover .feature-icon {
    transform: scale(1.1) rotate(5deg); background: var(--primary-red);
    color: white; box-shadow: 0 0 15px var(--primary-red-glow);
}
.feature-icon svg { width: 28px; height: 28px; }
.feature-box h3 { font-size: 1.3rem; margin-bottom: 0.8rem; }
.feature-box p { color: var(--text-muted); font-size: 0.95rem; line-height: 1.7; }

/* ==================== 下载板块 ==================== */
.download-area {
    text-align: center; padding: 120px 2rem;
    background: radial-gradient(circle at top, rgba(225, 29, 72, 0.08) 0%, transparent 60%);
    border-top: 1px solid rgba(255, 255, 255, 0.03);
}

.os-grid {
    max-width: 1100px; margin: 4rem auto 0; display: grid;
    grid-template-columns: repeat(5, 1fr); gap: 1.5rem;
}

.os-card {
    background: rgba(20, 20, 20, 0.8); padding: 3rem 1rem; border-radius: 20px;
    border: 1px solid var(--border-color); cursor: pointer;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    backdrop-filter: blur(5px);
}
.os-card:hover {
    border-color: var(--primary-red); background: rgba(225, 29, 72, 0.05);
    transform: translateY(-10px); box-shadow: 0 15px 30px rgba(225, 29, 72, 0.15);
}
.os-card i { font-size: 48px; margin-bottom: 1.5rem; color: #666; transition: all 0.4s ease; }
.os-card:hover i {
    color: var(--primary-red); transform: scale(1.15) translateY(-5px);
    filter: drop-shadow(0 5px 15px rgba(225, 29, 72, 0.5));
}
.os-name { font-weight: 700; font-size: 1rem; letter-spacing: 0.5px; }

/* ==================== 页脚 ==================== */
footer {
    border-top: 1px solid var(--border-color); padding: 5rem 2rem 2rem; background: #030303;
}
.footer-grid {
    max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 4rem;
}
.footer-brand .logo { margin-bottom: 1.5rem; }
.footer-brand p { color: var(--text-muted); font-size: 0.95rem; max-width: 350px; line-height: 1.8; }
.footer-col h4 { color: white; font-size: 0.95rem; text-transform: uppercase; letter-spacing: 2px; margin-bottom: 2rem; }
.footer-links { list-style: none; }
.footer-links li { margin-bottom: 1.2rem; }
.footer-links a { color: var(--text-muted); font-size: 0.95rem; }
.footer-links a:hover { color: var(--primary-red); padding-left: 5px; }
.footer-links strong { color: var(--text-primary); font-size: 0.95rem; font-weight: 600; }
.footer-bottom {
    max-width: 1200px; margin: 5rem auto 0; padding-top: 2rem; border-top: 1px solid var(--border-color);
    display: flex; justify-content: space-between; align-items: center; font-size: 0.85rem; color: var(--text-muted);
}

/* ==================== 移动端抽屉关闭按钮 ==================== */
.nav-close-btn {
    display: none;
    position: absolute;
    top: 1.2rem;
    right: 1.2rem;
    width: 36px;
    height: 36px;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    color: var(--text-muted);
    cursor: pointer;
    align-items: center;
    justify-content: center;
    transition: background 0.2s, color 0.2s;
    flex-shrink: 0;
}
.nav-close-btn:hover {
    background: rgba(225, 29, 72, 0.15);
    border-color: rgba(225, 29, 72, 0.4);
    color: var(--primary-red);
}

/* ==================== 汉堡菜单按钮 ==================== */
.nav-hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    cursor: pointer;
    padding: 8px;
    gap: 5px;
    transition: background 0.2s;
    flex-shrink: 0;
}
.nav-hamburger:hover { background: rgba(255, 255, 255, 0.09); }

.hamburger-line {
    width: 18px;
    height: 2px;
    background: var(--text-main);
    border-radius: 2px;
    transition: all 0.3s ease;
    display: block;
}

.nav-hamburger.open .hamburger-line:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open .hamburger-line:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-hamburger.open .hamburger-line:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ==================== 移动端导航遮罩 ==================== */
.nav-mobile-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.65);
    z-index: 998;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}
.nav-mobile-overlay.open { display: block; }

/* ==================== 响应式 ==================== */
@media (max-width: 992px) {
    .os-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 768px) {
    .nav-hamburger { display: flex; }

