:root {
    --primary-color: #256EBE;
    --secondary-color: #3d8df5;
    --accent-color: #2c3e50;
    --light-color: #f8f9fa;
    --dark-color: #333;
    --error-color: #e74c3c;
    --success-color: #2ecc71;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f4f4f4, #4c96dd);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    line-height: 1.6;
    color: #333;
}

.login-container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 10px;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 450px;
    overflow: hidden;
    transform: translateY(0);
    transition: var(--transition);
    animation: fadeIn 0.8s ease;
}

.login-header {
    background: var(--primary-color);
    color: white;
    padding: 25px 30px;
    text-align: center;
    position: relative;
}

.login-header h2 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 5px;
}

.login-header p {
    opacity: 0.9;
    font-size: 0.95rem;
}

.login-body {
    padding: 30px;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    position: relative;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--accent-color);
}

.input-icon {
    position: absolute;
    left: 12px;
    top: 42px;
    color: var(--primary-color);
    font-size: 18px;
}

.form-control {
    width: 100%;
    padding: 14px 14px 14px 40px;
    border: 2px solid #e1e5eb;
    border-radius: 8px;
    font-size: 16px;
    transition: var(--transition);
}

.form-control:focus {
    border-color: var(--secondary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

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

.captcha-input {
    flex: 1;
    padding: 14px;
    border: 2px solid #e1e5eb;
    border-radius: 8px;
    font-size: 16px;
}

.captcha-img {
    height: 50px;
    border-radius: 6px;
    cursor: pointer;
    transition: transform 0.3s ease;
    border: 1px solid #ddd;
}

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

.btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 14px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 10px;
}

.btn:hover {
    background: #1d5ba0;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.btn:active {
    transform: translateY(0);
}

.error-message {
    background: var(--error-color);
    color: white;
    padding: 12px 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
    animation: shake 0.5s;
}

.login-footer {
    text-align: center;
    padding: 20px 0 10px;
    color: #6c757d;
    font-size: 14px;
}

.login-footer a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: var(--transition);
}

.login-footer a:hover {
    text-decoration: underline;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

@media (max-width: 480px) {
    .login-container {
        border-radius: 8px;
    }

    .login-header {
        padding: 20px;
    }

    .login-body {
        padding: 20px;
    }

    .captcha-container {
        flex-direction: column;
        align-items: stretch;
    }
}