:root {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --accent-color: #e74c3c;
    --dark-color: #2c3e50;
    --light-color: #ecf0f1;
    --gray-color: #95a5a6;
    --transition-speed: 0.3s;
    --box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --gradient-bg: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

body {
    font-family: 'Roboto', 'Noto Sans SC', sans-serif;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
    overflow-x: hidden;
}

/* 自定义滚动条 */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}

/* 导航栏样式优化 */
.site-header {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    transition: all var(--transition-speed) ease;
    width: 100vw;
    max-width: 100vw;
    padding: 0;
    margin: 0;
    left: 0;
    right: 0;
    overflow-x: hidden;
}

.header-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 5px 0;
    width: 100%;
    margin: 0;
}

.site-header .container {
    width: 100%;
    max-width: 100%;
    padding-left: 0;
    padding-right: 0;
    margin: 0;
}

.branding {
    display: flex;
    align-items: center;
    text-decoration: none;
    transition: transform var(--transition-speed);
}

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

.logo {
    width: 50px;
    height: 50px;
    margin-right: 10px;
    object-fit: contain; /* 防止图标变形 */
}

.site-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--dark-color);
    margin: 0;
    background: var(--gradient-bg);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.site-description {
    font-size: 14px;
    color: var(--gray-color);
}

/* 导航菜单 */
.main-navigation {
    margin-right: 0;
    display: flex;
    justify-content: flex-end;
    flex: 1;
    padding-right: 0;
    width: auto;
}

.main-navigation .menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    justify-content: flex-end;
    padding-right: 0;
}

.main-navigation .menu-item:last-child a {
    margin-right: 0;
    padding-right: 10px !important;
    position: relative;
    right: 0;
}

.main-navigation .menu-item {
    margin: 0 10px;
    position: relative;
}

.main-navigation .menu-item a {
    padding: 10px 20px;
    color: var(--dark-color);
    font-weight: 500;
    text-decoration: none;
    display: block;
    border-radius: 30px;
    transition: all var(--transition-speed);
    min-width: 80px;
    text-align: center;
    white-space: nowrap;
}

.main-navigation .menu-item a:hover,
.main-navigation .current-menu-item a {
    background: var(--gradient-bg);
    color: white;
    box-shadow: 0 4px 10px rgba(52, 152, 219, 0.3);
    transform: translateY(-2px);
}

/* 为当前选中的菜单项添加特殊样式 */
.main-navigation .current-menu-item a {
    position: relative;
    font-weight: 600;
}

/* 为当前选中的菜单项添加标记 */
.main-navigation .current-menu-item a::before {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 50%;
    transform: translateX(-50%);
    width: 6px;
    height: 6px;
    background-color: white;
    border-radius: 50%;
    box-shadow: 0 0 8px rgba(255, 255, 255, 0.8);
}

/* 增强导航菜单项悬停效果 */
.main-navigation .menu-item a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: white;
    transition: all 0.3s ease;
    transform: translateX(-50%);
    opacity: 0;
}

.main-navigation .menu-item a:hover::after,
.main-navigation .current-menu-item a::after {
    width: 70%;
    opacity: 1;
    box-shadow: 0 0 5px rgba(255, 255, 255, 0.5);
}

/* 页面头部 */
.page-head {
    position: relative;
    padding: 100px 0;
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    overflow: hidden;
    margin-bottom: 30px;
}

.page-head::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../decorate/cta-bg.png');
    background-size: cover;
    background-position: center;
    opacity: 0.8;
    z-index: 0;
}

.page-head::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.9), rgba(46, 204, 113, 0.9));
    z-index: 1;
    opacity: 0.85;
}

.page-head .container {
    position: relative;
    z-index: 2;
}

.page-title {
    font-size: 52px;
    font-weight: 700;
    margin-bottom: 20px;
    letter-spacing: 1px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    transform: translateY(20px);
    opacity: 0;
    animation: fadeInUp 1s forwards 0.3s;
}

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

/* 进度阅读滚动条 */
.progress-container {
    position: fixed;
    top: 0;
    width: 100%;
    height: 4px;
    z-index: 1001;
}

