body {
    background-color: #0b0b0b;
    color: #ffffff;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.login-container {
    background-color: #141414;
    border: 1px solid #333;
    border-radius: 8px;
    padding: 40px 30px;
    width: 100%;
    max-width: 320px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.5);
}

.logo {
    max-width: 180px;
    margin-bottom: 5px;
}

.tester-label {
    color: #ff9800;
    font-size: 13px;
    font-weight: bold;
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-top: 0;
    margin-bottom: 25px;
}

input {
    width: 100%;
    padding: 14px;
    margin: 10px 0;
    background: #222;
    border: 1px solid #444;
    color: #fff;
    border-radius: 4px;
    box-sizing: border-box;
    font-size: 14px;
}

input:focus {
    outline: none;
    border-color: #d32f2f;
}

.warning-text {
    color: #ff5252;
    font-size: 12px;
    font-weight: 600;
    margin: 15px 0 20px 0;
}

button {
    width: 100%;
    padding: 14px;
    background-color: #d32f2f;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 15px;
    font-weight: bold;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #b71c1c;
}

button:disabled {
    background-color: #555;
    cursor: not-allowed;
}

#error-msg {
    color: #ff5252;
    margin-top: 15px;
    font-size: 13px;
    min-height: 20px;
}