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

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

.login-container {
    width: 100%;
    max-width: 420px;
    padding: 20px;
}

.login-box {
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 40px;
}

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

.login-header h1 {
    color: #333;
    font-size: 24px;
    font-weight: 600;
}

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

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

.form-group input[type="text"],
.form-group input[type="password"] {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e1e5eb;
    border-radius: 8px;
    font-size: 15px;
    transition: border-color 0.2s, box-shadow 0.2s;
    outline: none;
}

.form-group input[type="text"]:focus,
.form-group input[type="password"]:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.form-group input::placeholder {
    color: #aaa;
}

.captcha-row {
    display: flex;
    gap: 10px;
    align-items: center;
}

.captcha-row input {
    flex: 1;
    min-width: 0;
}

.captcha-row img {
    width: 130px;
    height: 48px;
    border-radius: 8px;
    border: 2px solid #e1e5eb;
    cursor: pointer;
    flex-shrink: 0;
    transition: border-color 0.2s, opacity 0.2s;
}

.captcha-row img:hover {
    border-color: #667eea;
    opacity: 0.85;
}

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

.form-group button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

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

.form-group button:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
}

.error-msg {
    color: #e74c3c;
    font-size: 13px;
    margin-top: 6px;
    min-height: 18px;
}