:root {
    --bg-color: #0f0f12;
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-main: #ffffff;
    --text-sub: #a0a0a0;
    --primary-color: #6c5ce7; /* 科技紫 */
    --accent-glow: rgba(108, 92, 231, 0.3);
    --shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* 专属色变量 */
    --color-video: #ff0055;
    --color-coding: #00ff9d;
    --color-drama: #ffbf00;
    --color-art: #00ccff;
    --color-music: #ff00ff;
    --color-agent: #7000ff;
    --color-ppt: #ff5e00;
    --color-logo: #ff0099; /* 蜂鸟社团专属色：品红 */
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(108, 92, 231, 0.1) 0%, transparent 20%),
        radial-gradient(circle at 90% 80%, rgba(0, 204, 255, 0.05) 0%, transparent 20%);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    padding-bottom: 100px; /* 为吸底按钮留出空间 */
}

/* 头部样式 */
header {
    text-align: center;
    padding: 60px 20px 40px;
    position: relative;
}

/* 极光背景效果 */
header::before {
    content: '';
    position: absolute;
    top: -50%;
    left: 50%;
    transform: translateX(-50%);
    width: 80%;
    height: 200px;
    background: linear-gradient(90deg, #ff0055, #00ff9d, #00ccff);
    filter: blur(80px);
    opacity: 0.15;
    z-index: -1;
    border-radius: 50%;
}

h1 {
    font-size: 2.5rem;
    color: var(--text-main);
    margin-bottom: 15px;
    font-weight: 800;
    letter-spacing: -1px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.5);
}

.subtitle {
    color: var(--text-sub);
    font-size: 1.1rem;
    font-weight: 300;
    letter-spacing: 1px;
}

/* 首页社团列表网格 */
.club-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr); /* 手机端默认2列 */
    gap: 15px;
    padding: 10px;
}

@media (min-width: 768px) {
    .club-grid {
        grid-template-columns: repeat(3, 1fr); /* 平板3列 */
        gap: 25px;
        padding: 20px;
    }
}

@media (min-width: 1024px) {
    .club-grid {
        grid-template-columns: repeat(4, 1fr); /* 电脑4列 */
    }
}

/* 卡片样式 */
.club-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 25px 15px;
    text-align: center;
    text-decoration: none;
    color: var(--text-main);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

/* 悬停特效 */
.club-card:hover {
    transform: translateY(-8px);
    border-color: rgba(255,255,255,0.3);
    box-shadow: 0 15px 30px rgba(0,0,0,0.4), 
                0 0 20px var(--hover-color, rgba(255,255,255,0.1));
}

.club-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.5), transparent);
    opacity: 0;
    transition: var(--transition);
}

.club-card:hover::after {
    opacity: 1;
}

.club-icon {
    width: 80px;
    height: 80px;
    background-color: rgba(255,255,255,0.05);
    border-radius: 16px;
    margin-bottom: 15px;
    object-fit: cover;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: #666;
    border: 1px solid rgba(255,255,255,0.1);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    transition: var(--transition);
}

.club-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 16px;
}

.club-card:hover .club-icon {
    transform: scale(1.05) rotate(3deg);
    box-shadow: 0 8px 24px var(--hover-color, rgba(255,255,255,0.2));
}

.club-name {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 6px;
    display: block;
}

.club-slogan {
    font-size: 0.8rem;
    color: var(--text-sub);
    display: block;
    font-weight: 400;
}

/* 详情页特定样式 */
.page-header {
    background: transparent;
    padding: 20px 0;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--card-border);
}

.page-header h1 {
    font-size: 1.2rem;
    margin: 0;
    text-shadow: none;
}

.back-btn {
    text-decoration: none;
    color: var(--text-sub);
    font-weight: 500;
    display: flex;
    align-items: center;
    padding: 8px 16px;
    background: rgba(255,255,255,0.05);
    border-radius: 20px;
    transition: var(--transition);
}

.back-btn:hover {
    background: rgba(255,255,255,0.1);
    color: var(--text-main);
}

.back-btn::before {
    content: "←";
    margin-right: 5px;
}

/* 社团介绍次级按钮 */
.intro-btn {
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 600;
    padding: 8px 16px;
    border: 1px solid var(--primary-color);
    border-radius: 20px;
    font-size: 0.9rem;
    transition: var(--transition);
    background: rgba(108, 92, 231, 0.1);
    white-space: nowrap;
}

.intro-btn:hover {
    background: var(--primary-color);
    color: white;
}

.poster-container {
    max-width: 600px;
    margin: 0 auto;
    background: rgba(255,255,255,0.02);
    padding: 0; /* 海报无缝 */
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 30px rgba(0,0,0,0.3);
}

@media (min-width: 768px) {
    .poster-container {
        border: 1px solid var(--card-border);
        padding: 20px;
        backdrop-filter: blur(20px);
        background: rgba(25, 25, 30, 0.8);
    }
}

.poster-img {
    width: 100%;
    height: auto;
    display: block;
    min-height: 400px;
    background-color: #1a1a1a;
    color: #444;
}

/* 吸底按钮 */
.sticky-footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 15px 20px;
    background: rgba(15, 15, 18, 0.9);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--card-border);
    display: flex;
    justify-content: center;
    z-index: 100;
}

.cta-button {
    background: linear-gradient(135deg, #6c5ce7, #0984e3);
    color: white;
    text-decoration: none;
    padding: 14px 40px;
    border-radius: 30px;
    font-weight: 700;
    font-size: 1.1rem;
    box-shadow: 0 4px 15px rgba(108, 92, 231, 0.4);
    transition: var(--transition);
    width: 100%;
    max-width: 400px;
    text-align: center;
    letter-spacing: 1px;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(108, 92, 231, 0.6);
    filter: brightness(1.1);
}

.footer {
    text-align: center;
    padding: 40px;
    color: #555;
    font-size: 0.8rem;
}