    .nav-close-btn { display: flex; }

    /* 移动端导航抽屉 */
    .nav-links {
        display: flex !important;
        flex-direction: column;
        align-items: flex-start;
        position: fixed;
        top: 0;
        right: 0;
        width: 80vw;
        max-width: 300px;
        height: 100vh;
        background: rgba(8, 8, 8, 0.98);
        backdrop-filter: blur(24px);
        -webkit-backdrop-filter: blur(24px);
        border-left: 1px solid var(--border-color);
        padding: 80px 1.5rem 2rem;
        z-index: 999;
        gap: 0;
        transform: translateX(110%);
        transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
        overflow-y: auto;
    }
    .nav-links.open { transform: translateX(0); }

    .nav-links > a {
        width: 100%;
        padding: 0.85rem 0;
        border-bottom: 1px solid rgba(255, 255, 255, 0.06);
        font-size: 1rem;
    }

    /* 移动端 dropdown 点击展开 */
    .nav-dropdown {
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
        border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }
    .nav-dropdown::after { display: none; }
    .nav-dropdown-trigger {
        width: 100%;
        padding: 0.85rem 0;
        justify-content: space-between;
    }
    .nav-dropdown-trigger svg {
        transition: transform 0.25s ease;
    }
    .nav-dropdown.open .nav-dropdown-trigger svg {
        transform: rotate(180deg);
        opacity: 1;
    }
    /* 移动端菜单默认收起，点击后展开 */
    .nav-dropdown-menu {
        position: static;
        transform: none !important;
        opacity: 1 !important;
        visibility: visible !important;
        pointer-events: auto !important;
        width: 100%;
        box-shadow: none;
        border: 1px solid rgba(255, 255, 255, 0.06);
        background: rgba(255, 255, 255, 0.03);
        border-radius: 10px;
        margin: 0 0 0.8rem;
        padding: 0.25rem;
        display: none;
    }
    .nav-dropdown.open .nav-dropdown-menu {
        display: block;
    }
    .lang-switch {
        margin-top: 1.5rem;
        width: 100%;
        justify-content: flex-start;
    }
    .lang-dropdown-menu {
        position: static; box-shadow: none; border: 1px solid rgba(255, 255, 255, 0.08);
        background: rgba(255, 255, 255, 0.03); padding: 0.3rem;
        min-width: unset; display: block; margin-top: 0.5rem; border-radius: 8px;
    }
    .lang-switch-caret { display: none; }
    .lang-dropdown-item { padding: 0.4rem 0.7rem; font-size: 0.88rem; }

    .hero-content h1 { font-size: 2.4rem; letter-spacing: -1px; }
    .hero-content p { font-size: 1.05rem; }
    .trust-metrics { flex-direction: column; gap: 2.5rem; }
    .footer-grid { grid-template-columns: 1fr; gap: 3rem; }
    .footer-bottom { flex-direction: column; gap: 1rem; text-align: center; }
    .os-grid { grid-template-columns: repeat(2, 1fr); }
    .download-area { padding: 80px 1.5rem; }
    .features-wrapper { margin: 80px auto; }
    .hero-section { padding-top: 120px; }
    .cta-group { flex-direction: column; width: 100%; }
    .btn { width: 100%; justify-content: center; }
}

@media (max-width: 480px) {
    .hero-content h1 { font-size: 2rem; }
    .os-grid { grid-template-columns: repeat(2, 1fr); gap: 1rem; }
    .os-card { padding: 2rem 0.8rem; }
    .nav-container { padding: 0.85rem 1.2rem; }
}

/* ==================== Clash 是什么 ==================== */
.what-section {
    padding: 120px 2rem;
    border-top: 1px solid var(--border-color);
}
.what-inner {
    max-width: 1200px; margin: 0 auto;
    display: grid; grid-template-columns: 1fr 1fr; gap: 5rem; align-items: center;
}
.what-text h2 {
    font-size: 2.2rem; font-weight: 800; margin-bottom: 1.5rem; line-height: 1.2;
}
.what-text p {
    color: var(--text-muted); line-height: 1.9; margin-bottom: 1.2rem; font-size: 1rem;
}
.what-text p strong { color: var(--text-main); }
.what-list {
    list-style: none; margin-top: 1.8rem; display: flex; flex-direction: column; gap: 0.9rem;
}
.what-list li {
    display: flex; align-items: center; gap: 0.8rem;
    color: var(--text-muted); font-size: 0.95rem;
}
.what-list li i { color: var(--primary-red); font-size: 1rem; flex-shrink: 0; }

