body {
            margin: 0;
            font-family: "Segoe UI", Arial, sans-serif;
            background: #f4f6f8;
            color: #333;
        }

        header {
            background: linear-gradient(135deg, #0b3c5d, #1a73e8);
            color: #fff;
            padding: 50px 20px;
            text-align: center;
        }

        header h1 {
            margin: 0;
            font-size: 34px;
        }

        .container {
            max-width: 1000px;
            margin: -40px auto 0;
            padding: 30px 20px;
        }

        .content-box {
            background: #fff;
            border-radius: 12px;
            padding: 40px;
            box-shadow: 0 10px 30px rgba(0,0,0,.1);
        }

        h2 {
            color: #0b3c5d;
            margin-top: 30px;
            border-left: 5px solid #1a73e8;
            padding-left: 12px;
        }

        h3 {
            margin-top: 25px;
            color: #1a73e8;
        }

        p {
            line-height: 1.8;
            font-size: 15px;
            margin: 12px 0;
        }

        ul {
            margin-left: 20px;
        }

        ul li {
            margin-bottom: 8px;
        }

        footer {
            margin-top: 80px;
            background: #0b3c5d;
            color: #eaf1f7;
            text-align: center;
            padding: 25px 15px;
            font-size: 14px;
        }

        footer a {
            color: #cfe6ff;
            text-decoration: none;
        }

        footer a:hover {
            text-decoration: underline;
        }

        @media(max-width:768px){
            header h1 { font-size: 26px; }
            .content-box { padding: 25px; }
        }
        
.btn-back {
    display: inline-flex;
    align-items: center;
    gap: 8px;

    padding: 10px 18px;
    margin-bottom: 22px;

    background: #f0f6ff;
    color: #1a73e8;
    border: 1px solid #cfe0ff;
    border-radius: 999px;

    font-size: 14px;
    font-weight: 600;
    text-decoration: none;

    transition: all .25s ease;
}

.btn-back:hover {
    background: #1a73e8;
    color: #fff;
    border-color: #1a73e8;
    transform: translateX(-3px);
}

.btn-back:active {
    transform: translateX(0);
}

.btn-back::before {
    content: "←";
    font-weight: 700;
}