/* ============================================================
   App CSS — 记事本管理系统 v2
   设计方向：现代极简 · 卡片式 · 柔和蓝灰
   移动优先 · 无 CSS 框架依赖
   ============================================================ */

/* ----- CSS 变量 ----- */
:root {
    --primary:       #5b6abf;
    --primary-hover: #4a56a4;
    --primary-light: #eef0fb;
    --bg:            #f0f2f7;
    --surface:       #ffffff;
    --text:          #1e2130;
    --text-secondary:#6b7280;
    --text-muted:    #9ca3af;
    --border:        #e5e7f0;
    --border-light:  #f0f1f5;
    --danger:        #ef4444;
    --danger-hover:  #dc2626;
    --success:       #10b981;
    --success-light: #ecfdf5;
    --warning:       #f59e0b;
    --warning-light: #fffbeb;
    --radius-sm:     6px;
    --radius:        10px;
    --radius-lg:     14px;
    --shadow-sm:     0 1px 2px rgba(0,0,0,.04);
    --shadow:        0 1px 3px rgba(0,0,0,.04), 0 1px 2px rgba(0,0,0,.06);
    --shadow-md:     0 4px 12px rgba(0,0,0,.06);
    --shadow-lg:     0 8px 24px rgba(0,0,0,.08);
    --transition:    150ms ease;
}

/* ----- Reset ----- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition);
}
a:hover {
    color: var(--primary-hover);
}

img {
    max-width: 100%;
    height: auto;
}

/* ----- 布局 ----- */
.app-header {
    background: var(--surface);
    box-shadow: var(--shadow);
    padding: 0 20px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
    gap: 16px;
}

.app-header .logo {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
    white-space: nowrap;
    letter-spacing: -0.3px;
}

.app-header nav {
    display: flex;
    align-items: center;
    gap: 6px;
    flex: 1;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.app-header nav a {
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    white-space: nowrap;
    transition: background var(--transition), color var(--transition);
}

.app-header nav a:hover {
    background: var(--primary-light);
    color: var(--primary);
}

.app-header nav a.active,
.app-header nav a[aria-current="page"] {
    background: var(--primary-light);
    color: var(--primary);
    font-weight: 600;
}

.app-header .user-info {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    color: var(--text-secondary);
    white-space: nowrap;
}

.app-main {
    max-width: 960px;
    margin: 0 auto;
    padding: 24px 16px 48px;
}

/* ----- 卡片 ----- */
.card {
    background: var(--surface);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 24px;
    margin-bottom: 20px;
    border: 1px solid var(--border-light);
    transition: box-shadow var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-md);
}

.card-flush {
    padding: 0;
    overflow: hidden;
}

/* ----- 页面标题 ----- */
.page-title {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text);
    letter-spacing: -0.3px;
}

/* ----- Flash 消息 ----- */
.flash-wrapper {
    max-width: 960px;
    margin: 12px auto 0;
    padding: 0 16px;
}

.flash-error,
.flash-success {
    padding: 12px 18px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    line-height: 1.5;
}

.flash-error {
    background: #fef2f2;
    color: var(--danger);
    border: 1px solid #fecaca;
}

.flash-success {
    background: var(--success-light);
    color: var(--success);
    border: 1px solid #a7f3d0;
}

/* ----- 登录/认证卡片 ----- */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg);
}

.auth-card {
    background: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    padding: 40px;
    width: 100%;
    max-width: 420px;
}

.auth-card h2 {
    text-align: center;
    margin-bottom: 24px;
    color: var(--primary);
    font-size: 22px;
    font-weight: 700;
}

/* ----- 详情卡片 ----- */
.detail-card {
    background: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
    overflow: hidden;
    margin-bottom: 20px;
}

.detail-header {
    padding: 28px 28px 0;
}

.detail-header h1 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text);
    line-height: 1.3;
    letter-spacing: -0.3px;
}

.detail-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    padding: 16px 28px;
    font-size: 13px;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-light);
}

.detail-meta span {
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.detail-meta svg {
    flex-shrink: 0;
    color: var(--text-muted);
}

.detail-body {
    padding: 28px;
    font-size: 15px;
    line-height: 1.8;
    color: var(--text);
    word-break: break-word;
}

.detail-body img {
    border-radius: var(--radius-sm);
    margin: 8px 0;
    max-height: 400px;
    object-fit: contain;
}

.detail-body p {
    margin-bottom: 12px;
}

.detail-body h2,
.detail-body h3 {
    margin: 20px 0 8px;
    color: var(--text);
}

.detail-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 28px;
    border-top: 1px solid var(--border-light);
    gap: 12px;
    flex-wrap: wrap;
}

/* 图片网格 */
.image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
    margin-top: 16px;
}

.image-grid img {
    width: 100%;
    height: 160px;
    object-fit: cover;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition);
}

.image-grid img:hover {
    transform: scale(1.03);
    box-shadow: var(--shadow-md);
}

/* ----- 面包屑 ----- */
.breadcrumb-nav {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 20px;
    font-size: 14px;
    color: var(--text-muted);
}

