:root {
            --primary: #8B4513;
            --primary-light: #A0522D;
            --secondary: #2F4F4F;
            --accent: #DAA520;
            --bg-cream: #FDF5E6;
            --bg-paper: #FAF0E6;
            --text-dark: #2C1810;
            --text-light: #5C4033;
            --border: #D2B48C;
            --gold: #D4AF37;
        }
  * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
  .nav-logo {
            display: flex;
            align-items: center;
            gap: 15px;
        }
        .logo-text {
            color: #5c4a3d;
            font-size: 24px;
            font-weight: 700;
            letter-spacing: 4px;
        }

        .logo-text span {
            color: #b85450;
            font-size: 14px;
            display: block;
            letter-spacing: 2px;
            margin-top: 2px;
            font-weight: 400;
        }
               .seal::before {
            content: '河';
            position: absolute;
            font-size: 12px;
            top: 2px;
            right: 4px;
            opacity: 0.8;
        }
        .seal {
            width: 50px;
            height: 50px;
            background: #b85450;
            border: 3px solid #8b4513;
            border-radius: 4px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 24px;
            font-weight: bold;
            box-shadow: 2px 2px 4px rgba(0,0,0,0.2);
            position: relative;
        }
         :root {
            --primary: #8B4513;
            --primary-light: #A0522D;
            --secondary: #2F4F4F;
            --accent: #DAA520;
            --bg-cream: #FDF5E6;
            --bg-paper: #FAF0E6;
            --text-dark: #2C1810;
            --text-light: #5C4033;
            --border: #D2B48C;
        }



        /* 导航栏 */
       nav {
            background: linear-gradient(to bottom, rgba(241, 239, 230, 0.95), rgba(225, 225, 220, 0.85));
            backdrop-filter: blur(10px);
            padding: 1rem 0;
            position: fixed;
            width: 100%;
            top: 0;
            z-index: 1000;
            border-bottom: 3px solid var(--accent);
            box-shadow: 0 2px 20px rgba(0,0,0,0.1);
        }

        .nav-container {
            max-width: 1900px;
            margin: 0 auto;
            padding: 0 2rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .logo {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.8rem;
            color: var(--accent);
            font-weight: 700;
            letter-spacing: 0.2em;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
        }

        .nav-links {
            display: flex;
            gap: 2rem;
            list-style: none;
        }

        .nav-links a {
            color:black;
            text-decoration: none;
            font-size: 1.5rem;
            transition: all 0.3s;
            position: relative;
            padding: 0.5rem 0;
            border: 1px black;
            font-family: 'Ma Shan Zheng', cursive;
        }

        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--accent);
            transition: width 0.3s;
        }

        .nav-links a:hover::after {
            width: 100%;
        }
        .nav-links a.active {
           
           font-weight:600;
        }
        body {
            font-family: 'Microsoft YaHei', 'PingFang SC', sans-serif;
            background:white;
            min-height: 100vh;
          line-height: 1.8;
            overflow-x: hidden;
        }
/*封面*/
        .container {
            max-width: 2000px;
            margin: 0 auto;
            padding: 40px 20px;
        }

      

        .show-section {
            background: rgba(255, 255, 255, 0.05);
            border-radius: 20px;
            padding: 40px;
            margin-bottom: 40px;
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.1);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }

        .show-section:hover {
            transform: translateY(-5px);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
        }

        .show-title {
            font-size: 2rem;
            margin-bottom: 20px;
            display: flex;
            align-items: center;
            gap: 15px;
        }

        .show-icon {
         
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
        }

  .hero {
            margin-top: 80px;
            height: 70vh;
            background: linear-gradient(rgba(0,0,0,0.4), rgba(0,0,0,0.4)), 
                        url('../images/cover5.jpg') center/cover;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            color:white;
            position: relative;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
        }

        .hero-content {
            position: relative;
            z-index: 2;
            max-width: 800px;
            padding: 2rem;
        }
    .hero  h1 {
            font-family: 'Zhi Mang Xing', cursive;
            font-size: 3.2rem;
            margin-bottom: 1rem;
            letter-spacing: 0.3em;
            text-shadow: 3px 3px 6px rgba(0,0,0,0.5);
            animation: fadeInUp 1s ease-out;
            color: white;
        
