body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background: linear-gradient(to right, #4e54c8, #8f94fb);
    color: #333;
}

.container {
    text-align: center;
    background-color: #fff;
    padding: 25px 20px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    width: 100%;
    max-width: 420px;
    animation: fadeIn 1s ease-in-out;
}

@keyframes fadeIn {
    0% { opacity: 0; transform: scale(0.95); }
    100% { opacity: 1; transform: scale(1); }
}

h1 {
    margin-bottom: 15px;
    font-size: 1.8em;
    color: #4e54c8;
    position: relative;
    display: inline-block;
}

h1::after {
    content: '';
    width: 50px;
    height: 3px;
    background-color: #4e54c8;
    display: block;
    margin: 8px auto 0;
    border-radius: 3px;
}

#scanner {
    margin: 20px 0;
    border: 2px dashed #8f94fb;
    border-radius: 12px;
    overflow: hidden;
    display: none;
}

video {
    width: 100%;
    height: auto;
}

iframe {
    width: 100%;
    height: 500px;
    margin-top: 20px;
    border: 2px solid #ddd;
    border-radius: 8px;
    display: none;
}

select {
    margin-bottom: 10px;
    padding: 8px 12px;
    width: 100%;
    font-size: 1em;
    border: 1px solid #ddd;
    border-radius: 8px;
    background-color: #f9f9f9;
    color: #555;
    transition: all 0.3s ease;
}

select:focus {
    border-color: #8f94fb;
    outline: none;
    box-shadow: 0 0 8px rgba(143, 148, 251, 0.5);
}

#startButton {
    background-color: #4e54c8;
    color: #fff;
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1em;
    transition: background-color 0.3s ease, transform 0.2s;
}

#startButton:hover {
    background-color: #8f94fb;
    transform: scale(1.05);
}

#startButton:focus {
    outline: none;
    box-shadow: 0 0 8px rgba(78, 84, 200, 0.5);
}