/* 航空主题CSS变量 */
    :root {
        --sky-blue: #4A90E2;
        --cloud-white: #F8FAFE;
        --horizon-blue: #6BB6FF;
        --deep-blue: #2C5282;
        --aircraft-silver: #C0C8D1;
        --sunset-orange: #FF8C42;
        --gold: #FFD700;
        --silver: #C0C0C0;
        --bronze: #CD7F32;
        --header-height: 70px;
    }

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

    body {
        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        background: linear-gradient(135deg, var(--sky-blue) 0%, var(--horizon-blue) 50%, var(--cloud-white) 100%);
        min-height: 100vh;
        padding-top: var(--header-height);
        line-height: 1.6;
    }

    /* 浮动云朵装饰 */
    .cloud-decoration {
        position: fixed;
        top: 20%;
        right: -100px;
        width: 100px;
        height: 60px;
        background: rgba(255, 255, 255, 0.8);
        border-radius: 50px;
        opacity: 0.6;
        animation: float 15s infinite ease-in-out;
        z-index: 1;
    }

    .cloud-decoration::before {
        content: '';
        position: absolute;
        top: -25px;
        left: 10px;
        width: 50px;
        height: 50px;
        background: rgba(255, 255, 255, 0.8);
        border-radius: 50%;
    }

    .cloud-decoration::after {
        content: '';
        position: absolute;
        top: -25px;
        right: 15px;
        width: 30px;
        height: 30px;
        background: rgba(255, 255, 255, 0.8);
        border-radius: 50%;
    }

    @keyframes float {
        0%, 100% { transform: translateX(0) translateY(0); }
        25% { transform: translateX(-20px) translateY(-10px); }
        50% { transform: translateX(-40px) translateY(0); }
        75% { transform: translateX(-20px) translateY(10px); }
    }

    /* 主容器 */
    .ranking-container {
        max-width: 1400px;
        margin: 0 auto;
        padding: 2rem;
        position: relative;
        z-index: 2;
    }

    /* 纸质卡片样式 */
    .paper-sheet {
        background: linear-gradient(135deg, var(--cloud-white) 0%, #ffffff 100%);
        border-radius: 20px;
        padding: 2rem;
        margin-bottom: 2rem;
        box-shadow: 0 15px 35px rgba(74, 144, 226, 0.15);
        border: 1px solid rgba(74, 144, 226, 0.1);
        position: relative;
        backdrop-filter: blur(10px);
    }

    /* 页面标题 */
    .page-title {
        text-align: center;
        color: var(--deep-blue);
        font-size: 2.5rem;
        font-weight: 700;
        margin-bottom: 1rem;
        text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
    }

    .page-subtitle {
        text-align: center;
        color: rgba(44, 82, 130, 0.7);
        font-size: 1.1rem;
        margin-bottom: 2rem;
    }

    /* 统计周期徽章 */
    .date-range-badge {
        display: inline-flex;
        align-items: center;
        gap: 0.5rem;
        background: linear-gradient(135deg, var(--sunset-orange), #FF6B35);
        color: white;
        padding: 0.8rem 1.5rem;
        border-radius: 25px;
        font-size: 1rem;
        font-weight: 600;
        box-shadow: 0 4px 15px rgba(255, 140, 66, 0.3);
        margin-bottom: 2rem;
    }

    /* 导航选项卡 */
    .ranking-nav {
        display: flex;
        justify-content: center;
        flex-wrap: wrap;
        gap: 1rem;
        margin-bottom: 2rem;
    }

    .nav-tab {
        padding: 0.8rem 1.5rem;
        background: rgba(255, 255, 255, 0.8);
        border: 2px solid rgba(74, 144, 226, 0.2);
        border-radius: 25px;
        text-decoration: none;
        color: var(--deep-blue);
        font-weight: 600;
        transition: all 0.3s ease;
        position: relative;
        overflow: hidden;
    }

    .nav-tab:hover {
        background: rgba(74, 144, 226, 0.1);
        border-color: var(--sky-blue);
        transform: translateY(-2px);
        box-shadow: 0 5px 15px rgba(74, 144, 226, 0.2);
        text-decoration: none;
        color: var(--deep-blue);
    }

    .nav-tab.active {
        background: linear-gradient(135deg, var(--sky-blue), var(--deep-blue));
        color: white;
        border-color: var(--sky-blue);
        box-shadow: 0 8px 25px rgba(74, 144, 226, 0.3);
    }

