body {
    font-family: 'Roboto', sans-serif;
    background-size: cover;
    background-attachment: fixed;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-image: url('/img/rink.jpg');
    color: white;
}

#difficulty-selection a {
    padding: 5px;
    text-decoration: none;
    color: white;
}

#difficulty-selection a.active {
    font-weight: bold;
    text-decoration: underline;
}

.container {
    background-color: rgba(0, 0, 0, 0.85);
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    color: white;
    max-width: 90%;
    box-shadow: 0px 0px 20px rgba(0, 0, 0, 0.2);
}

.header {
    margin-bottom: 20px;
    border: 1px solid white;
    border-width: 1px 0;
    padding: 5px 0;
}

.header h1 {
    font-size: 1.66em;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.header h1 img {
    margin-inline-end: 10px;
}

#image-container {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
}

#image-container img {
    max-width: 100%;
    height: auto;
    max-height: 280px;
    border: none;
    margin: 0 5px;
    border-radius: 8px;
    box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.2);
    display: block;
    margin: 0 auto;
}

#image-container img.double {
    max-width: 48%;
}

#image-container div {
    display: flex;
    justify-content: center;
    margin-top: 10px;
    clear: both;
}

.hidden,
#score.hidden {
    display: none;
}

label {
    display: block;
    margin-block-end: 10px;
    text-align: left;
    padding-left: 20px;
}

input[type="radio"] {
    margin-right: 10px;
}

label:nth-of-type(odd) {
    background-color: rgba(0, 0, 0, 0.5);
    padding: 5px 5px 5px 20px;
    border-radius: 5px;
}

#correct-answers,
.correct-text {
    color: #4CAF50;
}

#incorrect-answers,
.incorrect-text {
    color: #F44336;
    pointer-events: none;
    letter-spacing: 0;
}

#correct-answers,
#incorrect-answers {
    padding: 10px;
    font-weight: bold;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

#correct-answers.blink {
    animation: blink-green 1s ease-in-out 3;
}

#incorrect-answers.blink {
    animation: blink-red 1s ease-in-out 3;
}

@keyframes blink-green {
    0% {
        background-color: lightgreen;
    }

    50% {
        background-color: darkgreen;
    }

    100% {
        background-color: lightgreen;
    }
}

@keyframes blink-red {
    0% {
        background-color: lightcoral;
    }

    50% {
        background-color: darkred;
    }

    100% {
        background-color: lightcoral;
    }
}

#score {
    font-size: 1.2em;
    margin-top: 20px;
    padding: 10px;
    border-radius: 10px;
    display: inline-block;
    letter-spacing: 1px;
    background-color: rgba(0, 0, 0, 0.5);
}

#score span {
    padding: 0 10px;
    font-weight: bold;
}

#dropdown-container {
    margin-top: 20px;
    text-align: center;
}

#rule-dropdown {
    background-color: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 10px;
    border: 1px solid #bdc3c7;
    border-radius: 8px;
    font-size: 16px;
    margin-right: 10px;
    margin-bottom: 20px;
    width: 100%;
    box-sizing: border-box;
    appearance: none;
    background-image: url("data:image/svg+xml;utf8,<svg fill='white' height='24' viewBox='0 0 24 24' width='24' xmlns='http://www.w3.org/2000/svg'><path d='M7 10l5 5 5-5z'/><path d='M0 0h24v24H0z' fill='none'/></svg>");
    background-repeat: no-repeat;
    background-position: right 10px center;
    background-size: 1.5em;
}

#rule-dropdown:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 5px rgba(52, 152, 219, 0.3);
}

#submit-answer {
    background-color: #3498db;
    color: white;
    padding: 12px 25px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s;
    box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.15);
}

#submit-answer:hover {
    background-color: #2980b9;
    transform: scale(1.05);
    box-shadow: 3px 3px 7px rgba(0, 0, 0, 0.2);
}

#submit-answer:active {
    transform: scale(0.95);
    box-shadow: 1px 1px 3px rgba(0, 0, 0, 0.1);
}

#submit-answer:disabled {
    background-color: #bdc3c7;
    cursor: default;
    opacity: 0.6;
    box-shadow: none;
    transform: none;
}

@media (max-width: 767px) {
    body {
        display: block;
        padding-top: 10px;
    }

    .container {
        max-width: 90%;
        margin: 0 auto;
    }

    #rule-dropdown {
        width: 95%;
        margin: 0 auto;
        margin-bottom: 10px;
    }
}