/* --- 全局 CSS 变量 (便于后期维护) --- */
        :root {
            --primary-color: #ff5100; /* 标志性橙色 */
            --primary-glow: rgba(255, 81, 0, 0.15);
            --bg-light: #ffffff;
            --bg-dark: #08090a;
            --text-main: #111111;
            --text-muted: #666666;
            --glass-bg: rgba(255, 255, 255, 0.7);
            --border-radius: 32px;
            --transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
        }

        /* --- 基础重置 --- */
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { 
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            background-color: var(--bg-light);
            color: var(--text-main);
            line-height: 1.5;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
        }
        a { text-decoration: none; color: inherit; transition: var(--transition); }
        ul { list-style: none; }

        /* --- 响应式容器 --- */
        .container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

  /* nav */
     .btn {
              display: inline-flex;
              align-items: center;
              justify-content: center;
              gap: 10px;
              padding: 15px 28px;
              border-radius: 999px;
              font-size: 15px;
              font-weight: 600;
              border: none;
              cursor: pointer;
              transition: var(--transition);
              white-space: nowrap;
          }
  
          .btn-primary {
              background: var(--primary-color);
              color: #fff;
              box-shadow: 0 12px 30px var(--primary-glow);
          }
  
          .btn-primary:hover {
              transform: translateY(-3px);
              box-shadow: 0 16px 38px var(--primary-glow);
          }
  
          .btn-secondary {
              background: #f4f5f7;
              color: #111;
          }
  
          .btn-secondary:hover {
              transform: translateY(-2px);
              background: #ededf0;
          }
        .nav-wrapper {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            background: var(--glass-bg);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border-bottom: 1px solid var(--border-color);
        }

        .nav-content {
            height: 74px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 20px;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 20px;
            font-weight: 800;
            flex-shrink: 0;
        }

        .logo-icon {
            width: 30px;
            height:30px;
            border-radius: 8px;
            background: var(--primary-color);
            box-shadow: 0 8px 20px var(--primary-glow);
        }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 28px;
            font-size: 14px;
            font-weight: 500;
            color: #444;
        }

        .nav-links a:hover {
            color: var(--primary-color);
        }

        .nav-btns {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        #nav-toggle {
            display: none;
        }

        .mobile-menu-btn {
            display: none;
            width: 44px;
            height: 44px;
            border: 1px solid #eee;
            background: #fff;
            border-radius: 12px;
            align-items: center;
            justify-content: center;
            cursor: pointer;
        }

        .mobile-menu-btn span,
        .mobile-menu-btn span::before,
        .mobile-menu-btn span::after {
            content: "";
            display: block;
            width: 18px;
            height: 2px;
            background: #111;
            position: relative;
            transition: .3s ease;
            border-radius: 2px;
        }

        .mobile-menu-btn span::before {
            position: absolute;
            top: -6px;
            left: 0;
        }

        .mobile-menu-btn span::after {
            position: absolute;
            top: 6px;
            left: 0;
        }

        .mobile-menu {
            display: none;
            position: fixed;
            top: 74px;
            left: 0;
            width: 100%;
            background: rgba(255,255,255,0.96);
            backdrop-filter: blur(16px);
            border-bottom: 1px solid #eee;
            z-index: 999;
        }

        .mobile-menu-inner {
            padding: 18px 24px 24px;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .mobile-menu a {
            padding: 14px 0;
            border-bottom: 1px solid #f2f2f2;
            font-size: 15px;
            color: #222;
        }

        .mobile-menu-actions {
            display: flex;
            flex-direction: column;
            gap: 12px;
            padding-top: 8px;
        }
 @media (max-width: 900px) {
            .nav-links,
            .nav-btns {
                display: none;
            }

            .mobile-menu-btn {
                display: inline-flex;
            }

            #nav-toggle:checked + .mobile-menu {
                display: block;
            }

            .stat-row {
                grid-template-columns: 1fr;
            }

            .bento-grid {
                grid-template-columns: repeat(2, 1fr);
            }

