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

body {
    font-family: 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
}

/* Header Navigation */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    /* background: #1a12cc; */
    /* backdrop-filter: blur(10px); */
    z-index: 1000;
    padding: 15px 0;
    /* transition: all 0.3s ease; */
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo {
    height: 42px;
}

.logo img {
    width: 120px;
    height: 42px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-menu a {
    color: white;
    text-decoration: none;
    transition: color 0.3s ease;
    font-size: 1rem;
}

.nav-menu a:hover {
    color: #60a5fa;
    border-bottom: 2px solid #60a5fa;
    padding-bottom: 5px;
}

.nav-menu a.active {
    color: #fbbf24;
    border-bottom: 2px solid #fbbf24;
    padding-bottom: 5px;
    font-weight: 600;
}


/* Hero Section */
.hero {
    background: url(../images/banner.png) no-repeat center center/cover;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    /* justify-content: center; */
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 600"><rect width="1200" height="600" fill="%23000033" opacity="0.3"/><circle cx="200" cy="150" r="3" fill="%23ffffff" opacity="0.6"><animate attributeName="opacity" values="0.6;1;0.6" dur="2s" repeatCount="indefinite"/></circle><circle cx="800" cy="100" r="2" fill="%23ffffff" opacity="0.4"><animate attributeName="opacity" values="0.4;0.8;0.4" dur="3s" repeatCount="indefinite"/></circle><circle cx="1000" cy="200" r="2.5" fill="%23ffffff" opacity="0.5"><animate attributeName="opacity" values="0.5;1;0.5" dur="2.5s" repeatCount="indefinite"/></circle></svg>') center/cover;
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

.hero-content {
    position: relative;
    z-index: 2;
    padding: 200px 20px;
}

.hero h1 {
    font-size: clamp(24px, 5vw, 48px);
    color: white;
    margin-bottom: 10px;
    font-weight: 300;
    letter-spacing: 2px;
    animation: fadeInUp 1s ease-out;
}

.hero h2 {
    font-size: 68px;
    color: #fff;
    margin-bottom: 30px;
    font-weight: 400;
    animation: fadeInUp 1s ease-out 0.3s both;
}

.hero-subtitle {
    font-size: 30px;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 40px;
    font-weight: 400;
    animation: fadeInUp 1s ease-out 0.6s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(100px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Event Introduction Section */
.event-intro {
    padding: 80px 20px;
    background: url(../images/bg-ssjj.png) no-repeat center center/cover;
    color: white;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    margin-bottom: 40px;
    text-align: left;
    position: relative;
}

.section-title .en {
    text-align: left;
    font-size: 24px;
}

.section-title .cn {
    text-align: left;
    font-size: 40px;
}

.section-title img {
    width:30px;
}

.intro-content {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 40px;
    align-items: center;
}

.intro-text {
    font-size: 18px;
    line-height: 1.8;
    opacity: 0.9;
    width: 500px;
    text-align: justify;
}

.intro-text h3 {
    font-size: 28px;
    margin-bottom: 30px;
}

.intro-image {
    border-radius: 10px;
}

.video {
    width: 700px;
    height: 220px;
    object-fit: cover;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

/* Question Description Section */
.question-section {
    color: white;
    height: 830px;
    background: url(../images/bg-stsm.jpg) no-repeat center center/cover;
}

.question-section .cover {
    width: 100vw;
    /* height: 100vh; */
    background: url(../images/cover-stsm.png) no-repeat center center/cover;
}

.question-section .container {
    padding: 80px 0px;
}

.question-content {
    text-align: center;
    margin: 0 auto;
    width: 1000px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.diagram-center {
    width: 500px;
    height: 500px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.diagram-bg-rotating {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    animation: rotate360 60s linear infinite;
    z-index: 1;
}

.diagram-center-content {
    position: relative;
    z-index: 2;
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    row-gap: 0px;
}

.diagram-center-title {
    font-size: 24px;
    font-weight: 400;
    margin-bottom: 20px;
}

.diagram-center-text {
    height: 250px;
    padding: 0 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 300;
    font-size: 17px;
    text-align: justify;
    text-indent: 2em;
}

@keyframes rotate360 {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.diagram-center .diagram-btn {
    margin: 0 auto;
}

.diagram-item {
    display: flex;
    flex-direction: column;
    row-gap: 200px;
}

.diagram-btn {
    padding: 10px 30px;
    border: 1px solid white;
    border-radius: 24px;
    color: white;
    font-size: 16px;
    cursor: pointer;
    transition: background 0.3s ease;
    width: 160px;
}

.diagram-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.diagram-btn.active {
    background: rgba(255, 255, 255, 0.3);
    border-color: #fbbf24;
    color: #fbbf24;
}


/* Competition Process */
.process-section {
    padding: 80px 20px;
    background: url(../images/bg-dslc.png) no-repeat center center/cover;
    color: #333;
}

.process-timeline {
    margin-top: 100px;
}

.process-timeline img {
    width:100%;
    margin: 0 auto;
}

.process-step {
    display: flex;
    text-align: center;
    justify-content: space-between;
}

