:root {
    --bg-main: #f5fafd; 
    --glass-bg: rgba(255, 255, 255, 0.65);
    --glass-border: rgba(255, 255, 255, 0.5);
    --glass-shadow: 0 8px 32px rgba(129, 212, 250, 0.15);
    
    --primary: #81D4FA;
    --primary-hover: #40B5D8;
    --text-main: #2C3E50;
    --text-muted: #7F8C8D;
    --accent: #E1F5FE;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: 'Inter', 'Noto Sans TC', sans-serif;
    background: var(--bg-main);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.hidden { display: none !important; }

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--glass-border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-main);
    cursor: pointer;
}
.logo span { color: var(--primary-hover); }

.nav-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* Glass UI Elements */
.glass-input, .glass-select {
    padding: 0.6rem 1rem;
    border: 1px solid var(--glass-border);
    background: rgba(255, 255, 255, 0.8);
    border-radius: 12px;
    font-size: 0.95rem;
    color: var(--text-main);
    outline: none;
    transition: all 0.2s;
}

.glass-input:focus, .glass-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--accent);
}

.btn {
    padding: 0.6rem 1.2rem;
    border: none;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 4px 12px rgba(129, 212, 250, 0.4);
}
.btn-primary:not(:disabled):hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.8);
    color: var(--text-main);
    border: 1px solid var(--glass-border);
}
.btn-secondary:hover {
    background: #fff;
}

.btn-warning {
    background: linear-gradient(135deg, #FFB74D, #FF8F00);
    color: #fff;
    box-shadow: 0 4px 12px rgba(255, 143, 0, 0.35);
    font-size: 0.88rem;
}
.btn-warning:hover {
    background: linear-gradient(135deg, #FFA726, #E65100);
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(255, 143, 0, 0.45);
}
.btn-warning:active {
    transform: translateY(0);
    animation: pulse-warn 0.3s ease;
}
@keyframes pulse-warn {
    0% { box-shadow: 0 0 0 0 rgba(255, 143, 0, 0.5); }
    100% { box-shadow: 0 0 0 10px rgba(255, 143, 0, 0); }
}

/* Views */
.view {
    flex: 1;
    opacity: 0;
    transition: opacity 0.4s ease;
    display: none;
}
.view.section-active {
    display: flex;
    flex-direction: column;
    opacity: 1;
}

/* Home View */
#home-view {
    align-items: center;
    padding-top: 4rem;
}

.hero {
    text-align: center;
    margin-bottom: 4rem;
}
.hero h1 { font-size: 2.8rem; margin-bottom: 1rem; letter-spacing: -0.5px; }
.hero p { font-size: 1.2rem; color: var(--text-muted); }

.card-grid {
    display: flex;
    gap: 2rem;
    width: 100%;
    max-width: 900px;
    padding: 0 2rem;
}

.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 2rem;
    box-shadow: var(--glass-shadow);
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: transform 0.2s;
}
.glass-card:hover { transform: translateY(-4px); }

.card-icon { font-size: 3rem; margin-bottom: 1rem; }
.glass-card h2 { margin-bottom: 0.5rem; }
.glass-card p { margin-bottom: 1.5rem; color: var(--text-muted); }

.yt-input-group {
    display: flex;
    gap: 0.5rem;
    width: 100%;
}
.yt-input-group input { flex: 1; }

.status-wrapper {
    margin-top: 1.5rem;
    width: 100%;
    text-align: left;
}
.status-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: 0.5rem;
}
.progress-track {
    width: 100%;
    height: 8px;
    background: rgba(0, 0, 0, 0.05);
    border-radius: 10px;
    overflow: hidden;
    position: relative;
}
.progress-thumb {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--primary-hover));
    box-shadow: 0 0 10px rgba(129, 212, 250, 0.5);
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Player View */
#player-view { padding: 1rem 2rem; align-items: center; justify-content: center; overflow-y: auto; }
.main-player-area { width: 100%; max-width: 1000px; display: flex; flex-direction: column; gap: 0.5rem; }

.player-container {
    width: 100%;
    height: auto;
    max-height: 65vh; /* 再次縮限，留出更多字幕空間 */
    aspect-ratio: 16 / 9;
    background: #000;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 12px 24px rgba(0,0,0,0.1);
    position: relative;
    display: flex;
    justify-content: center;
}

video, #yt-player-container iframe {
    width: 100%; height: 100%; object-fit: contain; pointer-events: auto; outline: none; border: none;
}
#yt-player-container { width: 100%; height: 100%; }