.breadcrumb-link {
    color: var(--primary);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    transition: color var(--transition);
}

.breadcrumb-link:hover {
    color: var(--primary-hover);
}

.breadcrumb-sep {
    color: var(--border);
    user-select: none;
}

/* ----- 按钮 ----- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 9px 18px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    cursor: pointer;
    text-decoration: none;
    line-height: 1.4;
    transition: all var(--transition);
    white-space: nowrap;
    min-height: 40px;
    user-select: none;
}

.btn:hover {
    background: #f9fafb;
    border-color: #d1d5db;
}

.btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.btn:active {
    transform: scale(0.97);
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.btn-primary:hover {
    background: var(--primary-hover);
    border-color: var(--primary-hover);
    color: #fff;
}

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

.btn-danger:hover {
    background: #fef2f2;
}

.btn-sm {
    padding: 5px 12px;
    font-size: 13px;
    min-height: 32px;
}

.btn-back {
    color: var(--text-secondary);
    border-color: transparent;
    background: transparent;
    padding-left: 4px;
}

.btn-back:hover {
    color: var(--primary);
    background: transparent;
}

.btn-prev,
.btn-next {
    font-size: 13px;
    padding: 7px 14px;
    min-height: 36px;
}

.btn-group {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
}

/* ----- 表单 ----- */
.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
}

.form-group input[type="text"],
.form-group input[type="password"],
.form-group input[type="email"],
.form-group input[type="url"],
.form-group input[type="number"],
.form-group input[type="search"],
.form-group input[type="file"],
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px 14px;
    font-size: 14px;
    font-family: inherit;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text);
    transition: border-color var(--transition), box-shadow var(--transition);
    outline: none;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(91,106,191,.12);
}

.form-group textarea {
    min-height: 140px;
    resize: vertical;
    line-height: 1.7;
}

.form-group select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 36px;
}

.form-group input[type="file"] {
    padding: 8px;
    font-size: 13px;
}

.form-group input.error,
.form-group textarea.error,
.form-group select.error {
    border-color: var(--danger);
    box-shadow: 0 0 0 3px rgba(239,68,68,.1);
}

.form-error {
    font-size: 12px;
    color: var(--danger);
    margin-top: 4px;
}

/* ----- 表格 ----- */
table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

thead {
    background: #fafbfc;
}

th {
    text-align: left;
    padding: 12px 16px;
    font-weight: 600;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    border-bottom: 2px solid var(--border);
}

td {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-light);
    color: var(--text);
}

tbody tr:hover {
    background: #fafbfd;
}

tbody tr:last-child td {
    border-bottom: none;
}

/* 移动端表格横向滚动 */
.table-wrap {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    border-radius: var(--radius);
}

/* ----- 分页 ----- */
.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    margin-top: 24px;
    flex-wrap: wrap;
}

.pagination a,
.pagination span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    height: 36px;
    padding: 0 10px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text-secondary);
    transition: all var(--transition);
}

.pagination a:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
}

.pagination .current {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
    font-weight: 600;
}

/* ----- 提示消息 ----- */
.flash-error,
.flash-success,
.flash-warning {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    margin-bottom: 16px;
    display: flex;
    align-items: flex-start;
    gap: 8px;
    line-height: 1.5;
}

.flash-error {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.flash-success {
    background: var(--success-light);
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.flash-warning {
    background: var(--warning-light);
    color: #92400e;
    border: 1px solid #fde68a;
}

/* ----- 空状态 ----- */
.empty-state {
    text-align: center;
    padding: 56px 24px;
    color: var(--text-muted);
}

.empty-state svg {
    margin-bottom: 16px;
    opacity: 0.4;
}

.empty-state p {
    font-size: 15px;
    margin-bottom: 4px;
}

.empty-state a {
    font-weight: 600;
}

/* ----- 实用工具 ----- */
.media-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap;
    border: 0;
}

.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-16 { margin-top: 16px; }
.mb-16 { margin-bottom: 16px; }
.flex-between {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
}

/* ----- 页面标题 ----- */
.page-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text);
}

/* ----- 容器（管理后台）----- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* ----- 导航栏（管理后台）----- */
.navbar {
    background: var(--primary);
    color: #fff;
    padding: 14px 20px;
    border-radius: var(--radius);
    margin-bottom: 24px;
    box-shadow: var(--shadow-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

.navbar a,
.nav-link {
    color: #fff;
    text-decoration: none;
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    transition: background var(--transition);
}

.navbar a:hover,
.nav-link:hover {
    background: rgba(255,255,255,.15);
}

.nav-link.active {
    background: rgba(255,255,255,.2);
    font-weight: 600;
}

/* ----- 卡片子分区 ----- */
.card-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-light);
    font-weight: 600;
    font-size: 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
}

.card-body {
    padding: 20px;
}

/* ----- 按钮扩展 ----- */
.btn-success {
    background: var(--success);
    color: #fff;
    border-color: var(--success);
}
.btn-success:hover {
    background: #059669;
    border-color: #059669;
}