.process-step .item {
    width: 200px;
}

.process-step .item .step-icon {
    width:80px;
    height:80px;
    margin-top: -100px;
}

.process-step .item .step-num {
    font-size: 60px;
    font-weight: bold;
    font-style: italic;
    color: rgba(140, 174, 220, 0.3);
    margin-bottom: 10px;
    height: 60px;
    overflow: hidden;
}

.process-step .item .step-title {
    font-size: 22px;
    font-weight: bold;
    margin-top: -20px;
    color:#333;
}

.process-step .item .step-date {
    font-size: 14px;
    color: #999;
}

.process-notice {
    margin-top: 50px;
    text-align: center;
    color: #333;
    font-size: 18px;
}

/* Awards Section */
.awards-section {
    padding: 80px 20px;
    background: url(../images/bg-jxsz.png) no-repeat center center/cover;
    color: white;
}

.track-tabs {
    display: flex;
    justify-content: center;
    gap: 50px;
    margin: 80px 0;
}

.track-tab {
    padding: 10px 24px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 25px;
    color: rgba(255, 255, 255, 0.7);
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 16px;
    background: rgba(255, 255, 255, 0.1);
}

.track-tab:hover {
    border-color: rgba(255, 255, 255, 0.6);
    color: rgba(255, 255, 255, 0.9);
    background: rgba(255, 255, 255, 0.2);
}

.track-tab.active {
    border-color: #fbbf24;
    color: #fbbf24;
    background: rgba(251, 191, 36, 0.2);
}

.awards-grid {
    display:flex;
    justify-content: center;
    column-gap: 30px;
}

.award-item {
    position: relative;
    z-index: 2;
}

.award-pic {
    width: 300px;
}
.award-title {
    position: absolute;
    top:150px;
    left:30px;
    font-size: 20px;
    font-weight: bold;
    margin-bottom: 10px;

}

.award-team {
    position: absolute;
    top: 200px;
    left: 30px;
    font-size: 16px;
    color: #fbbf24;
}

.award-team-bronze {
    position: absolute;
    top: 200px;
    left: 30px;
    font-size: 16px;
    color: #fbbf24;
}

.award-amount {
    position: absolute;
    top: 240px;
    left: 30px;
    font-size: 24px;
    color: #fbbf24;
    font-weight: bold;
}

.total-prize {
    text-align: center;
    position: relative;
    z-index: 1;
}

.total-prize img {
    width: 100%;
    margin-top: -40px;

}

.prize-sum {
    font-size: 24px;
    font-weight: bold;
    color: #fff;
    position: absolute;
    top: 25px;
    left: 500px;
}

/* Organization Structure */
.org-section {
    padding: 80px 20px;
    background-size: 100% 100%;
    background: url(../images/bg-zzjg.png) no-repeat center center/cover;
    color: white;
}

.org-content {
    display: flex;
    justify-content: space-between;
}

.org-grid {
    display: flex;
    flex-direction: column;
    row-gap: 40px;
}

.org-item {
    display: flex;
    column-gap: 20px;
}

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

.org-title {
    font-weight: 600;
    color: #fff;
    font-size: 20px;
    align-items: center;
    line-height: 1.6;
    display: flex;
}

.org-list {
    display: flex;
    flex-direction: row;
    column-gap: 10px;
}

.org-list span {
    display: block;
    font-size: 16px;
    line-height: 1.6;
    color: #fff;
    border: solid 1px #fff;
    padding: 10px;
    border-radius: 10px;
    width: 200px;
    text-align: center;
    background: linear-gradient( 180deg, rgba(0,64,152,0.2) 0%, rgba(77,156,223,0.1) 100%);
}

.qr-codes {
    display: flex;
    gap: 40px;
    margin-top: 40px;
    text-align: center;
}

.qr-code img{
    width:150px;
}
/* Footer */
.footer {
    background: #1a1a1a;
    color: white;
    padding: 40px 20px;
    text-align: center;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-title {
    font-size: 18px;
    margin-bottom: 20px;
}

.footer-info {
    font-size: 14px;
    opacity: 0.8;
    line-height: 1.6;
}

.footer-qr {
    width: 60px;
    height: 60px;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 60 60"><rect width="60" height="60" fill="white"/><rect x="5" y="5" width="50" height="50" fill="none" stroke="%23333" stroke-width="1"/><rect x="8" y="8" width="6" height="6" fill="%23333"/><rect x="46" y="8" width="6" height="6" fill="%23333"/><rect x="8" y="46" width="6" height="6" fill="%23333"/><rect x="20" y="20" width="20" height="20" fill="%23333"/></svg>') center/cover;
    margin: 20px auto 10px;
    border-radius: 5px;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    /* Header 优化 */
    .header {
        padding: 10px 0;
    }
    
    .nav-container {
        padding: 0 15px;
    }
    
    .logo img {
        width: 100px;
        height: 35px;
    }
    
    .nav-menu {
        display: none;
    }

    /* Hero 区域优化 */
    .hero {
        min-height: 70vh;
        padding: 20px;
    }
    
