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

body {
    font-family: 'Helvetica Neue', Helvetica, 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
    color: #111b21;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

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

/* 导航栏 */
.navbar {
    background-color: #e2fbd7; /* 匹配首屏背景色 */
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 20px;
    font-weight: 700;
    color: #25d366;
}

.nav-links {
    display: flex;
    gap: 32px;
    font-size: 15px;
    font-weight: 500;
}

.nav-links a:hover {
    text-decoration: underline;
}

.nav-buttons {
    display: flex;
    gap: 16px;
    align-items: center;
}

.btn-primary {
    background-color: #25d366;
    color: #111b21;
    padding: 12px 24px;
    border-radius: 40px;
    font-weight: 700;
    font-size: 15px;
    display: inline-flex;
    align-items: center;
    transition: background-color 0.2s;
}

.btn-primary:hover {
    background-color: #1da851;
}

.btn-outline {
    border: 1px solid #111b21;
    padding: 10px 20px;
    border-radius: 40px;
    font-weight: 700;
    font-size: 15px;
    background: transparent;
}

.btn-outline:hover {
    background-color: rgba(0,0,0,0.05);
}

/* 首屏 Hero */
.hero {
    background-color: #e2fbd7;
    padding: 60px 0 100px;
}

.hero-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
}

.hero-text {
    flex: 1;
    max-width: 550px;
}

.hero-text h1 {
    font-size: 56px;
    font-weight: 400;
    margin-bottom: 16px;
    letter-spacing: -1px;
}

.subtitle {
    font-size: 18px;
    margin-bottom: 12px;
}

.legal {
    font-size: 12px;
    color: #5e5e5e;
    margin-bottom: 40px;
}

.legal a {
    text-decoration: underline;
}

/* 下载卡片 */
.download-card {
    background: white;
    padding: 32px;
    border-radius: 24px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    margin-bottom: 24px;
}

.badge {
    font-size: 14px;
    color: #5e5e5e;
    margin-bottom: 8px;
    display: block;
}

.download-card h2 {
    font-size: 32px;
    font-weight: 400;
    margin-bottom: 16px;
}

.download-card p {
    font-size: 15px;
    color: #5e5e5e;
    margin-bottom: 24px;
    line-height: 1.6;
}

.store-btn {
    background: #000;
    color: white;
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 8px 20px;
    border-radius: 8px;
    text-decoration: none;
    transition: transform 0.2s;
}

.store-btn:hover {
    transform: translateY(-2px);
}

.store-icon {
    width: 24px;
    height: 24px;
}

.store-text {
    display: flex;
    flex-direction: column;
}

.store-text .small {
    font-size: 10px;
    line-height: 1;
    margin-bottom: 2px;
}

.store-text .big {
    font-size: 16px;
    font-weight: 600;
    line-height: 1;
}

.browser-link {
    font-weight: 700;
    font-size: 16px;
    border-bottom: 2px solid #25d366;
    padding-bottom: 4px;
    display: inline-block;
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
}

.hero-image img {
    width: 100%;
    max-width: 280px;
    object-fit: contain;
}

/* 通用双列滚动布局 */
.section-flex {
    display: flex;
    gap: 80px;
    align-items: center;
}

.section-header {
    flex: 0 0 300px;
}

.section-header h2 {
    font-size: 48px;
    font-weight: 400;
    line-height: 1.2;
    margin-bottom: 16px;
}

.section-header p {
    font-size: 16px;
    color: #5e5e5e;
    margin-bottom: 32px;
}

/* 创意排版加强 */
.gradient-heading {
    font-size: 56px !important;
    font-weight: 800 !important;
    line-height: 1.1 !important;
    letter-spacing: -2px;
    background: linear-gradient(135deg, #111b21 30%, #25d366 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 24px !important;
}

.highlight-desc {
    font-size: 20px !important;
    color: #5e5e5e !important;
    line-height: 1.6 !important;
    border-left: 4px solid #25d366;
    padding-left: 16px;
    margin-bottom: 40px !important;
    font-weight: 500;
}

.nav-arrows {
    display: flex;
    gap: 12px;
}

.arrow-btn {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 1px solid #111b21;
    background: transparent;
    cursor: pointer;
    font-size: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

.arrow-btn:hover {
    background: rgba(0,0,0,0.05);
}

.cards-slider {
    flex: 1;
    display: flex;
    gap: 24px;
    overflow-x: auto;
    padding: 20px 0;
    scrollbar-width: none; /* Firefox */
}
.cards-slider::-webkit-scrollbar {
    display: none; /* Chrome */
}

/* 其他下载选项 */
.other-downloads {
    background-color: #fcf5eb;
    padding: 100px 0;
}

.device-card {
    background: white;
    padding: 40px 32px;
    border-radius: 24px;
    min-width: 320px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.03);
    display: flex;
    flex-direction: column;
}

.new-badge {
    background: #e2fbd7;
    color: #075e54;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 700;
    display: inline-block;
    margin-bottom: 16px;
    align-self: flex-start;
}

