:root {
    --primary-color: #007bff; --dark-color: #333; --light-color: #f4f4f4;
    --text-color: #555; --white-color: #fff; --gap: 20px;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6; color: var(--text-color); background-color: var(--white-color);
}
.container { max-width: 1100px; margin: 0 auto; padding: 0 var(--gap); }
img { max-width: 100%; height: auto; display: block; }