* {
    margin: 0;
    padding: 0;
}
body {
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
    font-size: 2rem;
    color:#0a0e38;
    background-color: #f7f4eb;
    margin: 0 40px;
}

header {
    padding: 0 35px;
    padding-top: 20px;
}
.header-container {
    display: flex;
    justify-content: space-between;
}
.logo-link {
    display: flex;
    gap: 15px;
    text-decoration: none;
    color: #0a0e38;
    transition: color 0.3s ease;
}
.logo-link:hover {
    color: #ff822d;
}
.logo {
    height: 60px;
    width: 60px;
}
.info {
    display: flex;
    flex-direction: column;
}
.name {
    font-size: 2.3rem;
    font-weight: 800;
    line-height: 1.1;
}
.slogan {
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.2;
}
a {
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}
a:hover {
    color: #ff822d;
}
header nav {
    display: flex;
    align-items: center;
}
.menu {
    display: flex;
    gap: 32px;
    list-style: none;
}
.menu a {
    font-size: 1.2rem;
    color: #0d1469;
    padding: 6px 0;
    transition: color 0.3s;
}
.menu a:hover {
    color: #ff822d;
}

main {
    margin: 20px;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
    align-items: center;
}
.back-photo {
    background-image: url(./photo/background.jpg);
    background-size: cover;
    padding: 25% 25% ;
    border-radius: 25px;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    box-sizing: border-box;
}
.back-photo h1 {
    color: #f7f4eb;
    text-shadow: 0 0 5px #0a0e38;
    font-size: 2.6rem;
    margin-bottom: 30px;
}
.btn-main {
    display: inline-block;
    border: #f7f4eb 3px solid;
    background-color:rgb(10, 14, 56, 0.3);
    color: #f7f4eb;
    font-weight: 700;
    font-size: 1.6rem;
    border-radius: 30px;
    padding: 12px 25px;
    text-decoration: none;
    cursor: pointer;
    transition: background 0.3s;
}
.btn-main:hover {
    background-color: #ff822d;
    color: #f7f4eb;
}
.form-fon {
    background-image: url(./photo/airplan.png);
    background-size: 1000px auto;
    background-repeat: no-repeat;
    background-position: left 55% bottom 70%;
    width: 100%;
    box-sizing: border-box;
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 40px;
}
.form-auth {
    background-color:rgb(247, 244, 235, 0.6);
    backdrop-filter: blur(2px);
    box-shadow: 0 0 8px #bfbfbf;;
    padding: 40px 45px;
    border-radius: 30px;
    color: #0a0e38;
    text-align: center;
    width: 40%;
}
.form-auth h2 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 25px;
    color:#0a0e38;
    letter-spacing: 0.5px;
}
.form-auth label {
    display: block;
    text-align: left;
    font-size: 1rem;
    font-weight: 500;
    margin-top: 15px;
    margin-bottom: 4px;
    color: #0a0e38;
}
.form-auth input {
    width: 100%;
    padding: 12px 16px;
    border-radius: 25px;
    border: 2px solid #0a0e38;
    background: rgba(255,255,255,0.15);
    color: #0a0e38;
    font-size: 1.1rem;
    box-sizing: border-box;
    outline: 1px solid transparent;
    transition: 0.2s;
}
.form-auth input:focus {
    border: 2px solid #ff822d;
    outline: 1px solid #ff822d;
}
.form-auth .btn-main {
    width: 100%;
    margin-top: 25px;
    background: #0a0e38;
    border: none;
    color: #f7f4eb;
    font-weight: 700;
    padding: 14px;
    font-size: 1.4rem;
    transition: background 0.5s, color 0.5s;
}
.form-auth .btn-main:hover {
    background: #ff822d;
    color: #0a0e38;
}
.signature {
    font-size: 1rem;
    font-weight: 500;
    margin-top: 15px;
    color: #0a0e38;
}

footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
    color: #f7f4eb;
    background-color: #0a0e38;
    border-radius: 25px 25px 0 0;
    margin: 40px 20px 0 20px;
    padding: 20px 50px;
    font-size: 1.2rem;
}
.footer-left {
    display: flex;
    align-items: baseline;
    gap: 18px;
    flex-wrap: wrap;
    opacity: 0.9;
}
footer span {
    font-size: 2rem;
    font-weight: 600;
    color: #ff822d;
}
.footer-menu {
    display: flex;
    flex-direction: column;
    gap: 10px;
    list-style: none;
    text-align: right;
}
.footer-menu a {
    color: #f7f4eb;
    opacity: 0.9;
    text-decoration: none;
    transition: color 0.3s;
    padding: 2px 0;
}
.footer-menu a:hover {
    color: #f8902f;
}

@media (max-width: 1100px) {
    .form-fon {
        background-size: 700px auto;
    }
    .form-auth {
        width: 60%;
    }
}

@media (max-width: 840px) {
    .form-fon {
        background-size: 450px auto;
    }
    .form-auth {
        width: 100%;
    }
}

@media (max-width: 768px) {
    body {
        margin: 0 20px;
    }
    .menu a {
        font-size: 1.1rem;
    }
    .back-photo h1 {
        font-size: 1.8rem;
    }
    .btn-main {
        font-size: 1.2rem;
        padding: 10px 20px;
    }
    .form-auth {
        margin: 0;
    }
    .form-auth h2 {
        font-size: 1.8rem;
    }
    .form-auth .btn-main {
        font-size: 1.2rem;
    }
    footer {
        margin-top: 20px;
    }
    footer span {
        font-size: 1.8rem;
    }
    footer p {
        font-size: 1.1rem;
    }
    .footer-menu a {
        font-size: 1rem;
    }
}

@media (max-width: 520px) {
    body {
        margin: 0 10px;
    }
    .header-container {
        flex-direction: column;
        align-items: center; 
        gap: 12px;
    }
    header nav {
        width: 100%;
        display: flex;
        justify-content: center;
    }

    .menu {
        flex-direction: row;
        justify-content: center; 
        gap: 16px; 
        flex-wrap: wrap; 
    }
    .menu a {
        font-size: 0.9rem;
        white-space: nowrap; 
    }
    .name {
        font-size: 1.6rem;
    }
    .slogan {
        font-size: 0.85rem;
    }
    .logo {
        height: 45px;
        width: 45px;
    }
    .menu a {
        font-size: 0.9rem;
    }
    .back-photo h1 {
        font-size: 1.3rem;
    }
    .btn-main {
        font-size: 0.95rem;
        padding: 8px 16px;
        border-width: 2px;
    }
    .form-fon {
        background-size: 300px auto;
    }
    .form-auth input {
        padding: 8px 16px;
        font-size: 0.9rem;
        margin-top: 0;
    }
    .form-auth h2 {
        font-size: 1.3rem;
    }
    .form-auth .btn-main {
        font-size: 0.95rem;
        padding: 8px 16px;
        margin-top: 20px;
    }
    footer {
        margin-top: 10px;
    }
    footer span {
        font-size: 1.6rem;
    }
    footer p {
        font-size: 0.95rem;
    }
    .footer-menu {
        font-size: 0.95rem;
        text-align: left;
    }
}