@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@400;700;900&display=swap');
        
body {
    font-family: 'Noto Sans KR', sans-serif;
    background: linear-gradient(135deg, #e0f2fe 0%, #b3e5fc 100%);
    min-height: 100vh;
    overflow: hidden;
    user-select: none; 
}

.page {
    display: none;
    height: 100vh;
    width: 100vw;
    position: relative;
}

.page.active {
    display: block;
}

.btn-hover:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, #2196f3 0%, #1976d2 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 700;
    transition: all 0.3s ease;
}

/* 新增：練習頁面專用的水藍色按鈕 */
.btn-water {
    /* 使用青色(Cyan)到天藍色(Sky)的漸層，呈現清澈的水藍色 */
    background: linear-gradient(135deg, #00acc1 0%, #039be5 100%); 
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 700;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(0, 172, 193, 0.3); /* 給予一點陰影增加層次感 */
}

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

/* 確保喇叭圖示區域有足夠的點擊範圍 */
.audio-trigger-zone {
    padding: 4px 8px 4px 4px; /* 增加觸控面積 */
    margin-right: 4px;
    border-right: 1px solid rgba(255,255,255,0.2); /* 視覺分隔線(可選) */
    cursor: pointer;
    display: flex;
    align-items: center;
}

.btn-secondary {
    background: linear-gradient(135deg, #81c784 0%, #66bb6a 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 700;
    transition: all 0.3s ease;
}

.vocabulary-card {
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    padding: 1rem;
    transition: all 0.3s ease;
}

.vocabulary-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.drag-zone {
    border: 2px dashed #bbb;
    border-radius: 8px;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    width: 100px;
    font-size: 16px;
    line-height: 1.1;
    text-align: center;
    white-space: nowrap;
}

@media (min-width: 1024px) {
    .drag-zone {
        min-height: 60px;
        width: 120px;
        font-size: 18px;
    }
}

.drag-zone.drag-over {
    border-color: #2196f3;
    background-color: #e3f2fd;
}

.drag-zone.filled {
    border: 2px solid #2196f3;
    background-color: #2196f3;
    color: white;
}

.drag-zone.filled.incorrect {
    border: 2px solid #ef4444;
    background-color: #ef4444;
    color: white;
}

.draggable {
    cursor: move;
    user-select: none;
}

.draggable:hover {
    transform: scale(1.05);
}

.audio-player {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    padding: 1rem;
}

.countdown {
    font-weight: 900;
    text-shadow: 0 0 20px currentColor;
    animation: pulse 1s ease-in-out;
}

.countdown-large {
    font-size: 4rem;
}

.countdown-small {
    font-size: 4rem;
}

@media (max-width: 768px) {
    .countdown-large {
        font-size: 2rem;
    }
    .countdown-small {
        font-size: 2rem;
    }
}

.countdown-container {
    position: relative;
    display: inline-block;
}

.countdown-circle {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120px;
    height: 120px;
    border-radius: 50%;
    border: 4px solid transparent;
    animation: drawCircle 1s ease-out forwards;
}

@media (max-width: 768px) {
    .countdown-circle {
        width: 80px;
        height: 80px;
        border-width: 3px;
    }
}

@keyframes drawCircle {
    0% {
        border-color: transparent;
        transform: translate(-50%, -50%) rotate(0deg);
        border-top-color: currentColor;
        border-right-color: transparent;
        border-bottom-color: transparent;
        border-left-color: transparent;
    }
    25% {
        border-top-color: currentColor;
        border-right-color: currentColor;
        border-bottom-color: transparent;
        border-left-color: transparent;
        transform: translate(-50%, -50%) rotate(90deg);
    }
    50% {
        border-top-color: currentColor;
        border-right-color: currentColor;
        border-bottom-color: currentColor;
        border-left-color: transparent;
        transform: translate(-50%, -50%) rotate(180deg);
    }
    75% {
        border-top-color: currentColor;
        border-right-color: currentColor;
        border-bottom-color: currentColor;
        border-left-color: currentColor;
        transform: translate(-50%, -50%) rotate(270deg);
    }
    100% {
        border-color: currentColor;
        transform: translate(-50%, -50%) rotate(360deg);
    }
}

@keyframes pulse {
    0% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

.confetti {
    position: fixed;
    width: 10px;
    height: 10px;
    background: #f39c12;
    animation: confetti-fall 3s linear infinite;
}

@keyframes confetti-fall {
    0% {
        transform: translateY(-100vh) rotate(0deg);
        opacity: 1;
    }
    100% {
        transform: translateY(100vh) rotate(720deg);
        opacity: 0;
    }
}

