/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #1db954 0%, #191414 100%);
    color: white;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

#app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.section {
    background: rgba(0, 0, 0, 0.8);
    border-radius: 15px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    max-width: 800px;
    width: 100%;
    text-align: center;
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hidden {
    display: none !important;
}

/* Buttons */
.btn {
    background: #1db954;
    color: white;
    border: none;
    padding: 14px 28px;
    border-radius: 25px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 5px;
    min-width: 120px;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
    user-select: none;
    position: relative;
    z-index: 5;
}

.btn:hover {
    background: #1ed760;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(29, 185, 84, 0.4);
}

.btn:active {
    transform: translateY(0);
}

.btn-secondary {
    background: #535353;
}

.btn-secondary:hover {
    background: #727272;
}

.btn-danger {
    background: #e22134;
}

.btn-danger:hover {
    background: #ff4757;
}

@media (hover: none) {
    .btn:hover {
        transform: none;
        box-shadow: none;
    }
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 15px;
    position: relative;
    z-index: 10;
}

header h1 {
    color: #1db954;
    font-size: 2rem;
    flex: 1;
    min-width: 150px;
}

#user-info {
    color: #b3b3b3;
    font-size: 14px;
}

/* Game Mode Selection */
.mode-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.mode-card {
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(29, 185, 84, 0.3);
    border-radius: 15px;
    padding: 30px 20px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.mode-card:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: #1db954;
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(29, 185, 84, 0.2);
}

.mode-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.mode-card h3 {
    color: #1db954;
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.mode-card p {
    color: #b3b3b3;
    margin-bottom: 8px;
    font-size: 1.1rem;
}

.mode-detail {
    font-size: 0.9rem !important;
    color: #888 !important;
}

.mode-btn {
    margin-top: 15px;
    width: 100%;
}

/* Score Board */
#score-board {
    display: flex;
    justify-content: space-around;
    align-items: center;
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 15px;
}

.score-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 80px;
}

.score-label {
    color: #b3b3b3;
    font-size: 0.9rem;
    margin-bottom: 5px;
}

.score-value {
    color: #1db954;
    font-size: 1.5rem;
    font-weight: bold;
}

/* Question Container */
#question-container {
    margin-bottom: 30px;
    position: relative;
    z-index: 1;
}

#audio-player {
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 30px;
}

#play-btn {
    font-size: 18px;
    padding: 15px 40px;
    min-width: 200px;
    -webkit-tap-highlight-color: transparent;
    user-select: none;
}

#question {
    position: relative;
    z-index: 1;
}

#question h2 {
    margin-bottom: 25px;
    font-size: 1.5rem;
    color: #1db954;
}

/* Answer Buttons */
#answers {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-top: 20px;
}

.answer-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid transparent;
    padding: 20px 15px;
    border-radius: 10px;
    color: white;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    touch-action: manipulation;
    word-wrap: break-word;
}

.answer-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: #1db954;
    transform: scale(1.02);
}

.answer-btn:active {
    transform: scale(0.98);
}

.answer-btn.correct {
    background: #1db954;
    border-color: #1ed760;
    animation: pulse 0.5s ease;
}

.answer-btn.incorrect {
    background: #e22134;
    border-color: #ff4757;
    animation: shake 0.5s ease;
}

.answer-btn:disabled {
    cursor: not-allowed;
    opacity: 0.8;
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.05);
    }
}

@keyframes shake {

    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-10px);
    }

    75% {
        transform: translateX(10px);
    }
}

/* Result Section */
#result-section {
    background: rgba(255, 255, 255, 0.1);
    padding: 25px;
    border-radius: 10px;
    margin-top: 20px;
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

#result-section h2 {
    margin-bottom: 15px;
    font-size: 1.8rem;
}

#result-detail {
    margin-bottom: 20px;
    font-size: 18px;
    color: #b3b3b3;
}

/* Final Score */
#final-score {
    text-align: center;
}

#final-score h2 {
    color: #1db954;
    margin-bottom: 30px;
    font-size: 2rem;
}

.final-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.stat-item {
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(29, 185, 84, 0.3);
    border-radius: 10px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.stat-value {
    color: #1db954;
    font-size: 2.5rem;
    font-weight: bold;
}

.stat-label {
    color: #b3b3b3;
    font-size: 0.9rem;
}

.encouragement {
    font-size: 1.3rem !important;
    margin: 25px 0 !important;
    color: #1db954 !important;
    font-weight: bold;
}

.final-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
    margin-top: 25px;
}

