:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #eff6ff;
    --primary-lighter: #f0f9ff;
    --bg: #f5f7fa;
    --bg-card: #ffffff;
    --text: #1f2937;
    --text-muted: #6b7280;
    --text-light: #9ca3af;
    --border: #e5e7eb;
    --border-light: #f3f4f6;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --radius: 6px;
    --radius-lg: 10px;
    --shadow-xs: 0 1px 2px rgba(0,0,0,.05);
    --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,.07), 0 2px 4px -2px rgba(0,0,0,.04);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,.1), 0 4px 6px -4px rgba(0,0,0,.05);
    --header-h: 56px;
    --quick-h: 38px;
    --side-w: 200px;
}

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

html, body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    font-size: 14px;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    min-height: 100vh;
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
button { font-family: inherit; }

/* ========== Header ========== */
.site-header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    position: sticky; top: 0; z-index: 100;
    box-shadow: var(--shadow-xs);
}
.hdr-inner {
    height: var(--header-h);
    padding: 0 24px;
    display: flex;
    align-items: center;
    gap: 32px;
    max-width: 1600px;
    margin: 0 auto;
}
.logo {
    display: flex; align-items: center; gap: 10px;
    font-weight: 700;
    color: var(--text);
    flex-shrink: 0;
}
.logo-mark {
    display: inline-flex; align-items: center; justify-content: center;
    width: 30px; height: 30px;
    background: linear-gradient(135deg, var(--primary), #60a5fa);
    color: #fff;
    border-radius: var(--radius);
    font-size: 13px;
    font-weight: 800;
    letter-spacing: -0.5px;
}
.logo-text {
    font-size: 17px;
    font-weight: 700;
    letter-spacing: -0.3px;
}
.logo-text i {
    font-style: normal;
    font-weight: 700;
    color: var(--text);
    font-size: 17px;
    margin-left: 2px;
    letter-spacing: -0.3px;
}
.top-nav {
    display: flex; gap: 4px;
    flex: 1;
}
.nav-link {
    padding: 6px 14px;
    border-radius: var(--radius);
    color: var(--text-muted);
    font-weight: 500;
    font-size: 13px;
    transition: all .15s;
}
.nav-link:hover, .nav-link.active {
    color: var(--primary);
    background: var(--primary-light);
}
.search-box {
    position: relative;
    flex-shrink: 0;
}
.search-box .search-icon {
    position: absolute; left: 10px; top: 50%; transform: translateY(-50%);
    font-size: 12px; opacity: .5;
    pointer-events: none;
}
.search-box input {
    padding: 7px 12px 7px 30px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    width: 260px;
    font-size: 13px;
    outline: none;
    transition: all .15s;
    background: var(--bg);
}
.search-box input:focus {
    border-color: var(--primary);
    background: #fff;
    box-shadow: 0 0 0 3px rgba(37,99,235,.1);
}

/* ========== Quick Bar ========== */
.quick-bar {
    height: var(--quick-h);
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    overflow-x: auto;
    overflow-y: hidden;
}
.quick-bar-inner {
    height: 100%;
    padding: 0 24px;
    display: flex;
    align-items: center;
    gap: 4px;
    max-width: 1600px;
    margin: 0 auto;
    white-space: nowrap;
}
.quick-label {
    color: var(--text-muted);
    font-size: 12px;
    margin-right: 8px;
}
.quick-link {
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 12px;
    color: var(--text);
    background: var(--bg);
    border: 1px solid transparent;
    transition: all .15s;
}
.quick-link:hover {
    background: var(--primary-light);
    color: var(--primary);
    border-color: rgba(37,99,235,.2);
}

