:root {
    --primary-color: #2ecc71;
    --error-color: #e74c3c;
    --text-color: #2d3436;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
}

body {
    background-color: #f5f6fa;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.login-container {
    width: 100%;
    max-width: 400px;
    padding: 20px;
}

.login-box {
    background: white;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
}

h1 {
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 10px;
}

h2 {
    color: var(--text-color);
    text-align: center;
    margin-bottom: 30px;
    font-size: 1.5em;
}

.input-group {
    position: relative;
    margin-bottom: 30px;
}

input {
    width: 100%;
    padding: 10px;
    border: none;
    border-bottom: 2px solid #ddd;
    font-size: 16px;
    outline: none;
    transition: all 0.3s ease;
}

label {
    position: absolute;
    left: 0;
    top: 10px;
    font-size: 16px;
    color: #999;
    pointer-events: none;
    transition: all 0.3s ease;
}

input:focus + label,
input:valid + label {
    top: -20px;
    font-size: 14px;
    color: var(--primary-color);
}

input:focus {
    border-bottom-color: var(--primary-color);
}

button {
    width: 100%;
    padding: 12px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #27ae60;
}

.error-message {
    color: var(--error-color);
    text-align: center;
    margin-top: 20px;
    font-size: 14px;
}

@media (max-width: 480px) {
    .login-container {
        padding: 10px;
    }
    
    .login-box {
        padding: 20px;
    }
}