    .nav-tab.active:hover {
        color: white;
    }

    /* 图片网格布局 */
    .images-grid {
        display: grid;
        grid-template-columns: repeat(4, 1fr); /* 固定4列布局 */
        gap: 2rem;
        margin-bottom: 3rem;
    }

    /* 图片卡片样式 */
    .image-card {
        background: white;
        border-radius: 15px;
        overflow: hidden;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
        transition: all 0.3s ease;
        position: relative;
        cursor: pointer;
    }

    .image-card:hover {
        transform: translateY(-10px);
        box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    }

    .image-card img {
        width: 100%;
        height: 200px;
        object-fit: cover;
        transition: transform 0.3s ease;
    }

    .image-card:hover img {
        transform: scale(1.05);
    }

    /* 排名徽章 */
    .rank-badge {
        position: absolute;
        top: 10px;
        left: 10px;
        width: 35px;
        height: 35px;
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        font-weight: bold;
        font-size: 0.9rem;
        color: white;
        z-index: 3;
        box-shadow: 0 3px 10px rgba(0, 0, 0, 0.3);
    }

    .rank-badge.gold {
        background: linear-gradient(135deg, var(--gold), #FFB000);
    }

    .rank-badge.silver {
        background: linear-gradient(135deg, var(--silver), #A0A0A0);
    }

    .rank-badge.bronze {
        background: linear-gradient(135deg, var(--bronze), #A0622D);
    }

    .rank-badge.regular {
        background: linear-gradient(135deg, var(--aircraft-silver), #9FA8B2);
        color: var(--deep-blue);
    }

    /* 点赞徽章 */
    .likes-badge {
        position: absolute;
        top: 10px;
        right: 10px;
        background: linear-gradient(135deg, #e74c3c, #c0392b);
        color: white;
        padding: 5px 10px;
        border-radius: 15px;
        font-size: 0.85rem;
        font-weight: 600;
        display: flex;
        align-items: center;
        gap: 5px;
        z-index: 3;
        box-shadow: 0 3px 10px rgba(231, 76, 60, 0.3);
    }

    /* 图片ID徽章 */
    .image-id-badge {
        position: absolute;
        bottom: 10px;
        left: 10px;
        background: linear-gradient(135deg, #007bff, #0056b3);
        color: white;
        padding: 4px 8px;
        border-radius: 12px;
        font-size: 0.75rem;
        font-weight: 600;
        z-index: 3;
        box-shadow: 0 2px 8px rgba(0, 123, 255, 0.3);
        transition: all 0.3s ease;
    }

    .image-card:hover .image-id-badge {
        transform: scale(1.1);
        box-shadow: 0 3px 12px rgba(0, 123, 255, 0.4);
    }

    /* 图片信息 */
    .image-info {
        padding: 1.5rem;
    }

    .image-title {
        font-size: 1.1rem;
        font-weight: 600;
        color: var(--deep-blue);
        margin-bottom: 0.5rem;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .image-meta {
        display: flex;
        align-items: center;
        gap: 1rem;
        font-size: 0.9rem;
        color: rgba(44, 82, 130, 0.7);
    }

    .image-meta span {
        display: flex;
        align-items: center;
        gap: 0.3rem;
    }

    .image-meta .photographer-info {
        flex: 1;
        min-width: 0; /* 允许收缩 */
        overflow: hidden;
    }

    .image-meta .photographer-link {
        color: var(--sky-blue);
        text-decoration: none;
        font-weight: 500;
        display: inline-block;
        max-width: 80px; /* 限制用户名最大宽度 */
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
        vertical-align: bottom;
    }

    .image-meta .photographer-link:hover {
        color: var(--deep-blue);
        text-decoration: underline;
    }

    .image-meta .date-info {
        flex-shrink: 0; /* 防止日期被压缩 */
        white-space: nowrap;
    }

    /* 用户排行榜样式 */
    .users-list {
        display: flex;
        flex-direction: column;
        gap: 1.5rem;
    }

    .user-rank-item {
        background: white;
        border-radius: 15px;
        padding: 1.5rem;
        box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
        transition: all 0.3s ease;
        display: flex;
        align-items: center;
        gap: 1.5rem;
        position: relative;
    }

