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

:root {
    --primary: #07C160;
    --primary-dark: #06AD56;
    --secondary: #1A1A2E;
    --accent: #16213E;
    --bg: #F5F5F5;
    --card-bg: #FFFFFF;
    --text: #333333;
    --text-light: #666666;
    --border: #E8E8E8;
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
    --radius: 16px;
    --transition: all 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: 0 2px 20px rgba(0,0,0,0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-img {
    height: 40px;
    width: auto;
}

.brand-name {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.nav-menu {
    display: flex;
    gap: 30px;
}

.nav-link {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}

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

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

.nav-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text);
}

/* 英雄区 */
.hero {
    padding: 140px 20px 80px;
    background: linear-gradient(135deg, #f0fff4 0%, #e8f5e9 50%, #f1f8e9 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-text h1 {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 20px;
    font-weight: 800;
}

.highlight {
    color: var(--primary);
    background: linear-gradient(135deg, var(--primary), #00b894);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-text p {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 30px;
}

.hero-buttons {
    display: flex;
    gap: 15px;
}

.btn {
    padding: 14px 32px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 15px rgba(7, 193, 96, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(7, 193, 96, 0.4);
}

.btn-secondary {
    background: white;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-secondary:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
}

/* 手机模拟 */
.phone-mockup {
    width: 300px;
    height: 600px;
    background: #1a1a2e;
    border-radius: 40px;
    padding: 15px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    margin: 0 auto;
    position: relative;
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, #e8f5e9 0%, #c8e6c9 100%);
    border-radius: 30px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    overflow: hidden;
}

.chat-bubble {
    max-width: 80%;
    padding: 12px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    animation: fadeInUp 0.5s ease forwards;
    opacity: 0;
}

.chat-bubble.sent {
    background: var(--primary);
    color: white;
    align-self: flex-end;
    border-bottom-right-radius: 5px;
    animation-delay: 0.2s;
}

.chat-bubble.received {
    background: white;
    color: var(--text);
    align-self: flex-start;
    border-bottom-left-radius: 5px;
    animation-delay: 0.4s;
}

.chat-bubble:nth-child(3) {
    animation-delay: 0.6s;
}

.chat-bubble:nth-child(4) {
    animation-delay: 0.8s;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 功能特色 */
.features {
    padding: 100px 20px;
    background: white;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    font-weight: 700;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--primary);
    border-radius: 2px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 35px 25px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid transparent;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
    border-color: var(--primary);
}

.feature-icon {
    width: 70px;
    height: 70px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 2rem;
    color: white;
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* 消息列表 */
.messages {
    padding: 100px 20px;
    background: var(--bg);
}

.messages-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 20px;
}

.search-box {
    display: flex;
    align-items: center;
    background: white;
    border-radius: 50px;
    padding: 10px 20px;
    box-shadow: var(--shadow);
    flex: 1;
    max-width: 400px;
}

.search-box i {
    color: var(--text-light);
    margin-right: 10px;
}

.search-box input {
    border: none;
    outline: none;
    font-size: 1rem;
    width: 100%;
    background: transparent;
}

.filter-tabs {
    display: flex;
    gap: 10px;
}

.filter-btn {
    padding: 8px 20px;
    border: 2px solid var(--border);
    border-radius: 50px;
    background: white;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.messages-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 20px;
}

.message-card {
    background: white;
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 20px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.message-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

.message-card .avatar {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
}

.message-info {
    flex: 1;
    min-width: 0;
}

.message-info h3 {
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.message-info p {
    color: var(--text-light);
    font-size: 0.9rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.message-meta {
    text-align: right;
    flex-shrink: 0;
}

.message-time {
    font-size: 0.8rem;
    color: var(--text-light);
}

.badge {
    display: inline-block;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    width: 22px;
    height: 22px;
    line-height: 22px;
    text-align: center;
    font-size: 0.75rem;
    margin-top: 5px;
}

