* {
            box-sizing: border-box;
        }

        body {
            margin: 0;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
                         Roboto, Helvetica, Arial, sans-serif;
            color: #24292f;
            background: #f6f8fa;
            line-height: 1.6;
        }

        header {
            background: #ffffff;
            border-bottom: 1px solid #d8dee4;
        }

        nav {
            max-width: 900px;
            margin: auto;
            padding: 18px 24px;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .brand {
            font-size: 20px;
            font-weight: 600;
        }

        nav a {
            color: #57606a;
            text-decoration: none;
            margin-left: 22px;
        }

        nav a:hover {
            color: #0969da;
        }

        main {
            max-width: 900px;
            margin: 55px auto;
            padding: 0 24px;
        }

        .intro {
            margin-bottom: 45px;
        }

        h1 {
            font-size: 36px;
            margin-bottom: 10px;
        }

        .intro p {
            color: #57606a;
            font-size: 18px;
        }

        .posts {
            display: grid;
            gap: 16px;
        }

        article {
            background: white;
            padding: 22px 24px;
            border: 1px solid #d8dee4;
            border-radius: 8px;
        }

        article h2 {
            font-size: 20px;
            margin: 0 0 6px;
        }

        article p {
            margin: 0;
            color: #57606a;
        }

        .date {
            display: block;
            margin-top: 12px;
            font-size: 13px;
            color: #8c959f;
        }

        footer {
            max-width: 900px;
            margin: 70px auto 30px;
            padding: 20px 24px;
            border-top: 1px solid #d8dee4;
            color: #8c959f;
            font-size: 14px;
        }