/* Loading Overlay */
.loading-overlay {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(20px);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    opacity: 1;
    transition: opacity 0.8s ease;
}
.loading-overlay.fade-out { opacity: 0; pointer-events: none; }
.loader-content { text-align: center; }
.spinner {
    width: 40px; height: 40px;
    border: 4px solid rgba(129, 212, 250, 0.2);
    border-top: 4px solid var(--primary);
    border-radius: 50%;
    margin: 0 auto 1.5rem;
    animation: rotate 1s linear infinite;
}
.loader-text {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 0.5rem;
}
.loader-subtext { font-size: 0.85rem; color: var(--text-muted); }

@keyframes rotate { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

/* Subtitle Box */
.subtitle-box {
    padding: 1rem 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 120px; /* 絕對固定高度 */
    flex: none;    /* 強制不隨彈性佈局伸縮 */
    flex-shrink: 0;
    gap: 0.3rem;
    overflow: hidden;
    transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.subtitle { text-align: center; font-size: 1.1rem; width: 100%; word-break: break-all; }
.subtitle.original {
    font-weight: 500;
    color: var(--text-muted);
}
.subtitle.translated {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--primary-hover);
    line-height: 1.3;
    letter-spacing: 0.2px;
    transition: color 0.4s ease; /* 讓顏色切換更平滑 */
}

/* Animations */
@keyframes pulse { 0% { opacity: 0.6; } 50% { opacity: 1; } 100% { opacity: 0.6; } }

.text-pop { animation: pop 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards; }
@keyframes pop {
    0% { transform: translateY(10px); opacity: 0; }
    100% { transform: translateY(0); opacity: 1; }
}

/* Toggle Switch */
.toggle-switch { position: relative; display: inline-block; width: 44px; height: 24px; vertical-align: middle; }
.toggle-switch input { opacity: 0; width: 0; height: 0; }
.slider { position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0; background-color: #ccc; transition: .3s; border-radius: 24px; }
.slider:before { position: absolute; content: ""; height: 18px; width: 18px; left: 3px; bottom: 3px; background-color: white; transition: .3s; border-radius: 50%; }
input:checked + .slider { background-color: var(--primary); }
input:checked + .slider:before { transform: translateX(20px); }

.nav-toggle-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding-left: 0.5rem;
    border-left: 1px solid var(--glass-border);
}

.nav-toggle-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
}

.lang-badge {
    font-size: 0.75rem;
    background: var(--accent);
    color: var(--primary-hover);
    padding: 2px 8px;
    border-radius: 8px;
    font-weight: 600;
    margin-left: 0.5rem;
    white-space: nowrap;
    border: 1px solid var(--glass-border);
    animation: text-pop 0.3s forwards;
}

/* 移除舊有的樣式 */
/* .player-controls { display: flex; align-items: center; justify-content: flex-end; width: 100%; } */

/* --- Settings Modal --- */
.modal {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(6px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}
.modal.show {
    opacity: 1;
    pointer-events: auto;
}
.modal-content {
    width: 420px;
    max-width: 90%;
    padding: 2rem;
    transform: translateY(20px) scale(0.95);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}
.modal.show .modal-content {
    transform: translateY(0) scale(1);
}
.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}
.modal-header h2 { font-size: 1.4rem; font-weight: 700; margin: 0; color: var(--text); }
.btn-close {
    background: none; border: none; color: var(--text-muted);
    font-size: 1.5rem; cursor: pointer; transition: color 0.2s; padding: 0.5rem;
}
.btn-close:hover { color: var(--text); }

.setting-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 1.2rem;
    text-align: left;
}
.setting-group label {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

/* --- History List --- */
.history-list {
    list-style: none; padding: 0; margin-top: 5px; max-height: 400px; overflow-y: auto; text-align: left;
}
.history-list li {
    padding: 12px 14px; border-radius: 6px; font-size: 0.95rem; margin-bottom: 6px; cursor: pointer;
    background: transparent; border: 1px solid transparent; transition: all 0.2s;
    display: flex; justify-content: space-between; align-items: center;
}
.history-list li:hover { background: rgba(255,255,255,0.06); border-color: rgba(255,255,255,0.1); color: var(--primary); }
.history-filename { font-weight: 400; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; max-width: 65%; color: inherit; }
.history-date { color: var(--text-muted); font-size: 0.75rem; }