/* ===================================
   留言板 - 现代淡雅风格样式
   =================================== */

:root {
    /* 主色调 - 淡雅蓝绿色系 */
    --primary-50: #f0f9ff;
    --primary-100: #e0f2fe;
    --primary-200: #bae6fd;
    --primary-300: #7dd3fc;
    --primary-400: #38bdf8;
    --primary-500: #0ea5e9;
    --primary-600: #0284c7;
    
    /* 中性色 - 温暖灰 */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* 功能色 */
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --danger-light: #fef2f2;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* 圆角 */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    /* 过渡 */
    --transition: all 0.2s ease;
    --transition-slow: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--primary-50) 100%);
    min-height: 100vh;
    color: var(--gray-800);
    line-height: 1.6;
}

/* ===================================
   通用工具类
   =================================== */

.hidden { display: none !important; }

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* ===================================
   毛玻璃卡片效果
   =================================== */

.glass-card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

.card {
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-100);
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

/* ===================================
   认证模态框
   =================================== */

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 50;
    animation: fadeIn 0.2s ease;
}

.modal-content {
    background: #fff;
    border-radius: var(--radius-2xl);
    padding: 2rem;
    width: 100%;
    max-width: 400px;
    margin: 1rem;
    box-shadow: var(--shadow-xl);
    animation: slideUp 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { 
        opacity: 0;
        transform: translateY(20px);
    }
    to { 
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--gray-800);
}

/* ===================================
   表单元素
   =================================== */

.form-group {
    margin-bottom: 1rem;
}

.input {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 1.5px solid var(--gray-200);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    transition: var(--transition);
    background: var(--gray-50);
}

.input:focus {
    outline: none;
    border-color: var(--primary-400);
    background: #fff;
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
}

.input::placeholder {
    color: var(--gray-400);
}

.textarea {
    resize: none;
    min-height: 100px;
}

/* ===================================
   按钮
   =================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 0.9375rem;
    font-weight: 500;
    border-radius: var(--radius-lg);
    border: none;
    cursor: pointer;
    transition: var(--transition);
    gap: 0.5rem;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-500) 0%, var(--primary-600) 100%);
    color: #fff;
    box-shadow: 0 2px 4px rgba(14, 165, 233, 0.3);
}

.btn-primary:hover:not(:disabled) {
    background: linear-gradient(135deg, var(--primary-400) 0%, var(--primary-500) 100%);
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(14, 165, 233, 0.35);
}

.btn-secondary {
    background: var(--gray-100);
    color: var(--gray-700);
    border: 1px solid var(--gray-200);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--gray-200);
}

.btn-ghost {
    background: transparent;
    color: var(--gray-600);
    padding: 0.5rem;
}

.btn-ghost:hover:not(:disabled) {
    background: var(--gray-100);
    color: var(--gray-800);
}

.btn-danger-ghost {
    background: transparent;
    color: var(--danger);
    padding: 0.5rem;
}

.btn-danger-ghost:hover:not(:disabled) {
    background: var(--danger-light);
}

.btn-link {
    background: none;
    border: none;
    color: var(--primary-500);
    padding: 0;
    font-weight: 500;
    cursor: pointer;
}

.btn-link:hover {
    color: var(--primary-600);
    text-decoration: underline;
}

.btn-full {
    width: 100%;
}

/* ===================================
   Header
   =================================== */

.header {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-100);
    position: sticky;
    top: 0;
    z-index: 40;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    max-width: 800px;
    margin: 0 auto;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-500) 0%, var(--primary-600) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logout-btn {
    color: var(--gray-500);
    font-size: 0.875rem;
    background: none;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.logout-btn:hover {
    color: var(--danger);
}

/* ===================================
   Main Content Area
   =================================== */

.main {
    padding: 1.5rem 1rem;
    max-width: 800px;
    margin: 0 auto;
}

/* ===================================
   发布表单
   =================================== */

.post-form {
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.post-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.file-upload {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.file-name {
    font-size: 0.875rem;
    color: var(--gray-500);
    max-width: 150px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ===================================
   分页控制
   =================================== */

.pagination-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    background: var(--gray-50);
    border-radius: var(--radius-lg);
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.pagination-info {
    font-size: 0.875rem;
    color: var(--gray-600);
}

.pagination-size {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.pagination-size label {
    font-size: 0.875rem;
    color: var(--gray-600);
}

.pagination-size select {
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    background: #fff;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
}

.pagination-size select:focus {
    outline: none;
    border-color: var(--primary-400);
}

.pagination-nav {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.page-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--gray-200);
    background: #fff;
    border-radius: var(--radius);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
}