            .bento-card.card-wide {
                grid-column: span 2;
            }

            .panel-row {
                grid-template-columns: 1fr;
            }
        }


        /* --- 2. Hero Section (主视觉区) --- */
        .hero { 
            padding: 160px 0 100px; text-align: center;
            background: radial-gradient(circle at 80% 20%, #fff5f0 0%, transparent 40%);
        }
        .badge {
            display: inline-block; padding: 6px 16px; border-radius: 20px;
            background: #fff; border: 1px solid #eee; font-size: 11px; font-weight: 700; color: #888;
            margin-bottom: 32px; letter-spacing: 1px;
        }
        .hero h1 { font-size: clamp(40px, 8vw, 84px); font-weight: 800; letter-spacing: -3px; line-height: 1.05; margin-bottom: 24px; }
        .hero h1 span { color: var(--primary-color); }
        .hero p { max-width: 620px; margin: 0 auto 48px; font-size: clamp(16px, 2vw, 20px); color: var(--text-muted); }
        
        .btn-group { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }
        .btn { padding: 16px 36px; border-radius: 999px; font-weight: 600; font-size: 16px; cursor: pointer; transition: var(--transition); border: none; }
        .btn-primary { background: var(--primary-color); color: white; box-shadow: 0 10px 25px var(--primary-glow); }
        .btn-primary:hover { transform: translateY(-3px); box-shadow: 0 15px 35px var(--primary-glow); }
        .btn-secondary { background: #f4f5f7; color: #111; }

        /* --- 3. App Mockup (应用预览) --- */
        .browser-mockup {
            max-width: 1100px; margin: 0 auto 120px;
            background: white; border-radius: 24px; border: 1px solid #eee;
            box-shadow: 0 40px 100px rgba(0,0,0,0.06); overflow: hidden;
        }
        .browser-header {
            padding: 14px 20px; background: #f9f9f9; display: flex; align-items: center; border-bottom: 1px solid #eee;
        }
        .dots { display: flex; gap: 6px; }
        .dot { width: 10px; height: 10px; border-radius: 50%; background: #ddd; }
        .address-bar { margin: 0 auto; font-size: 12px; color: #999; background: #fff; padding: 4px 40px; border-radius: 6px; border: 1px solid #eee; }

        /* 模拟 Dashboard 内容 */
        .app-content { height: auto; text-align: left; background: #fff; }
        .sidebar { width: 220px;  padding: 30px; border-right: 1px solid #eee;   
    border-radius: 24px; }
        .main-panel { flex: 1; padding: 40px; }
        .stat-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 30px; }
        .stat-card { height: 140px; border-radius: 20px; border: 1px solid rgba(0,0,0,0.03); }

        /* --- 4. Bento Grid (特性展示区) --- */
        .features { padding: 120px 0; background: #fff; }
		.features-h2{
			font-size: 48px; letter-spacing: -1.5px;
		}
        .bento-grid { 
            display: grid; 
            grid-template-columns: repeat(3, 1fr); 
            grid-auto-rows: 320px; 
            gap: 24px; 
            margin-top: 60px;
        }
        .bento-card { 
            background: #fff; border: 1px solid #f0f0f0; border-radius: var(--border-radius); 
            padding: 40px; display: flex; flex-direction: column; justify-content: flex-end; 
            transition: var(--transition); position: relative;
        }
        .bento-card:hover { transform: translateY(-8px); box-shadow: 0 30px 60px rgba(0,0,0,0.05); }
        .card-wide { grid-column: span 2; }
        .bento-card h3 { font-size: 24px; margin-bottom: 12px; font-weight: 700; }
        .bento-card p { color: var(--text-muted); font-size: 15px; }
        .icon-box { width: 48px; height: 48px; border-radius: 14px; display: flex; align-items: center; justify-content: center; margin-bottom: auto; }

        @media (max-width: 900px) {
            .bento-grid { grid-template-columns: repeat(2, 1fr); }
            .card-wide { grid-column: span 2; }
        }
        @media (max-width: 600px) {
            .bento-grid { grid-template-columns: 1fr; grid-auto-rows: auto;display:block }
            .card-wide { grid-column: span 1; }
        }

        /* --- 5. Workflow (流程引导) --- */
        .workflow { padding:60px 0; text-align: center; }
        .steps-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px; margin-top: 80px; }
        .step-num { 
            font-size: 100px; font-weight: 800; line-height: 1; margin-bottom: 24px;
            color: transparent; -webkit-text-stroke: 1.5px #eee; transition: var(--transition);
        }
        .step-item:hover .step-num { -webkit-text-stroke: 1.5px #ddd; transform: translateY(-5px); }
        .step-line { width: 40px; height: 4px; border-radius: 2px; margin: 0 auto 32px; }

        @media (max-width: 900px) { .steps-grid { grid-template-columns: repeat(2, 1fr); } }
        @media (max-width: 600px) { .steps-grid { grid-template-columns: 1fr; } }