.device-type {
    font-size: 16px;
    color: #5e5e5e;
    margin-bottom: 4px;
}

.device-card h3 {
    font-size: 32px;
    font-weight: 400;
    margin-bottom: 16px;
}

.device-card p {
    font-size: 15px;
    color: #111b21;
    margin-bottom: 24px;
    flex-grow: 1;
}

.device-card .req {
    font-size: 12px;
    color: #5e5e5e;
    margin-bottom: 24px;
}

/* 私密收发消息 (深色) */
.private-messaging {
    background-color: #111b21;
    color: white;
    padding: 120px 0;
}

.private-messaging .section-flex {
    align-items: center;
}

.text-content {
    flex: 1;
    max-width: 450px;
}

.text-content h2 {
    font-size: 64px;
    font-weight: 400;
    line-height: 1.1;
    margin-bottom: 24px;
}

.text-green {
    color: #25d366;
}

.text-content p {
    font-size: 18px;
    color: #a0aab0;
    line-height: 1.6;
}

/* 隐私文字创意排版 */
.privacy-creative-text {
    margin-top: 32px;
    border-left: 2px solid rgba(37, 211, 102, 0.3);
    padding-left: 24px;
    position: relative;
}

.privacy-creative-text::before {
    content: '🔒';
    position: absolute;
    left: -18px;
    top: -10px;
    font-size: 24px;
    background-color: #111b21;
    padding: 4px 0;
}

.privacy-creative-text .p-lead {
    font-size: 24px;
    color: #ffffff;
    font-weight: 300;
    letter-spacing: 1px;
    margin-bottom: 16px;
}

.privacy-creative-text .p-body {
    font-size: 18px;
    color: #a0aab0;
    line-height: 1.8;
}

.glow-text {
    color: #25d366;
    font-weight: 700;
    text-shadow: 0 0 15px rgba(37, 211, 102, 0.4);
    letter-spacing: 0.5px;
}

.lock-highlight {
    background-color: rgba(255, 255, 255, 0.1);
    color: #ffffff;
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 16px;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.image-content {
    flex: 1.5;
    display: flex;
    justify-content: center;
}

.image-content img {
    width: 100%;
    max-width: 800px;
    border-radius: 24px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
}

/* 已经下载？ */
.already-downloaded {
    background-color: #ffffff;
    padding: 100px 0;
}

.feature-card {
    min-width: 350px;
    border-radius: 24px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.feature-card img {
    width: 100%;
    height: 240px;
    object-fit: cover;
    border-radius: 24px;
}

.fc-text h3 {
    font-size: 28px;
    font-weight: 400;
    margin-bottom: 16px;
}

.link-more {
    font-weight: 700;
    font-size: 16px;
    border-bottom: 2px solid #25d366;
    padding-bottom: 4px;
    display: inline-block;
    color: #111b21;
}

/* 复杂页脚 */
.footer-complex {
    background-color: #111b21;
    color: white;
    padding: 80px 0 40px;
}

.footer-top {
    display: flex;
    gap: 80px;
    margin-bottom: 80px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 32px;
}

.footer-links {
    display: flex;
    flex: 1;
    justify-content: space-between;
}

.footer-col {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.footer-col h4 {
    color: #a0aab0;
    font-size: 14px;
    font-weight: 500;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.footer-col a {
    font-size: 15px;
    font-weight: 500;
    color: white;
    transition: color 0.2s;
}

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

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 40px;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.footer-copy {
    display: flex;
    align-items: center;
    gap: 32px;
    font-size: 14px;
    color: #a0aab0;
}

.footer-social {
    display: flex;
    align-items: center;
    gap: 16px;
}

.social-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid white;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
    text-decoration: none;
    color: white;
}

.social-icon:hover {
    background-color: rgba(255,255,255,0.1);
}

.lang-selector select {
    background: transparent;
    color: white;
    border: 1px solid white;
    padding: 10px 32px 10px 16px;
    border-radius: 40px;
    appearance: none;
    cursor: pointer;
    font-size: 14px;
}

/* 翻转布局 */
.section-flex.reverse {
    flex-direction: row-reverse;
}

/* 语音与视频通话 */
.calls-section {
    background-color: #f0f8ff;
    padding: 120px 0;
}

.calls-section .text-content {
    color: #111b21;
}

/* 语音视频通话创意排版 */
.calls-creative-text .badge-pill {
    display: inline-block;
    background: #e1f0ff;
    color: #005bb5;
    padding: 6px 16px;
    border-radius: 40px;
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 24px;
    border: 1px solid #b6dbff;
}

.calls-creative-text .hero-heading {
    font-size: 56px;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 24px;
    color: #111b21;
    letter-spacing: -1px;
}

.text-gradient-green {
    background: linear-gradient(135deg, #128C7E, #25d366);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.calls-creative-text .desc-text {
    font-size: 20px;
    color: #5e5e5e;
    line-height: 1.8;
    margin-bottom: 40px;
}

