body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #ffffff;
    color: #2b2b2b;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}
.login-box {
    background: #f8f9fa;
    border: 1px solid #e0e0e0;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
    text-align: center;
    width: 100%;
    max-width: 360px;
}
h2 { color: #2e7d32; margin-bottom: 25px; }
input {
    width: 90%;
    padding: 12px;
    margin-bottom: 20px;
    background: #ffffff;
    border: 1px solid #ccc;
    color: #2b2b2b;
    border-radius: 6px;
    font-size: 16px;
    text-align: center;
}
button {
    width: 97%;
    padding: 12px;
    background: #4caf50;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.2s;
}
button:hover { opacity: 0.9; }
.hint-box { font-size: 13px; color: #6b7280; margin-top: 20px; line-height: 1.6; }