/* ========== Page wrap with sidebar ========== */
.page-wrap {
    max-width: 1600px;
    margin: 0 auto;
    display: flex;
    align-items: flex-start;
    gap: 0;
    min-height: calc(100vh - 250px);
}
.side-nav {
    width: var(--side-w);
    flex-shrink: 0;
    padding: 20px 0 20px 24px;
    position: sticky;
    top: calc(var(--header-h) + var(--quick-h));
    align-self: flex-start;
    height: calc(100vh - var(--header-h) - var(--quick-h));
    overflow-y: auto;
}
.side-nav-list { list-style: none; }
.side-nav-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    margin-bottom: 2px;
    color: var(--text-muted);
    font-size: 13px;
    font-weight: 500;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all .12s;
    border-left: 2px solid transparent;
    text-decoration: none;  /* 覆盖 <a> 的默认下划线 */
}
.side-nav-item:hover { text-decoration: none; }
.side-nav-item:visited { color: var(--text-muted); }
.side-nav-item:hover {
    background: var(--bg-card);
    color: var(--text);
}
.side-nav-item.active {
    background: var(--primary-light);
    color: var(--primary);
    border-left-color: var(--primary);
}
.side-nav-icon {
    width: 24px; height: 24px;
    display: inline-flex; align-items: center; justify-content: center;
    font-size: 14px;
    border-radius: 6px;
    background: var(--c-light, var(--bg));
    color: var(--c-main, var(--text-muted));
    transition: all .15s;
}
.side-nav-item:hover .side-nav-icon,
.side-nav-item.active .side-nav-icon {
    background: linear-gradient(135deg, var(--c-grad-from, var(--primary)), var(--c-grad-to, var(--primary-dark)));
    color: #fff;
}
.side-nav-count {
    margin-left: auto;
    font-size: 11px;
    color: var(--text-light);
    background: var(--border-light);
    padding: 1px 6px;
    border-radius: 10px;
    font-weight: 400;
}
.side-nav-item.active .side-nav-count {
    background: rgba(37,99,235,.15);
    color: var(--primary);
}

.main-content {
    flex: 1;
    padding: 20px 24px 40px;
    min-width: 0;
}

/* ========== Hero (homepage banner) ========== */
.hero {
    background: linear-gradient(135deg, #2563eb 0%, #4f46e5 100%);
    color: #fff;
    padding: 28px 32px;
    border-radius: var(--radius-lg);
    margin-bottom: 24px;
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    right: -40px; top: -40px;
    width: 200px; height: 200px;
    border-radius: 50%;
    background: rgba(255,255,255,.08);
}
.hero h1 {
    font-size: 24px;
    margin-bottom: 8px;
    position: relative;
    font-weight: 700;
}
.hero p {
    font-size: 14px;
    opacity: .92;
    position: relative;
    max-width: 700px;
}
.hero-stats {
    display: flex; gap: 24px;
    margin-top: 16px;
    position: relative;
}
.hero-stat strong {
    font-size: 22px;
    display: block;
    font-weight: 700;
}
.hero-stat span {
    font-size: 12px;
    opacity: .85;
}

/* ========== Categories ========== */
.category-section {
    margin-bottom: 28px;
    scroll-margin-top: calc(var(--header-h) + var(--quick-h) + 12px);
}
.category-title {
    display: flex; align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    padding: 4px 0;
}
.category-title h2 {
    font-size: 17px;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.2px;
}
.category-title .category-icon {
    width: 32px; height: 32px;
    display: inline-flex; align-items: center; justify-content: center;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--c-grad-from, var(--primary)), var(--c-grad-to, var(--primary-dark)));
    color: #fff;
    font-size: 16px;
    box-shadow: 0 2px 8px -2px var(--c-main, var(--primary));
}
.category-title .tool-count {
    margin-left: auto;
    font-size: 12px;
    color: var(--text-muted);
    font-weight: 400;
}
.category-title-lg {
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
}
.category-title-lg h2 { font-size: 20px; }

/* 分类页大 Banner(带渐变背景) */
.category-banner {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 22px 26px;
    margin-bottom: 18px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--c-grad-from, var(--primary)) 0%, var(--c-grad-to, var(--primary-dark)) 100%);
    color: #fff;
    box-shadow: 0 8px 24px -10px var(--c-main, var(--primary));
    position: relative;
    overflow: hidden;
}
.category-banner::after {
    content: '';
    position: absolute;
    right: -30px; bottom: -30px;
    width: 140px; height: 140px;
    border-radius: 50%;
    background: rgba(255,255,255,.1);
}
.category-banner .category-icon {
    width: 56px; height: 56px;
    display: inline-flex; align-items: center; justify-content: center;
    border-radius: 14px;
    background: rgba(255,255,255,.2);
    backdrop-filter: blur(10px);
    color: #fff;
    font-size: 26px;
    box-shadow: none;
    flex-shrink: 0;
}
.category-banner-text { position: relative; }
.category-banner-text h2 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 4px;
    color: #fff;
    letter-spacing: -0.3px;
}
.category-banner-text p {
    font-size: 13px;
    color: rgba(255,255,255,.85);
}

