/* ============================================
   火绒安全 - 全新极简设计 v3
   ============================================ */

:root {
    /* 品牌色 */
    --brand: #e8453c;
    --brand-dark: #c0392b;
    --brand-light: #fdecea;
    --brand-gradient: linear-gradient(135deg, #e8453c 0%, #ff6b4a 100%);

    /* 中性色 */
    --white: #ffffff;
    --bg: #fafbfc;
    --bg-secondary: #f1f3f5;
    --text: #1a1a2e;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    --border: #e5e7eb;

    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.05), 0 2px 4px rgba(0,0,0,0.04);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.06), 0 4px 10px rgba(0,0,0,0.03);
    --shadow-xl: 0 20px 50px rgba(0,0,0,0.08);

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

    /* 字体 */
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

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

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

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

/* ======== 导航栏 ======== */
.nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    height: 64px;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
}

.nav-inner {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text);
    font-weight: 700;
    font-size: 18px;
}

.nav-logo svg {
    width: 36px;
    height: 36px;
}

.nav-menu {
    display: flex;
    gap: 4px;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    padding: 8px 18px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s;
}

.nav-link:hover { color: var(--text); background: var(--bg-secondary); }

.nav-link.active { 
    color: var(--brand);
    background: var(--brand-light);
}

/* ======== 容器 ======== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 32px;
}

/* ======== Hero 区域 ======== */
.hero {
    padding-top: 160px;
    padding-bottom: 100px;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--brand-light);
    color: var(--brand);
    padding: 6px 16px;
    border-radius: 100px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 24px;
}

.hero-badge-dot {
    width: 8px; height: 8px;
    background: var(--brand);
    border-radius: 50%;
    animation: blink 1.5s ease infinite;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.3; }
}

.hero-title {
    font-size: clamp(44px, 5.5vw, 64px);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -1.5px;
    color: var(--text);
    margin-bottom: 20px;
}

.hero-title em {
    font-style: normal;
    color: var(--brand);
}

.hero-desc {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 36px;
    max-width: 440px;
}

.hero-actions {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

/* ======== 按钮 ======== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all 0.25s;
    font-family: inherit;
}

.btn-primary {
    background: var(--brand-gradient);
    color: white;
    box-shadow: 0 4px 20px rgba(232,69,60,0.35);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(232,69,60,0.45);
}

.btn-outline {
    background: white;
    color: var(--text);
    border: 1px solid var(--border);
}

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

.btn-lg { padding: 16px 36px; font-size: 16px; border-radius: 14px; }
.btn-block { width: 100%; justify-content: center; }

.btn-icon { font-size: 18px; }

/* ======== 英雄视觉区 ======== */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.shield-wrapper {
    position: relative;
    width: 380px;
    height: 380px;
}

.shield-center {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 160px; height: 180px;
    background: var(--brand-gradient);
    clip-path: polygon(50% 0%, 100% 20%, 100% 60%, 50% 100%, 0% 60%, 0% 20%);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2;
    animation: float 5s ease-in-out infinite;
}

.shield-center::after {
    content: '';
    width: 100px; height: 115px;
    background: white;
    clip-path: polygon(50% 5%, 95% 22%, 95% 58%, 50% 95%, 5% 58%, 5% 22%);
}

.shield-check {
    position: absolute;
    z-index: 3;
    font-size: 40px;
    top: 50%; left: 50%;
    transform: translate(-50%, -55%);
    color: var(--brand);
}

@keyframes float {
    0%, 100% { transform: translate(-50%, -50%) translateY(0); }
    50% { transform: translate(-50%, -50%) translateY(-12px); }
}

.shield-orbit {
    position: absolute;
    top: 50%; left: 50%;
    border-radius: 50%;
    border: 1.5px dashed var(--border);
    transform: translate(-50%, -50%);
}

.orbit-1 { width: 260px; height: 260px; animation: spin 20s linear infinite; }
.orbit-2 { width: 330px; height: 330px; animation: spin 25s linear infinite reverse; }
.orbit-3 { width: 400px; height: 400px; animation: spin 30s linear infinite; border-style: dotted; }