.progress-bar {
    height: 4px;
    background: var(--gradient-bg);
    width: 0%;
    box-shadow: 0 0 10px rgba(52, 152, 219, 0.5);
}

/* 回到顶部按钮 */
.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-bg);
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-speed);
    box-shadow: 0 3px 15px rgba(52, 152, 219, 0.3);
    z-index: 1000;
}

.scroll-top.active {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(52, 152, 219, 0.5);
}

/* 竞赛展示 */
.project-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin: 20px 0 40px;
    width: 100%;
}

/* 年份分隔标题 */
.year-divider {
    margin: 60px 0 30px;
    position: relative;
    text-align: left;
    display: flex;
    align-items: center;
}

.year-divider h2 {
    font-size: 32px;
    font-weight: 700;
    color: var(--dark-color);
    margin: 0;
    padding-right: 25px;
    background: var(--gradient-bg);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline;
}

.year-divider::after {
    content: '';
    flex-grow: 1;
    height: 2px;
    background: linear-gradient(to right, var(--primary-color), rgba(52, 152, 219, 0.1));
}

.container {  /*外侧容器大小*/
    max-width: 1650px; /* 增加50px */
    width: 98%;
    padding: 0 15px;
}

.project {
    position: relative;
    cursor: pointer;
    transition: all 0.3s ease;
    overflow: hidden;
    border-radius: 5px;
    width: 32%;
    margin-bottom: 18px;
}

.project:hover {
    transform: translateY(-5px);
}

.project-content {
    position: relative;
    width: 100%;
    height: 100%;
}

.project-content a {
    display: block;
    width: 100%;
    height: 100%;
    text-decoration: none;
}

.project-image {  /* 图片大小 */
    margin: 0;
    position: relative;
    width: 100%;
    height: 300px;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
    display: block;
    filter: brightness(0.95);
}

.project:hover .project-image img {
    transform: scale(1.05);
    filter: brightness(1.05);
}

.project-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 15px 10px;
    background: linear-gradient(to top, rgba(0,0,0,0.85), rgba(0,0,0,0.3), transparent);
    color: white;
    opacity: 0;
    transition: opacity 0.4s ease, transform 0.4s ease;
    transform: translateY(10px);
}

.project-overlay h4 {
    margin: 0 0 4px 0;
    font-size: 16px;
    font-weight: 600;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.project-overlay p {
    margin: 0 0 5px 0;
    font-size: 14px;
    opacity: 0.9;
}

.project:hover .project-overlay {
    opacity: 1;
    transform: translateY(0);
}

/* 奖项标签 */
.award-badge {
    position: absolute;
    top: 10px;
    right: 10px;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    color: white;
    z-index: 5;
    box-shadow: 0 3px 10px rgba(0,0,0,0.2);
}

.award-badge.national {
    background: linear-gradient(135deg, #e74c3c, #c0392b);
}

.award-badge.provincial {
    background: linear-gradient(135deg, #3498db, #2980b9);
}

.award-badge.international {
    background: linear-gradient(135deg, #9b59b6, #8e44ad);
}

/* 奖项含金量提示 */
.award-prestige {
    display: inline-block;
    margin-top: 3px;
    padding: 2px 5px;
    background-color: rgba(255,255,255,0.15);
    border-radius: 3px;
    font-size: 11px;
    line-height: 1.3;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    max-height: 30px;
}

.award-prestige i {
    margin-right: 3px;
    color: #f1c40f;
}

.project-zoom {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.8);
    width: 50px;
    height: 50px;
    background: var(--gradient-bg);
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 20px;
    opacity: 0;
    transition: all 0.4s ease;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.project:hover .project-zoom {
    opacity: 0.9;
    transform: translate(-50%, -50%) scale(1);
}

/* 竞赛标准介绍 */
.award-standards {
    background: white;
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 40px;
    box-shadow: var(--box-shadow);
}

.award-standards h3 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.award-standards p {
    margin-bottom: 15px;
    color: #555;
    line-height: 1.6;
}