.message-tag {
    position: absolute;
    top: 10px;
    right: 10px;
    padding: 2px 8px;
    border-radius: 10px;
    font-size: 0.7rem;
    font-weight: 600;
}

.tag-friend {
    background: #e3f2fd;
    color: #1976d2;
}

.tag-group {
    background: #fce4ec;
    color: #d32f2f;
}

.tag-starred {
    background: #fff3e0;
    color: #f57c00;
}

/* 关于我们 */
.about {
    padding: 100px 20px;
    background: white;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: start;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 30px;
    line-height: 1.8;
}

.stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.stat-item {
    text-align: center;
    padding: 20px;
    background: var(--bg);
    border-radius: var(--radius);
    transition: var(--transition);
}

.stat-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.stat-number {
    display: block;
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--primary);
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-top: 5px;
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.team-card {
    text-align: center;
    padding: 20px;
    background: var(--bg);
    border-radius: var(--radius);
    transition: var(--transition);
}

.team-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.team-card img {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 10px;
    border: 3px solid var(--primary);
}

.team-card h4 {
    font-size: 1rem;
    margin-bottom: 5px;
}

.team-card p {
    font-size: 0.85rem;
    color: var(--text-light);
}

/* 弹窗 */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(5px);
}

.modal.show {
    display: flex;
}

.modal-content {
    background: white;
    border-radius: 20px;
    width: 90%;
    max-width: 500px;
    max-height: 80vh;
    overflow: hidden;
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-light);
    transition: var(--transition);
}

.modal-close:hover {
    color: var(--text);
    transform: rotate(90deg);
}

.modal-header {
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
    border-bottom: 1px solid var(--border);
}

.modal-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    object-fit: cover;
}

.modal-body {
    padding: 20px;
    overflow-y: auto;
    max-height: 400px;
}

.chat-history {
    margin-bottom: 20px;
}

.chat-history .chat-msg {
    margin-bottom: 10px;
    padding: 10px 15px;
    border-radius: 15px;
    max-width: 80%;
}

.chat-history .chat-msg.sent {
    background: var(--primary);
    color: white;
    margin-left: auto;
    border-bottom-right-radius: 5px;
}

.chat-history .chat-msg.received {
    background: var(--bg);
    color: var(--text);
    margin-right: auto;
    border-bottom-left-radius: 5px;
}

.chat-input-area {
    display: flex;
    gap: 10px;
}

.chat-input-area input {
    flex: 1;
    padding: 12px 20px;
    border: 2px solid var(--border);
    border-radius: 25px;
    outline: none;
    font-size: 1rem;
    transition: var(--transition);
}

.chat-input-area input:focus {
    border-color: var(--primary);
}

/* 页脚 */
.footer {
    background: var(--secondary);
    color: white;
    padding: 60px 20px 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand .logo-img {
    height: 35px;
    margin-bottom: 15px;
}

.footer-brand p {
    color: #aaa;
}

.footer-links h4,
.footer-contact h4 {
    margin-bottom: 15px;
    font-size: 1.1rem;
}

.footer-links a {
    display: block;
    color: #aaa;
    text-decoration: none;
    margin-bottom: 8px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary);
    padding-left: 5px;
}

.footer-contact p {
    color: #aaa;
    margin-bottom: 8px;
}

.footer-contact i {
    margin-right: 8px;
    color: var(--primary);
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 20px;
    text-align: center;
    color: #aaa;
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 10px 30px rgba(0,0,0,0.1);
        gap: 15px;
    }

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

    .nav-toggle {
        display: block;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-text h1 {
        font-size: 2.5rem;
    }

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

    .phone-mockup {
        width: 250px;
        height: 500px;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .messages-header {
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        max-width: 100%;
    }

    .filter-tabs {
        justify-content: center;
    }

    .messages-list {
        grid-template-columns: 1fr;
    }

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

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

@media (max-width: 480px) {
    .hero-text h1 {
        font-size: 2rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .phone-mockup {
        width: 200px;
        height: 400px;
    }

    .feature-card {
        padding: 25px 15px;
    }
}