* { box-sizing: border-box; }
body {
 margin: 0;
 font-family: Arial, sans-serif;
 background: #f5f7fb;
 color: #1f2937;
}
.container {
 width: min(100% - 32px, 960px);
 margin: 0 auto;
}
.header {
 background: #111827;
 color: white;
 padding: 48px 0;
}
.card {
 background: white;
 padding: 24px;
 margin: 24px 0;
 border-radius: 12px;
 box-shadow: 0 8px 24px rgba(0,0,0,.08);
}