/* 子组小图标 */
.group-title-icon {
    display: inline-flex;
    align-items: center; justify-content: center;
    width: 22px; height: 22px;
    background: var(--g-light, var(--primary-light));
    color: var(--g-main, var(--primary));
    border-radius: 5px;
    font-size: 12px;
}

/* group section (二级子组) */
.group-section { scroll-margin-top: 110px; margin-bottom: 24px; }
.group-section:last-child { margin-bottom: 0; }
.group-title {
    display: flex; align-items: center; gap: 8px;
    margin: 18px 0 12px;
    font-size: 15px;
    font-weight: 700;
    color: var(--text);
    padding: 4px 0 4px 10px;
    border-left: 4px solid var(--g-main, var(--c-main, var(--primary)));
    letter-spacing: -0.1px;
}
.group-title:first-child { margin-top: 4px; }
.group-count {
    font-size: 12px;
    color: var(--text-muted);
    font-weight: 400;
}

/* 子组锚点导航条(彩色版) */
.group-anchors {
    display: flex; flex-wrap: wrap; gap: 8px;
    margin-bottom: 20px;
    padding: 12px 14px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xs);
}
.group-anchor {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    font-size: 12.5px;
    color: var(--text);
    background: var(--c-light, var(--bg));
    border: 1px solid transparent;
    border-radius: 16px;
    transition: all .15s;
    cursor: pointer;
    font-weight: 500;
}
.group-anchor:hover {
    background: linear-gradient(135deg, var(--c-grad-from, var(--primary)), var(--c-grad-to, var(--primary-dark)));
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 10px -3px var(--c-main, var(--primary));
}
.group-anchor-icon {
    font-size: 13px;
}
.group-anchor-count {
    background: rgba(0,0,0,.08);
    padding: 0 6px;
    border-radius: 8px;
    font-size: 10px;
    font-weight: 600;
}
.group-anchor:hover .group-anchor-count {
    background: rgba(255,255,255,.25);
}

/* ========== 分类配色 ========== */
.cat-text   { --c-main: #06b6d4; --c-light: #ecfeff; --c-grad-from: #22d3ee; --c-grad-to: #0891b2; }
.cat-code   { --c-main: #8b5cf6; --c-light: #f5f3ff; --c-grad-from: #a78bfa; --c-grad-to: #7c3aed; }
.cat-office { --c-main: #10b981; --c-light: #ecfdf5; --c-grad-from: #34d399; --c-grad-to: #059669; }
.cat-image  { --c-main: #ec4899; --c-light: #fdf2f8; --c-grad-from: #f472b6; --c-grad-to: #db2777; }
.cat-file   { --c-main: #f59e0b; --c-light: #fffbeb; --c-grad-from: #fbbf24; --c-grad-to: #d97706; }
.cat-info   { --c-main: #3b82f6; --c-light: #eff6ff; --c-grad-from: #60a5fa; --c-grad-to: #2563eb; }

/* 子组配色(在编程开发等大分类内的子组) */
.grp-json       { --g-main: #8b5cf6; --g-light: #f5f3ff; }
.grp-encode     { --g-main: #ef4444; --g-light: #fef2f2; }
.grp-color      { --g-main: #ec4899; --g-light: #fdf2f8; }
.grp-generator  { --g-main: #14b8a6; --g-light: #f0fdfa; }
.grp-time-regex { --g-main: #f59e0b; --g-light: #fffbeb; }
.grp-web        { --g-main: #3b82f6; --g-light: #eff6ff; }
.grp-code-misc  { --g-main: #6366f1; --g-light: #eef2ff; }
.grp-default    { --g-main: var(--c-main, #2563eb); --g-light: var(--c-light, #eff6ff); }

