* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
}

body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #333;
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.auth-container {
    max-width: 500px;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    padding: 40px;
    backdrop-filter: blur(10px);
}

.auth-header {
    text-align: center;
    margin-bottom: 30px;
}

.auth-header h1 {
    color: #2c3e50;
    font-size: 2rem;
    margin-bottom: 10px;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.auth-header h1 i {
    color: #667eea;
}

.auth-header p {
    color: #6c757d;
    font-size: 1.1rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    font-weight: 600;
    color: #495057;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.form-control {
    border-radius: 8px;
    padding: 12px 15px;
    border: 1px solid #ced4da;
    transition: all 0.3s;
    width: 100%;
    font-size: 1rem;
}

.form-control:focus {
    border-color: #80bdff;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.captcha-container {
    display: flex;
    gap: 15px;
    align-items: center;
}

.captcha-image {
    height: 45px;
    border-radius: 5px;
    cursor: pointer;
    border: 1px solid #ced4da;
    transition: transform 0.2s;
}

.captcha-image:hover {
    transform: scale(1.05);
}

.form-text {
    font-size: 0.85rem;
    color: #6c757d;
    margin-top: 5px;
    display: block;
}

.btn {
    border-radius: 8px;
    padding: 12px 20px;
    font-weight: 500;
    transition: all 0.3s;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.btn-lg {
    padding: 12px 20px;
    font-size: 1.1rem;
}

.d-grid {
    display: grid;
}

.auth-footer {
    text-align: center;
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #eaeaea;
    color: #6c757d;
    font-size: 0.9rem;
}

.alert {
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 20px;
}

.alert-danger {
    background-color: #f8d7da;
    border-color: #f5c6cb;
    color: #721c24;
}

.alert-success {
    background-color: #d4edda;
    border-color: #c3e6cb;
    color: #155724;
}

.btn-close {
    float: right;
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1;
    color: #000;
    text-shadow: 0 1px 0 #fff;
    opacity: 0.5;
    background: transparent;
    border: 0;
    padding: 0;
    cursor: pointer;
}

.btn-close:hover {
    opacity: 0.75;
}

.fade {
    transition: opacity 0.15s linear;
}

.fade.show {
    opacity: 1;
}

@media (max-width: 576px) {
    .auth-container {
        padding: 30px 20px;
    }
    
    .captcha-container {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .captcha-image {
        margin-top: 10px;
    }
}