:root {
    --bg: #f5f7fb;
    --card: #fff;
    --text: #111827;
    --muted: #6b7280;
    --primary: #2563eb;
    --success: #16a34a;
    --danger: #ef4444;
    --border: #e5e7eb;
    --radius: 10px;
}
* {
    box-sizing: border-box;
}
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 24px 16px;
}
.header-bar {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
}
.back-btn {
    padding: 8px 14px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    text-decoration: none;
    font-size: 14px;
}
.back-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}
h1 {
    font-size: 22px;
    font-weight: 700;
    margin: 0;
}
.page-header {
    text-align: center;
    margin-bottom: 40px;
}
.page-header .desc {
    color: var(--muted);
    font-size: 15px;
}
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}
.tool-card {
    background: #fff;
    border-radius: 14px;
    padding: 32px 20px;
    text-align: center;
    text-decoration: none;
    color: var(--text);
    border: 1px solid var(--border);
    transition: transform 0.2s, box-shadow 0.2s;
}
.tool-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.06);
    border-color: var(--primary);
}
.tool-card .icon {
    font-size: 36px;
    margin-bottom: 12px;
}
.tool-card h3 {
    font-size: 18px;
    margin-bottom: 6px;
}
.tool-card p {
    font-size: 14px;
    color: var(--muted);
}