/* --- CSS 樣式引擎 (專業優化版) --- */

/* * UI/UX 優化: 專業級雙主題設計 (明亮 & 暗黑)
 * 採用 CSS 變數實現無縫主題切換。
 * 預設為暗黑模式，並提供明亮模式選項。
 * 針對微交互、視覺層次與細節進行了精緻化處理。
*/

/* --- 顏色配置 --- */
:root {
    /* 字體設定 */
    --primary-font: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

    /* 動畫與過渡 */
    --transition-fast: 0.2s ease;
    --transition-smooth: 0.3s ease;
    --card-border-radius: 12px;
}

/* --- 明亮模式顏色變數 --- */
body.light-theme {
    --background-color: #F9FAFB;       /* 非常淺的灰色背景 */
    --primary-text-color: #111827;     /* 深藍灰主文字 */
    --secondary-text-color: #6B7280;   /* 中度灰色次要文字 */
    --accent-color: #14B8A6;           /* 鮮明的青色點綴 */
    --accent-color-hover: #0F766E;     /* 點綴色懸停狀態 */
    --border-color: #E5E7EB;           /* 淺灰色邊框 */
    --card-background: #FFFFFF;        /* 純白卡片背景 */
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --offer-text-color: #065F46;       /* 深綠色優惠文字 */
    --offer-background-color: #D1FAE5; /* 淺綠色優惠背景 */
    --success-color: #10B981;          /* 成功狀態顏色 */
    --header-background-start: #FFFFFF;
    --header-background-end: #F9FAFB;
    --skeleton-base-color: #E5E7EB;
    --skeleton-pulse-color: #F3F4F6;
    --theme-button-background: #E5E7EB;
    --theme-button-background-active: #FFFFFF;
    --theme-button-color: #6B7280;
    --theme-button-color-active: #14B8A6;
    --social-link-color: #6B7280;
    --social-link-color-hover: #111827;
    --category-nav-background: rgba(249, 250, 251, 0.85);
}

/* --- 暗黑模式顏色變數 --- */
body.dark-theme {
    --background-color: #111827;       /* 深藍灰主背景 */
    --primary-text-color: #E5E7EB;     /* 明亮清晰的灰白主文字 */
    --secondary-text-color: #9CA3AF;   /* 柔和的次要文字灰 */
    --accent-color: #5EEAD4;           /* 亮青色點綴 */
    --accent-color-hover: #2DD4BF;     /* 點綴色懸停狀態 */
    --border-color: #374151;           /* 邊框與分隔線顏色 */
    --card-background: #1F2937;        /* 卡片與表單背景 */
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.15), 0 4px 6px -2px rgba(0, 0, 0, 0.1);
    --offer-text-color: #A7F3D0;       /* 優惠標籤文字 */
    --offer-background-color: #10403c; /* 優惠標籤背景 */
    --success-color: #34D399;          /* 成功狀態顏色 */
    --header-background-start: #1F2937;
    --header-background-end: #111827;
    --skeleton-base-color: #374151;
    --skeleton-pulse-color: #4B5563;
    --theme-button-background: #374151;
    --theme-button-background-active: #1F2937;
    --theme-button-color: #9CA3AF;
    --theme-button-color-active: #5EEAD4;
    --social-link-color: #9CA3AF;
    --social-link-color-hover: #E5E7EB;
    --category-nav-background: rgba(17, 24, 39, 0.85);
}


/* --- 全局樣式重置與基礎設定 --- */
*, *::before, *::after {
    box-sizing: border-box;
}

body {
    font-family: var(--primary-font);
    background-color: var(--background-color);
    color: var(--primary-text-color);
    margin: 0;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color var(--transition-fast), color var(--transition-fast);
}


/* --- 主要佈局容器 --- */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 2rem; /* Remove top/bottom padding to allow sticky nav to work correctly */
}