.award-types {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    margin-top: 20px;
}

.award-type {
    width: 32%;
    padding: 15px;
    border-radius: 10px;
    margin-bottom: 15px;
    color: white;
}

.award-type.national {
    background: linear-gradient(135deg, #e74c3c, #c0392b);
}

.award-type.provincial {
    background: linear-gradient(135deg, #3498db, #2980b9);
}

.award-type.international {
    background: linear-gradient(135deg, #9b59b6, #8e44ad);
}

.award-type h4 {
    font-size: 18px;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
}

.award-type h4 i {
    margin-right: 8px;
}

.award-type p {
    margin: 0;
    font-size: 14px;
    opacity: 0.9;
    color: white;
}

/* 响应式调整 - 适应不同屏幕 */
@media (max-width: 1200px) {
    .project {
        flex: 0 0 calc(33.333% - 20px);
    }
    
    .project-image {
        height: 200px;
    }
    
    .award-type {
        flex: 0 0 calc(33.333% - 20px);
    }
    
    /* 竞赛统计响应式调整 */
    .stat-number {
        font-size: 36px;
    }
    
    .stat-label {
        font-size: 15px;
    }
}

@media (max-width: 992px) {
    .container {
        max-width: 95%;
    }
    
    .project {
        flex: 0 0 calc(50% - 15px);
    }
    
    .main-navigation .menu-item a {
        min-width: 70px;
    }
    
    /* 奖项说明响应式调整 - 改为单列布局 */
    .award-standards {
        padding: 20px;
        margin-bottom: 30px;
    }
    
    .award-standards h3 {
        font-size: 20px;
        margin-bottom: 12px;
    }
    
    .award-standards p {
        font-size: 15px;
        margin-bottom: 12px;
    }
    
    .award-types {
        flex-direction: column;
        gap: 15px;
    }
    
    .award-type {
        width: 100%;
        padding: 18px;
        margin-bottom: 0;
    }
    
    .award-type h4 {
        font-size: 17px;
        margin-bottom: 8px;
    }
    
    .award-type p {
        font-size: 14px;
        line-height: 1.5;
    }
    
    /* 竞赛统计响应式调整 */
    .contest-stats {
        padding: 20px 15px;
        flex-wrap: wrap;
    }
    
    .stat-item {
        flex: 0 0 calc(50% - 10px);
        margin-bottom: 15px;
    }
    
    .stat-item:not(:last-child)::after {
        display: none;
    }
    
    .stat-number {
        font-size: 32px;
    }
}

@media (max-width: 990px) {
    .menu-toggle {
        display: flex !important;
        margin-right: 1rem;
    }
    
    .main-navigation .menu {
        display: none !important;
    }
    
    .mobile-navigation {
        max-height: calc(100vh - 100px); /* 调整最大高度 */
    }
    
    .mobile-navigation .menu {
        padding-left: 1rem; /* 减少容器边距 */
        padding-right: 1rem;
    }
    
    .mobile-navigation .menu-item a {
        padding: 0.75rem 0.875rem; /* 调整内边距 */
        font-size: 0.9375rem; /* 15px */
        min-height: 2.75rem;
    }
    
    .mobile-navigation .menu-item a::before {
        width: 0.4375rem; /* 7px */
        height: 0.4375rem;
        margin-right: 0.625rem; /* 10px */
    }
}

@media (max-width: 768px) {
    .project {
        flex: 0 0 100%;
    }
    
    .year-divider h2 {
        font-size: 20px;
    }
    
    .main-navigation .menu-item a {
        min-width: auto;
        text-align: left;
    }
    
    /* 调整竞赛卡片布局 */
    .project {
        margin-bottom: 20px;
    }
    
    .project-image {
        height: 180px;
    }
    
    /* 奖项标准说明移动端布局优化 */
    .award-standards {
        padding: 15px;
        margin-bottom: 25px;
        border-radius: 12px;
    }
    
    .award-standards h3 {
        font-size: 18px;
        margin-bottom: 10px;
        text-align: center;
    }
    