/* 流量流向示意图 */
.flow-diagram {
    background: var(--card-bg); border: 1px solid var(--border-color);
    border-radius: 24px; padding: 2.5rem; backdrop-filter: blur(10px);
    display: flex; flex-direction: column; align-items: center; gap: 0;
}
.flow-node {
    display: flex; flex-direction: column; align-items: center; gap: 0.4rem;
    background: rgba(255,255,255,0.04); border: 1px solid var(--border-color);
    border-radius: 16px; padding: 1.2rem 1.8rem; min-width: 120px; text-align: center;
    transition: 0.3s;
}
.flow-node i { font-size: 1.6rem; margin-bottom: 0.2rem; }
.flow-node span { font-weight: 700; font-size: 0.9rem; }
.flow-node small { color: var(--text-muted); font-size: 0.75rem; }
.flow-node-you i { color: #60a5fa; }
.flow-node-clash {
    border-color: var(--primary-red); background: rgba(225,29,72,0.08);
    box-shadow: 0 0 20px rgba(225,29,72,0.15);
}
.flow-node-clash i { color: var(--primary-red); }
.flow-node-direct i { color: #4ade80; }
.flow-node-proxy i { color: #a78bfa; }

.flow-arrow {
    display: flex; flex-direction: column; align-items: center; gap: 4px;
    padding: 0.5rem 0;
}
.flow-label { font-size: 0.72rem; color: var(--text-muted); letter-spacing: 1px; }
.arrow-line {
    width: 2px; height: 30px;
    background: linear-gradient(to bottom, var(--border-color), var(--primary-red));
}

.flow-fork {
    display: flex; gap: 1.5rem; margin-top: 0.5rem;
}
.fork-branch {
    display: flex; flex-direction: column; align-items: center; gap: 0;
}
.arrow-line-h {
    width: 2px; height: 28px;
    background: linear-gradient(to bottom, var(--primary-red), var(--border-color));
}

/* ==================== 四步使用流程 ==================== */
.steps-section {
    padding: 120px 2rem;
    background: radial-gradient(circle at 50% 0%, rgba(225, 29, 72, 0.06) 0%, transparent 60%);
    border-top: 1px solid rgba(255,255,255,0.03);
}
.steps-inner { max-width: 1200px; margin: 0 auto; }

.steps-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 2rem; margin-top: 3rem;
    position: relative;
}
.steps-grid::before {
    content: ""; position: absolute; top: 42px; left: 10%; width: 80%; height: 2px;
    background: linear-gradient(to right, transparent, var(--primary-red), transparent);
    opacity: 0.3; pointer-events: none;
}

.step-card {
    background: var(--card-bg); border: 1px solid var(--border-color);
    border-radius: 20px; padding: 2rem 1.5rem; text-align: center;
    position: relative; transition: all 0.4s ease; backdrop-filter: blur(10px);
}
.step-card:hover {
    border-color: rgba(225,29,72,0.4); transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.4);
}
.step-num {
    position: absolute; top: -14px; left: 50%; transform: translateX(-50%);
    background: var(--primary-red); color: white;
    font-size: 0.75rem; font-weight: 800; letter-spacing: 1px;
    padding: 3px 12px; border-radius: 20px;
}
.step-icon {
    font-size: 2rem; color: var(--primary-red); margin: 1rem 0 1.2rem;
    height: 56px; display: flex; align-items: center; justify-content: center;
}
.step-card h3 { font-size: 1.1rem; margin-bottom: 0.8rem; }
.step-card p { color: var(--text-muted); font-size: 0.9rem; line-height: 1.7; }
.step-card p strong { color: var(--text-main); }

/* ==================== 协议对比 ==================== */
.protocols-section {
    padding: 120px 2rem;
    border-top: 1px solid var(--border-color);
}
.protocols-inner { max-width: 1200px; margin: 0 auto; }

.protocols-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; margin-top: 3rem;
}

