/* Define color variables for light mode (default) */
:root {
    --bg-color: #f4f4f4;
    --text-color: #333;
    --heading-color: #333;
    --secondary-text-color: #555;
    --container-bg-color: #ffffff;
    --container-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    --button-bg-color: #e9e9e9;
    --button-hover-bg-color: #dcdcdc;
    --button-active-bg-color: #c9c9c9;
    --button-border-color: #ccc;
    --button-text-color: #333;
    --play-button-bg-color: #1a7431; /* MODIFIED for contrast */
    --play-button-hover-bg-color: #155d27; /* MODIFIED for contrast */
    --play-button-disabled-bg-color: #cccccc;
    --play-button-text-color: #ffffff;
    --slider-value-color: #0056b3; /* MODIFIED for contrast */
    --input-bg-color: #ffffff;
    --input-border-color: #ccc;
    --input-text-color: #333;
}

/* Define color variables for dark mode using system preference */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #1a1a1a;
        --text-color: #e0e0e0;
        --heading-color: #ffffff;
        --secondary-text-color: #aaaaaa;
        --container-bg-color: #2c2c2c;
        --container-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
        --button-bg-color: #4a4a4a;
        --button-hover-bg-color: #5a5a5a;
        --button-active-bg-color: #6a6a6a;
        --button-border-color: #555;
        --button-text-color: #e0e0e0;
        --play-button-bg-color: #2a9134; /* MODIFIED for contrast */
        --play-button-hover-bg-color: #2a7e2f; /* MODIFIED for contrast */
        --play-button-disabled-bg-color: #555555;
        --slider-value-color: #61baff; /* MODIFIED for contrast */
        --input-bg-color: #3a3a3a;
        --input-border-color: #555;
        --input-text-color: #e0e0e0;
    }
}


/* Apply variables to elements */
body {
    font-family: sans-serif;
    text-align: center;
    background-color: var(--bg-color);
    color: var(--text-color);
    padding: 20px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.header-container {
    display: flex;
    justify-content: center;
    align-items: center;
    max-width: 900px;
    margin: 0 auto 10px auto;
}

h1 {
    color: var(--heading-color);
    margin: 0;
}

h2 {
    margin-top: 30px;
    color: var(--secondary-text-color);
}

p {
    color: var(--text-color);
}

em {
    color: var(--secondary-text-color);
}

.intro {
    max-width: 600px;
    margin: 20px auto 30px auto;
    font-size: 1.1em;
    line-height: 1.5;
    color: var(--text-color);
}


/* Settings Styles */
.settings-container,
.text-input-container,
.translation-container,
.manual-input-container,
.button-container,
.alphabet-list-container {
    background-color: var(--container-bg-color);
    padding: 20px 25px;
    border-radius: 8px;
    box-shadow: var(--container-shadow);
    max-width: 600px;
    margin: 30px auto;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.button-container {
    max-width: 800px;
}

.settings-container h2,
.text-input-container h2,
.translation-container h2,
.manual-input-container h2,
.button-container h2,
.alphabet-list-container h2 {
    text-align: center;
    margin-top: 0;
    margin-bottom: 20px;
    color: var(--secondary-text-color);
}

.setting {
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.setting:last-child {
    margin-bottom: 0;
}

.setting label {
    font-weight: bold;
    color: var(--text-color);
}

.setting label[for="speed-slider"],
.setting label[for="frequency-slider"] {
    min-width: 100px;
}


.setting input[type="range"] {
    flex-grow: 1;
    cursor: pointer;
}

.setting span {
    min-width: 70px;
    text-align: right;
    font-family: monospace;
    color: var(--slider-value-color);
}

/* Text Input Styles */
#text-input {
    width: 95%;
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid var(--input-border-color);
    border-radius: 4px;
    font-size: 1em;
    font-family: inherit;
    box-sizing: border-box;
    display: block;
    margin-left: auto;
    margin-right: auto;
    background-color: var(--input-bg-color);
    color: var(--input-text-color);
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

#morse-output {
    width: 95%;
    padding: 10px;
    border: 1px solid var(--input-border-color);
    border-radius: 4px;
    font-size: 1.1em;
    font-family: monospace;
    box-sizing: border-box;
    display: block;
    margin-left: auto;
    margin-right: auto;
    background-color: var(--bg-color);
    color: var(--secondary-text-color);
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
    resize: none;
    cursor: default;
}

.play-button {
    padding: 10px 20px;
    font-size: 1.1em;
    font-weight: bold;
    cursor: pointer;
    border: none;
    background-color: var(--play-button-bg-color);
    color: var(--play-button-text-color);
    border-radius: 5px;
    transition: background-color 0.2s ease;
    display: block;
    width: fit-content;
    margin: 0 auto;
}

.play-button:hover {
    background-color: var(--play-button-hover-bg-color);
}

.play-button:disabled {
    background-color: var(--play-button-disabled-bg-color);
    cursor: not-allowed;
}

/* Button Container */
.button-container h2 {
    width: 100%;
    text-align: center;
    margin-bottom: 15px;
}

.morse-button {
    padding: 10px 15px;
    font-size: 1.2em;
    font-weight: bold;
    min-width: 50px;
    cursor: pointer;
    border: 1px solid var(--button-border-color);
    background-color: var(--button-bg-color);
    color: var(--button-text-color);
    border-radius: 5px;
    transition: background-color 0.2s ease, transform 0.1s ease, color 0.3s ease, border-color 0.3s ease;
    text-align: center;
}

.morse-button:hover {
    background-color: var(--button-hover-bg-color);
}

.morse-button:active {
    background-color: var(--button-active-bg-color);
    transform: scale(0.95);
}

/* Morse Alphabet Definition List */
.dl-grid-wrapper {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0 20px;
}

.alphabet-list-container dl {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 8px 16px;
    text-align: left;
}

.alphabet-list-container dt {
    font-weight: bold;
    font-family: monospace;
    font-size: 1.2em;
    grid-column: 1;
}

.alphabet-list-container dd {
    grid-column: 2;
    margin: 0;
    font-family: monospace;
    font-size: 1.2em;
    letter-spacing: 2px;
    align-self: center;
}

/* Manual Input Buttons */
.manual-buttons-wrapper {
    display: flex;
    justify-content: center;
    gap: 20px;
}

.manual-button {
    font-size: 1.5em;
    font-weight: bold;
    padding: 20px 0;
    flex: 1;
    cursor: pointer;
    border: 1px solid var(--button-border-color);
    background-color: var(--button-bg-color);
    color: var(--button-text-color);
    border-radius: 8px;
    transition: background-color 0.2s ease, transform 0.1s ease;
}

.manual-button:hover {
    background-color: var(--button-hover-bg-color);
}

.manual-button:active {
    background-color: var(--button-active-bg-color);
    transform: scale(0.98);
}


/* Responsive Fix for Mobile */
@media (max-width: 480px) {
    .setting {
        flex-wrap: wrap;
        row-gap: 10px;
    }

    .setting label[for="speed-slider"],
    .setting label[for="frequency-slider"] {
        width: 100%;
        min-width: 0;
        text-align: left;
    }

    .setting input[type="range"] {
        flex-grow: 1;
    }

    .setting span {
        min-width: 65px;
    }

    .dl-grid-wrapper {
        grid-template-columns: repeat(2, 1fr); /* Use 2 columns on small mobile */
    }
}