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

:root {
    --card-bg: rgba(255, 255, 255, 0.15);
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.8);
    --github: rgba(51, 51, 51, 0.8);
    --twitter: rgba(29, 161, 242, 0.8);
    --instagram: rgba(225, 48, 108, 0.8);
    --linkedin: rgba(0, 119, 181, 0.8);
    --youtube: rgba(255, 0, 0, 0.8);
    --email: rgba(234, 67, 53, 0.8);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: #667eea;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    perspective: 1000px;
    overflow: hidden;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    z-index: 0;
    pointer-events: none;
}

/* 动态背景层 - 支持上传的背景图片 */
.background-layer {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    z-index: -1;
    will-change: transform;
}

/* 支持 CSS 变量设置背景 */
body.has-bg-image {
    background: none;
}

body.has-bg-image::before {
    background: rgba(0, 0, 0, var(--bg-overlay-opacity, 0.4));
}

.container {
    width: 100%;
    max-width: 480px;
    perspective: 1000px;
}

.profile-card {
    background: var(--card-bg);
    border-radius: 24px;
    padding: 48px 32px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transform-style: preserve-3d;
    transform: rotateX(0deg) rotateY(0deg);
    transition: transform 0.1s ease-out;
}

.profile-header {
    text-align: center;
    margin-bottom: 40px;
}

.avatar {
    width: 120px;
    height: 120px;
    margin: 0 auto 20px;
    border-radius: 50%;
    overflow: hidden;
    border: 4px solid white;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
    transition: transform 0.3s ease;
}

.avatar:hover {
    transform: scale(1.05);
}

.avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.username {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.bio {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.social-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.social-link {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    border-radius: 12px;
    text-decoration: none;
    color: white;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.1);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.social-link:hover::before {
    opacity: 1;
}

.social-link:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.social-link i {
    font-size: 24px;
    width: 32px;
    text-align: center;
}

.footer {
    margin-top: 40px;
    text-align: center;
}

.footer p {
    font-size: 13px;
    color: var(--text-secondary);
}

/* 响应式设计 */
@media (max-width: 480px) {
    .profile-card {
        padding: 36px 24px;
    }

    .username {
        font-size: 24px;
    }

    .bio {
        font-size: 14px;
    }

    .social-link {
        padding: 14px 18px;
        font-size: 15px;
    }
}

/* 加载动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.profile-card {
    animation: fadeInUp 0.6s ease;
}

.social-link {
    animation: fadeInUp 0.6s ease;
    animation-fill-mode: both;
}

.social-link:nth-child(1) { animation-delay: 0.1s; }
.social-link:nth-child(2) { animation-delay: 0.15s; }
.social-link:nth-child(3) { animation-delay: 0.2s; }
.social-link:nth-child(4) { animation-delay: 0.25s; }
.social-link:nth-child(5) { animation-delay: 0.3s; }
.social-link:nth-child(6) { animation-delay: 0.35s; }