    .user-rank-item:hover {
        transform: translateY(-5px);
        box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
    }

    .user-avatar {
        width: 60px;
        height: 60px;
        border-radius: 50%;
        background: linear-gradient(135deg, var(--sky-blue), var(--horizon-blue));
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 1.5rem;
        color: white;
        box-shadow: 0 5px 15px rgba(74, 144, 226, 0.3);
    }

    .user-info {
        flex: 1;
    }

    .username {
        font-size: 1.2rem;
        font-weight: 600;
        color: var(--deep-blue);
        margin-bottom: 0.5rem;
    }

    .username a {
        color: var(--deep-blue);
        text-decoration: none;
    }

    .username a:hover {
        color: var(--sky-blue);
        text-decoration: underline;
    }

    .user-stats {
        display: flex;
        align-items: center;
        gap: 1rem;
        font-size: 0.95rem;
        color: rgba(44, 82, 130, 0.7);
    }

    .approved-count {
        color: var(--sky-blue);
        font-weight: 600;
    }

    /* 进度条 */
    .progress-bar {
        width: 100%;
        height: 8px;
        background: rgba(74, 144, 226, 0.1);
        border-radius: 4px;
        overflow: hidden;
        margin-top: 0.5rem;
    }

    .progress-fill {
        height: 100%;
        background: linear-gradient(90deg, var(--sky-blue), var(--horizon-blue));
        border-radius: 4px;
        transition: width 0.8s ease;
    }

    /* 分页样式 */
    .pagination-wrapper {
        display: flex;
        justify-content: center;
        margin-top: 3rem;
    }

    .pagination {
        display: flex;
        align-items: center;
        gap: 0.5rem;
        background: white;
        padding: 1rem 2rem;
        border-radius: 25px;
        box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    }

    .pagination a,
    .pagination span {
        padding: 0.5rem 1rem;
        border-radius: 20px;
        text-decoration: none;
        color: var(--deep-blue);
        font-weight: 500;
        transition: all 0.3s ease;
    }

    .pagination a:hover {
        background: rgba(74, 144, 226, 0.1);
        color: var(--sky-blue);
    }

    .pagination .current {
        background: linear-gradient(135deg, var(--sky-blue), var(--deep-blue));
        color: white;
        box-shadow: 0 3px 10px rgba(74, 144, 226, 0.3);
    }

    /* 错误/空状态样式 */
    .empty-state {
        text-align: center;
        padding: 4rem 2rem;
        color: rgba(44, 82, 130, 0.7);
    }

    .empty-state i {
        font-size: 4rem;
        margin-bottom: 1rem;
        color: rgba(74, 144, 226, 0.3);
    }

    .empty-state h3 {
        color: var(--deep-blue);
        margin-bottom: 1rem;
    }

    /* 响应式设计 */
    @media (max-width: 1200px) {
        .images-grid {
            grid-template-columns: repeat(3, 1fr); /* 中等屏幕3列 */
        }
    }

    @media (max-width: 900px) {
        .images-grid {
            grid-template-columns: repeat(2, 1fr); /* 小屏幕2列 */
        }
    }

    @media (max-width: 768px) {
        .ranking-container {
            padding: 1rem;
        }

        .page-title {
            font-size: 2rem;
        }

        .images-grid {
            grid-template-columns: repeat(2, 1fr); /* 平板2列 */
            gap: 1.5rem;
        }

        .nav-tab {
            padding: 0.6rem 1rem;
            font-size: 0.9rem;
        }

        .user-rank-item {
            flex-direction: column;
            text-align: center;
            gap: 1rem;
        }

        .user-avatar {
            width: 50px;
            height: 50px;
            font-size: 1.2rem;
        }

        .rank-badge {
            width: 30px;
            height: 30px;
            font-size: 0.8rem;
        }
    }

    @media (max-width: 480px) {
        .images-grid {
            grid-template-columns: 1fr; /* 手机单列 */
        }

        .date-range-badge {
            font-size: 0.9rem;
            padding: 0.6rem 1rem;
        }

        .image-info {
            padding: 1rem;
        }

        .image-title {
            font-size: 1rem;
        }

        .image-meta {
            font-size: 0.8rem;
            gap: 0.5rem;
        }

        .image-meta .photographer-link {
            max-width: 60px; /* 移动端进一步缩短用户名 */
        }
    }