.highlight-inline {
    position: relative;
    display: inline-block;
    z-index: 1;
    font-weight: 600;
    color: #111b21;
}

.highlight-inline::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 0;
    width: 100%;
    height: 8px;
    background-color: rgba(0, 198, 255, 0.3);
    z-index: -1;
    border-radius: 4px;
}

.text-dark {
    color: #111b21;
    font-weight: 700;
}

/* 多人头像组 */
.avatars-group {
    display: flex;
    align-items: center;
}

.avatars-group img, .avatar-more {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 3px solid #f0f8ff;
    object-fit: cover;
    margin-left: -12px;
}

.avatars-group img:first-child {
    margin-left: 0;
}

.avatar-more {
    background: #0078D4;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 14px;
    z-index: 1;
}

.avatars-text {
    margin-left: 16px;
    font-size: 15px;
    color: #5e5e5e;
    font-weight: 500;
}

/* 表达真情实感 Bento Grid */
.express-section {
    background-color: #ffffff;
    padding: 120px 0;
}

.section-center-header {
    text-align: center;
    max-width: 650px;
    margin: 0 auto 60px;
}

.express-header .express-tag {
    display: inline-block;
    background: #e2fbd7;
    color: #128C7E;
    padding: 6px 16px;
    border-radius: 40px;
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 20px;
    border: 1px solid #c4f0b3;
    box-shadow: 0 4px 10px rgba(37, 211, 102, 0.1);
}

.section-center-header h2 {
    font-size: 56px;
    font-weight: 800;
    margin-bottom: 24px;
    letter-spacing: -1px;
    color: #111b21;
}

.section-center-header p {
    font-size: 20px;
    color: #5e5e5e;
    line-height: 1.8;
}

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

.bento-item {
    background-color: #fcf5eb;
    border-radius: 32px;
    padding: 40px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: transform 0.3s ease;
    position: relative;
    overflow: hidden;
}

.bento-item:hover {
    transform: translateY(-5px);
}

.bento-item h3 {
    font-size: 24px;
    font-weight: 600;
}

.bento-item p {
    color: #5e5e5e;
    font-size: 16px;
    z-index: 2;
}

/* 纯 CSS 语音波形动画 */
.voice-wave {
    display: flex;
    align-items: center;
    gap: 6px;
    height: 60px;
    margin-top: 30px;
    z-index: 2;
}

.voice-wave span {
    display: block;
    width: 8px;
    background-color: #25d366;
    border-radius: 4px;
    animation: wave 1.2s infinite ease-in-out;
}

.voice-wave span:nth-child(1) { height: 30%; animation-delay: 0.1s; }
.voice-wave span:nth-child(2) { height: 70%; animation-delay: 0.2s; }
.voice-wave span:nth-child(3) { height: 100%; animation-delay: 0.3s; }
.voice-wave span:nth-child(4) { height: 50%; animation-delay: 0.4s; }
.voice-wave span:nth-child(5) { height: 80%; animation-delay: 0.5s; }
.voice-wave span:nth-child(6) { height: 40%; animation-delay: 0.6s; }
.voice-wave span:nth-child(7) { height: 20%; animation-delay: 0.7s; }

@keyframes wave {
    0%, 100% { transform: scaleY(0.4); }
    50% { transform: scaleY(1); }
}

.sticker-mock {
    font-size: 40px;
    margin-top: 30px;
    letter-spacing: 12px;
    z-index: 2;
}

.status-rings {
    display: flex;
    gap: 12px;
    margin-top: 30px;
    z-index: 2;
}

.ring {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 3px solid #25d366;
    padding: 2px;
    position: relative;
}

.ring::after {
    content: '';
    display: block;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background-color: #e0e0e0;
}

/* 商务版 Banner */
.business-banner {
    padding: 0 0 100px;
    background-color: #ffffff;
}

.banner-content {
    background: linear-gradient(135deg, #128C7E, #25D366);
    border-radius: 32px;
    padding: 80px 40px;
    text-align: center;
    color: white;
    box-shadow: 0 20px 40px rgba(37, 211, 102, 0.2);
}

.banner-content h2 {
    font-size: 40px;
    font-weight: 600;
    margin-bottom: 20px;
}

.banner-content p {
    font-size: 18px;
    max-width: 600px;
    margin: 0 auto 32px;
    opacity: 0.9;
    line-height: 1.6;
}

.banner-content .btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
}

@media (max-width: 992px) {
    .section-flex.reverse {
        flex-direction: column;
    }
    .bento-grid {
        grid-template-columns: 1fr;
    }
    .section-flex {
        flex-direction: column;
        align-items: flex-start;
        gap: 40px;
    }
    .hero-content {
        flex-direction: column;
    }
    .footer-top {
        flex-direction: column;
    }
    .footer-links {
        flex-wrap: wrap;
        gap: 40px;
    }
    .footer-col {
        min-width: 40%;
    }
    .footer-bottom {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }
    .footer-copy {
        flex-direction: column;
        gap: 12px;
    }
}