:root {
    --bg-primary: #050510;
    --bg-secondary: rgba(15, 15, 30, 0.6);
    --glass-bg: rgba(20, 20, 40, 0.4);
    --glass-border: rgba(255, 255, 255, 0.1);
    --text-main: #f0f4f8;
    --text-muted: #8a9bb4;
    --accent-color: #00f0ff;
    --accent-hover: #00c3d0;
    --danger-color: #ff2a5f;
    --danger-hover: #d91c49;
    --success-color: #00ff88;
}

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

body {
    font-family: 'Noto Sans TC', sans-serif;
    background-color: var(--bg-primary);
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(0, 240, 255, 0.08), transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(255, 42, 95, 0.08), transparent 25%);
    background-attachment: fixed;
    color: var(--text-main);
    min-height: 100vh;
    overflow-x: hidden;
}

h1, h2, h3, .orbitron {
    font-family: 'Orbitron', sans-serif;
    letter-spacing: 1px;
}

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: rgba(0,0,0,0.2);
}
::-webkit-scrollbar-thumb {
    background: var(--glass-border);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent-color);
}

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    padding: 15px;
    gap: 15px;
}

.glass-header {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 15px 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
}

.logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo i {
    font-size: 1.8rem;
    color: var(--accent-color);
    text-shadow: 0 0 10px rgba(0, 240, 255, 0.5);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    text-transform: uppercase;
}

.logo span {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-family: 'Noto Sans TC', sans-serif;
    letter-spacing: 0;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 20px;
}

#active-count {
    font-family: 'Orbitron', sans-serif;
    font-size: 1.1rem;
    color: var(--success-color);
    text-shadow: 0 0 8px rgba(0, 255, 136, 0.4);
}

button {
    cursor: pointer;
    border: none;
    outline: none;
    font-family: 'Noto Sans TC', sans-serif;
    transition: all 0.3s ease;
}

.glow-btn {
    background: linear-gradient(135deg, rgba(0, 240, 255, 0.2), rgba(0, 240, 255, 0.05));
    border: 1px solid var(--accent-color);
    color: var(--accent-color);
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 0 15px rgba(0, 240, 255, 0.1);
}

.glow-btn:hover {
    background: var(--accent-color);
    color: #000;
    box-shadow: 0 0 20px rgba(0, 240, 255, 0.4);
    transform: translateY(-2px);
}

.glow-btn.outline {
    background: transparent;
}

.glow-btn.outline:hover {
    background: var(--accent-color);
    color: #000;
}

.primary-btn {
    background: var(--accent-color);
    color: #000;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
}

.primary-btn:hover {
    background: var(--accent-hover);
    box-shadow: 0 0 15px rgba(0, 240, 255, 0.4);
}

.icon-btn {
    background: transparent;
    color: var(--text-muted);
    font-size: 1.2rem;
    padding: 8px;
    border-radius: 50%;
}

.icon-btn:hover {
    color: var(--text-main);
    background: rgba(255, 255, 255, 0.1);
}

.grid-container {
    flex: 1;
    display: grid;
    gap: 15px;
    transition: all 0.3s ease;
    border-radius: 12px;
}

.grid-1 { grid-template-columns: 1fr; grid-template-rows: 1fr; }
.grid-2 { grid-template-columns: repeat(2, 1fr); grid-template-rows: 1fr; }
.grid-3 { grid-template-columns: repeat(2, 1fr); grid-template-rows: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(2, 1fr); grid-template-rows: repeat(2, 1fr); }
.grid-5, .grid-6 { grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(2, 1fr); }
.grid-7, .grid-8, .grid-9 { grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(3, 1fr); }

.monitor-cell {
    background: #000;
    border-radius: 10px;
    overflow: hidden;
    position: relative;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.5);
    border: 1px solid var(--glass-border);
    animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

.monitor-cell iframe {
    width: 100%;
    height: 100%;
    border: none;
    pointer-events: auto;
}

.cell-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    padding: 15px;
    background: linear-gradient(to bottom, rgba(0,0,0,0.9) 0%, transparent 100%);
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.monitor-cell:hover .cell-overlay {
    opacity: 1;
}

.cell-overlay button {
    pointer-events: auto;
}

.cell-actions {
    display: flex;
    gap: 8px;
}

.focus-btn {
    background: rgba(0, 240, 255, 0.2);
    color: var(--accent-color);
    border: 1px solid var(--accent-color);
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.8rem;
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
}

.focus-btn:hover {
    background: var(--accent-color);
    color: #000;
}

.remove-monitor-btn {
    background: rgba(255, 42, 95, 0.2);
    color: var(--danger-color);
    border: 1px solid var(--danger-color);
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.8rem;
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    transition: all 0.2s;
}