    .hero h1 {
        font-size: 24px;
        margin-bottom: 15px;
    }

    .hero h2 {
        font-size: 18px;
        margin-bottom: 20px;
    }
    
    .hero-subtitle {
        font-size: 16px;
        margin-bottom: 30px;
    }

    /* 容器通用优化 */
    .container {
        padding: 0 15px;
    }
    
    /* Section 标题优化 */
    .section-title .en {
        font-size: 18px;
    }
    
    .section-title .cn {
        font-size: 28px;
    }

    /* 赛事简介优化 */
    .event-intro {
        padding: 60px 15px;
    }
    
    .intro-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 30px;
    }
    
    .intro-text {
        width: 100%;
    }
    
    .intro-text h3 {
        font-size: 22px;
        margin-bottom: 20px;
    }

    .intro-image {
        width: 100%;
        max-width: 100%;
        margin: 0 auto;
    }
    
    .video {
        width: 100%;
        height: 180px;
    }

    /* 赛题说明区域优化 */
    .question-section {
        height: auto;
    }
    
    .question-section .container {
        padding: 40px 15px;
    }
    
    .question-content {
        width: 100%;
        flex-direction: column;
        gap: 30px;
    }
    
    .diagram-center {
        width: 300px;
        height: 300px;
        order: -1;
    }
    
    .diagram-center-text {
        padding: 0 20px;
        font-size: 14px;
        height: 150px;
    }
    
    .diagram-item {
        row-gap: 20px;
    }
    
    .diagram-btn {
        width: 140px;
        padding: 8px 20px;
        font-size: 14px;
    }

    /* 大赛流程优化 */
    .process-section {
        padding: 60px 15px;
    }

    .process-timeline .line {
        display: none;
    }
    
    .process-step {
        flex-direction: column;
        gap: 60px;
    }
    
    .process-step .item {
        width: 100%;
    }
    
    .process-step .item .step-icon {
        margin-top: -50px;
        width: 60px;
        height: 60px;
    }
    
    .process-step .item .step-num {
        font-size: 40px;
        height: 40px;
    }
    
    .process-step .item .step-title {
        font-size: 18px;
    }

    /* 奖项设置优化 */
    .awards-section {
        padding: 60px 15px;
    }
    
    .track-tabs {
        gap: 15px;
        margin: 40px 0;
        flex-wrap: wrap;
    }
    
    .track-tab {
        padding: 8px 16px;
        font-size: 14px;
        flex: 1;
        min-width: 120px;
    }
    
    .awards-grid {
        flex-direction: column;
        gap: 20px;
        align-items: center;
    }
    
    .award-item {
        width: 250px;
    }
    
    .award-pic {
        width: 250px;
    }
    
    .award-title {
        top: 125px;
        left: 25px;
        font-size: 18px;
    }
    
    .award-team {
        top: 165px;
        left: 25px;
        font-size: 14px;
    }
    
    .award-amount {
        top: 200px;
        left: 25px;
        font-size: 20px;
    }
    
    .prize-sum {
        font-size: 18px;
        top: 20px;
        left: 50%;
        transform: translateX(-50%);
    }

    .prize-sum {
        width: 100%;
    }

    /* 组织架构优化 */
    .org-section {
        padding: 60px 15px;
    }
    
    .org-content {
        flex-direction: column;
        gap: 30px;
    }
    
    .org-grid {
        row-gap: 30px;
    }
    
    .org-item {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    
    .org-title {
        font-size: 18px;
    }
    
    .org-list {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .org-list span {
        width: auto;
        min-width: 120px;
        padding: 8px 15px;
        font-size: 14px;
        margin-top: 10px;
    }

    .qr-codes {
        flex-direction: column;
        align-items: center;
        gap: 20px;
    }
    
    .qr-code img {
        width: 120px;
    }
}

/* 更小屏幕优化 */
@media (max-width: 480px) {
    .hero h1 {
        font-size: 20px;
    }
    
    .hero h2 {
        font-size: 16px;
    }
    
    .section-title .cn {
        font-size: 24px;
    }
    
    .diagram-center {
        width: 400px;
        height: 400px;
    }

    .diagram-bg-rotating {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        object-fit: cover;
        animation: rotate360 60s linear infinite;
        z-index: 1;
    }
    
    .track-tabs {
        flex-direction: column;
        gap: 10px;
    }
    
    .track-tab {
        width: 100%;
    }
    
    .award-item {
        width: 200px;
    }
    
    .award-pic {
        width: 200px;
    }
    
    .award-title {
        top: 100px;
        left: 20px;
        font-size: 16px;
    }
    
    .award-team {
        top: 130px;
        left: 20px;
        font-size: 12px;
    }
    
    .award-amount {
        top: 160px;
        left: 20px;
        font-size: 18px;
    }
}

/* Scroll animations */
.scroll-reveal {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s ease;
}

.scroll-reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}