/* Your CSS with improvements */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400..900;1,400..900&family=Poppins:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&display=swap');

:root {
    --primary-color: rgb(2, 2, 52);
    --secondary-color: rgb(245, 162, 8);
    --text-dark: #0f172a;
    --primary: #0077b6;
    --text-light: whitesmoke;
    --extra-light: rgb(3, 5, 67);
    --box-shadow: 0 .5rem 1rem rgba(0,0,0,0.1);
    --white: #ffffff;
    --max-width:1200px;
    --btn-color: rgb(26, 86, 251);
    --header-font: "Playfair Display", serif;  
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    background: var(--white);
    box-shadow: var(--box-shadow);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.5rem;
}

.header .logo {
    font-size: 2rem;
    font-weight: bolder;
    color: var(--secondary-color);
    text-decoration: none;
}

.header .logo i {
    color: var(--extra-light);
    padding-right: .8rem;
    margin-left: 2.5rem;
}

.form .details span {
    color: var(--secondary-color);
}

.back-btn {
    text-decoration: none;
    color: var(--btn-color);
    font-size: 1.2rem;
    margin-right: auto;
    margin-left: 1rem;
}

.btn {
    text-decoration: none;
    padding: .5rem 2rem;
    background: var(--secondary-color);
    color: var(--white);
    border: none;
    border-radius: 0.5rem;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: 0 1px 2px var(--box-shadow);
    transition: background-color 0.3s ease;
    margin-left: 38.5rem;
    margin-top: 2rem;
}

.btn:hover {
    background-color: var(--btn-color);
}

.container {
    position: relative;
    max-width: 900px;
    margin-top: 8rem;
    margin-bottom: 2rem;
    border-radius: .5rem;
    padding: 30px;
    background-color: var(--white);
    box-shadow: 0 5px 10px rgba(0,0,0,0.6);
}

.container h1 {
    font-size: 2rem;
    font-weight: 600;
    color: var(--text-dark);
    text-align: center;
}

.container form {
    margin-top: 16px;
    min-height: 490px;
    background-color: var(--white);
}

.container form .title {
    font-size: 1.2rem;
    font-weight: 500;
    margin: 6px 0;
    margin-left: .6rem;
}

.container form .fields {
    display: flex;
    flex-wrap: wrap;
}

.container form .input-field,
.container form .input-address,
.container form .input-zip,
.container form .input-gender,
.container form .input-img,
.container form .input-payment,
.container form .input-rooms {
    width: calc(100% / 3 - 20px);
    margin: 10px;
    display: flex;
    flex-direction: column;
}

.input-field label,
.input-address label,
.input-zip label,
.input-gender label,
.input-img label,
.input-payment label,
.input-rooms label {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-dark);
    margin-bottom: 6px;
}

.input-field input,
.input-address input,
.input-zip input,
.input-gender select,
.input-img input,
.input-payment select,
.input-rooms select {
    font-size: 1rem;
    font-weight: 400;
    color: var(--text-dark);
    border-radius: .5rem;
    border: 1px solid #aaa;
    padding: 0 15px;
    height: 42px;
    outline: none;
    transition: border-color 0.3s, box-shadow 0.3s;
    box-sizing: border-box;
}

.input-field input:hover,
.input-address input:hover,
.input-zip input:hover,
.input-gender select:hover,
.input-img input:hover,
.input-payment select:hover,
.input-rooms select:hover {
    border-color: #000;
}

.input-field input:focus,
.input-address input:focus,
.input-zip input:focus,
.input-gender select:focus,
.input-img input:focus,
.input-payment select:focus,
.input-rooms select:focus {
    border-color: #000;
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.2);
}


@media only screen and (max-width: 768px) {
    .container {
        margin-left: 0;
        margin-right: 0;
        flex-direction: column; 
        align-items: center;

    }

    .container h1 {
        font-size: 1.5rem; 
        margin-bottom: 2rem; 
    }

    .form .details.personal {
        margin-bottom: 2rem; 
    }

    .btn {
        margin-left: 3.5rem; 
        margin-right: auto; 
        margin-top: 2rem; 
        font-size: 1.2rem; 
    }

    .back-btn {
        margin-left: auto; 
        margin-right: auto; 
        font-size: 1rem; 
    }


    .fields {
        width: 300%; 
        display: flex; 
        flex-direction: column; 
    }

    .input-field,
    .input-address,
    .input-gender,
    .input-rooms {
        width: calc(150% - 20px); 
        margin: 10px; 
    }
}