        }

        .hero p {
            font-size: 1.5rem;
            letter-spacing: 0.2em;
            opacity: 0.9;
            animation: fadeInUp 1s ease-out 0.3s both;
            font-family: 'Ma Shan Zheng', cursive;
        }

          .scroll-indicator {
            position: absolute;
            bottom: 30px;
            left: 50%;
            transform: translateX(-50%);
            animation: bounce 2s infinite;
        }

        .scroll-indicator::after {
            content: '▼';
            color: var(--accent);
            font-size: 2rem;
        }
        /* 大河上下 - 黄河主题 */
        .river-section .show-icon {
            background: linear-gradient(135deg, #f39c12, #e74c3c);
        }

        /* 顶部介绍区域 - 左图右文 */
        .river-header {
            display: flex;
            gap: 40px;
            margin-bottom: 50px;
            align-items: center;
            background: #d5e3ed;
            padding: 30px;
            border-radius: 15px;
            border: 1px solid rgba(243, 156, 18, 0.3);
            height: 800px;
        }

        .river-header-image {
            flex: 0 0 45%;
            max-width: 900px;
        }

        .river-header-image img {
            width: 100%;
            height: 600px;
            object-fit: cover;
            border-radius: 10px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
            border: 3px solid rgba(243, 156, 18, 0.5);
        }

        .river-header-content {
            flex: 1;
            position: relative;
            height: 400px;
           
        }

        .river-header-content h3 {
            font-size: 1.8rem;
            color: #f39c12;
            margin-bottom: 20px;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .river-header-content p {
            font-size: 1.2rem;
            line-height: 1.8;
            color: black;
            margin-bottom: 15px;

        }
        .river-header-content h4 {
                  width:100% ;
                   margin-top: 400px;
        }
        .river-time {
            position: absolute;
            list-style: none;
            font-size: 20px ;
            left:15%;
            top:82%;
        }
        .jiantou {
            margin-top: 50px;
        }
        .river-click {
            position: absolute;
            display: flex;
           width: 150px;
           left: 60%;
    
        }
        .tiaohzuan {
           
            width: 500px;
        }
        .tiaozhuan a {
            list-style: none;
            text-decoration: none;
            margin-top: 120px;
           font-size: 1.7rem;
           color:rgb(236, 139, 27);
           
        }
        /*
       .river-header-content a {
            margin-top: 60px;
            position: absolute;
            font-size: 1.7rem;
           
            color:bisque;
            text-decoration: none;
         
          
          
        }*/
        .river-stats {
            display: flex;
            gap: 30px;
            margin-top: 20px;
            flex-wrap: wrap;
        }

        .stat-item {
            text-align: center;
            padding: 15px 20px;
            background: rgba(243, 156, 18, 0.2);
            border-radius: 10px;
            border: 1px solid rgba(243, 156, 18, 0.3);
        }

        .stat-number {
            font-size: 2rem;
            font-weight: bold;
            color: #f39c12;
            display: block;
        }

        .stat-label {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.8);
        }

        /* 时间轴样式 */
        .river-timeline {
            position: relative;
            padding: 20px 0;
        }

        .river-path {
            position: absolute;
            left: 70%;
            transform: translateX(-50%);
            width: 6px;
            height: 100%;
            background: linear-gradient(to bottom, 
                #f39c12 0%, 
                #e67e22 25%, 
                #d35400 50%, 
                #e74c3c 75%, 
                #c0392b 100%);
            border-radius: 3px;
            box-shadow: 0 0 20px rgba(243, 156, 18, 0.5);
        }

        .river-node {
            position: relative;
            margin: 60px 0;
            display: flex;
            align-items: center;
            justify-content: space-between;
            color: #090a0f;
        }

        /* 奇数节点：内容在左，图片在右 */
        .river-node:nth-child(odd) {
            flex-direction: row;
        }

        /* 偶数节点：图片在左，内容在右 */
        .river-node:nth-child(even) {
            flex-direction: row-reverse;
        }

        .node-content-wrapper {
            width: 30%;
            display: flex;
            flex-direction: column;
            gap: 15px;
        }

        .node-content {
            background: rgba(255, 255, 255, 0.1);
            padding: 25px;
            border-radius: 15px;
            border-left: 4px solid #f39c12;
            transition: all 0.3s ease;
        }

        .river-node:nth-child(even) .node-content {
            border-left: none;
            border-right: 4px solid #f39c12;
            text-align: right;
        }

