* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

:root {
    --primary: #165DFF;
    --primary-dark: #0D47A1;
    --primary-light: #E8F0FE;
    --black: #1D2129;
    --gray-100: #F2F3F5;
    --gray-200: #E5E6EB;
    --gray-300: #C9CDD4;
    --gray-400: #86909C;
    --gray-500: #4E5969;
    --white: #FFFFFF;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.12);
}

body {
    background-color: var(--gray-100);
    color: var(--black);
    line-height: 1.6;
}

/* 登录注册页面 */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--white) 100%);
}

.auth-card {
    background: var(--white);
    padding: 40px;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 420px;
}

.auth-title {
    text-align: center;
    margin-bottom: 30px;
    color: var(--black);
    font-size: 28px;
    font-weight: 600;
}

.auth-title span {
    color: var(--primary);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--gray-500);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--gray-200);
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s ease;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(22, 93, 255, 0.1);
}

.btn {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: var(--primary);
    color: var(--white);
}

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

.auth-switch {
    text-align: center;
    margin-top: 20px;
    color: var(--gray-400);
}

.auth-switch a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

.auth-switch a:hover {
    text-decoration: underline;
}

.alert {
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert-danger {
    background-color: #FFF2F0;
    color: #F53F3F;
    border: 1px solid #FFCCC7;
}

.alert-success {
    background-color: #F6FFED;
    color: #00B42A;
    border: 1px solid #B7EB8F;
}

/* 主界面 */
.header {
    background-color: var(--white);
    box-shadow: var(--shadow);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 16px;
}

.user-details {
    text-align: right;
}

.user-nickname {
    font-weight: 600;
    color: var(--black);
}

.user-username {
    font-size: 12px;
    color: var(--gray-400);
}

.logout-btn {
    padding: 8px 16px;
    background-color: var(--gray-100);
    color: var(--gray-500);
    border: none;
    border-radius: 6px;
    cursor: pointer;
    text-decoration: none;
    font-size: 14px;
    transition: all 0.3s ease;
}

.logout-btn:hover {
    background-color: var(--gray-200);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

.page-title {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 30px;
    color: var(--black);
}

/* 便签网格 */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 80px;
}

.note-card {
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
    padding: 20px;
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.note-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.note-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--primary-dark) 100%);
}

.note-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--black);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.note-content {
    color: var(--gray-500);
    font-size: 14px;
    line-height: 1.6;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 4;
    -webkit-box-orient: vertical;
    margin-bottom: 16px;
}

.note-time {
    font-size: 12px;
    color: var(--gray-400);
}

/* 创建便签按钮 */
.create-btn {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: var(--primary);
    color: var(--white);
    border: none;
    font-size: 28px;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    transition: all 0.3s ease;
    z-index: 1000;
}

.create-btn:hover {
    background-color: var(--primary-dark);
    transform: scale(1.1);
}

/* 编辑页面 */
.edit-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px;
}

.edit-form {
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    padding: 40px;
}

.note-input-title {
    width: 100%;
    font-size: 28px;
    font-weight: 700;
    border: none;
    border-bottom: 2px solid var(--gray-200);
    padding: 12px 0;
    margin-bottom: 24px;
    color: var(--black);
    transition: border-color 0.3s ease;
}

.note-input-title:focus {
    outline: none;
    border-bottom-color: var(--primary);
}

.note-input-content {
    width: 100%;
    min-height: 400px;
    font-size: 16px;
    line-height: 1.8;
    border: none;
    resize: vertical;
    color: var(--gray-500);
}

.note-input-content:focus {
    outline: none;
}

.btn-group {
    display: flex;
    gap: 16px;
    margin-top: 30px;
}

.btn-secondary {
    background-color: var(--gray-100);
    color: var(--gray-500);
}

.btn-secondary:hover {
    background-color: var(--gray-200);
}

.btn-danger {
    background-color: #F53F3F;
    color: var(--white);
}

.btn-danger:hover {
    background-color: #D93026;
}

/* 管理员后台 */
.admin-header {
    background-color: var(--black);
    color: var(--white);
}

.admin-header .logo {
    color: var(--white);
}

.admin-nav {
    display: flex;
    gap: 24px;
}

.admin-nav a {
    color: var(--gray-300);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.admin-nav a:hover,
.admin-nav a.active {
    color: var(--white);
}

.table-container {
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
}

.data-table th,
.data-table td {
    padding: 16px 20px;
    text-align: left;
    border-bottom: 1px solid var(--gray-200);
}

.data-table th {
    background-color: var(--gray-100);
    font-weight: 600;
    color: var(--gray-500);
}

.data-table tr:hover {
    background-color: var(--gray-100);
}

.action-btn {
    padding: 6px 12px;
    border: none;
    border-radius: 4px;
    font-size: 12px;
    cursor: pointer;
    text-decoration: none;
    margin-right: 8px;
}

/* 响应式 */
@media (max-width: 768px) {
    .auth-card {
        padding: 30px 20px;
        margin: 20px;
    }
    
    .edit-form {
        padding: 20px;
    }
    
    .note-input-title {
        font-size: 24px;
    }
    
    .create-btn {
        bottom: 20px;
        right: 20px;
        width: 56px;
        height: 56px;
        font-size: 24px;
    }
    
    .header-content {
        flex-direction: column;
        gap: 16px;
        padding: 16px 20px;
    }
    
    .user-info {
        width: 100%;
        justify-content: space-between;
    }
}