* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', sans-serif;

}

body {
    background: linear-gradient(to right, #cdfcff, #135eff);

}

.navbar {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 15px 40px;
    background: url('mountain-bg.jpg') center/cover no-repeat;
    position: relative;
    width: 80%;
}

.logo img {
    height: 80px;
    padding-left: 60px;
}

.menu {
    display: flex;
    position: relative;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    padding: 20px 20px;

}

.menu a {
    position: relative;
    padding: 12px 20px;
    margin: 0 5px;
    color: #002147;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.menu a:hover {
    color: #f58220;
}

.indicator {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: #f58220;
    border-radius: 2px;
    transition: all 0.3s ease;
}

.container {
    max-width: 900px;
    margin: 60px auto;
    background: rgba(255, 255, 255, 0.9);
    padding: 40px 50px;
    border-radius: 15px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    animation: slideUp 0.8s ease;
}

@keyframes slideUp {
    from {
        transform: translateY(40px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

h1 {
    text-align: center;
    color: #003366;
    margin-bottom: 20px;
    font-size: 2.2em;
}

p {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
}

/* ===== Form mượn sách ===== */
form {

    display: flex;
    flex-direction: column;
    gap: 20px;
}




label {
    font-weight: 600;
    color: #003366;
}

input,
select,
textarea {
    padding: 12px 14px;
    border: 1.5px solid #aac4ff;
    border-radius: 8px;
    font-size: 15px;
    outline: none;
    transition: all 0.3s ease;
}

input:focus,
select:focus,
textarea:focus {
    border-color: #4e8fff;
    box-shadow: 0 0 6px rgba(78, 143, 255, 0.5);
}

textarea {
    resize: none;
}

button {
    padding: 12px 0;
    background: linear-gradient(to right,#ff5100, #a7fd1c);
    color: white;
    font-weight: bold;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(78, 143, 255, 0.4);
}

/* ===== Footer ===== */
footer {
    text-align: center;
    padding: 20px 0;
    color: #003366;
    font-size: 14px;
    opacity: 0.8;
}