    .award-standards p {
        font-size: 14px;
        margin-bottom: 10px;
        text-align: center;
        line-height: 1.5;
    }
    
    .award-types {
        flex-direction: column;
        gap: 12px;
        margin-top: 15px;
    }
    
    .award-type {
        width: 100%;
        padding: 15px;
        margin-bottom: 0;
        border-radius: 8px;
    }
    
    .award-type h4 {
        font-size: 16px;
        margin-bottom: 6px;
        text-align: center;
    }
    
    .award-type h4 i {
        margin-right: 6px;
        font-size: 14px;
    }
    
    .award-type p {
        font-size: 13px;
        line-height: 1.4;
        text-align: left;
        margin: 0;
    }
    
    /* 竞赛统计移动端布局 */
    .contest-stats {
        flex-wrap: wrap;
        gap: 15px;
        padding: 15px 10px;
    }
    
    .stat-item {
        flex: 0 0 calc(50% - 10px);
        padding: 10px 5px;
    }
    
    .stat-number {
        font-size: 28px;
        margin-bottom: 5px;
    }
    
    .stat-label {
        font-size: 14px;
    }
    
    /* 确保图片内容居中 */
    .project-image img {
        object-position: center;
    }
    
    /* 缩小徽章大小 */
    .award-badge {
        font-size: 11px;
        padding: 5px 10px;
        right: 10px;
        top: 10px;
    }
    
    /* 提高覆盖层可读性 */
    .project-overlay {
        padding: 12px;
    }
    
    .project-overlay h4 {
        font-size: 16px;
    }
    
    .menu-toggle {
        display: flex !important;
        margin-right: 1rem;
    }
    
    .main-navigation .menu {
        display: none !important;
    }
    
    .mobile-navigation {
        max-height: calc(100vh - 90px);
    }
    
    .mobile-navigation .menu {
        padding: 2.5rem 1rem 1rem;
        gap: 0.375rem;
    }
    
    .mobile-navigation .menu-item a {
        padding: 0.75rem 1rem;
        font-size: 0.9375rem;
        min-height: 2.5rem;
    }
    
    .mobile-navigation .menu-item a::before {
        width: 0.4375rem;
        height: 0.4375rem;
        margin-right: 0.625rem;
    }
}

@media (max-width: 576px) {
    .container {
        padding-left: 10px;
        padding-right: 10px;
        max-width: 100%;
    }
    
    .project {
        margin-bottom: 15px;
    }
    
    .project-image {
        height: 160px;
    }
    
    .year-divider {
        margin: 30px 0 20px;
    }
    
    /* 超小屏幕奖项说明优化 */
    .award-standards {
        padding: 12px;
        margin-bottom: 20px;
    }
    
    .award-standards h3 {
        font-size: 16px;
        margin-bottom: 8px;
    }
    
    .award-standards p {
        font-size: 13px;
        margin-bottom: 8px;
        line-height: 1.4;
    }
    
    .award-types {
        gap: 10px;
        margin-top: 12px;
    }
    
    .award-type {
        padding: 12px;
        border-radius: 6px;
    }
    
    .award-type h4 {
        font-size: 15px;
        margin-bottom: 5px;
        display: block;
        text-align: left;
    }
    
    .award-type h4 i {
        margin-right: 5px;
        font-size: 13px;
        display: inline-block;
        width: 16px;
        text-align: center;
    }
    
    .award-type p {
        font-size: 12px;
        line-height: 1.3;
        text-align: left;
    }
    
    /* 竞赛统计在小屏幕上单列显示 */
    .contest-stats {
        padding: 15px 10px;
    }
    
    .stat-item {
        flex: 0 0 100%;
        margin-bottom: 15px;
        padding: 8px 5px;
    }
    
    .stat-item:last-child {
        margin-bottom: 0;
    }
    
    .stat-number {
        font-size: 28px;
        margin-bottom: 3px;
    }
    
    .stat-label {
        font-size: 14px;
    }
    
    /* 提高图片加载速度 */
    .project-image img {
        object-fit: cover;
        will-change: transform;
    }
    
