/* ============ 基础重置 ============ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #1a4f8b;
    --primary-dark: #0f3a6b;
    --primary-light: #e8f0fa;
    --accent: #d4a857;
    --text-1: #0f1f3a;
    --text-2: #4a5568;
    --text-3: #718096;
    --bg: #ffffff;
    --bg-soft: #f5f8fc;
    --bg-dark: #0a1a2e;
    --border: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(15, 31, 58, 0.06);
    --shadow: 0 4px 16px rgba(15, 31, 58, 0.08);
    --shadow-lg: 0 12px 40px rgba(26, 79, 139, 0.15);
    --radius: 12px;
    --radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue",
                 Helvetica, Arial, sans-serif;
    color: var(--text-1);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition);
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ============ 导航栏 ============ */
.navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--border);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 20px;
    color: var(--text-1);
}

.logo-icon {
    height: 40px;
    width: auto;
    max-width: 160px;
    object-fit: contain;
}

.logo-text {
    background: linear-gradient(135deg, var(--primary), #2c6cb0);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 0.02em;
}

.nav-links {
    display: flex;
    gap: 36px;
}

.nav-links a {
    font-size: 15px;
    color: var(--text-2);
    font-weight: 500;
    position: relative;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
    transform: translateX(-50%);
}

.nav-links a:hover::after {
    width: 100%;
}

/* ============ Hero 区域 ============ */
.hero {
    padding: 80px 0 100px;
    background: linear-gradient(180deg, #f0f5fb 0%, var(--bg) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -200px;
    right: -200px;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(26, 79, 139, 0.12) 0%, transparent 70%);
    border-radius: 50%;
    z-index: 0;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -300px;
    left: -200px;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(212, 168, 87, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    z-index: 0;
}

.hero-inner {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.badge {
    display: inline-block;
    padding: 7px 16px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 20px;
    border: 1px solid rgba(26, 79, 139, 0.15);
}

.hero-text h1 {
    font-size: 48px;
    line-height: 1.25;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--text-1);
    letter-spacing: -0.02em;
}

.subtitle {
    font-size: 17px;
    color: var(--text-2);
    margin-bottom: 32px;
    line-height: 1.75;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: var(--radius);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    white-space: nowrap;
    text-align: center;
    gap: 8px;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 4px 14px rgba(26, 79, 139, 0.3);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(26, 79, 139, 0.4);
}

.btn-ghost {
    background: transparent;
    color: var(--text-1);
    border: 1.5px solid var(--border);
}

.btn-ghost:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.btn-download {
    padding: 14px 28px;
    font-size: 15px;
}

.btn-download svg {
    width: 18px;
    height: 18px;
}

.hero-stats {
    display: flex;
    gap: 48px;
}

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

.stat strong {
    font-size: 24px;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 4px;
}

.stat span {
    font-size: 13px;
    color: var(--text-3);
}

/* 手机模型 */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.phone-mockup {
    width: 280px;
    height: 560px;
    background: linear-gradient(145deg, #0a1a2e 0%, #1a2a4a 100%);
    border-radius: 40px;
    padding: 16px;
    box-shadow: 0 30px 60px rgba(26, 79, 139, 0.3), 0 0 0 8px rgba(255, 255, 255, 0.1);
    position: relative;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, #e8f0fa 0%, #f5f8fc 100%);
    border-radius: 28px;
    padding: 60px 20px 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    overflow: hidden;
}

.chat-bubble {
    max-width: 75%;
    padding: 10px 14px;
    background: #fff;
    border-radius: 16px;
    font-size: 13px;
    color: var(--text-1);
    box-shadow: var(--shadow-sm);
    align-self: flex-start;
    animation: slideIn 0.6s ease-out backwards;
    line-height: 1.5;
}

.chat-bubble b {
    color: var(--primary);
    font-weight: 600;
}

.chat-bubble:nth-child(1) { animation-delay: 0.2s; }
.chat-bubble:nth-child(2) { animation-delay: 0.5s; }
.chat-bubble:nth-child(3) { animation-delay: 0.8s; }
.chat-bubble:nth-child(4) { animation-delay: 1.1s; }

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

.chat-bubble.me {
    background: var(--primary);
    color: #fff;
    align-self: flex-end;
}

/* ============ 通用 Section ============ */
section {
    padding: 90px 0;
}

.section-title {
    font-size: 36px;
    font-weight: 800;
    text-align: center;
    margin-bottom: 12px;
    color: var(--text-1);
    letter-spacing: -0.02em;
}

.section-subtitle {
    font-size: 16px;
    color: var(--text-3);
    text-align: center;
    margin-bottom: 56px;
}

/* ============ 核心优势（特性）区域 ============ */
.features {
    background: var(--bg);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg);
    padding: 36px 28px;
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
    border: 1.5px solid var(--border);
}

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

.feature-icon {
    width: 72px;
    height: 72px;
    margin: 0 auto 20px;
    border-radius: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
}