.image-option {
    transition: all 0.3s ease;
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    -webkit-user-drag: none;
    -khtml-user-drag: none;
    -moz-user-drag: none;
    -o-user-drag: none;
    user-drag: none;
}

.image-option:hover {
    transform: scale(1.05);
    box-shadow: 0 0 20px rgba(33, 150, 243, 0.8);
    cursor: pointer;
}

.image-option img {
    pointer-events: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    -webkit-user-drag: none;
    -khtml-user-drag: none;
    -moz-user-drag: none;
    -o-user-drag: none;
    user-drag: none;
}

.nav-button {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    transition: all 0.3s ease;
    cursor: pointer;
}

.nav-button:hover {
    transform: scale(1.1);
}

.nav-button.current {
    border: 3px solid rgba(33, 150, 243, 1);
    box-shadow: 0 0 0 0 rgba(33, 150, 243, 1), 0 0 25px rgba(33, 150, 243, 0);
    animation: currentGlow 2s ease-in-out infinite alternate;
}

@keyframes currentGlow {
    0% {
        box-shadow: 0 0 0 0 rgba(33, 150, 243, 1), 0 0 25px rgba(33, 150, 243, 0);
    }
    100% {
        box-shadow: 0 0 0 8px rgba(33, 150, 243, 0), 0 0 25px rgba(33, 150, 243, 0.8);
    }
}

/* Idle Hint Animation */
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in {
    animation: fadeIn 1s forwards, float 2s ease-in-out infinite;
}

/* Task 1: Idle Hint Responsive Font Size */
#idle-hint {
    font-size: 0.875rem; /* Default (Mobile) */
}

@media (min-width: 768px) {
    #idle-hint {
        font-size: 1.75rem !important; /* 2x size for Desktop */
    }
}

/* Mobile button positioning adjustments */
@media (max-width: 639px) {
    .mobile-nav-up {
        top: calc(var(--original-top, 89.5%) - 2%) !important;
    }
    .mobile-nav-buttons-up {
        top: calc(var(--original-top, 85.5%) - 3%) !important;
    }
    .mobile-images-top-down {
        top: calc(var(--original-top, 23.5%) - 2%) !important;
    }
    .mobile-images-bottom-up {
        top: calc(var(--original-top, 55%) - 5%) !important;
    }
    .mobile-countdown-up {
        top: calc(var(--original-top, 49%) - 3%) !important;
    }
}

@media (min-width: 640px) {
    .home-nav-buttons {
        top: 89.5% !important;
    }
}

.vocab-title {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

@media (max-width: 768px) {
    .vocab-title {
        font-size: clamp(1.2rem, 8vw, 2rem);
        letter-spacing: -0.1em;
        transform: scaleX(0.85);
        transform-origin: center;
    }
}

/* Subtitle adjustments for mobile */
@media (max-width: 768px) {
    #subtitle-container {
        top: 20% !important; 
    }
    #subtitles {
        white-space: nowrap;
    }
    #subtitle-korean, #subtitle-chinese {
        letter-spacing: -1px; 
    }
}

.overflow-menu {
    position: relative;
}

.overflow-panel {
    position: absolute;
    top: 100%;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    border: 2px solid rgba(0, 0, 0, 0.2);
    border-radius: 10px;
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    padding: 6px;
    z-index: 1000;
    width: 130px;
    min-width: 130px;
    backdrop-filter: blur(5px);
}

.overflow-panel button.menu-item {
    width: 100%;
    text-align: center;
    display: block;
    padding: 4px 12px;
    margin: 2px 0;
    border: none;
    border-radius: 5px;
    background: #d1d5db;
    cursor: pointer;
    transition: background 0.2s;
    font-size: 14px;
    height: 28px;
    white-space: nowrap;
    line-height: 20px;
}

.overflow-panel button.menu-item:hover {
    background: #dbeafe;
}

.overflow-panel button.menu-item.active {
    background: #3b82f6;
    color: white;
}

.overflow-panel button.close-button {
    width: 20px !important;
    height: 20px !important;
    display: flex !important;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: #ef4444;
    color: white;
    font-size: 12px;
    font-weight: bold;
    position: absolute;
    top: -8px;
    left: -8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

/* Blur mask animation */
.mask-fade-enter {
    opacity: 0;
}
.mask-fade-enter-active {
    opacity: 1;
    transition: opacity 1.5s ease-in;
}
.mask-fade-exit {
    opacity: 1;
}
.mask-fade-exit-active {
    opacity: 0;
    transition: opacity 1s ease-out;
}