:root {
    --glass: rgba(255, 255, 255, 0.2);
    --border: rgba(255, 255, 255, 0.4);
    --accent: #ffb7c5;
    /* 樱花粉 */
    --text: #4a5568;
}

body {
    min-height: 100vh;
    background: url('https://api.dujin.org/bing/1920.php') no-repeat center center/cover;
    background-attachment: fixed;
    font-family: 'PingFang SC', sans-serif;
    display: flex;
    justify-content: center;
    color: var(--text);
    overflow-x: hidden;
}

/* 玻璃遮罩背景 */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    z-index: -1;
}

.container {
    width: 90%;
    max-width: 800px;
    padding: 50px 0;
    z-index: 1;
}

.board-header {
    text-align: center;
    margin-bottom: 40px;
    color: #5a67d8;
}

.board-header h1 {
    font-size: 2.2rem;
    margin-bottom: 10px;
}

/* 通用玻璃卡片 */
.card {
    background: var(--glass);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: 20px;
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.1);
    padding: 20px;
    margin-bottom: 25px;
}

/* 输入框区域 */
textarea {
    width: 100%;
    /* 确保宽度包含内边距，防止撑破框框 */
    box-sizing: border-box;

    /* 如果还觉得太挤，可以把宽度稍微调小 */
    /* width: calc(100% - 10px); */

    height: 100px;
    background: rgba(255, 255, 255, 0.3);
    border: none;
    border-radius: 12px;
    padding: 15px;
    resize: none;
    outline: none;
    font-size: 1rem;
    color: var(--text);
}

.input-footer {
    display: flex;
    gap: 15px;
    margin-top: 15px;
}

#nickname-input {
    flex: 1;
    box-sizing: border-box;
    /* 同样加上这一行 */
    background: rgba(255, 255, 255, 0.3);
    border: none;
    padding: 10px 15px;
    border-radius: 10px;
    outline: none;
}

#submit-btn {
    background: var(--accent);
    color: white;
    border: none;
    padding: 10px 30px;
    border-radius: 10px;
    cursor: pointer;
    transition: 0.3s;
}

#submit-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 15px rgba(255, 183, 197, 0.4);
}

/* 留言列表项 */
.message-item {
    animation: slideUp 0.5s ease-out backwards;
}

.msg-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    font-size: 0.85rem;
    opacity: 0.8;
}

.msg-author {
    font-weight: bold;
    color: #5a67d8;
}

.msg-content {
    line-height: 1.6;
}

.back-home {
    display: block;
    text-align: center;
    margin-top: 30px;
    text-decoration: none;
    color: var(--text);
    font-size: 0.9rem;
    opacity: 0.6;
    transition: 0.3s;
}

.back-home:hover {
    opacity: 1;
    color: var(--accent);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 手机端适配 */
@media (max-width: 600px) {
    .input-footer {
        flex-direction: column;
    }

    #submit-btn {
        width: 100%;
    }
}


/* 管理员删除按钮样式 */
.del-btn {
    margin-top: 10px;
    background: #ff4d4f;
    color: white;
    border: none;
    padding: 5px 12px;
    border-radius: 5px;
    font-size: 12px;
    cursor: pointer;
    transition: 0.3s;
}

.del-btn:hover {
    background: #ff7875;
}

.board-header h1 {
    user-select: none;
    /* 标准语法 */
    -webkit-user-select: none;
    /* Safari 浏览器 */
    cursor: pointer;
    /* 让鼠标悬停时显示手型，提示可以点击 */
}