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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.login-box {
    max-width: 400px;
    margin: 100px auto;
    background: white;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.login-box h1 {
    text-align: center;
    color: #2c3e50;
    margin-bottom: 10px;
    font-size: 28px;
}

.login-box h2 {
    text-align: center;
    color: #7f8c8d;
    margin-bottom: 30px;
    font-size: 20px;
    font-weight: normal;
}

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

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: #555;
    font-weight: 500;
}

.form-group input[type="text"],
.form-group input[type="password"] {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    transition: border-color 0.3s;
}

.form-group input[type="text"]:focus,
.form-group input[type="password"]:focus {
    outline: none;
    border-color: #3498db;
}

.form-group.checkbox {
    display: flex;
    align-items: center;
}

.form-group.checkbox label {
    margin-bottom: 0;
    margin-left: 5px;
    font-weight: normal;
    cursor: pointer;
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    text-decoration: none;
    transition: background-color 0.3s;
}

.btn-primary {
    background-color: #3498db;
    color: white;
    width: 100%;
    padding: 12px;
    font-weight: 500;
}

.btn-primary:hover {
    background-color: #2980b9;
}

.btn-secondary {
    background-color: #95a5a6;
    color: white;
}

.btn-secondary:hover {
    background-color: #7f8c8d;
}

.error-message {
    background-color: #e74c3c;
    color: white;
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 20px;
    text-align: center;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    border-bottom: 1px solid #ddd;
    margin-bottom: 30px;
}

header h1 {
    color: #2c3e50;
}

header nav {
    display: flex;
    align-items: center;
    gap: 20px;
}

.welcome-message {
    background: white;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    text-align: center;
}

.welcome-message h2 {
    color: #2c3e50;
    margin-bottom: 15px;
}

.welcome-message p {
    color: #7f8c8d;
    font-size: 18px;
}