.protocol-card {
    background: var(--card-bg); border: 1px solid var(--border-color);
    border-radius: 20px; padding: 2rem; transition: all 0.4s ease;
    backdrop-filter: blur(10px); position: relative; overflow: hidden;
}
.protocol-card::after {
    content: ""; position: absolute; bottom: 0; left: 0; right: 0; height: 3px;
    background: var(--primary-red); transform: scaleX(0); transition: 0.4s;
    transform-origin: left;
}
.protocol-card:hover { transform: translateY(-8px); border-color: rgba(225,29,72,0.3); }
.protocol-card:hover::after { transform: scaleX(1); }

.proto-badge {
    display: inline-flex; align-items: center; justify-content: center;
    width: 52px; height: 52px; border-radius: 14px;
    background: linear-gradient(135deg, var(--primary-red), #7f1d1d);
    color: white; font-size: 1rem; font-weight: 900; letter-spacing: 0.5px;
    margin-bottom: 1.2rem; box-shadow: 0 4px 15px rgba(225,29,72,0.3);
}
.proto-badge-vmess { background: linear-gradient(135deg, #7c3aed, #3730a3); box-shadow: 0 4px 15px rgba(124,58,237,0.3); }
.proto-badge-trojan { background: linear-gradient(135deg, #0369a1, #0c4a6e); box-shadow: 0 4px 15px rgba(3,105,161,0.3); }
.proto-badge-hysteria { background: linear-gradient(135deg, #0d9488, #065f46); box-shadow: 0 4px 15px rgba(13,148,136,0.3); }

.protocol-card h3 { font-size: 1.15rem; margin-bottom: 0.8rem; }
.proto-desc { color: var(--text-muted); font-size: 0.88rem; line-height: 1.7; margin-bottom: 1.2rem; }
.proto-tags {
    list-style: none; display: flex; flex-wrap: wrap; gap: 0.5rem;
}
.proto-tags li {
    background: rgba(255,255,255,0.05); border: 1px solid var(--border-color);
    border-radius: 20px; padding: 3px 10px; font-size: 0.78rem; color: var(--text-muted);
}

/* ==================== FAQ ==================== */
.faq-section {
    padding: 120px 2rem;
    background: radial-gradient(circle at 50% 100%, rgba(225, 29, 72, 0.05) 0%, transparent 60%);
    border-top: 1px solid rgba(255,255,255,0.03);
}
.faq-inner { max-width: 800px; margin: 0 auto; }

.faq-list { margin-top: 3rem; display: flex; flex-direction: column; gap: 1rem; }

.faq-item {
    background: var(--card-bg); border: 1px solid var(--border-color);
    border-radius: 16px; overflow: hidden; transition: border-color 0.3s;
    backdrop-filter: blur(10px);
}
.faq-item:has(.faq-q[aria-expanded="true"]) { border-color: rgba(225,29,72,0.4); }

.faq-q {
    width: 100%; background: none; border: none; color: var(--text-main);
    padding: 1.4rem 1.8rem; font-size: 1rem; font-weight: 600;
    display: flex; justify-content: space-between; align-items: center;
    cursor: pointer; text-align: left; gap: 1rem;
}
.faq-q:hover { color: var(--primary-red); }
.faq-q span { flex: 1; }

.faq-icon {
    flex-shrink: 0; transition: transform 0.35s ease; color: var(--text-muted); font-size: 0.85rem;
}
.faq-q[aria-expanded="true"] .faq-icon { transform: rotate(180deg); color: var(--primary-red); }

.faq-a {
    max-height: 0; overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), padding 0.3s;
    padding: 0 1.8rem;
}
.faq-a.open {
    max-height: 300px;
    padding: 0 1.8rem 1.4rem;
}
.faq-a p { color: var(--text-muted); line-height: 1.8; font-size: 0.95rem; }
.faq-a p strong { color: var(--text-main); }

/* ==================== 新增区块响应式 ==================== */
@media (max-width: 1024px) {
    .protocols-grid { grid-template-columns: repeat(2, 1fr); }
    .steps-grid { grid-template-columns: repeat(2, 1fr); }
    .steps-grid::before { display: none; }
}
@media (max-width: 768px) {
    .what-inner { grid-template-columns: 1fr; gap: 3rem; }
    .flow-diagram { display: none; }
    .steps-grid { grid-template-columns: 1fr; }
    .protocols-grid { grid-template-columns: 1fr; }
    .what-section,
    .steps-section,
    .protocols-section,
    .faq-section { padding: 80px 2rem; }
}