.page-btn:hover:not(:disabled) {
    background: var(--gray-50);
    border-color: var(--primary-300);
}

.page-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.page-current {
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
    color: var(--gray-700);
    font-weight: 500;
}

/* ===================================
   消息列表
   =================================== */

.messages-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.message-card {
    padding: 1.25rem;
}

.message-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.75rem;
}

.message-user {
    font-size: 0.875rem;
    color: var(--gray-500);
    font-weight: 500;
}

.message-meta {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.message-time {
    font-size: 0.75rem;
    color: var(--gray-400);
}

.message-edited {
    font-size: 0.625rem;
    color: var(--gray-400);
    background: var(--gray-100);
    padding: 0.125rem 0.375rem;
    border-radius: var(--radius-sm);
}

.message-actions {
    display: flex;
    gap: 0.25rem;
}

.message-content {
    color: var(--gray-800);
    white-space: pre-wrap;
    word-break: break-word;
    line-height: 1.7;
}

.message-file {
    margin-top: 1rem;
}

.message-image {
    max-width: 100%;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
}

.message-image:hover {
    opacity: 0.95;
}

.message-video {
    max-width: 100%;
    border-radius: var(--radius);
}

.file-download {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: var(--gray-50);
    border-radius: var(--radius);
    color: var(--gray-700);
    font-size: 0.875rem;
    margin-top: 0.75rem;
}

.download-btn {
    padding: 0.5rem 1rem;
    font-size: 0.8125rem;
}

/* ===================================
   骨架屏加载
   =================================== */

.skeleton {
    background: linear-gradient(90deg, var(--gray-100) 25%, var(--gray-50) 50%, var(--gray-100) 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius);
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.skeleton-card {
    padding: 1.25rem;
    background: #fff;
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-100);
}

.skeleton-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.skeleton-avatar {
    width: 100px;
    height: 16px;
}

.skeleton-time {
    width: 60px;
    height: 14px;
}

.skeleton-text {
    height: 16px;
    margin-bottom: 0.5rem;
}

.skeleton-text:last-child {
    width: 60%;
}

/* ===================================
   空状态
   =================================== */

.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--gray-500);
}

.empty-state svg {
    width: 64px;
    height: 64px;
    margin-bottom: 1rem;
    opacity: 0.5;
}

/* ===================================
   媒体预览模态框
   =================================== */

.media-modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 60;
}

.media-modal-content {
    max-width: 90vw;
    max-height: 90vh;
}

.media-modal img,
.media-modal video {
    max-width: 100%;
    max-height: 90vh;
    object-fit: contain;
}

.media-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    border-radius: 50%;
    color: #fff;
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.media-close:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* ===================================
   加载指示器
   =================================== */

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-center {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem;
    color: var(--gray-500);
    gap: 1rem;
}

.loading-center .spinner {
    width: 32px;
    height: 32px;
    border-width: 3px;
    border-top-color: var(--primary-500);
}

/* ===================================
   响应式设计
   =================================== */

/* ===================================
   响应式设计与移动端优化
   =================================== */

@media (max-width: 640px) {
    .container, .main, .header-inner {
        padding: 0 0.75rem; /* 减小边距增加内容空间 */
    }

    .modal-content {
        margin: 1rem;
        padding: 1.25rem;
        width: calc(100% - 2rem);
    }
    
    /* 调整发布区域布局 */
    .post-actions {
        flex-direction: column;
        align-items: stretch;
        gap: 1rem;
    }
    
    .file-upload {
        justify-content: flex-start;
        width: 100%;
        background: var(--gray-50);
        padding: 0.5rem;
        border-radius: var(--radius);
    }

    .file-name {
        flex: 1;
        text-align: right;
    }
    
    /* 增大点击区域 */
    .btn, .page-btn, .input {
        min-height: 44px; /* 移动端标准触控高度 */
        font-size: 16px; /* 防止 iOS 自动缩放 */
    }

    /* 调整分页控件 */
    .pagination-controls {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
        text-align: center;
    }
    
    .pagination-nav {
        justify-content: space-between;
        width: 100%;
    }

    .pagination-size {
        justify-content: center;
    }

    /* 消息卡片调整 */
    .message-card {
        padding: 1rem;
    }

    .message-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.25rem;
    }
}

/* ===================================
   微信/内置浏览器特定优化
   =================================== */
@supports (-webkit-touch-callout: none) {
    /* iOS 弹性滚动修复 */
    body {
        -webkit-overflow-scrolling: touch;
    }
}

/* 更好的输入框体验 */
textarea {
    -webkit-appearance: none;
    border-radius: var(--radius-lg);
}