/* Basic Reset & Dark Theme Variables */
:root {
    --bg-color: #1a1a1a;
    --text-color: #e0e0e0;
    --primary-text-color: #ffffff;
    --button-bg: #333333;
    --button-text: #ffffff;
    --correct-color: #4CAF50;
    --incorrect-color: #f44336;
    --button-active-bg: #555555;
    --screen-bg: rgba(0, 0, 0, 0.85);
    --info-button-bg: #555; /* Slightly different bg for info buttons */
    --info-button-active-bg: #777;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html, body {
    height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    touch-action: manipulation;
    overflow: hidden;
    position: relative;
}

/* Main App Container */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    width: 100vw;
}

/* Info Area */
#info-area {
    display: flex;
    justify-content: space-between; /* Distributes space between items */
    align-items: center; /* Vertically align items */
    padding: 8px 15px; /* Adjusted padding slightly */
    font-size: 1.1rem;
    background-color: #222;
    flex-shrink: 0;
    color: var(--text-color);
    min-height: 50px; /* Ensure enough height for button */
}

/* Style for Timer and Score displays */
#timer-display, #score-display {
    flex-basis: 30%; /* Give them some base width */
    text-align: left; /* Align text left/right */
}
#score-display {
    text-align: right;
}

/* New Info Button Style (for Quit button) */
.info-button {
    padding: 6px 12px;
    font-size: 0.95rem; /* Slightly smaller font */
    font-weight: bold;
    background-color: var(--info-button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.1s ease-out, transform 0.05s ease-out;
    user-select: none;
    line-height: 1.2;
    /* Let it take natural width, centered by justify-content: space-between */
}

.info-button:active {
    background-color: var(--info-button-active-bg);
    transform: scale(0.97);
}


/* Question Area */
#question-area {
    flex-grow: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 5px;
    position: relative;
}

#question-display {
    font-size: clamp(8rem, 25vh, 14rem);
    font-weight: bold;
    color: var(--primary-text-color);
    line-height: 1;
    transition: color 0.2s ease-out;
    user-select: none;
}

/* Button Area */
#button-area {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 15px;
    background-color: #222;
    flex-shrink: 0;
}

/* Buttons Styling */
.note-button {
    padding: 18px 10px;
    font-size: clamp(1.5rem, 4vw, 2.2rem);
    font-weight: bold;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.1s ease-out, transform 0.05s ease-out;
    user-select: none;
    text-align: center;
    line-height: 1.2;
}
.note-button:nth-child(5) { grid-column: 1 / 2; }
.note-button:nth-child(6) { grid-column: 2 / 3; }
.note-button:nth-child(7) { grid-column: 3 / 4; }
.note-button:active {
    background-color: var(--button-active-bg);
    transform: scale(0.96);
}

/* Feedback Classes */
.correct-feedback {
    color: var(--correct-color) !important;
}
.incorrect-feedback {
    color: var(--incorrect-color) !important;
    animation: shake 0.3s ease-in-out;
}
@keyframes shake {
  0%, 100% { transform: translateX(0); } 25% { transform: translateX(-5px); }
  50% { transform: translateX(5px); } 75% { transform: translateX(-3px); }
}

/* Screen Styling (Start/Results) */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--screen-bg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 20px;
    z-index: 10;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease-in-out, visibility 0.3s ease-in-out;
}

.screen.active {
    opacity: 1;
    visibility: visible;
}

.screen h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: var(--primary-text-color);
}

.screen p {
    font-size: 1.1rem;
    margin-bottom: 25px;
    max-width: 80%;
}

#final-score-display {
    font-size: 3rem;
    font-weight: bold;
    color: var(--correct-color);
    margin-bottom: 30px;
}

/* Notation Mode Selection Styling */
#mode-selection {
    margin-bottom: 30px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    align-items: flex-start;
    background-color: rgba(255, 255, 255, 0.05);
    padding: 15px;
    border-radius: 8px;
    max-width: 90%;
}

#mode-selection label {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.0rem;
    cursor: pointer;
    color: var(--text-color);
    line-height: 1.3;
}

#mode-selection input[type="radio"] {
    appearance: none;
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border: 2px solid var(--text-color);
    border-radius: 50%;
    position: relative;
    cursor: pointer;
    outline: none;
    flex-shrink: 0;
}

#mode-selection input[type="radio"]:checked {
    border-color: var(--correct-color);
}

#mode-selection input[type="radio"]:checked::before {
    content: '';
    display: block;
    width: 10px;
    height: 10px;
    background-color: var(--correct-color);
    border-radius: 50%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}


/* Control Buttons (Start/Restart) */
.control-button {
    padding: 15px 30px;
    font-size: 1.4rem;
    font-weight: bold;
    background-color: var(--correct-color);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s ease;
}
.control-button:hover {
    background-color: #388E3C;
}
.control-button:active {
    transform: scale(0.98);
}

/* Utility Class */
.hidden {
    display: none !important;
}

/* Hide noscript */
body:not(.no-js) noscript {
    display: none;
}