        .node-content:hover {
            background: rgba(255, 255, 255, 0.15);
            transform: scale(1.02);
        }

        .node-year {
            font-size: 1.5rem;
            font-weight: bold;
            color: #f39c12;
            margin-bottom: 8px;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .river-node:nth-child(even) .node-year {
            justify-content: flex-end;
        }

        .node-title {
            font-size: 1.2rem;
            margin-bottom: 10px;
            color: black;
            font-weight: 600;
        }

        .node-desc {
            font-size: 1.2rem;
            color:black;
            line-height: 1.7;
        }

        /* 节点图片样式 */
        .node-image {
            
            width: 60%;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4);
            border: 2px solid rgba(243, 156, 18, 0.4);
            transition: transform 0.3s ease;
        }

        .node-image:hover {
            transform: scale(1.03);
            border-color: rgba(243, 156, 18, 0.8);
        }

        .node-image img {
            width: 100%;
            height: 400px;
            object-fit: cover;
            display: block;
        }

        .image-caption {
            background: rgba(0, 0, 0, 0.7);
            padding: 10px;
            text-align: center;
            font-size: 0.85rem;
            color: rgba(255, 255, 255, 0.9);
        }

        .node-dot {
            position: absolute;
            left: 70%;
            transform: translateX(-50%);
            width: 28px;
            height: 28px;
            background: #f39c12;
            border-radius: 50%;
            border: 5px solid #1a1a2e;
            box-shadow: 0 0 0 4px #f39c12, 0 0 25px rgba(243, 156, 18, 0.9);
            z-index: 10;
            animation: pulse 2s infinite;
        }

        @keyframes pulse {
            0%, 100% { transform: translateX(-50%) scale(1); }
            50% { transform: translateX(-50%) scale(1.2); }
        }

        /* 盛世元朝 */
        .yuan-section .show-icon {
            background: linear-gradient(135deg, #fff, #fff);
        }

        .yuan-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
            margin-top: 20px;
        }

        .yuan-card {
            background: white;
            padding: 20px;
            border-radius: 10px;
            border: 1px solid rgba(155, 89, 182, 0.3);
            text-align: center;
            transition: transform 0.3s;
        }
        .yuan-card img{
                 width: 100%;
                 height: 100%;
        }

        .yuan-card:hover {
            transform: translateY(-5px);
            background: rgba(232, 228, 233, 0.3);
        }

        .yuan-card h3 {
            color: #fff;
            margin-bottom: 10px;
        }

        /* 华林园灯光秀 */
        .light-section .show-icon {
            background: linear-gradient(135deg, #3498db, #2980b9);
        }

        .light-showcase {
            display: flex;
            justify-content: space-around;
            flex-wrap: wrap;
            gap: 20px;
            margin-top: 20px;
        }

        .light-effect {
            width: 150px;
            height: 150px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            position: relative;
            overflow: hidden;
        }

        .light-effect::before {
            content: '';
            position: absolute;
            width: 100%;
            height: 100%;
            background: radial-gradient(circle, rgba(52, 152, 219, 0.8) 0%, transparent 70%);
            animation: glow 3s ease-in-out infinite;
        }

        @keyframes glow {
            0%, 100% { transform: scale(1); opacity: 0.8; }
            50% { transform: scale(1.2); opacity: 0.4; }
        }

        .light-effect span {
            position: relative;
            z-index: 1;
        }

        /* 华林园夜间烟花修 */
         .firework-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
            margin-top: 20px;
        }

        .firework-card {
            background: white;
            padding: 20px;
            border-radius: 10px;
            border: 1px solid rgba(155, 89, 182, 0.3);
            text-align: center;
            transition: transform 0.3s;
        }
        .firework-card img{
                 width: 100%;
                 height: 100%;
        }

        .firework-section .show-icon {
            background: linear-gradient(135deg, #e74c3c, #c0392b);
        }

        .firework-display {
            height: 600px;
            position: relative;
            background: radial-gradient(ellipse at bottom, #f0f1f3 0%, #e7e8eb 100%);
            border-radius: 15px;
            overflow: hidden;
            margin-top: 20px;
        }

      
        .firework-info {
            position: absolute;
            bottom: 20px;
            left: 50%;
            transform: translateX(-50%);
            text-align: center;
            background: rgba(0,0,0,0.5);
            padding: 15px 30px;
            border-radius: 30px;
        }