/* ========== Tool Cards Grid ========== */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 14px;
}
.tool-card {
    --card-color: var(--g-main, var(--c-main, var(--primary)));
    --card-light: var(--g-light, var(--c-light, var(--primary-light)));
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 16px 18px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: all .18s ease;
    color: var(--text);
    position: relative;
    overflow: hidden;
    min-height: 84px;
}
.tool-card::before {
    content: '';
    position: absolute;
    left: 0; top: 0; bottom: 0;
    width: 4px;
    background: var(--card-color);
    opacity: 0.6;
    transition: opacity .18s, width .18s;
}
.tool-card:hover {
    border-color: var(--card-color);
    box-shadow: 0 6px 20px -8px var(--card-color), 0 2px 4px -1px rgba(0,0,0,.04);
    transform: translateY(-2px);
    color: var(--text);
    background: linear-gradient(180deg, #fff 0%, var(--card-light) 100%);
}
.tool-card:hover::before {
    opacity: 1;
    width: 5px;
}
.tool-card-icon {
    flex-shrink: 0;
    width: 38px; height: 38px;
    border-radius: 10px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    background: var(--card-light);
    color: var(--card-color);
    transition: all .18s;
}
.tool-card:hover .tool-card-icon {
    background: var(--card-color);
    color: #fff;
    transform: scale(1.05);
}
.tool-card-body { flex: 1; min-width: 0; }
.tool-card-name {
    font-weight: 600;
    font-size: 14.5px;
    margin-bottom: 5px;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 6px;
    line-height: 1.3;
}
.tool-card-name .tag-new {
    font-size: 10px;
    background: var(--success);
    color: #fff;
    padding: 1px 6px;
    border-radius: 8px;
    font-weight: 500;
}
.tool-card-name .tag-backend {
    font-size: 10px;
    background: var(--warning);
    color: #fff;
    padding: 1px 6px;
    border-radius: 8px;
    font-weight: 500;
}
.tool-card-desc {
    font-size: 12.5px;
    color: var(--text-muted);
    line-height: 1.55;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

/* ========== Tool Page ========== */
.tool-page {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    padding: 24px;
    box-shadow: var(--shadow-xs);
}
.breadcrumb {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 14px;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--primary); }
.tool-title {
    font-size: 20px;
    margin-bottom: 4px;
    font-weight: 600;
}
.tool-desc {
    color: var(--text-muted);
    margin-bottom: 18px;
    font-size: 13px;
}
.tool-body { display: grid; gap: 14px; }

/* ========== Forms ========== */
.form-group { margin-bottom: 10px; }
.form-label {
    display: block;
    font-weight: 500;
    margin-bottom: 6px;
    font-size: 13px;
    color: var(--text);
}
.form-control {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-family: inherit;
    font-size: 13px;
    outline: none;
    transition: all .15s;
    background: #fff;
    color: var(--text);
}
.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37,99,235,.1);
}
textarea.form-control {
    min-height: 140px;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    resize: vertical;
    line-height: 1.5;
}

.input-row {
    display: flex; gap: 8px; align-items: center;
    flex-wrap: wrap;
}

/* ========== Buttons ========== */
.btn {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 7px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: #fff;
    color: var(--text);
    cursor: pointer;
    font-size: 13px;
    font-weight: 500;
    transition: all .12s;
    user-select: none;
}
.btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
}
.btn-primary {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
}
.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    color: #fff;
}
.btn-success { background: var(--success); border-color: var(--success); color: #fff; }
.btn-success:hover { background: #059669; color: #fff; }
.btn-danger { background: var(--danger); border-color: var(--danger); color: #fff; }
.btn-sm { padding: 4px 10px; font-size: 12px; }
.btn-group { display: flex; gap: 8px; flex-wrap: wrap; }

/* ========== Output ========== */
.output {
    padding: 12px;
    background: #f9fafb;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 13px;
    white-space: pre-wrap;
    word-break: break-all;
    min-height: 60px;
    max-height: 500px;
    overflow: auto;
    line-height: 1.55;
}