/* --- 頁首 --- */
.header {
    padding: 1.5rem 1rem;
    text-align: center;
}
.header-top {
    display: flex;
    justify-content: space-between; /* Space between social links and theme switcher */
    align-items: center;
    margin-bottom: 1.5rem;
}
.header h1 {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
    letter-spacing: -1.5px;
    margin-bottom: 1rem;
    color: var(--primary-text-color);
    text-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
}
.header p {
    font-size: 1.15rem;
    color: var(--secondary-text-color);
    max-width: 680px;
    margin: 0.5rem auto 0;
    line-height: 1.7;
}
.header #disclaimer-text {
    font-size: 0.9rem;
    color: var(--secondary-text-color);
    margin: 2.5rem auto 0;
    padding: 1.25rem 1.5rem;
    background-color: rgba(31, 41, 55, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    max-width: 650px;
    line-height: 1.7;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.1);
}
body.dark-theme .header #disclaimer-text {
    background-color: rgba(31, 41, 55, 0.5);
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.2);
}
.header #disclaimer-text h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary-text-color);
    margin-bottom: 0.5rem;
}

/* --- 社交連結 --- */
.social-links {
    display: flex;
    align-items: center;
    gap: 1rem;
}
.social-links a {
    color: var(--social-link-color);
    transition: color var(--transition-fast), transform var(--transition-fast);
    display: inline-block; /* Needed for transform */
}
.social-links a:hover {
    color: var(--social-link-color-hover);
    transform: scale(1.15); /* Add a subtle scale effect on hover */
}

/* --- 主題切換器 --- */
.theme-switcher {
    display: inline-flex;
    background-color: var(--theme-button-background);
    border-radius: 999px;
    padding: 0.25rem;
    transition: background-color var(--transition-fast);
}
.theme-button {
    border: none;
    background-color: transparent;
    color: var(--theme-button-color);
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}
.theme-button:hover {
    color: var(--theme-button-color-active);
}
.theme-button.active {
    background-color: var(--theme-button-background-active);
    color: var(--theme-button-color-active);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}


/* --- 分類導航列 --- */
.category-nav {
    position: sticky;
    top: -1px; /* Prevents a 1px gap on some browsers */
    background-color: var(--category-nav-background);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid transparent; /* Start with a transparent border */
    z-index: 900;
    padding: 0.75rem 0;
    margin-bottom: 2.5rem;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.category-nav.scrolled {
    border-bottom-color: var(--border-color);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}
body.dark-theme .category-nav.scrolled {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}
.category-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.5rem 0.75rem;
}
.category-link {
    text-decoration: none;
    color: var(--primary-text-color);
    font-weight: 600; /* Make text slightly bolder */
    padding: 0.6rem 1.1rem;
    display: block;
    border-radius: 8px;
    transition: all var(--transition-fast);
    cursor: pointer;
    border: 1px solid transparent;
}
.category-link:hover {
    background-color: var(--border-color);
    color: var(--primary-text-color);
}
.category-link.active {
    color: var(--accent-color);
    font-weight: 700;
    background-color: var(--offer-background-color);
    border-color: var(--accent-color);
    transform: scale(1.05); /* Add a slight scale to the active item */
}


/* --- 主內容區 --- */
.main-content {
    padding-top: 1rem; /* Add padding to the top of the main content */
}


/* --- 優惠網格容器 --- */
.deals-container {
    width: 100%;
}


/* --- 控制項標頭 (搜尋 + 排序) --- */
.controls-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}
.search-container {
    position: relative;
    flex-grow: 1;
    max-width: 450px;
}
.search-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--secondary-text-color);
    pointer-events: none;
    width: 20px;
    height: 20px;
    transition: color var(--transition-fast);
}
#search-bar {
    width: 100%;
    padding: 0.75rem 2.5rem;
    font-size: 1rem;
    background-color: var(--card-background);
    color: var(--primary-text-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    outline: none;
    transition: all var(--transition-fast);
}
#search-bar:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.2);
}
body.dark-theme #search-bar:focus {
    box-shadow: 0 0 0 3px rgba(94, 234, 212, 0.2);
}
#search-bar:focus + .search-icon {
    color: var(--accent-color);
}


