* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.login-container {
    width: 100%;
    max-width: 420px;
}

.login-form {
    background-color: #fff;
    border-radius: 12px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    padding: 40px;
    text-align: center;
}

.logo {
    margin-bottom: 30px;
}

.logo h1 {
    color: #333;
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 8px;
}

.logo p {
    color: #666;
    font-size: 14px;
}

h2 {
    text-align: center;
    margin-bottom: 30px;
    color: #333;
    font-size: 20px;
    font-weight: 500;
}

.form-group {
    margin-bottom: 20px;
    text-align: left;
}

label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    color: #555;
    font-weight: 500;
}

input {
    width: 100%;
    padding: 12px 16px;
    font-size: 16px;
    border: 2px solid #e1e8ed;
    border-radius: 8px;
    transition: all 0.3s ease;
    background-color: #f8f9fa;
}

input:focus {
    outline: none;
    border-color: #667eea;
    background-color: #fff;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.login-button {
    width: 100%;
    padding: 12px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 10px;
}

.login-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.login-button:active {
    transform: translateY(0);
}

.login-button:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.error-message {
    color: #e74c3c;
    font-size: 14px;
    margin-bottom: 20px;
    padding: 10px;
    background-color: #ffeaea;
    border: 1px solid #ffd6d6;
    border-radius: 6px;
    min-height: 20px;
    display: none;
}

.error-message.show {
    display: block;
}

/* Success message */
.success-message {
    color: #27ae60;
    font-size: 14px;
    margin-bottom: 20px;
    padding: 10px;
    background-color: #eafaf1;
    border: 1px solid #a9dfbf;
    border-radius: 6px;
    min-height: 20px;
    display: none;
}

.success-message.show {
    display: block;
}

/* Form description */
.form-description {
    color: #666;
    font-size: 14px;
    margin-bottom: 20px;
    text-align: center;
    line-height: 1.5;
}

/* Form footer with links */
.form-footer {
    margin-top: 20px;
    text-align: center;
}

.forgot-password-link,
.back-link {
    color: #667eea;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s ease;
}

.forgot-password-link:hover,
.back-link:hover {
    color: #764ba2;
    text-decoration: underline;
}

/* Secondary button */
.secondary-button {
    width: 100%;
    padding: 12px;
    background: #f8f9fa;
    color: #666;
    border: 2px solid #e1e8ed;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 10px;
}

.secondary-button:hover {
    background: #e9ecef;
    border-color: #d1d8de;
}

/* Modal styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal-content {
    background-color: #fff;
    border-radius: 12px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
    padding: 30px;
    width: 90%;
    max-width: 400px;
    text-align: center;
}

.modal-content h3 {
    color: #333;
    font-size: 20px;
    font-weight: 500;
    margin-bottom: 15px;
}

.modal-content p {
    color: #666;
    font-size: 14px;
    margin-bottom: 20px;
    line-height: 1.5;
}

.modal-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.modal-buttons .login-button,
.modal-buttons .secondary-button {
    margin-top: 0;
}

/* Loading state */
.loading-state {
    text-align: center;
    padding: 20px;
}

.loading-state p {
    color: #666;
    font-size: 16px;
}

/* Invalid state */
.invalid-state {
    text-align: center;
}

/* Field feedback */
.field-feedback {
    display: block;
    font-size: 12px;
    margin-top: 4px;
    min-height: 16px;
}

.field-feedback.error {
    color: #e74c3c;
}

.field-feedback.success {
    color: #27ae60;
}

/* Optional label */
.optional {
    color: #999;
    font-weight: normal;
}

/* Password strength indicator */
.password-strength {
    margin-top: 8px;
}

.strength-bar {
    height: 4px;
    background: #e1e8ed;
    border-radius: 2px;
    overflow: hidden;
    margin-bottom: 4px;
}

.strength-fill {
    height: 100%;
    transition: width 0.3s ease, background 0.3s ease;
}

.strength-text {
    font-size: 12px;
}

/* Divider */
.divider {
    display: flex;
    align-items: center;
    margin: 20px 0;
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: #e1e8ed;
}

.divider span {
    padding: 0 15px;
    color: #999;
    font-size: 14px;
}

/* Google Sign-in Button */
.google-signin {
    margin-top: 10px;
}

.google-button {
    width: 100%;
    padding: 12px;
    background: #fff;
    color: #333;
    border: 2px solid #e1e8ed;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.google-button:hover {
    background: #f8f9fa;
    border-color: #d1d8de;
}

.google-icon {
    flex-shrink: 0;
}

/* reCAPTCHA container */
.recaptcha-container {
    margin: 15px 0;
    display: flex;
    justify-content: center;
}

/* Verification icon */
.verification-icon {
    margin: 20px 0;
    text-align: center;
}

/* 响应式设计 */
@media (max-width: 480px) {
    .login-form {
        padding: 30px 20px;
    }

    .logo h1 {
        font-size: 20px;
    }

    h2 {
        font-size: 18px;
    }

    .modal-content {
        padding: 20px;
    }
}