/* ========== Misc ========== */
.badge {
    display: inline-block;
    padding: 2px 8px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 12px;
    font-size: 11px;
    font-weight: 500;
}
.io-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}
.color-preview {
    display: inline-block;
    width: 36px; height: 36px;
    border-radius: 6px;
    border: 1px solid var(--border);
    vertical-align: middle;
    margin-right: 8px;
}
.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }
.mt-1 { margin-top: 8px; } .mt-2 { margin-top: 16px; }
.mb-1 { margin-bottom: 8px; } .mb-2 { margin-bottom: 16px; }
.flex { display: flex; }
.flex-1 { flex: 1; }
.gap-1 { gap: 8px; } .gap-2 { gap: 16px; }
.hidden { display: none !important; }

.toast {
    position: fixed;
    top: 70px; right: 20px;
    padding: 10px 16px;
    background: var(--text);
    color: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    animation: slideIn .2s ease;
    font-size: 13px;
}
.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }
@keyframes slideIn {
    from { transform: translateX(20px); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

table.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
}
table.data-table th, table.data-table td {
    padding: 7px 10px;
    border: 1px solid var(--border);
    text-align: left;
    vertical-align: top;
}
table.data-table th {
    background: #f9fafb;
    font-weight: 600;
    color: var(--text);
}
table.data-table tbody tr:hover { background: var(--primary-lighter); }

/* ========== Footer ========== */
.site-footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 24px 0;
    margin-top: 40px;
}
.footer-inner {
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 24px;
    text-align: center;
}
.footer-brand strong {
    font-size: 16px;
    color: var(--text);
    display: block;
    margin-bottom: 4px;
}
.footer-brand p {
    color: var(--text-muted);
    font-size: 13px;
    margin-bottom: 16px;
}
.footer-stats {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin: 16px 0;
}
.footer-stat strong {
    display: block;
    font-size: 22px;
    color: var(--primary);
    font-weight: 700;
}
.footer-stat span {
    font-size: 12px;
    color: var(--text-muted);
}
.footer-copy {
    color: var(--text-light);
    font-size: 12px;
    margin-top: 12px;
}

/* ========== Hamburger Button (only mobile) ========== */
.menu-btn {
    display: none;
    align-items: center; justify-content: center;
    width: 36px; height: 36px;
    border: 1px solid var(--border);
    background: #fff;
    border-radius: var(--radius);
    cursor: pointer;
    flex-shrink: 0;
    margin-right: 4px;
}
.menu-btn:active { background: var(--bg); }
.menu-btn span {
    display: block;
    width: 18px; height: 2px;
    background: var(--text);
    position: relative;
}
.menu-btn span::before, .menu-btn span::after {
    content: ''; position: absolute; left: 0;
    width: 18px; height: 2px;
    background: var(--text);
}
.menu-btn span::before { top: -6px; }
.menu-btn span::after { top: 6px; }

/* 抽屉式侧边栏(手机) */
.drawer-mask {
    display: none;
    position: fixed; inset: 0;
    background: rgba(0,0,0,.45);
    z-index: 200;
    animation: fadeIn .15s;
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideInLeft { from { transform: translateX(-100%); } to { transform: translateX(0); } }
body.drawer-open .drawer-mask { display: block; }
body.drawer-open { overflow: hidden; }

/* ========== 平板 (≤ 1024px) ========== */
@media (max-width: 1024px) {
    .top-nav { display: none; }
    .search-box input { width: 180px; }
    .hdr-inner { gap: 12px; padding: 0 14px; }
    .main-content { padding: 14px; }
    .quick-bar-inner { padding: 0 14px; }

    /* 侧边栏变抽屉 */
    .menu-btn { display: inline-flex; }
    .side-nav {
        position: fixed;
        top: 0; left: 0; bottom: 0;
        width: 240px;
        background: var(--bg-card);
        z-index: 201;
        height: 100vh;
        padding: 14px 12px 14px 14px;
        box-shadow: 4px 0 24px rgba(0,0,0,.08);
        transform: translateX(-100%);
        transition: transform .2s;
    }
    body.drawer-open .side-nav {
        transform: translateX(0);
    }
    .page-wrap { display: block; }
    .main-content { width: 100%; }
}

