body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    font-family: 'Pretendard', sans-serif;
    color: #fff;
    overflow: hidden;
}

#particles-js {
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: #000;
    background-image: url('');
    background-size: cover;
    background-position: 50% 50%;
    background-repeat: no-repeat;
    z-index: -1;
}

.login-container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
    text-align: center;
    position: relative;
    z-index: 1;
}

h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    letter-spacing: 2px;
    text-shadow: 0 0 10px #00aaff, 0 0 20px #00aaff, 0 0 30px #00aaff;
}

#login-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    width: 320px;
}

input[type="password"] {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid #00aaff;
    border-radius: 50px;
    padding: 1rem;
    color: #fff;
    font-size: 1.1rem;
    text-align: center;
    outline: none;
    transition: box-shadow 0.3s ease;
}

input[type="password"]::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

input[type="password"]:focus {
    box-shadow: 0 0 15px #00aaff;
}

button[type="submit"] {
    background: transparent;
    border: 2px solid #00aaff;
    color: #00aaff;
    padding: 1rem;
    border-radius: 50px;
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    letter-spacing: 1px;
    transition: background 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
}

button[type="submit"]:hover {
    background: #00aaff;
    color: #000;
    box-shadow: 0 0 20px #00aaff;
}

#message {
    margin-top: 1rem;
    color: #ff4d4d;
    text-shadow: 0 0 5px #ff4d4d;
    font-weight: bold;
    opacity: 0;
    transition: opacity 0.3s ease;
}

#message:not(.hidden) {
    opacity: 1;
}

.hidden {
    display: none;
}