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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.login-card {
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    padding: 40px;
    width: 100%;
    max-width: 380px;
}

h1 {
    text-align: center;
    color: #1a1a2e;
    margin-bottom: 30px;
    font-size: 24px;
    font-weight: 600;
}

.form-group {
    margin-bottom: 24px;
}

.captcha-box {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
    padding: 14px 16px;
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 8px;
}

.captcha-question {
    flex: 1;
    font-size: 18px;
    font-weight: 600;
    color: #495057;
    letter-spacing: 1px;
}

.refresh-btn {
    width: 32px;
    height: 32px;
    padding: 0;
    border: none;
    border-radius: 6px;
    background: #e9ecef;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    transition: background 0.2s;
}

.refresh-btn:hover {
    background: #dee2e6;
}

input[type="text"] {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

input[type="text"]:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

button[type="submit"] {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

button[type="submit"]:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.35);
}

button[type="submit"]:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.error {
    color: #dc3545;
    text-align: center;
    margin-top: 16px;
    font-size: 14px;
    display: none;
}