/* === 动态字体大小变量 (默认:小字体) === */
        :root {
            --fs-h1: 24px;
            --fs-welcome: 16px;
            --fs-meaning: 26px;
            --fs-french: 22px;
            --fs-pronun: 18px;
            --fs-btn: 15px;
            --fs-opt-pronun: 15px;
            --fs-opt-french: 14px;
            --fs-p: 13px;
            --fs-label: 15px;
            --fs-table: 14px;
            --fs-header: 13px;
            --fs-footer: 11px;
        }

        body.font-medium {
            --fs-h1: 28px;
            --fs-welcome: 18px;
            --fs-meaning: 32px;
            --fs-french: 28px;
            --fs-pronun: 22px;
            --fs-btn: 17px;
            --fs-opt-pronun: 18px;
            --fs-opt-french: 16px;
            --fs-p: 15px;
            --fs-label: 17px;
            --fs-table: 16px;
            --fs-header: 15px;
            --fs-footer: 12px;
        }

        body.font-large {
            --fs-h1: 32px;
            --fs-welcome: 20px;
            --fs-meaning: 38px;
            --fs-french: 34px;
            --fs-pronun: 26px;
            --fs-btn: 19px;
            --fs-opt-pronun: 21px;
            --fs-opt-french: 18px;
            --fs-p: 17px;
            --fs-label: 19px;
            --fs-table: 18px;
            --fs-header: 17px;
            --fs-footer: 13px;
        }

        /* === 基础重置与背景设定 === */
        body, html {
            margin: 0;
            padding: 0;
            width: 100%;
            height: 100%;
            background-color: #03040a; 
            font-family: 'Helvetica Neue', Arial, sans-serif;
            color: #ffffff;
            overflow-x: hidden;
            transition: all 0.3s ease;
        }

        /* 极弱粒子背景 */
        #particles-canvas {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: 1;
            opacity: 0.4;
            pointer-events: none;
        }

        /* === 视图容器 === */
        .view { 
            position: relative; 
            z-index: 10; 
            width: 100%; 
            max-width: 600px; 
            height: 100%; 
            margin: 0 auto; 
            padding: 30px 20px; 
            box-sizing: border-box; 
            display: flex;
            flex-direction: column; 
            align-items: center; 
            overflow-y: auto; 
            gap: 15px;
        }
        .active { display: flex !important; }
        .hidden { display: none !important; }
        .hidden-text { visibility: hidden; }
        
        /* === 标题与文字样式 === */
        h1 { 
            font-size: var(--fs-h1); 
            font-weight: 300; 
            letter-spacing: 2px; 
            margin: 0 0 10px 0; 
            color: #ffda99; 
            text-shadow: 0 0 20px rgba(255, 200, 100, 0.3); 
            text-align: center; 
            transition: font-size 0.3s ease;
        }
        .welcome-text { 
            color: #ffda99; 
            font-size: var(--fs-welcome); 
            font-weight: 300; 
            letter-spacing: 1px; 
            margin-bottom: 5px;
            transition: font-size 0.3s ease;
        }
        .header-bar { 
            width: 100%; 
            display: flex; 
            justify-content: space-between; 
            font-size: var(--fs-header); 
            color: rgba(255, 255, 255, 0.4); 
            border-bottom: 1px solid rgba(255, 255, 255, 0.1); 
            padding-bottom: 10px; 
            transition: font-size 0.3s ease;
        }
        .user-info { color: #ffda99; }
        
        /* === 玻璃拟态卡片 (通用) === */
        .glass-card {
            background: rgba(255, 255, 255, 0.03);
            border: 1px solid rgba(255, 255, 255, 0.1);
            border-radius: 12px;
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            padding: 25px 20px;
            width: 100%;
            text-align: center;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
            display: flex;
            flex-direction: column;
            align-items: center;
        }

        /* 学习与测验内容区 */
        .content-area { justify-content: center; min-height: 180px; gap: 15px; }
        .meaning-text { font-size: var(--fs-meaning); font-weight: bold; color: #ffffff; text-shadow: 0 0 10px rgba(255, 255, 255, 0.2); transition: font-size 0.3s ease; }
        .french-text { font-size: var(--fs-french); font-weight: bold; color: #aaffaa; min-height: 30px; letter-spacing: 1px; transition: font-size 0.3s ease; }
        .pronun-text { font-size: var(--fs-pronun); color: #ffda99; min-height: 25px; transition: font-size 0.3s ease; }
        .feedback-text { font-size: var(--fs-btn); font-weight: 300; min-height: 25px; margin-top: 5px; }
        .text-green { color: #aaffaa; text-shadow: 0 0 10px rgba(100, 255, 100, 0.3); }
        .text-red { color: #ffaaaa; text-shadow: 0 0 10px rgba(255, 100, 100, 0.3); }

        /* 级别选择器 */
        .level-selector p { color: #aaaaaa; font-size: var(--fs-p); margin: 0 0 10px 0; letter-spacing: 1px; transition: font-size 0.3s ease; }
        .custom-dropdown-content { 
            background: rgba(20, 25, 35, 0.95); 
            border: 1px solid rgba(255, 255, 255, 0.1); 
            border-radius: 12px; 
            padding: 15px; 
            display: flex; 
            flex-direction: column; 
            gap: 12px; 
            max-height: 180px; 
            overflow-y: auto; 
            margin-top: 10px; 
            width: 100%;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8); 
        }
        .custom-dropdown-content label { display: flex; align-items: center; font-size: var(--fs-label); cursor: pointer; color: #ccc; transition: color 0.2s, font-size 0.3s ease; }
        .custom-dropdown-content label:hover { color: #ffda99; }
        .custom-dropdown-content input { margin-right: 10px; transform: scale(1.2); accent-color: #ffda99; }

