/* ===== 全局重置 ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --sidebar-w: 260px;
    --primary: #4f6ef7;
    --primary-hover: #3b57d9;
    --bg: #f0f2f5;
    --card-bg: #ffffff;
    --text: #1a1a2e;
    --text-secondary: #6b7280;
    --border: #e2e8f0;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --radius: 8px;
    --radius-sm: 6px;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", sans-serif;
    --mono: "SF Mono", "Cascadia Code", "Fira Code", Consolas, monospace;
}

html, body {
    height: 100%;
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    font-size: 15px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* ===== 侧边栏 ===== */
#sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: var(--sidebar-w);
    background: var(--card-bg);
    border-right: 1px solid var(--border);
    overflow-y: auto;
    z-index: 100;
    display: flex;
    flex-direction: column;
}

.sidebar-header {
    padding: 24px 20px 16px;
    border-bottom: 1px solid var(--border);
}

.header-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.sidebar-header h1 {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary);
}

#lang-toggle {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 4px 14px;
    font-size: 13px;
    font-weight: 700;
    color: var(--primary);
    cursor: pointer;
    transition: all 0.2s;
    letter-spacing: 0.5px;
}

#lang-toggle:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.tagline {
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 2px;
}

.search-box {
    padding: 12px 16px;
}

.search-box input {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    outline: none;
    transition: border-color 0.2s;
    background: var(--bg);
}

.search-box input:focus {
    border-color: var(--primary);
}

.nav-groups {
    flex: 1;
    overflow-y: auto;
    padding: 4px 0;
}

.nav-group {
    margin-bottom: 4px;
}

.nav-group-title {
    padding: 10px 20px 4px;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.nav-item {
    display: block;
    padding: 7px 20px 7px 28px;
    color: var(--text);
    text-decoration: none;
    font-size: 14px;
    transition: all 0.15s;
    border-left: 3px solid transparent;
}

.nav-item:hover {
    background: var(--bg);
    color: var(--primary);
}

.nav-item.active {
    background: rgba(79, 110, 247, 0.08);
    color: var(--primary);
    font-weight: 600;
    border-left-color: var(--primary);
}

.nav-item.hidden {
    display: none;
}

.nav-group.hidden {
    display: none;
}

.sidebar-footer {
    padding: 12px 20px;
    border-top: 1px solid var(--border);
    font-size: 11px;
    color: var(--text-secondary);
    text-align: center;
}

/* ===== 移动端顶栏 ===== */
#mobile-header {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 52px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    z-index: 99;
    align-items: center;
    padding: 0 16px;
    font-weight: 600;
    font-size: 17px;
    color: var(--primary);
}

#menu-toggle {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    margin-right: 12px;
    color: var(--text);
}

#lang-toggle-mobile {
    margin-left: auto;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 3px 12px;
    font-size: 12px;
    font-weight: 700;
    color: var(--primary);
    cursor: pointer;
    transition: all 0.2s;
}

#lang-toggle-mobile:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* ===== 主内容 ===== */
#main-content {
    margin-left: var(--sidebar-w);
    padding: 32px;
    min-height: 100vh;
}

/* ====== 首页工具网格 ====== */
#home-grid {
    display: none;
    max-width: 900px;
    margin: 0 auto;
}

#home-grid.active {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 16px;
    animation: fadeIn 0.2s ease;
}

.tool-card, .home-card {
    background: #fff;
    border-radius: 12px;
    padding: 20px;
    cursor: pointer;
    transition: box-shadow 0.2s, transform 0.15s;
    border: 1px solid #e8ecf1;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.tool-card:hover, .home-card:hover {
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
    transform: translateY(-2px);
}

.tool-card h3, .home-card .home-card-name {
    margin: 0 0 8px 0;
    font-size: 16px;
    font-weight: 600;
    color: #1a1a2e;
}

.tool-card p, .home-card .home-card-desc {
    margin: 0;
    font-size: 13px;
    color: #6b7280;
    line-height: 1.4;
}

.home-card .home-card-icon {
    font-size: 24px;
    margin-bottom: 4px;
}

/* ====== 工具面板 ====== */
.tool-panel {
    display: none;
    max-width: 900px;
    margin: 0 auto;
}

.tool-panel.active {
    display: block;
    animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.tool-header {
    margin-bottom: 24px;
}

.tool-header h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 4px;
}

.tool-desc {
    color: var(--text-secondary);
    font-size: 14px;
}

/* ===== 通用组件 ===== */
.full-textarea {
    width: 100%;
    min-height: 150px;
    padding: 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    font-family: var(--font);
    resize: vertical;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
    line-height: 1.6;
    background: var(--card-bg);
}

.full-textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 110, 247, 0.1);
}

.full-textarea.mono {
    font-family: var(--mono);
    font-size: 13px;
}

.result-area {
    margin-top: 16px;
    background: #f8fafc;
}

.btn-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 12px 0;
    align-items: center;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.15s, transform 0.1s;
    white-space: nowrap;
}

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

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

.btn-secondary {
    background: var(--card-bg);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--bg);
    border-color: var(--primary);
    color: var(--primary);
}

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

.checkbox-label {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: 14px;
    cursor: pointer;
    user-select: none;
}