.remove-monitor-btn:hover {
    background: var(--danger-color);
    color: #fff;
}

/* --- Focus Mode (Enlarge Single Video) --- */
.monitor-cell.focused {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    width: 100vw !important;
    height: 100vh !important;
    z-index: 9999 !important;
    border: none !important;
    border-radius: 0 !important;
    background: black !important;
}

.monitor-cell.focused .cell-overlay {
    padding: 20px 30px;
    background: linear-gradient(to bottom, rgba(0,0,0,0.95) 0%, rgba(0,0,0,0.6) 50%, transparent 100%);
}

.monitor-cell.focused .cell-title {
    font-size: 1.5rem !important;
    max-width: 80% !important;
}

.monitor-cell.focused .cell-actions button {
    padding: 10px 15px;
    font-size: 1.2rem;
}

.empty-state {
    grid-column: 1 / -1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border: 1px dashed var(--glass-border);
    border-radius: 12px;
    color: var(--text-muted);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 20px;
    color: rgba(255, 255, 255, 0.1);
}

.empty-state h2 {
    color: var(--text-main);
    margin-bottom: 10px;
}

.empty-state p {
    margin-bottom: 25px;
}

/* Panel Overlay */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(5px);
    z-index: 1000;
    opacity: 1;
    transition: opacity 0.4s ease;
}

.modal-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

/* Side Panel */
.glass-panel {
    position: absolute;
    top: 0;
    right: 0;
    height: 100vh;
    width: 450px;
    background: rgba(12, 12, 24, 0.95);
    border-left: 1px solid var(--glass-border);
    box-shadow: -15px 0 50px rgba(0,0,0,0.8), inset 1px 0 0 rgba(255,255,255,0.05);
    display: flex;
    flex-direction: column;
    transform: translateX(0);
    transition: transform 0.5s cubic-bezier(0.19, 1, 0.22, 1);
}

.modal-overlay.hidden .glass-panel {
    transform: translateX(100%);
}

.modal-header {
    padding: 25px;
    border-bottom: 1px solid rgba(255,255,255,0.05);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
}

.modal-header h2 {
    font-size: 1.3rem;
    color: var(--accent-color);
}

.modal-body {
    padding: 25px;
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.input-group {
    display: flex;
    gap: 10px;
    margin-top: 15px;
}

input[type="text"], textarea {
    flex: 1;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 12px 15px;
    color: var(--text-main);
    font-family: inherit;
    transition: border-color 0.3s;
    resize: vertical;
}

input[type="text"]:focus, textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 10px rgba(0, 240, 255, 0.1);
}

.helper-text {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 8px;
}

.quick-selector {
    margin-top: 20px;
    background: rgba(0, 0, 0, 0.2);
    padding: 15px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.quick-selector h4 {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 12px;
    font-weight: 500;
}

.quick-selector h4 i {
    color: var(--accent-color);
    margin-right: 5px;
}

.chip-container {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.icon-chip {
    background: rgba(15, 15, 25, 0.6);
    border: 1px solid var(--glass-border);
    color: var(--text-muted);
    width: 48px;
    height: 48px;
    border-radius: 12px;
    font-family: 'Orbitron', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    transition: all 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.icon-chip::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(135deg, rgba(0, 240, 255, 0.2), transparent);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.icon-chip:hover {
    color: var(--accent-color);
    border-color: var(--accent-color);
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 240, 255, 0.2), inset 0 0 10px rgba(0, 240, 255, 0.1);
}

.icon-chip:hover::before {
    opacity: 1;
}

/* Custom Grid Layout Icons */
.layout-icon {
    display: grid;
    gap: 3px;
    width: 22px;
    height: 22px;
    pointer-events: none;
}
.layout-icon span {
    background: var(--text-muted);
    border-radius: 2px;
    transition: all 0.3s ease;
}
.icon-chip:hover .layout-icon span {
    background: var(--accent-color);
    box-shadow: 0 0 5px rgba(0, 240, 255, 0.5);
}
.grid-2-icon { grid-template-columns: 1fr 1fr; }
.grid-4-icon { grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; }
.grid-6-icon { grid-template-columns: 1fr 1fr 1fr; grid-template-rows: 1fr 1fr; width: 26px; height: 18px; }
.grid-9-icon { grid-template-columns: 1fr 1fr 1fr; grid-template-rows: 1fr 1fr 1fr; }

/* Group Section */
.group-section {
    margin-top: 25px;
    background: rgba(0, 0, 0, 0.2);
    padding: 15px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.group-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.group-header h4 {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 500;
}

.group-header h4 i {
    color: var(--accent-color);
    margin-right: 5px;
}

.action-btn {
    background: linear-gradient(135deg, rgba(0, 240, 255, 0.1), rgba(0, 240, 255, 0.02));
    border: 1px solid rgba(0, 240, 255, 0.4);
    color: var(--accent-color);
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 500;
    transition: all 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
}