@keyframes spin {
    from { transform: translate(-50%, -50%) rotate(0deg); }
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.orbit-dot {
    position: absolute;
    width: 10px; height: 10px;
    background: var(--brand);
    border-radius: 50%;
    top: -5px; left: 50%;
    box-shadow: 0 0 12px rgba(232,69,60,0.5);
}

.orbit-2 .orbit-dot { background: #f59e0b; box-shadow: 0 0 12px rgba(245,158,11,0.5); }
.orbit-3 .orbit-dot { background: #8b5cf6; box-shadow: 0 0 12px rgba(139,92,246,0.5); }

/* ======== 统计栏 ======== */
.stats {
    padding: 0 0 100px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.stat-item {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 32px 24px;
    text-align: center;
    transition: all 0.3s;
    cursor: default;
}

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

.stat-icon { font-size: 32px; margin-bottom: 12px; }

.stat-num {
    font-size: 44px;
    font-weight: 800;
    color: var(--text);
    line-height: 1;
    margin-bottom: 8px;
}

.stat-num.green { color: #16a34a; }

.stat-txt {
    color: var(--text-muted);
    font-size: 14px;
    font-weight: 500;
}

/* ======== 区块标题 ======== */
.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    background: var(--brand-light);
    color: var(--brand);
    padding: 6px 16px;
    border-radius: 100px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(32px, 3.5vw, 44px);
    font-weight: 800;
    margin-bottom: 12px;
    letter-spacing: -0.5px;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 17px;
}

/* ======== 功能卡片 ======== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.feature-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 36px;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: var(--brand-gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s;
}

.feature-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-6px);
    border-color: transparent;
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-icon {
    width: 56px; height: 56px;
    background: var(--brand-light);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 26px;
    margin-bottom: 20px;
    transition: transform 0.3s;
}

.feature-card:hover .feature-icon {
    transform: scale(1.1);
    background: var(--brand-gradient);
}

.feature-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 8px;
}

.feature-desc {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.7;
}

/* ======== 对比区块 ======== */
.compare-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    max-width: 900px;
    margin: 0 auto;
}

.compare-card {
    background: white;
    border-radius: var(--radius-xl);
    padding: 40px;
    border: 2px solid var(--border);
    transition: all 0.3s;
}

.compare-card:hover {
    box-shadow: var(--shadow-md);
}

.compare-card.win {
    border-color: #bbf7d0;
    background: #f0fdf4;
}

.compare-card.lose {
    border-color: #fecaca;
    background: #fef2f2;
}

.compare-badge {
    width: 44px; height: 44px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 16px;
}

.compare-card.win .compare-badge {
    background: #dcfce7;
    color: #16a34a;
}

.compare-card.lose .compare-badge {
    background: #fee2e2;
    color: #dc2626;
}

.compare-name {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 20px;
}

.compare-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.compare-list li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.5;
}

.compare-card.win .compare-list li::before {
    content: '✓';
    color: #16a34a;
    font-weight: 700;
    flex-shrink: 0;
    margin-top: 1px;
}

.compare-card.lose .compare-list li::before {
    content: '✗';
    color: #dc2626;
    font-weight: 700;
    flex-shrink: 0;
    margin-top: 1px;
}

/* ======== 下载页 ======== */
.download-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 100px 20px 60px;
}

.download-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 56px 48px;
    max-width: 480px;
    width: 100%;
    text-align: center;
    box-shadow: var(--shadow-xl);
    position: relative;
    overflow: hidden;
}

.download-card::before {
    content: '';
    position: absolute;
    top: -80px; left: -80px;
    width: 200px; height: 200px;
    background: var(--brand);
    opacity: 0.04;
    border-radius: 50%;
}

.download-card::after {
    content: '';
    position: absolute;
    bottom: -80px; right: -80px;
    width: 250px; height: 250px;
    background: var(--brand);
    opacity: 0.04;
    border-radius: 50%;
}

.download-icon-wrap {
    width: 100px; height: 100px;
    background: var(--brand-gradient);
    border-radius: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
    box-shadow: 0 12px 40px rgba(232,69,60,0.3);
    position: relative;
    z-index: 1;
}

.download-icon-wrap svg {
    width: 50px; height: 50px;
}

.download-name {
    font-size: 30px;
    font-weight: 800;
    margin-bottom: 6px;
    position: relative;
    z-index: 1;
}

