body, html {
    height: 100%;
    margin: 0;
    font-family: 'Segoe UI', Arial, sans-serif;
    background: #f5f6fa;
}
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}
form {
    background: #fff;
    padding: 2em 2.5em;
    border-radius: 16px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.08);
    width: 100%;
    max-width: 350px;
    display: flex;
    flex-direction: column;
    gap: 1em;
}
h2 {
    margin: 0 0 0.5em 0;
    text-align: center;
    color: #00b894;
}
input[type="text"], input[type="password"] {
    padding: 0.8em;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1em;
    outline: none;
    transition: border 0.2s;
}
input[type="text"]:focus, input[type="password"]:focus {
    border: 1.5px solid #00b894;
}
button {
    padding: 0.8em;
    background: #00b894;
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 1.1em;
    cursor: pointer;
    transition: background 0.2s;
}
button:hover {
    background: #098c6c;
}
.error-msg {
    background: #ffe0e0;
    color: #d63031;
    padding: 0.5em 1em;
    border-radius: 6px;
    margin-bottom: 0.5em;
    text-align: center;
    font-size: 0.95em;
}
@media (max-width: 500px) {
    form { padding: 1.2em 0.5em; }
}