:root {
    --background-dark: #1e1e24;
    --surface-dark: #2c2c34;
    --primary-text: #f0f0f5;
    --secondary-text: #a0a0b0;
    --primary-blue: #007acc;
    --primary-blue-hover: #0098ff;
    --accent-green: #2a9d8f;
    --accent-green-hover: #2ddcb1;
    --accent-teal: #264653;
    --accent-teal-hover: #3a687a;
    --accent-red: #e76f51;
    --accent-red-hover: #f4a261;
    --highlight-yellow: #e9c46a;
    --border-color: #555;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: var(--background-dark);
    color: var(--primary-text);
    margin: 0;
    padding: 1rem;
    box-sizing: border-box;
}

.container {
    background-color: var(--surface-dark);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    width: 100%;
    max-width: 650px;
    border: 1px solid var(--border-color);
}

h1, h2 {
    text-align: center;
    color: var(--primary-text);
    font-weight: 500;
}

h2 {
    color: var(--secondary-text);
    font-size: 1.1rem;
    margin-top: 2rem;
}

textarea, #outputText, select {
    width: 100%;
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 1rem;
    background-color: var(--background-dark);
    color: var(--primary-text);
    font-size: 1rem;
    box-sizing: border-box;
}

#outputText {
    min-height: 110px;
    font-size: 1.25rem;
    line-height: 1.7;
    word-wrap: break-word;
    font-family: 'Roboto Mono', monospace;
    background-color: #1a1a1f; /* Slightly darker for contrast */
}

.buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

button {
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 8px;
    background-color: var(--primary-blue);
    color: white;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s, opacity 0.2s, transform 0.1s;
}

button:hover:not(:disabled) {
    background-color: var(--primary-blue-hover);
    transform: translateY(-2px);
}

button:active:not(:disabled) {
    transform: translateY(0);
}

button:disabled {
    background-color: #555;
    cursor: not-allowed;
    opacity: 0.6;
}

.playback-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 1rem;
    min-height: 80px;
}

#hearInMorseBtn {
    background-color: var(--accent-green);
    grid-column: 1;
    grid-row: 1;
}
#hearInMorseBtn:hover:not(:disabled) { background-color: var(--accent-green-hover); }

.accent-controls {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    grid-column: 2;
    grid-row: 1;
}

#accent-select {
    padding: 0.6rem;
    font-size: 0.9rem;
}

#hearInAccentBtn {
    background-color: var(--accent-teal);
    width: 100%;
}
#hearInAccentBtn:hover:not(:disabled) { background-color: var(--accent-teal-hover); }

#stopBtn {
    background-color: var(--accent-red);
    grid-row: 1;
}
#stopBtn:hover { background-color: var(--accent-red-hover); }


#errorMessage {
    color: var(--accent-red);
    margin-top: 1rem;
    min-height: 1.2em;
    text-align: center;
    font-weight: bold;
}

.morse-char.highlight {
    background-color: var(--highlight-yellow);
    color: black;
    border-radius: 3px;
    padding: 0.1em 0;
}