.checkbox-label input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--primary);
}

.info-text {
    font-size: 13px;
    color: var(--success);
    font-weight: 500;
}

.error-text {
    color: var(--danger) !important;
}

/* ===== 双栏布局 ===== */
.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.two-col .col {
    display: flex;
    flex-direction: column;
}

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

.two-col .full-textarea {
    flex: 1;
}

/* ===== 统计卡片 ===== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-top: 16px;
}

.stat-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
    text-align: center;
    box-shadow: var(--shadow);
}

.stat-val {
    display: block;
    font-size: 28px;
    font-weight: 700;
    color: var(--primary);
    line-height: 1.2;
}

.stat-label {
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 4px;
}

/* ===== 转换网格 ===== */
.convert-grid {
    display: grid;
    gap: 12px;
}

.convert-row {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 12px 16px;
}

.convert-row label {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-secondary);
    min-width: 140px;
    white-space: nowrap;
}

.convert-row input[type="text"],
.convert-row input[type="datetime-local"] {
    flex: 1;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-family: var(--mono);
    outline: none;
    transition: border-color 0.2s;
    background: var(--bg);
}

.convert-row input:focus {
    border-color: var(--primary);
}

/* ===== 正则工具 ===== */
.regex-controls {
    display: flex;
    align-items: center;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 8px 12px;
}

.regex-slash {
    font-size: 20px;
    color: var(--primary);
    font-weight: 700;
    font-family: var(--mono);
}

.regex-input {
    flex: 1;
    border: none;
    outline: none;
    font-size: 15px;
    font-family: var(--mono);
    padding: 4px 8px;
    background: transparent;
}

.regex-flags {
    width: 50px;
    border: none;
    outline: none;
    font-size: 15px;
    font-family: var(--mono);
    padding: 4px;
    color: var(--primary);
    background: transparent;
}

.regex-highlight-box {
    margin-top: 12px;
    padding: 14px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    min-height: 60px;
    font-family: var(--mono);
    font-size: 14px;
    line-height: 1.8;
    white-space: pre-wrap;
    word-break: break-all;
}

.regex-highlight-box .match {
    background: rgba(79, 110, 247, 0.2);
    border-bottom: 2px solid var(--primary);
    padding: 1px 0;
}

.matches-list {
    margin-top: 12px;
}

.match-item {
    display: inline-block;
    background: rgba(79, 110, 247, 0.1);
    border: 1px solid rgba(79, 110, 247, 0.3);
    border-radius: 4px;
    padding: 2px 8px;
    margin: 3px 4px 3px 0;
    font-family: var(--mono);
    font-size: 13px;
}

/* ===== 密码生成 ===== */
.password-display {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    margin-bottom: 16px;
}

.password-display span {
    flex: 1;
    font-family: var(--mono);
    font-size: 18px;
    font-weight: 600;
    letter-spacing: 1px;
    word-break: break-all;
}

.pwd-options {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
}

.option-row {
    margin-bottom: 12px;
}

.option-row label {
    font-size: 14px;
    font-weight: 500;
}

.option-row input[type="range"] {
    width: 100%;
    margin-top: 6px;
    accent-color: var(--primary);
}

.option-row.checkboxes {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

/* ===== 时间戳 ===== */
.current-ts {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 12px 16px;
    margin-bottom: 20px;
    font-size: 14px;
}

.current-ts strong {
    font-family: var(--mono);
    font-size: 16px;
    color: var(--primary);
}

.convert-section {
    margin-bottom: 20px;
}

.convert-section h3 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text);
}

.convert-section .convert-row {
    background: transparent;
    border: none;
    padding: 0;
}

.result-text {
    margin-top: 8px;
    padding: 10px 14px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-family: var(--mono);
    font-size: 14px;
    min-height: 20px;
}

/* ===== 颜色转换 ===== */
.color-preview {
    width: 100%;
    height: 80px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    margin-bottom: 16px;
    background: #3498db;
    transition: background 0.3s;
}

/* ===== 替换控件 ===== */
.replace-controls {
    display: flex;
    gap: 8px;
    margin: 12px 0;
    align-items: center;
    flex-wrap: wrap;
}

.replace-controls input[type="text"] {
    flex: 1;
    min-width: 120px;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    outline: none;
}

.replace-controls input:focus {
    border-color: var(--primary);
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    :root {
        --sidebar-w: 0px;
    }

    #sidebar {
        transform: translateX(-100%);
        transition: transform 0.25s ease;
        width: 280px;
        box-shadow: var(--shadow-md);
    }

    #sidebar.open {
        transform: translateX(0);
    }

    #mobile-header {
        display: flex;
    }

    #main-content {
        margin-left: 0;
        padding: 68px 16px 32px;
    }

    .two-col {
        grid-template-columns: 1fr;
    }

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

    .convert-row {
        flex-direction: column;
        align-items: stretch;
    }

    .convert-row label {
        min-width: auto;
    }

    .tool-header h2 {
        font-size: 20px;
    }
}

/* ===== 滚动条美化 ===== */
#sidebar::-webkit-scrollbar,
.nav-groups::-webkit-scrollbar {
    width: 4px;
}

#sidebar::-webkit-scrollbar-thumb,
.nav-groups::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 4px;
}