        /* === 字体设置区 === */
        .font-selector-card {
            padding: 12px 20px;
            flex-direction: row;
            justify-content: space-between;
            align-items: center;
            gap: 15px;
        }
        .font-size-controls { display: flex; gap: 10px; width: 100%; justify-content: flex-end; }
        .font-btn { margin: 0; padding: 8px 0; border-radius: 8px; flex: 1; max-width: 60px; font-size: var(--fs-p); }
        .font-btn.active { border-color: #ffda99; color: #ffda99; background: rgba(255,200,100,0.15); box-shadow: 0 0 10px rgba(255, 200, 100, 0.2); }

        /* === 按钮样式 === */
        button, .custom-select-btn {
            text-decoration: none;
            color: #ffffff;
            font-size: var(--fs-btn);
            letter-spacing: 1px;
            padding: 14px 20px;
            border: 1px solid rgba(255, 255, 255, 0.2);
            border-radius: 25px;
            background: rgba(255, 255, 255, 0.05);
            backdrop-filter: blur(4px); 
            -webkit-backdrop-filter: blur(4px);
            transition: all 0.3s ease;
            cursor: pointer;
            outline: none;
            width: 100%;
            margin: 5px 0;
            display: flex;
            justify-content: center;
            align-items: center;
        }

        button:hover, .custom-select-btn:hover {
            border-color: rgba(255, 200, 100, 0.6);
            color: #ffda99;
            background: rgba(255, 200, 100, 0.1);
            box-shadow: 0 0 15px rgba(255, 150, 0, 0.2);
        }

        /* 颜色变体 */
        .btn-primary { border-color: rgba(100, 200, 255, 0.4); color: #aaddff; }
        .btn-primary:hover { background: rgba(100, 200, 255, 0.1); border-color: #88ccff; box-shadow: 0 0 15px rgba(100, 200, 255, 0.2); color: #88ccff; }
        
        .btn-success { border-color: rgba(100, 255, 100, 0.4); color: #aaffaa; }
        .btn-success:hover { background: rgba(100, 255, 100, 0.1); border-color: #88ff88; box-shadow: 0 0 15px rgba(100, 255, 100, 0.2); color: #88ff88; }
        
        .btn-warning { border-color: rgba(255, 200, 100, 0.4); color: #ffda99; }
        .btn-warning:hover { background: rgba(255, 200, 100, 0.1); border-color: #ffda99; box-shadow: 0 0 15px rgba(255, 200, 100, 0.2); color: #ffda99; }
        
        .btn-info { border-color: rgba(200, 150, 255, 0.4); color: #eebbff; }
        .btn-info:hover { background: rgba(200, 150, 255, 0.1); border-color: #dd99ff; box-shadow: 0 0 15px rgba(200, 150, 255, 0.2); color: #dd99ff; }
        
        .btn-close { border-color: rgba(255, 100, 100, 0.4); color: #ffaaaa; margin-top: 20px; width: 70%; border-radius: 25px; }
        .btn-close:hover { background: rgba(255, 100, 100, 0.1); border-color: #ff8888; box-shadow: 0 0 15px rgba(255, 100, 100, 0.2); color: #ff8888; }

        /* 网格控制区 */
        .options-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; width: 100%; margin-top: 10px; margin-bottom: 15px; }
        .options-grid button { 
            padding: 12px 5px; 
            border-radius: 12px; 
            flex-direction: column; 
            gap: 5px; 
            margin: 0;
            background: rgba(255, 255, 255, 0.02);
        }
        .opt-pronun { color: #ffda99; font-size: var(--fs-opt-pronun); font-weight: 300; transition: font-size 0.3s ease; }
        .opt-french { color: #aaffaa; font-size: var(--fs-opt-french); letter-spacing: 1px; transition: font-size 0.3s ease; }

        .learn-controls { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; width: 100%; margin-bottom: 10px; }
        .learn-controls button { border-radius: 12px; margin: 0; }

        /* === 表格样式 === */
        .records-container { max-height: 350px; padding: 0; overflow: hidden; }
        .table-scroll { width: 100%; max-height: 350px; overflow-y: auto; overflow-x: auto; }
        table { width: 100%; border-collapse: collapse; text-align: center; }
        th, td { padding: 12px 10px; border-bottom: 1px solid rgba(255, 255, 255, 0.05); font-size: var(--fs-table); transition: font-size 0.3s ease; }
        th { font-weight: 400; color: #ffda99; background: rgba(0, 0, 0, 0.2); position: sticky; top: 0; z-index: 2; }
        td { font-weight: 300; color: #e0e0e0; }
        
        /* 底部作者信息 */
        .footer-author { font-size: var(--fs-footer); color: rgba(255, 255, 255, 0.2); margin-top: auto; text-align: center; width: 100%; letter-spacing: 2px; padding-top: 20px;}