:root {
    --page-max: 960px;
    --space-md: 16px;
    --space-lg: 24px;
    --touch-min: 44px;
    --color-bg: #f5f6f8;
    --color-primary: #1976d2;
    --color-muted: #666;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    padding: var(--space-lg);
    font-family: Arial, Helvetica, sans-serif;
    background: var(--color-bg);
    color: #222;
    min-width: 320px;
}

.app-shell {
    max-width: var(--page-max);
    margin: 0 auto;
}

.page-header {
    display: flex;
    justify-content: space-between;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.page-header-main { flex: 1; min-width: 0; }

h1 {
    margin: 0 0 8px;
    font-size: clamp(1.4rem, 3vw, 2rem);
}

.subtitle {
    margin: 0;
    color: var(--color-muted);
}

.lang-toggle { display: flex; gap: 4px; }

.lang-btn {
    min-height: var(--touch-min);
    padding: 6px 14px;
    font-weight: bold;
    border: 1px solid #bbb;
    border-radius: 4px;
    background: #e0e0e0;
    cursor: pointer;
}

.lang-btn.active {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

.tool-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
}

.tool-card {
    display: block;
    padding: var(--space-lg);
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 10px;
    text-decoration: none;
    color: inherit;
    transition: box-shadow 0.15s, border-color 0.15s;
}

.tool-card:hover {
    border-color: var(--color-primary);
    box-shadow: 0 4px 16px rgba(25, 118, 210, 0.12);
}

.tool-name {
    margin: 0 0 8px;
    font-size: 1.15rem;
    color: #0d47a1;
}

.tool-desc {
    margin: 0 0 10px;
    color: var(--color-muted);
    line-height: 1.45;
}

.tool-port {
    font-size: 0.85rem;
    color: #888;
    font-family: Consolas, monospace;
}

@media (min-width: 640px) {
    .tool-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (min-width: 1024px) {
    .tool-grid {
        grid-template-columns: 1fr 1fr 1fr;
    }
}