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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #8b5cf6;
    --accent: #06b6d4;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --dark: #1e293b;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --white: #ffffff;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--dark);
    line-height: 1.6;
}

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

/* ===== 导航栏 ===== */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
}

.nav-brand i {
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links a {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--gray-600);
    font-weight: 500;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav-links a:hover {
    background: var(--gray-100);
    color: var(--primary);
}

.nav-links a.active {
    background: var(--primary);
    color: white;
}

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

.nav-links .btn-logout:hover {
    background: #fef2f2;
    color: var(--danger);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--gray-600);
    cursor: pointer;
    padding: 8px;
    border-radius: var(--radius-sm);
}

/* ===== 主内容区 ===== */
main {
    padding-top: 80px;
    padding-bottom: 40px;
}

/* ===== 区块标题 ===== */
.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--white);
    margin-bottom: 12px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.section-header h1 i {
    background: rgba(255, 255, 255, 0.2);
    padding: 8px;
    border-radius: var(--radius);
    margin-right: 8px;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 12px;
}

.section-header .subtitle {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1.1rem;
}

/* ===== 工具卡片 ===== */
.tool-card {
    background: var(--white);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow-xl);
    transition: var(--transition);
}

.tool-card:hover {
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
}

/* ===== 表单样式 ===== */
.tool-form {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 600;
    color: var(--gray-600);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 6px;
}

textarea {
    width: 100%;
    padding: 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-family: 'SF Mono', 'Fira Code', monospace;
    transition: var(--transition);
    resize: vertical;
    min-height: 120px;
    line-height: 1.5;
}

textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* ===== 操作按钮组 ===== */
.action-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

.btn-action {
    padding: 12px 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    background: var(--white);
    color: var(--gray-600);
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-action:hover {
    border-color: var(--primary);
    background: #eef2ff;
    color: var(--primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-action:active {
    transform: translateY(0);
}

.btn-action i {
    font-size: 1.1rem;
}

/* ===== 分隔符选项 ===== */
.delimiter-group {
    background: var(--gray-100);
    padding: 16px;
    border-radius: var(--radius-sm);
}

.delimiter-options {
    display: flex;
    gap: 12px;
    align-items: center;
}

.delimiter-options select {
    padding: 10px 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    background: var(--white);
    cursor: pointer;
    transition: var(--transition);
}

.delimiter-options select:focus {
    outline: none;
    border-color: var(--primary);
}

.delimiter-options input {
    padding: 10px 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    flex: 1;
    transition: var(--transition);
}

.delimiter-options input:focus {
    outline: none;
    border-color: var(--primary);
}

/* ===== 错误提示 ===== */
.error-msg {
    padding: 12px 16px;
    background: #fef2f2;
    border: 1px solid #fecaca;
    border-radius: var(--radius-sm);
    color: var(--danger);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
}

.success-msg {
    padding: 12px 16px;
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
    border-radius: var(--radius-sm);
    color: var(--success);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 20px;
}

/* ===== 结果区域 ===== */
.result-section {
    margin-top: 24px;
    border-top: 2px solid var(--gray-200);
    padding-top: 24px;
}

.result-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.result-header h3 {
    color: var(--success);
    display: flex;
    align-items: center;
    gap: 8px;
}

.badge {
    padding: 4px 12px;
    background: var(--primary);
    color: white;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.result-stats {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 16px;
}

.stat {
    padding: 6px 14px;
    background: #eef2ff;
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 6px;
}

.stat.removed {
    background: #fef2f2;
    color: var(--danger);
}

.stat code {
    background: var(--white);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.85rem;
}

.result-parts {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 400px;
    overflow-y: auto;
}

.part-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    background: var(--gray-100);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.part-item:hover {
    background: #eef2ff;
}

.part-num {
    font-weight: 700;
    color: var(--primary);
    min-width: 32px;
    font-size: 0.9rem;
}

.part-text {
    flex: 1;
    word-break: break-all;
    font-size: 0.95rem;
}

.btn-copy {
    padding: 6px 10px;
    border: none;
    background: var(--white);
    border-radius: 6px;
    cursor: pointer;
    color: var(--gray-500);
    transition: var(--transition);
}

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

.result-text textarea {
    background: var(--gray-100);
    border-color: var(--gray-200);
}