        /* --- 6. Final CTA (行动召唤) --- */
        .cta-section { padding: 100px 0; }
        .cta-card {
            background: var(--bg-dark); border-radius: 48px; padding: 100px 40px; text-align: center;
            color: white; position: relative; overflow: hidden;
        }
        .cta-card h2 { font-size: clamp(32px, 6vw, 64px); font-weight: 800; margin-bottom: 24px; letter-spacing: -2px; }
        .cta-card p { color: rgba(255,255,255,0.5); font-size: 20px; margin-bottom: 48px; }

        /* --- 7. Footer (大页脚) --- */
        .footer { background: var(--bg-dark); color: white; padding: 100px 0 40px; }
        .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 60px; margin-bottom: 80px; }
        .footer-brand p { color: rgba(255,255,255,0.4); margin: 24px 0 32px; max-width: 300px; }
        .footer-col h4 { font-size: 14px; margin-bottom: 24px; color: #fff; }
        .footer-col a { display: block; margin-bottom: 14px; color: rgba(255,255,255,0.4); font-size: 14px; }
        .footer-col a:hover { color: #fff; }
        .footer-bottom { border-top: 1px solid rgba(255,255,255,0.05); padding-top: 40px; display: flex; justify-content: space-between; font-size: 13px; color: rgba(255,255,255,0.3); }

        @media (max-width: 900px) {
            .footer-grid { grid-template-columns: 1fr 1fr; gap: 40px; }
            .footer-bottom { flex-direction: column; gap: 20px; text-align: center; }
        }
		
		
		.app-container {
		    display: flex;
		    padding: 30px;
		    /* background: #f8f9fb; */
		    font-family: var(--font-family);
		}
		
		/* 桌面端侧边栏 */
		.sidebar {
		    width: 240px;
		    background: #f0f2f5;
		    padding: 24px 16px;
		    display: flex;
		    flex-direction: column;
		    border-right: 1px solid #eee;
		    position: sticky;
		    top: 0;
		    gap: 110px;
		}
		
		.mobile-header  {
		/*	display: contents; */
			}
			 /* 默认不干预布局 */
		
		.sidebar-brand {
		    font-size: 10px;
		    font-weight: 800;
		    color: #bbb;
		    letter-spacing: 2px;
		    margin-bottom: 32px;
		    padding-left: 12px;
		}
		
		.nav-item {
		    display: flex;
		    align-items: center;
		    padding: 12px 16px;
		    text-decoration: none;
		    color: #666;
		    font-size: 14px;
		    font-weight: 600;
		    border-radius: 12px;
		    margin-bottom: 4px;
		    transition: 0.2s;
		}
		
		.nav-item.active { background: white; color: #111; box-shadow: 0 4px 12px rgba(0,0,0,0.05); }
		.nav-item .icon { margin-right: 12px; }
		
		.pendant-card {
		    margin-top: auto;
		    background: rgba(255, 81, 0, 0.08);
		    border-radius: 16px;
		    padding: 12px;
		    display: flex;
		    align-items: center;
		    gap: 12px;
			border: 1px #ffc2b2 solid;
		}
		
		.pendant-icon { width: 32px; height: 32px; background: #ffede5; color: #ff5100; border-radius: 8px; display: flex; align-items: center; justify-content: center; }
		.pendant-name { font-size: 13px; font-weight: 700; }
		.pendant-status { font-size: 11px; color: #ff5100; }
		
		/* 内容区域 */
		.app-content { flex: 1; padding:0 40px; max-width: 1200px; margin: 0 auto; width: 100%; }
		.content-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 32px; }
		.status-badge { background: #e6f7ef; color: #27c93f; padding: 6px 12px; border-radius: 20px; font-size: 12px; font-weight: 600; }
		