    /* 简化悬停效果，提高性能 */
    .project:hover .project-image img {
        transform: scale(1.05);
    }
    
    /* 为触摸设备优化 */
    .project-zoom {
        opacity: 1;
        transform: translate(-50%, -50%) scale(0.9);
        background: rgba(0, 0, 0, 0.5);
    }
    
    .project:hover .project-zoom {
        transform: translate(-50%, -50%) scale(1);
    }
    
    /* 确保覆盖层文字在小屏幕上可读 */
    .project-overlay h4 {
        font-size: 15px;
        margin-bottom: 5px;
    }
    
    .project-overlay p {
        font-size: 12px;
        margin-bottom: 5px;
    }
    
    .award-prestige {
        font-size: 11px;
    }
    
    .mobile-navigation {
        max-height: calc(100vh - 90px);
    }
    
    .mobile-navigation .menu {
        padding: 0.75rem 0;
        padding-left: 0.75rem; /* 进一步减少容器边距 */
        padding-right: 0.75rem;
    }
    
    .mobile-navigation .menu-item a {
        padding: 0.625rem 0.75rem; /* 调整内边距 */
        font-size: 0.875rem; /* 14px */
        min-height: 2.5rem;
    }
    
    .mobile-navigation .menu-item a::before {
        width: 0.375rem; /* 6px */
        height: 0.375rem;
        margin-right: 0.5rem; /* 8px */
    }
}

/* 超小屏幕优化 */
@media (max-width: 375px) {
    .project-image {
        height: 140px;
    }
    
    .award-badge {
        font-size: 10px;
        padding: 4px 8px;
    }
    
    .year-divider h2 {
        font-size: 18px;
    }
    
    .stat-number {
        font-size: 24px;
    }
    
    .stat-label {
        font-size: 12px;
    }
    
    /* 极小屏幕奖项说明进一步优化 */
    .award-standards {
        padding: 10px;
        margin-bottom: 15px;
    }
    
    .award-standards h3 {
        font-size: 15px;
        margin-bottom: 6px;
    }
    
    .award-standards p {
        font-size: 12px;
        margin-bottom: 6px;
        line-height: 1.3;
    }
    
    .award-types {
        gap: 8px;
        margin-top: 10px;
    }
    
    .award-type {
        padding: 10px;
    }
    
    .award-type h4 {
        font-size: 14px;
        margin-bottom: 4px;
    }
    
    .award-type h4 i {
        font-size: 12px;
        width: 14px;
    }
    
    .award-type p {
        font-size: 11px;
        line-height: 1.2;
    }
}

/* 确保内容不会溢出 */
.site-content {
    overflow-x: hidden;
}

/* 改进加载性能 */
img {
    will-change: transform;
    transform: translateZ(0);
}

/* 导航菜单包装器样式 */
.main-navigation > div {
    width: 100%;
    display: flex;
    justify-content: flex-end;
    padding-right: 10px;
    margin-right: 0;
}

/* 菜单切换按钮 */
.menu-toggle {
    display: none;
    background: transparent;
    border: none;
    color: var(--dark-color);
    font-size: 1.5rem; /* 24px */
    cursor: pointer;
    padding: 0.5rem; /* 8px */
    transition: all 0.3s ease;
    z-index: 1001;
    border-radius: 0.25rem; /* 4px */
    position: relative;
    width: 2.5rem; /* 40px */
    height: 2.5rem; /* 40px */
    display: flex;
    align-items: center;
    justify-content: center;
}

.menu-toggle:hover {
    color: var(--primary-color);
    background-color: rgba(52, 152, 219, 0.1);
    transform: scale(1.05);
}

.menu-toggle:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.menu-toggle:active {
    transform: scale(0.95);
}

/* 汉堡菜单图标动画 */
.menu-toggle .fa-bars {
    transition: transform 0.3s ease;
}

.menu-toggle.active .fa-bars {
    transform: rotate(90deg);
}

/* 屏幕阅读器专用文本 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* 移动端导航菜单样式 - 与about页面完全一致 */
.mobile-navigation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    z-index: 999;
    transform: translateY(-100%);
    transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    overflow-y: auto;
    display: none;
    box-shadow: 0 0.5rem 1.5rem rgba(0, 0, 0, 0.15);
    border-radius: 0 0 1rem 1rem;
    border-top: 2px solid var(--primary-color);
    max-height: calc(100vh - 100px);
}