.feature-icon svg {
    width: 34px;
    height: 34px;
}

.icon-1 { background: linear-gradient(135deg, #1a4f8b, #2c6cb0); }
.icon-2 { background: linear-gradient(135deg, #d4a857, #c89a45); }
.icon-3 { background: linear-gradient(135deg, #2d6a4f, #40916c); }
.icon-4 { background: linear-gradient(135deg, #6b4423, #8b5a3c); }

.feature-card h3 {
    font-size: 19px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-1);
}

.feature-card p {
    font-size: 14px;
    color: var(--text-3);
    line-height: 1.7;
}

/* ============ 安全合规区域 ============ */
.security {
    background: linear-gradient(180deg, var(--bg-soft) 0%, #e8f0fa 100%);
}

.security-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.security-item {
    background: #fff;
    padding: 32px 28px;
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.security-item:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow);
    border-left-color: var(--accent);
}

.security-num {
    font-size: 28px;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 12px;
    font-family: "SF Mono", Consolas, monospace;
    opacity: 0.4;
}

.security-item h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-1);
}

.security-item p {
    font-size: 14px;
    color: var(--text-3);
    line-height: 1.7;
}

/* ============ 应用场景区域 ============ */
.scenarios {
    background: var(--bg);
}

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

.scenario-card {
    background: linear-gradient(135deg, var(--bg-soft) 0%, #fff 100%);
    padding: 32px 24px;
    border-radius: var(--radius-lg);
    border: 1.5px solid var(--border);
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.scenario-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition);
}

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

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

.scenario-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--primary);
}

.scenario-card p {
    font-size: 14px;
    color: var(--text-3);
    line-height: 1.7;
}

/* ============ 下载区域 ============ */
.download {
    background: linear-gradient(180deg, #e8f0fa 0%, var(--bg-soft) 100%);
}

.download-main {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 32px;
    align-items: stretch;
    margin-bottom: 60px;
}

.download-primary {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow);
    border: 1.5px solid var(--border);
    display: flex;
    align-items: center;
}

.download-platform {
    display: flex;
    align-items: center;
    gap: 28px;
    width: 100%;
}

.platform-icon-large {
    width: 88px;
    height: 88px;
    min-width: 88px;
    background: linear-gradient(135deg, var(--primary), #2c6cb0);
    color: #fff;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 8px 20px rgba(26, 79, 139, 0.25);
}

.platform-icon-large svg {
    width: 48px;
    height: 48px;
}

.download-info h3 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-1);
    margin-bottom: 4px;
}

.platform-desc {
    font-size: 14px;
    color: var(--text-3);
    margin-bottom: 12px;
}

.version-info {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
}

.version-tag {
    display: inline-block;
    padding: 3px 10px;
    background: #fff5e1;
    color: #b8861a;
    font-size: 12px;
    font-weight: 600;
    border-radius: 6px;
}

.version-num {
    font-size: 14px;
    color: var(--text-2);
    font-weight: 500;
    font-family: "SF Mono", Consolas, monospace;
}

/* 二维码区 */
.download-qrcode {
    display: flex;
    align-items: center;
}

.qrcode-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    box-shadow: var(--shadow);
    border: 1.5px solid var(--border);
    text-align: center;
    width: 100%;
}

.qrcode-card h4 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-1);
    margin-bottom: 20px;
}

.qrcode {
    width: 180px;
    height: 180px;
    margin: 0 auto 16px;
    border: 2px solid var(--border);
    border-radius: 12px;
    padding: 8px;
    background: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
}

.qrcode img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.qrcode-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-soft);
    color: var(--text-3);
    font-size: 12px;
    text-align: center;
    border-radius: 6px;
    line-height: 1.5;
}

.qrcode-card p {
    color: var(--text-2);
    font-size: 13px;
    line-height: 1.6;
}

/* 其他平台入口 */
.download-others {
    margin-bottom: 40px;
}

.others-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-1);
    text-align: center;
    margin-bottom: 24px;
    position: relative;
}

.others-title::before,
.others-title::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 60px;
    height: 1px;
    background: var(--border);
}

.others-title::before { left: calc(50% - 130px); }
.others-title::after { right: calc(50% - 130px); }

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

.other-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 28px 20px;
    box-shadow: var(--shadow);
    border: 1.5px solid var(--border);
    display: flex;
    align-items: center;
    gap: 16px;
    transition: var(--transition);
    cursor: pointer;
    color: var(--text-1);
}

.other-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.other-card-web {
    background: linear-gradient(135deg, #1a4f8b 0%, #2c6cb0 100%);
    color: #fff;
    border-color: transparent;
}

.other-card-web:hover {
    border-color: var(--accent);
    box-shadow: 0 12px 32px rgba(26, 79, 139, 0.35);
}

.other-card-web .other-info h4,
.other-card-web .other-info p,
.other-card-web .other-info .other-link {
    color: #fff;
}

.other-icon {
    width: 52px;
    height: 52px;
    min-width: 52px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
}

