* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', sans-serif;
}

body {
    height: 100vh;
    background: radial-gradient(circle at top, #1a1a1a, #000);
    display: flex;
    justify-content: center;
    align-items: center;
}

.login-container {
    width: 360px;
    padding: 40px;
    background: rgba(0,0,0,0.75);
    border-radius: 15px;
    box-shadow: 0 0 25px #00ffea;
    text-align: center;
}

.login-container h1 {
    color: #00ffea;
    margin-bottom: 5px;
    letter-spacing: 2px;
}

.tagline {
    color: #aaa;
    margin-bottom: 25px;
}

.input-box {
    position: relative;
    margin: 25px 0;
}

.input-box input {
    width: 100%;
    padding: 10px;
    background: transparent;
    border: none;
    border-bottom: 2px solid #555;
    color: #fff;
    font-size: 16px;
    outline: none;
}

.input-box label {
    position: absolute;
    left: 0;
    top: 50%;
    color: #777;
    transform: translateY(-50%);
    pointer-events: none;
    transition: 0.3s;
}

.input-box input:focus ~ label,
.input-box input:valid ~ label {
    top: -5px;
    color: #00ffea;
    font-size: 12px;
}

button {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 25px;
    background: linear-gradient(90deg, #00ffea, #0066ff);
    color: #000;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

button:hover {
    box-shadow: 0 0 15px #00ffea;
}

#error {
    color: red;
    margin-top: 15px;
    font-size: 14px;
}