body {
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            height: 100vh;

            /* --- 背景图魔法开始 --- */
            background-image: url('yinghua1.jpg');
            /* 确保这里的名字和你上传的一模一样 */
            background-size: cover;
            /* 让图片按比例缩放，铺满整个屏幕 */
            background-position: center;
            /* 无论屏幕多宽，都把图片最中心的美景露出来 */
            background-repeat: no-repeat;
            /* 防止图片像瓷砖一样重复拼贴 */
            background-attachment: fixed;
            /* 让背景图固定，如果有滚动条也不会跟着滚 */
            /* --- 背景图魔法结束 --- */



            font-family: 'Microsoft YaHei', sans-serif;
            color: #d6336c;
            margin: 0;
            overflow: hidden;
            /* 防止出现滚动条 */
            position: relative;
        }

        /* 主体内容的容器 - 提升 z-index 保证在背景爱心之上 */
        .content-wrapper {
            display: flex;
            flex-direction: column;
            align-items: center;
            position: relative;
            z-index: 10;
        }

        h1 {
            font-size: 2.5rem;
            margin-bottom: 10px;
        }

        .timer {
            font-size: 1.5rem;
            font-weight: bold;
            background: rgba(255, 255, 255, 0.9);
            /* 加一点透明度，隐约透出背景 */
            padding: 20px;
            border-radius: 15px;
            box-shadow: 0 4px 15px rgba(214, 51, 108, 0.2);
            text-align: center;
            margin-bottom: 30px;
        }

        /* --- 密码锁相关的样式 --- */
        .lock-box {
            background: white;
            padding: 40px;
            border-radius: 20px;
            box-shadow: 0 4px 20px rgba(214, 51, 108, 0.15);
            text-align: center;
        }

        .lock-box h2 {
            font-size: 1.5rem;
            margin-top: 0;
            margin-bottom: 20px;
        }

        .lock-box input {
            padding: 12px;
            font-size: 1rem;
            border: 2px solid #ffd6e0;
            border-radius: 10px;
            outline: none;
            text-align: center;
            width: 200px;
            color: #d6336c;
            transition: border-color 0.3s;
        }

        .lock-box input:focus {
            border-color: #d6336c;
        }

        .lock-box button {
            margin-top: 20px;
            padding: 10px 30px;
            font-size: 1rem;
            color: white;
            background-color: #d6336c;
            border: none;
            border-radius: 10px;
            cursor: pointer;
            transition: background-color 0.3s;
            font-weight: bold;
        }

        .lock-box button:hover {
            background-color: #b02756;
        }

        .error-msg {
            color: red;
            font-size: 0.9rem;
            margin-top: 15px;
            display: none;
        }

        /* --- 功能入口按钮样式 --- */
        .nav-container {
            display: flex;
            gap: 15px;
            flex-wrap: wrap;
            justify-content: center;
        }

        .nav-btn {
            background-color: white;
            color: #d6336c;
            border: 2px solid #ffd6e0;
            padding: 15px 25px;
            border-radius: 12px;
            font-size: 1.1rem;
            font-weight: bold;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 10px rgba(214, 51, 108, 0.1);
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .nav-btn:hover {
            background-color: #d6336c;
            color: white;
            border-color: #d6336c;
            transform: translateY(-5px);
            box-shadow: 0 6px 15px rgba(214, 51, 108, 0.3);
        }

        /* --- ✨ 新增：背景冒泡爱心样式 ✨ --- */
        .heart-bubble {
            position: absolute;
            background-color: rgba(214, 51, 108, 0.4);
            /* 半透明的主题粉色 */
            display: inline-block;
            /* 标准 CSS 画爱心的方法 */
            transform: rotate(-45deg);
            z-index: 1;
            /* 在最底层漂浮 */
            bottom: -50px;
            /* 从屏幕下方开始冒出来 */
            animation: bubble-up linear infinite;
            /* 绑定动画 */
        }

        .heart-bubble:after,
        .heart-bubble:before {
            content: "";
            background-color: inherit;
            /* 继承父元素的半透明粉色 */
            border-radius: 50%;
            position: absolute;
        }

        /* 控制爱心圆弧部分的大小和位置 */
        .heart-bubble:after {
            top: 0;
            left: 50%;
        }

        .heart-bubble:before {
            top: -50%;
            left: 0;
        }

        /* 定义爱心冒泡向上的动画 */
        @keyframes bubble-up {
            0% {
                transform: rotate(-45deg) translateY(0);
                opacity: 0;
            }

            10% {
                opacity: 1;
                /* 刚出现时迅速显现 */
            }

            80% {
                opacity: 0.8;
                /* 快到顶部时稍微淡一点 */
            }

            100% {
                /* 上升到屏幕上方，并带一点点横向偏移，更像气泡 */
                transform: rotate(-45deg) translateY(-110vh) translateX(30px);
                opacity: 0;
                /* 完全消失 */
            }
        }



        /* --- ✨ 新增：日记本弹窗样式 ✨ --- */
        .modal-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.6);
            z-index: 100;
            display: none;
            justify-content: center;
            align-items: center;
        }

        .diary-box {
            background: white;
            width: 90%;
            max-width: 500px;
            height: 80vh;
            border-radius: 20px;
            padding: 20px;
            display: flex;
            flex-direction: column;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
            position: relative;
        }

        .close-btn {
            position: absolute;
            right: 20px;
            top: 15px;
            font-size: 1.8rem;
            color: #ccc;
            cursor: pointer;
            transition: color 0.3s;
        }

        .close-btn:hover {
            color: #d6336c;
        }

        .diary-box h2 {
            margin-top: 0;
            color: #d6336c;
            text-align: center;
            font-size: 1.5rem;
        }

        .diary-input {
            width: 100%;
            height: 100px;
            border: 2px solid #ffd6e0;
            border-radius: 12px;
            padding: 10px;
            box-sizing: border-box;
            resize: none;
            font-family: inherit;
            font-size: 1rem;
            outline: none;
            margin-bottom: 10px;
            color: #333;
        }

        .diary-input:focus {
            border-color: #d6336c;
        }

        .submit-btn {
            background: #d6336c;
            color: white;
            border: none;
            padding: 12px;
            border-radius: 12px;
            cursor: pointer;
            font-size: 1rem;
            font-weight: bold;
            transition: 0.3s;
            margin-bottom: 20px;
        }

        .submit-btn:hover {
            background: #b02756;
        }

        .diary-list {
            flex-grow: 1;
            overflow-y: auto;
            padding-right: 5px;
        }

        .diary-item {
            background: #fff5f7;
            border-left: 4px solid #ffd6e0;
            padding: 15px;
            border-radius: 8px;
            margin-bottom: 15px;
            text-align: left;
            transition: all 0.3s;
        }

        .diary-item:hover {
            border-left-color: #d6336c;
            box-shadow: 0 2px 10px rgba(214, 51, 108, 0.1);
        }

        .diary-time {
            font-size: 0.8rem;
            color: #999;
            margin-bottom: 8px;
            font-family: monospace;
        }

        .diary-text {
            color: #444;
            line-height: 1.5;
            white-space: pre-wrap;
            font-size: 0.95rem;
        }

        .diary-list::-webkit-scrollbar {
            width: 6px;
        }

        .diary-list::-webkit-scrollbar-thumb {
            background-color: #ffd6e0;
            border-radius: 3px;
        }