body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: rgba(28, 108, 178, 0.9);
    color: white;
    padding: 20px;
    width: 100%;
    position: fixed;
    top: 0;
    z-index: 1000;
}

.header-content {
    display: flex;
    align-items: center;
    width: 100%;
    justify-content: space-between;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    margin-left: 20px;
}

.nav-buttons {
    display: flex;
    gap: 20px;
}

.nav-buttons a {
    color: white;
    text-decoration: none;
    font-size: 16px;
    padding: 10px;
    border-radius: 5px;
}

.nav-buttons a:hover {
    background-color: #155a8c;
}

.user-menu {
    position: relative;
    display: flex;
    align-items: center;
    margin-right: 20px;
}

.user-menu span {
    margin-right: 10px;
}

.dropdown {
    position: relative;
    display: inline-block;
}

.dropbtn {
    background-color: rgba(28, 108, 178, 0.9);
    color: white;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
    right: 0;
}

.dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}

.dropdown-content a:hover {
    background-color: #f1f1f1;
}

.dropdown:hover .dropdown-content {
    display: block;
}

main {
    flex: 1;
    width: 80%;
    margin: 20px auto;
    padding-top: 80px; /* 给主内容增加顶部填充，以避免被固定导航栏遮挡 */
}

h2 {
    text-align: center;
    color: #1c6cb2;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

table, th, td {
    border: 1px solid #ccc;
}

th, td {
    padding: 10px;
    text-align: center;
}

th {
    background-color: #f2f2f2;
}

.flight-row {
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-radius 0.3s ease;
}

.flight-row:hover {
    transform: scale(1.02);
    box-shadow: 0 0 10px rgba(28, 108, 178, 0.5);
    border-radius: 10px;
}

.flight-info th, .flight-info td {
    padding: 10px;
    border: 1px solid #ccc;
}

.no-results {
    text-align: center;
    color: red;
    font-size: 18px;
    margin-top: 20px;
}

footer {
    background-color: rgba(28, 108, 178, 0.9);
    color: white;
    text-align: center;
    padding: 10px 0;
    width: 100%;
    position: relative;
    margin-top: auto;
}

.content {
    background-color: rgba(255, 255, 255, 0.8);
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    width: 80%;
    margin: 20px auto;
    position: relative;
}

.form-group {
    margin-bottom: 15px;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
}

.form-group input {
    width: 100%;
    padding: 8px;
    font-size: 16px;
    border: 1px solid #ccc;
    border-radius: 5px;
}

.btn {
    padding: 10px 20px;
    background-color: #1c6cb2;
    color: white;
    border: none;
    border-radius: 5px;
    text-decoration: none;
    display: inline-block;
    cursor: pointer;
}

.btn:hover {
    background-color: #155a8c;
}