/* ========== 手机 (≤ 768px) ========== */
@media (max-width: 768px) {
    :root {
        --header-h: 50px;
        --quick-h: 36px;
    }
    /* logo 文字精简 */
    .logo-text { font-size: 15px; }
    .logo-text i { display: none; }
    .logo-mark { width: 26px; height: 26px; font-size: 11px; }

    /* search 全屏宽度 */
    .search-box { flex: 1; min-width: 0; }
    .search-box input { width: 100%; }

    /* quick-bar 紧凑滚动 */
    .quick-bar { height: var(--quick-h); }
    .quick-bar-inner { padding: 0 12px; gap: 3px; }
    .quick-link { padding: 3px 8px; font-size: 11.5px; }
    .quick-label { display: none; }

    /* 卡片单列 */
    .tool-grid { grid-template-columns: 1fr; gap: 10px; }
    .tool-card { padding: 14px; min-height: auto; }
    .tool-card-icon { width: 34px; height: 34px; font-size: 16px; border-radius: 8px; }
    .tool-card-name { font-size: 14px; }
    .tool-card-desc { font-size: 12px; -webkit-line-clamp: 2; }

    /* hero 紧凑 */
    .hero { padding: 18px 16px; border-radius: 8px; }
    .hero h1 { font-size: 19px; }
    .hero p { font-size: 13px; line-height: 1.5; }
    .hero-stats { gap: 16px; margin-top: 12px; }
    .hero-stat strong { font-size: 18px; }

    /* category 标题 */
    .category-section { margin-bottom: 22px; }
    .category-title h2 { font-size: 15px; }
    .category-title .category-icon { width: 26px; height: 26px; font-size: 13px; border-radius: 6px; }
    .category-title .tool-count { font-size: 11px; }

    /* category banner(分类页顶部) */
    .category-banner { padding: 16px 18px; border-radius: 8px; gap: 12px; }
    .category-banner .category-icon { width: 44px; height: 44px; font-size: 20px; border-radius: 10px; }
    .category-banner-text h2 { font-size: 18px; }
    .category-banner-text p { font-size: 12px; }

    /* 锚点条横向滚动 */
    .group-anchors { overflow-x: auto; flex-wrap: nowrap; padding: 8px 10px; }
    .group-anchor { white-space: nowrap; flex-shrink: 0; padding: 5px 10px; font-size: 11.5px; }

    /* group title */
    .group-title { font-size: 14px; padding-left: 8px; }
    .group-title-icon { width: 20px; height: 20px; font-size: 11px; }

    /* 工具页 */
    .tool-page { padding: 16px; border-radius: 8px; }
    .tool-title { font-size: 18px; }
    .tool-desc { font-size: 12.5px; margin-bottom: 14px; }
    .breadcrumb { font-size: 12px; margin-bottom: 12px; }

    /* form 控件 */
    .form-control { padding: 10px 12px; font-size: 14px; }   /* iOS 不缩放需要 ≥16px,这里折中 14 */
    textarea.form-control { min-height: 120px; font-size: 13px; }
    .form-label { font-size: 12.5px; margin-bottom: 5px; }
    .btn { padding: 9px 14px; font-size: 13px; }   /* 增大点击区域,触摸友好 */
    .btn-sm { padding: 6px 10px; }

    /* IO 双栏改单栏 */
    .io-grid { grid-template-columns: 1fr; gap: 12px; }

    /* 表格横向滚动 */
    table.data-table { font-size: 12px; }
    table.data-table th, table.data-table td { padding: 6px 8px; }
    .table-wrap, .data-table-wrap {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        margin: 0 -16px;
        padding: 0 16px;
    }

    /* 输出区 */
    .output { padding: 10px; font-size: 12px; max-height: 360px; }

    /* footer 紧凑 */
    .site-footer { padding: 18px 0; margin-top: 28px; }
    .footer-stats { gap: 18px; margin: 12px 0; }
    .footer-stat strong { font-size: 18px; }
    .footer-brand strong { font-size: 14px; }
    .footer-brand p { font-size: 12px; }
    .footer-copy { font-size: 11px; }

    /* toast 居中 */
    .toast { top: auto; right: 16px; left: 16px; bottom: 20px; text-align: center; }