          /* 页脚 */
        .footer {
            color:black;
          background: var(--text-dark);
            width: 100%;
            padding:12px 20px;
            display:flex;
            flex-wrap:wrap;
            align-items:center;
            justify-content:space-between;
        }
        .footer-head {
            display: flex;
            flex-direction: column;
            flex:0  0 460px;
            justify-content: center;
            align-items: center;
            
        }
        .footer-brand {
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .footer-logo {
            width: 34px;
            height: 34px;
            background: linear-gradient(135deg, var(--gold), #b8944f);
            border-radius: 6px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 18px;
            font-weight: bold;
            font-family: 'Noto Serif SC', serif;
        }
        .footer-title {
            font-size: 32px;
            font-weight: 700;
            letter-spacing: 2px;
            font-family: 'Noto Serif SC', serif;
            color: white;
        }
        .footer-desc {
            color: rgba(193, 189, 189, 0.855);
            font-size: 18px;
            line-height: 1.5;
            margin-top:4px;
        }
        .footer-container {
            width: 2000px;
            justify-content: center;
            display:flex;
            flex-wrap:wrap;
            gap:25px;
            align-items:center;
            
        }
        .rechieve {
            display: grid;
            grid-template-columns: repeat(3,1fr);
            gap:120px;
        }
        .rechieve-right {
            display: flex;
            flex-direction: column;
            gap:20px;
         margin-left: 200px;
          
        }
        .rechieve-first,.rechieve-second,.rechieve-third{
            text-align: center;
        }
        .rechieve-fourth,.rechieve-fifth,.rechieve-sixth{
            padding:6px 8px;
            display: flex;
            align-items: center;
            gap:6px;
            width:100%;
        }
        
        #image-fourth,#image-fifth,#image-six {
            width:60px;
        }
        #image-first,#image-second,#image-third{
                    width: 90px;
          }
        #focus-first ,#focus-second,#focus-third,#focus-fourth,#focus-fifth,#focus-six{
            outline: none;
            border: none;
            color:white;
            font-size:18px;
            text-decoration:none;
        }
        #focus-first:hover,#focus-second:hover,#focus-third:hover,#focus-fourth:hover,#focus-fifth:hover,#focus-six:hover {
            cursor: pointer;
            color: #f8e9d8;
        }
        .footer-bottom {
            width:100%;
            text-align: center;
            color: white;
            font-size: 16px;
            padding-top:6px;
            margin-top:6px;
            border-top:1px solid rgba(255,255,255,0.15);
        }
         /* 响应式调整（仅防止极端情况，主要面向桌面） */
        @media (max-width: 1024px) {
            .buildings-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            
            .hero-title {
                font-size: 60px;
            }
        }

        @media (max-width: 768px) {
            .buildings-grid {
                grid-template-columns: 1fr;
            }
            
            .nav-links {
                display: none;
            }
            
            .timeline::before {
                left: 30px;
            }
            
            .timeline-item {
                flex-direction: column;
                align-items: flex-start;
                padding-left: 70px;
            }
            
            .timeline-content {
                width: 100%;
                text-align: left !important;
            }
            
            .timeline-year {
                text-align: left !important;
            }
            
            .timeline-dot {
                left: 30px;
            }
            
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 40px;
            }
        }
        
        /* 响应式适配 */
        @media (max-width: 968px) {
            .river-header {
                flex-direction: column;
            }

            .river-header-image {
                flex: 1;
                width: 100%;
                max-width: 100%;
            }

            .river-node, 
            .river-node:nth-child(odd), 
            .river-node:nth-child(even) {
                flex-direction: column;
                gap: 20px;
            }

            .node-content-wrapper,
            .node-image {
                width: 100%;
            }

            .river-node:nth-child(even) .node-content {
                border-right: none;
                border-left: 4px solid #f39c12;
                text-align: left;
            }

            .river-node:nth-child(even) .node-year {
                justify-content: flex-start;
            }

            .river-path {
                left: 20px;
            }

            .node-dot {
                left: 20px;
            }

            .node-image {
                order: 2;
            }

            .node-content-wrapper {
                order: 1;
            }
        }

        @media (max-width: 600px) {
            h1 {
                font-size: 2rem;
            }

            .show-title {
                font-size: 1.5rem;
            }

            .river-header-content h3 {
                font-size: 1.4rem;
            }
        }