:root {
    --brand-color: #007bff;
    --border-color: #e0e0e0;
    --panel-bg: #ffffff;
    --body-bg: #f4f7f6;
    --text-primary: #333;
    --text-secondary: #777;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--body-bg);
    color: var(--text-primary);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* --- Header --- */
header {
    padding: 1rem 1.5rem; /* 增加左右 padding */
    background-color: var(--panel-bg);
    box-shadow: var(--shadow);
    z-index: 100;
}

/* 標題與選單的 Flex 容器 */
.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 0;
    white-space: nowrap;
    flex-grow: 1;
    text-align: center;
}

.header-group {
    display: flex;
    align-items: center;
    flex-basis: 60px; 
}

.header-group.header-left {
    justify-content: flex-start;
}

.header-group.header-right {
    justify-content: flex-end;
    min-width: 44px; 
}

.language-selector {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 1rem;
    width: 100%;
}
/* --- Header 結束 --- */

.lang-control {
    position: relative;
}

.lang-btn {
    font-size: 1rem;
    font-weight: 500;
    padding: 0.6rem 1rem;
    width: 100%;
    border: 0px solid var(--border-color);
    border-radius: 8px;
    background-color: transparent;
    cursor: pointer;
    transition: background-color 0.2s, box-shadow 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.lang-btn:hover {
    background-color: transparent;
}



/* 為按鈕內的圖示設定樣式 */
.lang-btn .material-symbols-outlined {
    font-size: 20px;
    line-height: 1;
}

.swap-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 0px solid var(--border-color);
    background-color: transparent;
    color: var(--brand-color);
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s;
}

.swap-btn:hover {
    transform: scale(1.1) rotate(180deg);
    background-color: transparent;
}

.swap-btn .material-symbols-outlined {
    font-size: 24px;
}

/* --- Popover Menu --- */
.popover {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    width: 100%;
    background-color: var(--panel-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: var(--shadow);
    z-index: 200;
    max-height: 300px;
    overflow-y: auto;
    padding: 0.5rem;
}

.popover.hidden {
    display: none;
}

.popover button {
    display: block;
    width: 100%;
    padding: 0.75rem 1rem;
    text-align: left;
    background: none;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1rem;
}

.popover button:hover {
    background-color: #f0f0f0;
}

.popover button.active {
    background-color: #e6f2ff;
    color: var(--brand-color);
    font-weight: 600;
}

.popover button:disabled {
    color: #aaa;
    background-color: #f9f9f9;
    cursor: not-allowed;
}

/* 【新增】語言選單的 Grid 樣式 */
.popover-lang-grid {
    /* 覆蓋 .popover 的 width: 100% */
    width: auto;
    min-width: 320px;
    max-width: 400px;

    /* Grid 佈局 */
    display: grid;
    /* 建立多欄，每欄最小 90px，最大 1fr (均分) */
    grid-template-columns: repeat(auto-fit, minmax(90px, 1fr));
    gap: 0.25rem;
    padding: 0.5rem; /* 確保 padding 一致 */
}

/* 修正右側選單的對齊 (使其靠右) */
#popoverRight.popover-lang-grid {
    left: auto;
    right: 0;
}

/* Grid 內按鈕的樣式 */
.popover-lang-grid button {
    /* 覆蓋 .popover button 的 text-align: left */
    text-align: center;
    width: 100%; /* 填滿 grid 欄位 */
    padding: 0.6rem 0.5rem; /* 調整 padding */
    font-size: 0.95rem;
    white-space: nowrap;
}

/* 覆蓋 .popover button:hover */
.popover-lang-grid button:hover {
    background-color: #f0f0f0;
}

/* 覆蓋 .popover button.active */
.popover-lang-grid button.active {
    background-color: #e6f2ff;
    color: var(--brand-color);
    font-weight: 600;
}

/* --- Main Content --- */
.translator-container {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    gap: 0rem;
    padding: 1.5rem 1.5rem 3rem 1.5rem;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
}

/* 包裹兩個翻譯面板的容器 */
.panels-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    flex-grow: 1;
    width: 100%;
    min-height: 0; 
}

.panel {
    display: flex;
    flex-direction: column;
    background-color: var(--panel-bg);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

textarea {
    flex-grow: 1;
    min-height: 300px;
    width: 100%;
    padding: 1.25rem 1.25rem 1.25rem 1.25rem;
    border: none;
    resize: none;
    outline: none;
    font-size: 1.1rem;
    line-height: 1.7;
    font-family: inherit;
    background-color: transparent;
    border-top-left-radius: 12px;
    border-top-right-radius: 12px;
}

textarea#textOutput {
    color: var(--text-primary);
}

/* --- Toolbars --- */
.panel-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background-color: #fdfdfd;
    border-bottom-left-radius: 12px;
    border-bottom-right-radius: 12px;
}

.toolbar-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* 右側工具列（只有一組按鈕） */
.panel-right .panel-toolbar {
    justify-content: flex-end;
}

.icon-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: none;
    color: var(--text-secondary);
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    transition: background-color 0.2s;
}

.icon-btn:hover {
    background-color: #f0f0f0;
}

.icon-btn .material-symbols-outlined {
    font-size: 20px;
}

/* 【新增】即時翻譯控制項 */
.translate-controls {
    gap: 1rem;
}

.instant-translate-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
    cursor: pointer;
    user-select: none; /* 防止選取文字 */
}

.instant-translate-label input[type="checkbox"] {
    width: 16px;
    height: 16px;
    cursor: pointer;
}