.download-slogan {
    color: var(--text-secondary);
    font-size: 15px;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
}

.version-pill {
    display: inline-block;
    background: var(--brand-gradient);
    color: white;
    padding: 6px 20px;
    border-radius: 100px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 28px;
    position: relative;
    z-index: 1;
}

.download-info {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: 20px;
    margin-bottom: 20px;
    text-align: left;
    position: relative;
    z-index: 1;
}

.info-row {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    font-size: 14px;
}

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

.info-label { color: var(--text-muted); }
.info-val { color: var(--text); font-weight: 500; }

.download-pledge {
    display: flex;
    justify-content: center;
    gap: 28px;
    margin-bottom: 28px;
    position: relative;
    z-index: 1;
}

.pledge-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--text-secondary);
}

.pledge-item .pledge-icon { font-size: 22px; }

.back-btn {
    display: inline-block;
    margin-top: 20px;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
    position: relative;
    z-index: 1;
}

.back-btn:hover { color: var(--brand); }

/* ======== 联系我们 ======== */
.contact {
    padding: 100px 0;
    background: white;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.contact-icon {
    font-size: 60px;
    margin-bottom: 16px;
}

.contact-title {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 8px;
}

.contact-desc {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.form-group { text-align: left; }

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--text);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    font-family: var(--font);
    transition: border-color 0.2s;
    background: var(--bg);
    color: var(--text);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--brand);
    box-shadow: 0 0 0 3px var(--brand-light);
}

.form-group textarea { min-height: 100px; resize: vertical; }

/* ======== 404 页 ======== */
.error-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 20px 60px;
}

.error-wrap {
    text-align: center;
}

.error-num {
    font-size: 160px;
    font-weight: 900;
    line-height: 1;
    color: var(--brand);
    opacity: 0.12;
    margin-bottom: -30px;
    pointer-events: none;
    user-select: none;
}

.error-shield-wrap {
    position: relative;
    width: 180px; height: 180px;
    margin: 0 auto 32px;
}

.error-shield {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    font-size: 72px;
    opacity: 0.25;
}

.error-ring-a {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 140px; height: 140px;
    border: 2px solid var(--border);
    border-radius: 50%;
    animation: errorPulse 2s infinite;
}

.error-ring-b {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 200px; height: 200px;
    border: 1.5px solid var(--border);
    border-radius: 50%;
    animation: errorPulse 2s infinite 0.4s;
}

@keyframes errorPulse {
    0%, 100% { opacity: 0.4; transform: translate(-50%, -50%) scale(1); }
    50% { opacity: 0.15; transform: translate(-50%, -50%) scale(1.06); }
}

.error-msg h2 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 8px;
}

.error-msg p {
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.error-btns {
    display: flex;
    gap: 14px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ======== 页脚 ======== */
.footer {
    text-align: center;
    padding: 32px 20px;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 14px;
}

.footer a {
    color: var(--brand);
    text-decoration: none;
}

.footer a:hover { text-decoration: underline; }

/* ======== 动画类 ======== */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ======== 响应式 ======== */
@media (max-width: 1024px) {
    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 60px;
    }
    .hero-desc { margin: 0 auto 36px; }
    .hero-actions { justify-content: center; }
    .hero-visual { order: -1; }
    .shield-wrapper { width: 280px; height: 280px; }
    .shield-center { width: 120px; height: 135px; }
    .shield-center::after { width: 76px; height: 88px; }
    .orbit-1 { width: 200px; height: 200px; }
    .orbit-2 { width: 250px; height: 250px; }
    .orbit-3 { width: 300px; height: 300px; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .contact-grid { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
    .nav-inner { padding: 0 20px; }
    .container { padding: 0 20px; }
    .hero { padding-top: 140px; padding-bottom: 60px; }
    .hero-title { font-size: 36px; }
    .hero-actions { flex-direction: column; }
    .btn { width: 100%; justify-content: center; }
    .stats-grid { grid-template-columns: 1fr 1fr; }
    .features-grid { grid-template-columns: 1fr; }
    .compare-grid { grid-template-columns: 1fr; }
    .download-card { padding: 40px 24px; }
    .download-pledge { gap: 16px; }
    .section { padding: 60px 0; }
    .error-btns { flex-direction: column; }
}