.mobile-navigation.show {
    display: block;
    transform: translateY(0);
}

.mobile-navigation .menu {
    list-style: none;
    padding: 2rem 1.5rem 1rem;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.375rem;
}

.mobile-navigation .menu-item {
    opacity: 0;
    transform: translateY(-20px);
    animation: slideInDown 0.4s ease forwards;
}

.mobile-navigation .menu-item:nth-child(1) { animation-delay: 0.05s; }
.mobile-navigation .menu-item:nth-child(2) { animation-delay: 0.1s; }
.mobile-navigation .menu-item:nth-child(3) { animation-delay: 0.15s; }
.mobile-navigation .menu-item:nth-child(4) { animation-delay: 0.2s; }
.mobile-navigation .menu-item:nth-child(5) { animation-delay: 0.25s; }

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

.mobile-navigation .menu-item a {
    display: flex;
    align-items: center;
    padding: 0.875rem 1rem;
    color: var(--dark-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: all 0.3s ease;
    border-radius: 0.5rem;
    border-left: 3px solid transparent;
    min-height: 3rem;
}

.mobile-navigation .menu-item:last-child a {
    border-bottom: none;
}

.mobile-navigation .menu-item a:hover,
.mobile-navigation .menu-item a:focus {
    background-color: rgba(52, 152, 219, 0.05);
    color: var(--primary-color);
    border-left: 3px solid var(--primary-color);
}

.mobile-navigation .menu-item a:active {
    background-color: rgba(52, 152, 219, 0.1);
    transform: scale(0.98);
}

.mobile-navigation .menu-item a::before {
    content: '';
    width: 0.5rem;
    height: 0.5rem;
    border-radius: 50%;
    background-color: var(--gray-color);
    margin-right: 0.75rem;
    flex-shrink: 0;
    transition: all 0.3s ease;
}

.mobile-navigation .menu-item a:hover::before,
.mobile-navigation .menu-item a:focus::before {
    background-color: var(--primary-color);
    transform: scale(1.2);
}

/* 移动端导航打开时禁止页面滚动 */
body.mobile-nav-open {
    overflow: hidden;
    position: fixed;
    width: 100%;
}

/* 竞赛统计样式 */
.contest-stats {
    display: flex;
    justify-content: space-between;
    background: white;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 40px;
    box-shadow: var(--box-shadow);
    text-align: center;
    overflow: hidden;
    position: relative;
}

.contest-stats::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 3px;
    background: var(--gradient-bg);
    animation: slidein 2s ease-in-out forwards;
}

@keyframes slidein {
    to {
        left: 0;
    }
}

.stat-item {
    flex: 1;
    padding: 15px;
    position: relative;
    transform: translateY(20px);
    opacity: 0;
    animation: fadeUp 0.8s ease forwards;
}

.stat-item:nth-child(1) { animation-delay: 0.3s; }
.stat-item:nth-child(2) { animation-delay: 0.5s; }
.stat-item:nth-child(3) { animation-delay: 0.7s; }
.stat-item:nth-child(4) { animation-delay: 0.9s; }

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

.stat-item:not(:last-child)::after {
    content: '';
    position: absolute;
    right: 0;
    top: 20%;
    height: 60%;
    width: 1px;
    background: linear-gradient(to bottom, transparent, rgba(0,0,0,0.1), transparent);
}

.stat-number {
    font-size: 42px;
    font-weight: 700;
    background: var(--gradient-bg);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 10px;
    line-height: 1.2;
    display: inline-block;
    position: relative;
}

.stat-number::after {
    content: attr(data-suffix);
    font-size: 60%;
    position: absolute;
    top: 5px;
    right: -15px;
}

.stat-label {
    font-size: 16px;
    color: var(--gray-color);
    font-weight: 500;
    position: relative;
}