		.stats-row { display: flex; gap: 20px; margin-bottom: 24px; }
		.mini-card { flex: 1; padding: 24px; border-radius: 24px; border: 1px solid rgba(0,0,0,0.02); }
		.card-icon{
			width: 32px;
			height: 32px;
			background: #ffede5;
			color: #ff5100;
			border-radius: 8px;
			display: flex;
			align-items: center;
			justify-content: center
		}
		.card-orange { background: #fff5f0;border: 1px #ffe2da solid; }
		.card-green { background: #ecfdf5; border: 1px #d0f0e4 solid; }
		.card-purple { background: #f5f3ff; border: 1px #e6dcfd solid;}
		.card-purple .card-icon{background: #e6dcfd;}
		.card-green .card-icon{background: #d0f0e4;}
		.card-orange .card-icon{background: #ffe2da;}
		.card-val { font-size: 24px; font-weight: 800; }
		.card-label { font-size: 13px; color: #999; margin-bottom: 8px; }
		.mini-card .card-trend{font-size: 13px;}
		.card-purple .card-trend{color:#7c3aed;}
		.card-green .card-trend{color:#059669;}
		.card-orange .card-trend{color:#fe4d1a;}
		.next-session-card { background: #fff1ed; border-radius: 28px; padding: 32px; display: flex; justify-content: space-between; align-items: center;     border: 1px #ffc2b2 solid;}
		.play-btn { width: 56px; height: 56px; background: linear-gradient(135deg, #ff5100, #ff8c00); border: none; border-radius: 50%; color: white; cursor: pointer; box-shadow: 0 10px 20px rgba(255, 81, 0, 0.2); }
		.session-info .up-next-tag{color:#fe4d1a; font-size: 13px;}  
		.session-info .time-info{font-size: 13px; color: var(--text-m);}
		/* --- 响应式手机端适配 (关键部分) --- */
		@media (max-width: 768px) {
		    .app-container { flex-direction: column; }
		
		    /* 移动端导航栏转换 */
		    .mobile-header {
		        display: flex;
		        align-items: center;
		        justify-content: space-between;
		        padding: 16px 0px;
		        background: white;
		        position: sticky;
		        top: 0;
		        z-index: 100;
		        border-bottom: 1px solid #eee;
		    }
			.browser-mockup{
				margin: 0 auto 0;
			}
		    .sidebar-brand { margin-bottom: 0; padding-left: 0; }
		
		    /* 侧边栏变为抽屉式菜单 */
		    .sidebar {
		        position: fixed;
		        left: -100%;
		        top: 60px; /* header 高度 */
		        width: 80%;
		        height: calc(100vh - 60px);
		        background: white;
		        transition: 0.3s ease;
		        box-shadow: 20px 0 50px rgba(0,0,0,0.05);
		        z-index: 99;
		    }
		
		    /* 汉堡按钮逻辑 */
		    .nav-toggle { display: none; }
		    .nav-toggle-label {
		        width: 30px; height: 30px;
		        display: flex; align-items: center; justify-content: center;
		        cursor: pointer;
		    }
		    .nav-toggle-label span, .nav-toggle-label span::before, .nav-toggle-label span::after {
		        content: ""; display: block; background: #333; height: 2px; width: 20px; position: relative; transition: 0.3s;
		    }
		    .nav-toggle-label span::before { bottom: 6px; }
		    .nav-toggle-label span::after { top: 6px; }
		
		    /* 选中状态：展开侧边栏 */
		    .nav-toggle:checked ~ .sidebar { left: 0; }
		    .nav-toggle:checked ~ .nav-toggle-label span { background: transparent; }
		    .nav-toggle:checked ~ .nav-toggle-label span::before { transform: rotate(45deg); top: 0; }
		    .nav-toggle:checked ~ .nav-toggle-label span::after { transform: rotate(-45deg); top: -2px; }
		
		    /* 内容区域压缩 */
		    .app-content { padding:0; }
		    .content-header { flex-direction: column; gap: 12px; align-items: flex-start; }
		
		    /* 统计卡片垂直排列 */
		    .stats-row { flex-direction: column; }
		    .mini-card { padding: 20px; }
			
		    /* 下一课卡片调整 */
		    .next-session-card { padding: 24px; flex-direction: row; }
		    .next-session-card h3 { font-size: 16px; }
			.features{padding: 60px 0 30px}
			.features-h2{
				font-size: 34px; letter-spacing: -1.5px;
			}
			.bento-card{
				padding: 20px;
				margin-bottom:20px
			}

			.workflow{
				padding: 60px 0 0;
			}
			.cta-card{
				padding: 30px;
			}
			.cta-section{
				padding: 50px 0;
			}
			.step-row{
				grid-template-columns: 1fr !important;
			}
			.story-glow{
			width:auto !important;
			}
			.detail-grid {
    display: grid;
    grid-template-columns: repeat(1, 1fr)!important;
    gap: 20px;
}
						.overview-grid {
    display:block !important;
  
    gap: 22px;
}
		}