.manual-translate-btn {
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.4rem 0.8rem;
    border: 1px solid var(--brand-color);
    background-color: var(--brand-color);
    color: white;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s, opacity 0.2s;
}

.manual-translate-btn:hover {
    background-color: #0056b3;
}

.manual-translate-btn.hidden {
    display: none;
}
/* --- Toolbars 結束 --- */

/* --- 【新增】分離式翻譯按鈕 --- */
.split-btn-container {
    position: relative; /* 為了 popover 定位 */
    display: inline-flex; /* 讓兩個按鈕並排 */
    align-items: center;
    border-radius: 6px;
    /* overflow: hidden;  <-- 已移除這一行 */
    border: 1px solid var(--brand-color);
    background-color: var(--brand-color);
    color: white;
}

/* 隱藏整個容器 (取代舊的 .manual-translate-btn.hidden) */
.split-btn-container.hidden {
    display: none;
}

/* 主動作按鈕 (左側) */
.split-btn-action {
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.4rem 0.8rem;
    background-color: transparent;
    color: white;
    border: none;
    cursor: pointer;
    transition: background-color 0.2s;
    /* 讓按鈕文字可以被 JS 變更 */
    white-space: nowrap; 
}
.split-btn-action:hover {
    background-color: #0056b3;
}

/* 下拉選單觸發按鈕 (右側) */
.split-btn-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.4rem 0.2rem; /* 左右 padding 窄一點 */
    background-color: transparent;
    color: white;
    border: none;
    /* 中間的分隔線 */
    border-left: 1px solid rgba(255, 255, 255, 0.4); 
    cursor: pointer;
    transition: background-color 0.2s;
}
.split-btn-toggle:hover {
    background-color: #0056b3;
}
.split-btn-toggle .material-symbols-outlined {
    font-size: 20px;
}

/* 翻譯選項 Popover 的特定樣式 */
.translate-popover {
    /* 覆蓋 .popover 的預設值 */
    top: auto; /* <-- 關鍵修改：取消繼承的 top */
    bottom: calc(100% + 4px); /* 維持向上彈開 */
    left: auto; /* 取消左側對齊 */
    right: 0; /* 改為右側對齊 */
    width: auto;
    min-width: 150px;
    white-space: nowrap;
    max-height: unset; 
    overflow-y: visible;
}
/* --- 分離式按鈕 結束 --- */

/* --- 【新增】Toast 提示樣式 --- */
#toastContainer {
    position: fixed;
    top: 15%;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.toast-message {
    background-color: rgba(30, 30, 30, 0.9);
    color: white;
    padding: 0.75rem 1.25rem;
    border-radius: 2rem;
    font-size: 0.9rem;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    animation: toast-fade-in 0.3s ease-out, toast-fade-out 0.3s ease-in 2.7s;
}

@keyframes toast-fade-in {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes toast-fade-out {
    from {
        opacity: 1;
        transform: translateY(0);
    }
    to {
        opacity: 0;
        transform: translateY(20px);
    }
}
/* --- Toast 結束 --- */





/* --- Sidebar Settings --- */
.backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.4);
    z-index: 999;
    opacity: 1;
    transition: opacity 0.3s ease-in-out;
}
.backdrop.hidden {
    opacity: 0;
    pointer-events: none;
}

.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 300px;
    max-width: 80vw;
    background-color: var(--panel-bg);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transform: translateX(-100%);
    transition: transform 0.3s ease-in-out;
}

.sidebar:not(.hidden) {
    transform: translateX(0);
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 0;
}

.sidebar-content {
    padding: 1.5rem;
    overflow-y: auto;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.setting-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.setting-item label {
    font-weight: 500;
    font-size: 0.95rem;
}

.setting-item input[type="text"] {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    font-family: inherit;
}

.setting-item small {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.setting-item select {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    font-family: inherit;
    background-color: var(--panel-bg); /* 確保背景色 */
}



/* --- End Sidebar --- */





/* --- Responsive (Mobile) --- */
@media (max-width: 768px) {
    header {
        padding: 1rem;
    }

	/* 標題與選單改為堆疊 */
    .header-content {
        gap: 0.5rem; /* 縮小標題與按鈕的間距 */
    }

    header h1 {
        font-size: 1.25rem;
    }

	.header-group {
        /* 縮小左右群組的基礎寬度，讓標題有更多空間 */
        flex-basis: 44px; 
    }

    .language-selector {
        max-width: 100%;
        gap: 0.75rem;
    }

    .lang-btn {
        padding: 0.5rem 0.8rem;
        font-size: 0.9rem;
    }

    .swap-btn {
        width: 40px;
        height: 40px;
    }
    .swap-btn .material-symbols-outlined {
        font-size: 22px;
    }

    .translator-container {
        padding: 1rem;
        gap: 1rem;
    }

    /* 讓面板在行動版堆疊 */
    .panels-wrapper {
        grid-template-columns: 1fr;
    }

    .panel {
        height: auto;
    }

    textarea {
        min-height: 170px;
        font-size: 1.2rem;
    }

    .panel-toolbar {
        gap: 0.75rem;
    }
    
    .toolbar-group {
    }

    /* 右側工具列在行動版上也要靠右 */
    .panel-right .panel-toolbar {
        justify-content: flex-end;
    }
	/* 行動版 Grid 彈窗樣式 */
    .popover-lang-grid {
        min-width: 0;
        width: 100%; /* 在行動版上，彈窗寬度 = 父層寬度 */
        max-width: 100%;
        /* 使用 3 欄固定，或 auto-fit 讓它自動排 */
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    }

    .popover-lang-grid button {
        font-size: 0.9rem;
        padding: 0.6rem 0.25rem;
    }
}