/* Auth Section */
#auth-section h1 {
    color: #1db954;
    font-size: 3rem;
    margin-bottom: 20px;
}

#auth-section p {
    font-size: 18px;
    margin-bottom: 30px;
    color: #b3b3b3;
    line-height: 1.5;
}

#auth-status {
    margin-top: 20px;
    padding: 15px;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
}

/* Loading animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #1db954;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

/* Responsive design */
/* Tablet */
@media (max-width: 1024px) {
    .section {
        padding: 30px;
        max-width: 90%;
    }

    header h1 {
        font-size: 1.8rem;
    }

    .mode-cards {
        grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
        gap: 15px;
    }

    .final-stats {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Mobile */
@media (max-width: 768px) {
    body {
        font-size: 14px;
    }

    .section {
        padding: 20px;
        margin: 10px;
        border-radius: 10px;
    }

    header {
        flex-direction: column;
        text-align: center;
        gap: 10px;
        align-items: stretch;
    }

    header h1 {
        font-size: 1.5rem;
        margin-bottom: 8px;
    }
    
    header button {
        width: 100%;
        margin: 0;
    }

    .mode-cards {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .mode-card {
        padding: 25px 15px;
    }

    .mode-icon {
        font-size: 2.5rem;
    }

    #answers {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .answer-btn {
        padding: 18px 12px;
        font-size: 15px;
        min-height: 55px;
    }

    #score-board {
        flex-direction: row;
        justify-content: space-around;
        padding: 15px;
        gap: 10px;
    }

    .score-item {
        min-width: 60px;
    }

    .score-label {
        font-size: 0.8rem;
    }

    .score-value {
        font-size: 1.3rem;
    }

    #play-btn {
        font-size: 16px;
        padding: 12px 30px;
        width: 100%;
        min-width: unset;
    }

    #question-container {
        margin-bottom: 20px;
    }

    #audio-player {
        padding: 18px;
        margin-bottom: 25px;
    }

    #question {
        margin-top: 15px;
        padding: 0 5px;
    }

    #question h2 {
        font-size: 1.3rem;
        margin-bottom: 20px;
    }

    #question-text {
        line-height: 1.4;
        word-wrap: break-word;
    }

    #auth-section h1 {
        font-size: 2rem;
    }

    #auth-section p {
        font-size: 16px;
    }

    .btn {
        padding: 12px 20px;
        font-size: 15px;
        min-width: 100px;
    }

    .final-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }

    .stat-value {
        font-size: 2rem;
    }

    .stat-label {
        font-size: 0.85rem;
    }

    .encouragement {
        font-size: 1.1rem !important;
    }

    #final-score h2 {
        font-size: 1.5rem;
    }

    .final-buttons {
        flex-direction: column;
        width: 100%;
    }

    .final-buttons .btn {
        width: 100%;
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    .section {
        padding: 15px;
    }

    header h1 {
        font-size: 1.3rem;
    }

    .mode-icon {
        font-size: 2rem;
    }

    .mode-card h3 {
        font-size: 1.2rem;
    }

    .answer-btn {
        padding: 15px 10px;
        font-size: 14px;
        min-height: 50px;
    }

    #score-board {
        padding: 12px;
    }

    .score-value {
        font-size: 1.2rem;
    }

    .score-label {
        font-size: 0.75rem;
    }

    #question-container {
        margin-bottom: 15px;
    }

    #audio-player {
        padding: 15px;
        margin-bottom: 20px;
    }

    #question {
        margin-top: 12px;
        padding: 0 5px;
    }

    #question h2 {
        font-size: 1.1rem;
        margin-bottom: 15px;
        line-height: 1.5;
        word-wrap: break-word;
    }

    #question-text {
        padding: 0 5px;
    }

    .btn {
        padding: 12px 20px;
        font-size: 1rem;
        min-height: 48px; /* Touch-friendly minimum size */
    }

    #play-btn {
        min-height: 50px;
        font-size: 1.1rem;
    }

    #result-section {
        padding: 15px;
    }

    #result-section h2 {
        font-size: 1.3rem;
    }

    #result-detail {
        font-size: 16px;
    }

    .final-stats {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .stat-item {
        padding: 15px;
    }

    .stat-value {
        font-size: 1.8rem;
    }

    .encouragement {
        font-size: 1rem !important;
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    .answer-btn {
        padding: 20px 15px;
        min-height: 65px;
    }

    .btn {
        padding: 15px 25px;
        min-height: 48px;
    }

    .mode-card {
        padding: 30px 20px;
    }
}

/* Loading animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #1db954;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}