.result-actions {
    margin-top: 16px;
    display: flex;
    gap: 12px;
}

/* ===== 统计结果网格 ===== */
.result-stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.stat-card {
    text-align: center;
    padding: 24px;
    background: var(--gray-100);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.stat-card:hover {
    background: #eef2ff;
    transform: translateY(-2px);
}

.stat-card i {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 12px;
}

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--dark);
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--gray-500);
    margin-top: 4px;
}

/* ===== 按钮样式 ===== */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

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

.btn-danger:hover {
    background: #dc2626;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-sm {
    padding: 6px 12px;
    font-size: 0.85rem;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

/* ===== 历史记录 ===== */
.history-section {
    margin-top: 40px;
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.history-item {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.history-item:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-lg);
}

.history-time {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--gray-500);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.history-action {
    margin-bottom: 12px;
}

.history-preview {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    background: var(--gray-100);
    padding: 12px;
    border-radius: var(--radius-sm);
}

.preview-input label,
.preview-output label {
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--gray-500);
    display: block;
    margin-bottom: 4px;
}

.preview-input p,
.preview-output p {
    font-size: 0.9rem;
    color: var(--gray-600);
    word-break: break-all;
}

/* ===== 管理后台 ===== */
.admin-section {
    margin-top: 20px;
}

.admin-card {
    background: var(--white);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow-xl);
}

.admin-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--gray-200);
}

.admin-header h2 {
    font-size: 1.5rem;
    color: var(--dark);
    display: flex;
    align-items: center;
    gap: 8px;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--gray-400);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 16px;
}

/* ===== 管理表格 ===== */
.admin-table {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.table-header {
    display: grid;
    grid-template-columns: 160px 100px 1fr 1fr 80px;
    gap: 12px;
    padding: 12px 16px;
    background: var(--gray-100);
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--gray-500);
}

.table-row {
    display: grid;
    grid-template-columns: 160px 100px 1fr 1fr 80px;
    gap: 12px;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    align-items: center;
    font-size: 0.9rem;
}

.table-row:hover {
    background: var(--gray-100);
}

.col-time {
    font-size: 0.85rem;
    color: var(--gray-500);
}

.col-input,
.col-result {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    color: var(--gray-600);
}

.col-actions {
    display: flex;
    gap: 4px;
}

/* ===== 登录弹窗 ===== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background: var(--white);
    border-radius: var(--radius);
    padding: 40px;
    width: 100%;
    max-width: 420px;
    box-shadow: var(--shadow-xl);
    position: relative;
    animation: slideUp 0.3s ease;
}

.close {
    position: absolute;
    top: 16px;
    right: 20px;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--gray-400);
    transition: var(--transition);
}

.close:hover {
    color: var(--dark);
}

.modal-header {
    text-align: center;
    margin-bottom: 24px;
}

.modal-header i {
    font-size: 3rem;
    color: var(--primary);
    margin-bottom: 12px;
}

.modal-header h2 {
    font-size: 1.5rem;
    color: var(--dark);
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.login-form input {
    padding: 12px 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: var(--transition);
}

.login-form input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* ===== 页脚 ===== */
.footer {
    text-align: center;
    padding: 24px;
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

/* ===== 动画 ===== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

/* ===== 响应式设计 ===== */
@media (max-width: 1200px) {
    .container {
        max-width: 100%;
    }
}

@media (max-width: 768px) {
    .section-header h1 {
        font-size: 1.8rem;
    }

    .section-header h2 {
        font-size: 1.5rem;
    }

    .tool-card {
        padding: 20px;
    }

    .action-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .result-stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .history-preview {
        grid-template-columns: 1fr;
    }

    .table-header,
    .table-row {
        grid-template-columns: 1fr;
        gap: 4px;
    }

    .table-header {
        display: none;
    }

    .table-row {
        padding: 16px;
        border: 1px solid var(--gray-200);
        margin-bottom: 8px;
    }

    .col-time {
        font-weight: 600;
    }

    .col-actions {
        margin-top: 8px;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 16px;
        box-shadow: var(--shadow-lg);
    }

    .nav-links.show {
        display: flex;
    }

    .nav-toggle {
        display: block;
    }

    .delimiter-options {
        flex-direction: column;
    }

    .delimiter-options select,
    .delimiter-options input {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .action-grid {
        grid-template-columns: 1fr 1fr;
    }

    .result-stats-grid {
        grid-template-columns: 1fr 1fr;
    }

    .section-header h1 {
        font-size: 1.5rem;
    }

    .modal-content {
        margin: 20px;
        padding: 24px;
    }
}