    /* 拖拽区 */
    .drag-zone { padding: 22px 14px; }
    .drag-zone-icon { font-size: 28px; }

    /* 文件项 */
    .file-item { padding: 8px 10px; font-size: 12.5px; }
    .file-item .file-size { display: none; }   /* 手机隐藏字节数省空间 */
}

/* ========== 小屏 (≤ 480px) 进一步精简 ========== */
@media (max-width: 480px) {
    .hdr-inner { gap: 8px; padding: 0 10px; }
    .quick-bar-inner { padding: 0 10px; }
    .main-content { padding: 12px; }
    .tool-page { padding: 14px 12px; }
    .hero { padding: 16px 14px; }
    .hero h1 { font-size: 17px; }
    .hero-stats { gap: 12px; }
    .hero-stat strong { font-size: 16px; }
    .footer-stats { flex-wrap: wrap; gap: 12px 18px; }
    .btn-group { gap: 6px; }
    .btn { padding: 8px 11px; font-size: 12.5px; }
    .nav-link { padding: 5px 10px; font-size: 12px; }
}

/* ========== 触摸优化:hover 仅桌面生效 ========== */
@media (hover: none) {
    .tool-card:hover { transform: none; }
    .tool-card:active { background: var(--card-light); }
    .btn:hover { background: #fff; }
    .btn:active { background: var(--bg); }
    .quick-link:hover { background: var(--bg); }
    .quick-link:active { background: var(--primary-light); color: var(--primary); }
}

/* drag area */
.drag-zone {
    padding: 32px;
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    text-align: center;
    color: var(--text-muted);
    cursor: pointer;
    transition: all .15s;
    background: #fafbfc;
}
.drag-zone:hover, .drag-zone.dragging {
    border-color: var(--primary);
    background: var(--primary-light);
    color: var(--primary);
}
.drag-zone-icon { font-size: 32px; opacity: .5; margin-bottom: 8px; }

/* file list */
.file-list {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}
.file-item {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border);
    font-size: 13px;
}
.file-item:last-child { border-bottom: none; }
.file-item .file-name { flex: 1; word-break: break-all; }
.file-item .file-size { color: var(--text-muted); font-size: 12px; }
.file-item .file-remove {
    color: var(--danger); cursor: pointer;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 14px;
}
.file-item .file-remove:hover { background: #fee2e2; }

.progress {
    height: 8px; background: var(--border-light);
    border-radius: 4px; overflow: hidden;
    margin: 8px 0;
}
.progress-bar {
    height: 100%;
    background: var(--primary);
    transition: width .15s;
}

/* ========== 广告位 ==========
   静态 HTML 里 .ad-slot 是空 <aside>, 默认不显示 (display:none).
   app.js loadAds() 注入 html 后会移除 aria-hidden, 通过 [aria-hidden] 选择器解除隐藏.
   爬虫看到的就是空 aside, 不影响 SEO. */
.ad-slot {
    display: none;
}
.ad-slot:not([aria-hidden]) {
    display: block;
    margin: 14px auto;
    padding: 8px;
    background: #fafafa;
    border: 1px solid #f1f5f9;
    border-radius: 6px;
    text-align: center;
    overflow: hidden;
    min-height: 60px;
}
.ad-slot-top-banner,
.ad-slot-bottom-banner {
    max-width: 970px;
    width: 100%;
}
.ad-slot-tool-top,
.ad-slot-tool-bottom {
    max-width: 970px;
    margin: 14px 0;
}
.ad-slot-sidebar-bottom {
    margin: 12px 4px;
    padding: 6px;
}
.ad-slot-sidebar-bottom:not([aria-hidden]) img {
    max-width: 100%;
    height: auto;
}
/* 卡片网格内插入的广告卡 — 样式跟 .tool-card 对齐, 用户感觉不突兀 */
.tool-card.ad-card {
    background: #fafafa;
    border: 1px dashed #cbd5e1;
    color: #64748b;
    cursor: default;
}
.tool-card.ad-card::before {
    content: '推广';
    position: absolute;
    top: 6px;
    right: 8px;
    font-size: 10px;
    color: #94a3b8;
    background: #fff;
    padding: 1px 4px;
    border-radius: 3px;
}