/* Banner部分 */
.about-banner {
    background: linear-gradient(rgba(0,0,0,0.75), rgba(0,0,0,0.8));
    min-height: 400px;
    display: flex;
    align-items: center;
    color: #fff;
    padding: 120px 0 60px;
    position: relative;
    overflow: hidden;
}

.about-banner .banner-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('https://images.unsplash.com/photo-1600132806370-bf17e65e942f?auto=format&fit=crop&w=1920&q=80') center/cover;
    opacity: 0.3;
    z-index: -1;
}

.banner-content {
    text-align: center;
    width: 100%;
}

.banner-title {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.banner-desc {
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto;
    opacity: 0.9;
    line-height: 1.6;
}

/* 平台优势 */
.platform-advantages {
    padding: 80px 0;
    background: #fff;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 50px;
    color: #333;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.advantage-card {
    text-align: center;
    padding: 40px 20px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.advantage-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.advantage-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--primary-color), #00bcd4);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 32px;
}

.advantage-card h3 {
    font-size: 20px;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
}

.advantage-card p {
    font-size: 14px;
    color: #666;
    line-height: 1.6;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 平台内容介绍 */
.platform-intro {
    padding: 80px 0;
    background: #f8f9fa;
}

.intro-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.intro-card {
    background: #fff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.intro-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.intro-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.intro-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.intro-card:hover .intro-image img {
    transform: scale(1.1);
}

.intro-content {
    padding: 25px;
}

.intro-content h3 {
    font-size: 20px;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
}

.intro-content p {
    font-size: 14px;
    color: #666;
    line-height: 1.6;
    margin-bottom: 20px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.intro-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: gap 0.3s ease;
}

.intro-link:hover {
    gap: 12px;
}

/* 响应式调整 */
@media screen and (max-width: 992px) {
    .advantages-grid,
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .intro-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media screen and (max-width: 768px) {
    .about-banner {
        min-height: 300px;
        padding: 100px 0 40px;
    }

    .banner-title {
        font-size: 32px;
    }

    .banner-desc {
        font-size: 16px;
    }

    .section-title {
        font-size: 28px;
        margin-bottom: 30px;
    }

    .timeline::before {
        left: 0;
    }

    .timeline-item {
        width: 100%;
        padding-left: 30px;
        padding-right: 0;
    }

    .timeline-item:nth-child(even) {
        padding-left: 30px;
    }

    .timeline-date {
        right: auto;
        left: -90px;
    }

    .timeline-item:nth-child(even) .timeline-date {
        left: -90px;
    }

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

    .contact-form {
        padding: 30px;
    }
}

@media screen and (max-width: 576px) {
    .advantages-grid,
    .stats-grid {
        grid-template-columns: 1fr;
    }

    .advantage-card {
        padding: 30px 20px;
    }

    .timeline-date {
        position: relative;
        left: 0;
        display: inline-block;
        margin-bottom: 10px;
    }

    .timeline-item:nth-child(even) .timeline-date {
        left: 0;
    }

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

    .intro-image {
        height: 180px;
    }
}

/* 平台数据 */
.platform-stats {
    padding: 80px 0;
    background: linear-gradient(135deg, #2196f3 0%, #1976d2 100%);
    color: #fff;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.stat-card {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 30px;
    text-align: center;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.15);
}

.stat-icon {
    font-size: 36px;
    margin-bottom: 15px;
}

.stat-number {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 5px;
    background: linear-gradient(135deg, #fff 0%, rgba(255,255,255,0.8) 100%);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
}

.stat-label {
    font-size: 16px;
    opacity: 0.9;
}

/* 发展历程 */
.platform-history {
    padding: 80px 0;
    background: #f8f9fa;
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: 100%;
    background: var(--primary-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 60px;
    width: 50%;
    padding-right: 40px;
}

.timeline-item:nth-child(even) {
    margin-left: auto;
    padding-right: 0;
    padding-left: 40px;
}

.timeline-date {
    position: absolute;
    top: 0;
    right: -120px;
    background: var(--primary-color);
    color: #fff;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 14px;
}

.timeline-item:nth-child(even) .timeline-date {
    right: auto;
    left: -120px;
}

.timeline-content {
    background: #fff;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
}

/* 联系我们 */
.contact-section {
    padding: 80px 0;
    background: #fff;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 50px;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 20px;
}

.info-item i {
    width: 50px;
    height: 50px;
    background: rgba(33, 150, 243, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 20px;
}

.info-content h3 {
    font-size: 18px;
    font-weight: 600;
    color: #333;
    margin-bottom: 5px;
}

.info-content p {
    font-size: 14px;
    color: #666;
    margin: 0;
}

.contact-form {
    background: #fff;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #eee;
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.3s ease;
}

.form-group textarea {
    height: 150px;
    resize: none;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.1);
}

.submit-btn {
    width: 100%;
    padding: 14px;
    background: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.submit-btn:hover {
    background: #1976d2;
    transform: translateY(-2px);
}