.action-btn:hover {
    background: var(--accent-color);
    color: #000;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 240, 255, 0.3);
}

.group-chip {
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, rgba(20, 20, 40, 0.8), rgba(15, 15, 30, 0.9));
    border: 1px solid var(--glass-border);
    padding: 8px 16px;
    border-radius: 30px;
    font-size: 0.85rem;
    transition: all 0.3s ease;
    cursor: pointer;
}

.group-chip:hover {
    border-color: var(--accent-color);
    background: rgba(0, 240, 255, 0.05);
    box-shadow: 0 4px 12px rgba(0, 240, 255, 0.15);
    transform: translateY(-1px);
}

.group-name {
    margin-right: 8px;
    color: var(--text-main);
}

.delete-group-btn {
    background: none;
    border: none;
    color: var(--danger-color);
    opacity: 0.6;
    padding: 2px;
    font-size: 0.8rem;
}

.delete-group-btn:hover {
    opacity: 1;
    transform: scale(1.2);
}

.channel-list-section {
    margin-top: 30px;
    display: flex;
    flex-direction: column;
    flex: 1;
    overflow: hidden;
}

.channel-list-section h3 {
    margin-bottom: 15px;
    font-size: 1.1rem;
    border-bottom: 1px solid rgba(255,255,255,0.05);
    padding-bottom: 10px;
    flex-shrink: 0;
}

#channel-list {
    list-style: none;
    flex: 1;
    overflow-y: auto;
    padding-right: 5px;
}

.channel-item {
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.05);
    border-radius: 8px;
    padding: 12px 15px;
    margin-bottom: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.2s;
}

.channel-item:hover {
    background: rgba(255,255,255,0.06);
    border-color: rgba(255,255,255,0.1);
}

.channel-info {
    display: flex;
    align-items: center;
    gap: 15px;
    flex: 1;
    overflow: hidden;
}

.channel-thumb {
    width: 70px;
    height: 40px;
    background: #000;
    border-radius: 4px;
    background-size: cover;
    background-position: center;
    flex-shrink: 0;
}

.channel-details {
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.channel-title {
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    font-size: 0.95rem;
}

.channel-id {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.channel-actions {
    display: flex;
    gap: 8px;
}

.watch-btn {
    background: rgba(0, 255, 136, 0.1);
    color: var(--success-color);
    border: 1px solid rgba(0, 255, 136, 0.2);
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.85rem;
}

.watch-btn:hover {
    background: var(--success-color);
    color: #000;
}

.watch-btn.active {
    background: var(--success-color);
    color: #000;
    box-shadow: 0 0 10px rgba(0, 255, 136, 0.4);
}

.delete-btn {
    background: rgba(255, 42, 95, 0.1);
    color: var(--danger-color);
    border: 1px solid rgba(255, 42, 95, 0.2);
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.85rem;
}

.delete-btn:hover {
    background: var(--danger-color);
    color: #fff;
}

/* --- 手機版響應式設計 (Mobile Responsive) --- */
@media (max-width: 768px) {
    /* 1. 將網格改為上下垂直排列 */
    .grid-container {
        display: flex !important;
        flex-direction: column !important;
        overflow-y: auto !important;
        gap: 15px !important;
        padding-bottom: 30px;
    }

    /* 2. 每個影片保持 16:9 比例 */
    .monitor-cell {
        width: 100% !important;
        height: auto !important;
        aspect-ratio: 16 / 9;
        flex-shrink: 0; /* 防止被 flex 擠壓變形 */
    }

    /* 3. 調整頂部 Header 排版 */
    .glass-header {
        flex-direction: column;
        gap: 12px;
        padding: 12px;
    }

    .header-controls {
        width: 100%;
        justify-content: center;
        gap: 10px;
    }

    .header-controls button {
        padding: 6px 12px;
        font-size: 0.85rem;
        margin-right: 0 !important;
    }

    /* 4. 控制面板寬度與按鈕文字微調 */
    .modal-content.glass-panel {
        width: 95%;
        margin-right: 0; /* 覆蓋大螢幕靠右的設定 */
        align-self: center;
    }

    #share-url-btn span {
        display: none; /* 手機版太擠時，可以考慮用 CSS 隱藏文字，但我們目前沒包 span，先留著 */
    }

    /* 5. 解決手機版容易誤觸影片的問題 (防誤觸遮罩) */
    .monitor-cell::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 75%; /* 覆蓋影片上方 75% 區域，專門用來滑動 */
        z-index: 5;
    }

    .cell-overlay {
        z-index: 10; /* 確保控制按鈕在防誤觸遮罩之上 */
    }
}