body {
    background-color: #1a237e;
    position: relative;
    min-height: 100vh;
    margin: 0;
    padding: 0;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../img/full_bg_1.png');
    background-position: center center;
    background-repeat: no-repeat;
    background-size: cover;
    opacity: 0.6;
    z-index: -1;
}

/* Navbar styles */
.navbar {
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    background-color: rgba(16, 21, 71, 0.45) !important;
    min-height: 30px !important;
    position: relative;
    z-index: 1000;
}

.navbar .nav-link {
    color: #fff !important;
    padding-top: 0.3rem !important;
    padding-bottom: 0.3rem !important;
}

/* Logo styles */
.navbar-brand.nav-link {
    font-family: 'Roboto', sans-serif;
    font-size: 1.8rem !important;
    padding: 0;
    display: inline-flex;
    align-items: center;
    letter-spacing: 0.05em;
    text-decoration: none;
}

.brand-wrapper {
    display: flex;
    align-items: center;
}

.brand-main {
    display: flex;
    align-items: center;
}

.brand-i {
    color: #ff6600;
    font-style: italic;
    font-weight: 500;
    margin-right: 0.05em;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
}

.brand-conf {
    color: #fff;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    letter-spacing: 0.03em;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
}

.brand-globe {
    color: #3498db;
    font-size: 0.75em;
    margin: 0 0.08em;
    animation: globe-spin 10s linear infinite;
    display: inline-block;
    transform-origin: center 55%;
}

@keyframes globe-spin {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

.brand-subtitle {
    font-size: 0.8rem !important;
    color: rgba(255, 255, 255, 0.85);
    margin-left: 0.8rem;
    padding-left: 0.8rem;
    border-left: 2px solid rgba(255, 255, 255, 0.3);
    font-weight: 300;
    letter-spacing: 0.05em;
    font-family: 'Roboto', sans-serif;
}

/* Button styles */
.btn-group {
    margin-bottom: 1rem;
}

/* Radio button styles */
.btn-check:checked + .btn-outline-primary {
    background-color: #1a237e !important;
    border-color: #1a237e !important;
    color: white !important;
}

.btn-check:focus + .btn-outline-primary {
    box-shadow: 0 0 0 0.2rem rgba(26, 35, 126, 0.25) !important;
}

/* Input styles */
input:focus {
    border-color: #1a237e !important;
    box-shadow: 0 0 0 0.2rem rgba(26, 35, 126, 0.25) !important;
    outline: none !important;
}

/* Copyright section */
.copyright-section {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.8rem;
    margin-top: 1rem;
}

/* Title buttons responsive styles */
@media (max-width: 768px) {
    .btn-group {
        flex-direction: column !important;
        width: 100%;
    }

    .btn-group .btn {
        width: 100%;
        border-radius: 0.25rem !important;
        margin-bottom: 0.25rem;
    }

    .btn-group .btn:not(:last-child) {
        border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    }
}

/* Navbar mobile styles */
@media (max-width: 991px) {
    .navbar-collapse {
        background-color: rgba(16, 21, 71, 0.95);
        padding: 1rem;
        border-radius: 0.5rem;
        margin-top: 0.5rem;
        backdrop-filter: blur(8px);
        -webkit-backdrop-filter: blur(8px);
    }

    .navbar-collapse.show {
        display: block;
    }

    .navbar-nav {
        padding: 0.5rem 0;
    }

    .nav-item {
        padding: 0.25rem 0;
    }
}

/* Main content styles */
main {
    margin-top: -56px; /* 抵消导航栏的高度 */
    padding-top: 56px; /* 添加与导航栏相同的内边距 */
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    position: relative;
    z-index: 1;
}

/* Form container styles */
.form-container {
    animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}