.btn-warning {
    background: var(--warning);
    color: #fff;
    border-color: var(--warning);
}
.btn-warning:hover {
    background: #d97706;
    border-color: #d97706;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 12px;
}

/* ----- 徽章 ----- */
.badge {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 99px;
    font-size: 12px;
    font-weight: 600;
    line-height: 1.4;
}

.badge-success {
    background: #d1fae5;
    color: #065f46;
}

.badge-warning {
    background: #fef3c7;
    color: #92400e;
}

.badge-danger {
    background: #fee2e2;
    color: #991b1b;
}

.badge-info {
    background: #dbeafe;
    color: #1e40af;
}

/* ----- 警告框 ----- */
.alert {
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
    font-size: 14px;
    border: 1px solid transparent;
}

.alert-success {
    color: #065f46;
    background: #d1fae5;
    border-color: #a7f3d0;
}

.alert-danger {
    color: #991b1b;
    background: #fee2e2;
    border-color: #fecaca;
}

.alert-warning {
    color: #92400e;
    background: #fef3c7;
    border-color: #fde68a;
}

.alert-info {
    color: #1e40af;
    background: #dbeafe;
    border-color: #bfdbfe;
}

/* ----- 表格变体 ----- */
.table-striped tbody tr:nth-child(even) {
    background: #fafbfd;
}

.table-hover tbody tr:hover {
    background: #f0f2f8;
}

/* ----- 分页（Bootstrap 风格）----- */
.page-item {
    display: inline-block;
    margin: 0 3px;
}

.page-link {
    display: block;
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--primary);
    text-decoration: none;
    border: 1px solid var(--border);
    font-size: 14px;
    transition: all var(--transition);
}

.page-link:hover {
    background: var(--primary-light);
    border-color: var(--primary);
}

.page-item.active .page-link {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
    font-weight: 600;
}

/* ----- 表单控件扩展 ----- */
.form-control {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-family: inherit;
    color: var(--text);
    background: var(--surface);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(91,106,191,.12);
}

.form-select {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-family: inherit;
    color: var(--text);
    background: var(--surface);
    appearance: auto;
}

.form-label {
    display: block;
    font-weight: 600;
    font-size: 13px;
    margin-bottom: 6px;
    color: var(--text-secondary);
}

/* ----- 模态框 ----- */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,.45);
    overflow: auto;
}

.modal-content {
    background: var(--surface);
    margin: 8% auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 520px;
    width: 90%;
    overflow: hidden;
}

.modal-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    font-size: 16px;
}

.modal-header .close {
    font-size: 22px;
    font-weight: 400;
    cursor: pointer;
    color: var(--text-muted);
    line-height: 1;
    background: none;
    border: none;
    padding: 0 4px;
}

.modal-header .close:hover {
    color: var(--text);
}

.modal-body {
    padding: 20px;
}

.modal-footer {
    padding: 14px 20px;
    border-top: 1px solid var(--border-light);
    display: flex;
    justify-content: flex-end;
    gap: 8px;
}

/* ----- 搜索栏 ----- */
.search-bar {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.search-bar input,
.search-bar select {
    padding: 8px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-family: inherit;
    min-width: 160px;
}

.search-bar input:focus,
.search-bar select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(91,106,191,.1);
}

/* ----- 响应式 ----- */
@media (max-width: 768px) {
    .app-header {
        padding: 0 12px;
    }

    .app-header .logo {
        font-size: 16px;
    }

    .app-header nav a {
        padding: 5px 10px;
        font-size: 13px;
    }

    .app-header .user-info {
        font-size: 13px;
        gap: 8px;
    }

    .app-main {
        padding: 16px 12px 36px;
    }

    .card {
        padding: 16px;
    }

    .detail-header {
        padding: 20px 20px 0;
    }

    .detail-header h1 {
        font-size: 20px;
    }

    .detail-meta {
        padding: 12px 20px;
        gap: 12px;
        font-size: 12px;
    }

    .detail-body {
        padding: 20px;
        font-size: 14px;
    }

    .detail-footer {
        padding: 16px 20px;
    }

    .btn {
        padding: 8px 14px;
        font-size: 13px;
    }

    .image-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 8px;
    }

    .image-grid img {
        height: 120px;
    }

    table {
        font-size: 13px;
    }

    th, td {
        padding: 10px 12px;
    }
}

@media (max-width: 480px) {
    .app-header nav {
        gap: 0;
    }

    .app-header nav a {
        padding: 4px 8px;
        font-size: 12px;
    }

    .detail-meta {
        flex-direction: column;
        gap: 8px;
    }

    .detail-footer {
        flex-direction: column;
        align-items: stretch;
    }

    .detail-footer .btn-back,
    .detail-footer .btn-group {
        width: 100%;
    }

    .detail-footer .btn-group {
        justify-content: center;
    }

    .pagination a,
    .pagination span {
        min-width: 32px;
        height: 32px;
        font-size: 13px;
    }
}