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

body {
    font-family: Arial, sans-serif;
    background: #f5f7fb;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    padding: 20px;
}

.login-box {
    max-width: 420px;
    margin: auto;
    background: #ffffff;
    padding: 35px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

h1 {
    text-align: center;
    margin-bottom: 15px;
    font-size: 28px;
}

.notice {
    text-align: center;
    color: #666;
    font-size: 13px;
    margin-bottom: 20px;
}

input {
    width: 100%;
    padding: 14px;
    margin-bottom: 15px;
    border: 1px solid #dcdcdc;
    border-radius: 6px;
    font-size: 15px;
}

button {
    width: 100%;
    padding: 14px;
    border: none;
    border-radius: 6px;
    background: #1f6fff;
    color: white;
    font-size: 16px;
    cursor: pointer;
}

button:hover {
    opacity: 0.9;
}

.hidden {
    display: none;
}

#loading {
    text-align: center;
    font-size: 18px;
    color: #1f6fff;
    padding: 20px 0;
}

#errorMessage {
    margin-top: 15px;
    padding: 18px;
    border-radius: 8px;
    background: #fff4f4;
    border: 1px solid #ffbdbd;
    color: #c62828;
    text-align: center;
    line-height: 1.7;
}