/* ========================================
   About Page - 关于页
   ======================================== */

/* About Hero */
.about-hero {
    background: linear-gradient(135deg, var(--primary-color), #1a252f);
    color: white;
    padding: 4rem 5%;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.about-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.3;
}

.about-hero-content {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.about-hero h1 {
    font-size: 2rem;
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.about-hero p {
    font-size: 1rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* About Container */
.about-container {
    max-width: 1755px;
    margin: 0 auto;
    padding: 3rem 5%;
}

.about-card {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    overflow: hidden;
    margin-bottom: 2rem;
}

.about-card-content {
    padding: 3rem 10%;
}

.about-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.about-header h1 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.about-header p {
    color: var(--text-light);
}

.about-section {
    margin-bottom: 2rem;
}

.about-section:last-child {
    margin-bottom: 0;
}

.about-section h2 {
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.about-section h2 i {
    color: var(--secondary-color);
}

.about-section p {
    color: #555;
    margin-bottom: 0.5rem;
    line-height: 1.8;
}

/* Topic List */
.topic-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.topic-item {
    background: var(--light-bg);
    padding: 1.25rem;
    border-radius: 10px;
    text-align: center;
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
}

.topic-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(0,0,0,0.1);
}

.topic-item .icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.topic-item .name {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.35rem;
    font-size: 0.9rem;
}

.topic-item .desc {
    font-size: 0.75rem;
    color: var(--text-light);
}

/* Features List */
.features-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--light-bg);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.feature-item:hover {
    background: rgba(52, 152, 219, 0.1);
}

.feature-item i {
    font-size: 1.25rem;
    color: var(--secondary-color);
    margin-top: 0.15rem;
}

.feature-item h4 {
    font-size: 0.9rem;
    margin-bottom: 0.35rem;
    color: var(--primary-color);
}

.feature-item p {
    font-size: 0.8rem;
    color: var(--text-light);
    margin: 0;
}

/* Contact Info */
.contact-info {
    background: var(--light-bg);
    padding: 1.5rem;
    border-radius: 10px;
    margin-top: 1rem;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.5rem;
    margin-top: 1rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.contact-item i {
    font-size: 1.25rem;
    color: var(--secondary-color);
    width: 40px;
    height: 40px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.contact-item .info h4 {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-bottom: 0.2rem;
}

.contact-item .info p {
    font-size: 0.9rem;
    color: var(--primary-color);
    margin: 0;
    font-weight: 500;
}

/* Responsive */
@media (max-width: 768px) {
    .about-hero {
        padding: 3rem 5%;
    }
    
    .about-hero h1 {
        font-size: 1.5rem;
    }
    
    .about-card-content {
        padding: 1.5rem;
    }
    
    .topic-list {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
}