.banner {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    background: url("../pycon2025.34f72f6ecfcc.jpg") center/cover no-repeat;
    background-attachment: fixed;
    position: relative;
    height: 100vh;
    overflow: hidden;
    margin-bottom: 80px;
}

.banner h1 {
    font-size: 4rem; /* Adjusted to use rem units */
    margin-bottom: 30px;
    text-shadow: 4px 4px 8px rgba(0, 0, 0, 0.8), 0 0 20px rgba(0, 0, 0, 0.5);
    position: relative;
    z-index: 2;
    color: #ffffff;
    font-weight: bold;
}
.banner p {
    font-size: 1.4rem; /* Adjusted to use rem units */
    margin-bottom: 25px;
    text-shadow: 3px 3px 6px rgba(0, 0, 0, 0.8), 0 0 15px rgba(0, 0, 0, 0.5);
    position: relative;
    z-index: 2;
    color: #ffffff;
    font-weight: 600;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    position: relative;
    z-index: 2;
}

.cta-buttons > a {
    display: inline-block;
    padding: 15px 30px;
    font-size: 1.2rem; /* Adjusted to use rem units */
    text-decoration: none;
    color: #ffffff;
    background: linear-gradient(135deg, #7c3aed 0%, #b994fd 100%);
    border-radius: 25px;
    transition: all 0.3s ease;
    box-shadow: 0 8px 20px rgba(124, 58, 237, 0.3);
    border: 2px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.cta-buttons > a::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.cta-buttons > a:hover::before {
    left: 100%;
}

.cta-buttons > a:hover {
    background: linear-gradient(135deg, #8b5cf6 0%, #d6bef8 100%);
    color: #ffffff;
    transform: translateY(-3px);
    box-shadow: 0 12px 30px rgba(139, 92, 246, 0.4);
    border-color: rgba(255, 255, 255, 0.4);
}

/* 卡片进入动画 */
.card {
    opacity: 0;
    transform: translateY(30px);
    animation: slideInUp 0.6s ease-out forwards;
}

.card:nth-child(2) { animation-delay: 0.1s; }
.card:nth-child(3) { animation-delay: 0.2s; }
.card:nth-child(4) { animation-delay: 0.3s; }
.card:nth-child(5) { animation-delay: 0.4s; }

@keyframes slideInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 移动端优化 */
@media (max-width: 480px) {
    .banner {
        padding: 120px 15px 80px;
        min-height: 70vh;
    }

    .banner h1 {
        font-size: 2rem;
    }

    .banner p {
        font-size: 1rem;
    }

    .cta-buttons > a {
        padding: 12px 24px;
        font-size: 1rem;
    }
}