.other-icon svg {
    width: 28px;
    height: 28px;
}

.icon-ios { background: linear-gradient(135deg, #1a1a1a, #424242); }
.icon-windows { background: linear-gradient(135deg, #0078d4, #00a2ed); }
.icon-mac { background: linear-gradient(135deg, #555, #888); }
.icon-web {
    background: rgba(255, 255, 255, 0.2);
    border: 1.5px solid rgba(255, 255, 255, 0.4);
}

.other-info h4 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 4px;
    color: var(--text-1);
}

.other-info p {
    font-size: 12px;
    color: var(--text-3);
    margin-bottom: 6px;
}

.other-link {
    font-size: 12px;
    color: var(--primary);
    font-weight: 600;
}

.other-card-web .other-link {
    color: var(--accent);
}

/* 安装说明 */
.install-tips {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow);
    border: 1.5px solid var(--border);
}

.install-tips h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-1);
    margin-bottom: 24px;
    text-align: center;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.tip-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
}

.tip-num {
    width: 36px;
    height: 36px;
    min-width: 36px;
    background: linear-gradient(135deg, var(--primary), #2c6cb0);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 16px;
    box-shadow: 0 4px 10px rgba(26, 79, 139, 0.25);
}

.tip-item h4 {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-1);
    margin-bottom: 4px;
}

.tip-item p {
    font-size: 13px;
    color: var(--text-3);
    line-height: 1.6;
}

/* ============ 页脚 ============ */
.footer {
    background: var(--bg-dark);
    color: #cbd5e0;
    padding: 60px 0 24px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.2fr 2fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-info h4 {
    color: #fff;
    font-size: 22px;
    margin-bottom: 12px;
    background: linear-gradient(135deg, #fff, #d4a857);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 700;
}

.footer-info p {
    color: #a0aec0;
    font-size: 14px;
    line-height: 1.7;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.footer-col h5 {
    color: #fff;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-col a {
    display: block;
    color: #a0aec0;
    font-size: 14px;
    margin-bottom: 10px;
    transition: var(--transition);
}

.footer-col a:hover {
    color: #d4a857;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 24px;
    text-align: center;
    color: #718096;
    font-size: 13px;
}

/* ============ 浮动下载按钮（仅移动端） ============ */
.floating-download {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--primary);
    color: #fff;
    padding: 14px 20px;
    border-radius: 50px;
    box-shadow: 0 8px 24px rgba(26, 79, 139, 0.4);
    z-index: 99;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 15px;
    animation: pulse 2s infinite;
}

.floating-download svg {
    width: 20px;
    height: 20px;
}

@keyframes pulse {
    0%, 100% { box-shadow: 0 8px 24px rgba(26, 79, 139, 0.4); }
    50% { box-shadow: 0 8px 32px rgba(26, 79, 139, 0.7); }
}

/* ============ 响应式 ============ */
@media (max-width: 968px) {
    .hero-inner {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero-text h1 {
        font-size: 38px;
    }
    .hero-actions {
        justify-content: center;
    }
    .hero-stats {
        justify-content: center;
    }
    .phone-mockup {
        width: 240px;
        height: 480px;
    }
    .feature-grid,
    .scenario-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .security-grid {
        grid-template-columns: 1fr;
    }
    .download-main {
        grid-template-columns: 1fr;
    }
    .others-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 640px) {
    .container {
        padding: 0 16px;
    }
    section {
        padding: 60px 0;
    }
    .hero {
        padding: 50px 0 70px;
    }
    .hero-text h1 {
        font-size: 30px;
    }
    .subtitle {
        font-size: 15px;
    }
    .section-title {
        font-size: 26px;
    }
    .section-subtitle {
        font-size: 14px;
        margin-bottom: 36px;
    }
    .nav-links {
        display: none;
    }
    .hero-stats {
        gap: 24px;
        flex-wrap: wrap;
    }
    .stat strong {
        font-size: 20px;
    }
    .stat span {
        font-size: 12px;
    }
    .feature-grid,
    .scenario-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .others-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    .other-card {
        padding: 20px 16px;
    }
    .tips-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
    .floating-download {
        display: flex;
    }
    .phone-mockup {
        width: 200px;
        height: 400px;
    }
    .phone-screen {
        padding: 40px 14px 14px;
    }
    .chat-bubble {
        font-size: 12px;
        padding: 8px 10px;
    }
    .download-primary,
    .qrcode-card,
    .install-tips {
        padding: 24px;
    }
    .download-platform {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }
    .platform-icon-large {
        width: 72px;
        height: 72px;
        min-width: 72px;
    }
    .platform-icon-large svg {
        width: 38px;
        height: 38px;
    }
    .version-info {
        justify-content: center;
    }
}

@media (max-width: 380px) {
    .hero-text h1 {
        font-size: 26px;
    }
    .btn {
        padding: 12px 24px;
        font-size: 14px;
    }
    .floating-download span {
        display: none;
    }
    .floating-download {
        padding: 14px;
    }
}