/* --- 篩選標籤 (最熱門 / 最近新增) --- */
.tabs {
    display: flex;
    gap: 0.5rem;
    background-color: var(--card-background);
    padding: 0.25rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}
.tab-link {
    padding: 0.5rem 1rem;
    cursor: pointer;
    border: none;
    background-color: transparent;
    border-radius: 6px;
    font-weight: 600;
    color: var(--secondary-text-color);
    transition: all var(--transition-fast);
}
.tab-link:hover {
    color: var(--primary-text-color);
}
.tab-link.active {
    color: var(--background-color);
    background-color: var(--accent-color);
    box-shadow: 0 2px 8px rgba(20, 184, 166, 0.2);
}
body.dark-theme .tab-link.active {
    box-shadow: 0 2px 8px rgba(94, 234, 212, 0.2);
}


/* --- 優惠卡片網格 --- */
.deals-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}


/* * UI/UX 優化: 精緻化卡片設計與微交互
*/
.deal-card {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--card-border-radius);
    display: flex;
    flex-direction: column;
    text-decoration: none;
    color: inherit;
    transition: transform var(--transition-smooth), box-shadow var(--transition-smooth), border-color var(--transition-fast);
    box-shadow: var(--card-shadow);
    overflow: hidden;
}
.deal-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--card-shadow-hover);
    border-color: var(--accent-color-hover);
}
.card-content-link {
    padding: 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    text-decoration: none;
    color: inherit;
}
.card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}
.card-logo {
    width: 48px;
    height: 48px;
    object-fit: contain;
    border-radius: 8px;
    background-color: #fff;
    padding: 4px;
    border: 1px solid var(--border-color);
}
.card-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-text-color);
    margin: 0;
}
.card-body {
    flex-grow: 1;
}
.card-description {
    font-size: 0.95rem;
    color: var(--secondary-text-color);
    margin: 0 0 1.5rem 0;
    line-height: 1.5;
}
.card-offer {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--offer-text-color);
    background-color: var(--offer-background-color);
    padding: 0.4rem 0.75rem;
    border-radius: 6px;
    display: inline-block;
    margin-bottom: 0.5rem;
}
.card-savings {
    font-size: 0.85rem;
    color: var(--secondary-text-color);
    margin: 0;
}

/* * UI/UX 優化: 新增實用功能 - 複製連結按鈕
*/
.card-footer {
    padding: 0.75rem 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: transparent;
}
body.dark-theme .card-footer {
    background-color: rgba(17, 24, 39, 0.5);
}
.card-cta {
    font-weight: 600;
    color: var(--accent-color);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: background-color var(--transition-fast), color var(--transition-fast);
}
.card-cta:hover {
    background-color: var(--accent-color);
    color: var(--background-color);
}
.copy-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--border-color);
    border: 1px solid transparent;
    color: var(--secondary-text-color);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}
.copy-button:hover {
    background-color: #D1D5DB;
    color: var(--primary-text-color);
    border-color: var(--secondary-text-color);
}
body.dark-theme .copy-button:hover {
    background-color: #4B5563;
    color: var(--primary-text-color);
}
.copy-button.success {
    background-color: var(--success-color);
    border-color: transparent;
    color: #fff;
}
.copy-button .icon {
    width: 16px;
    height: 16px;
}


/* --- 智慧型空狀態 --- */
.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 4rem 2rem;
    background-color: var(--card-background);
    border-radius: var(--card-border-radius);
    border: 1px dashed var(--border-color);
}
.empty-state h4 {
    font-size: 1.5rem;
    margin: 0 0 0.5rem 0;
}
.empty-state p {
    color: var(--secondary-text-color);
    max-width: 400px;
    margin: 0 auto;
}


/* --- 頁尾 --- */
.footer {
    text-align: center;
    margin-top: 4rem;
    padding: 2rem 0;
    border-top: 1px solid var(--border-color);
    font-size: 0.9rem;
    color: var(--secondary-text-color);
}
.footer p {
    margin: 0.5rem 0;
}


/* --- 響應式設計 (RWD) --- */
@media (max-width: 768px) {
   .controls-header {
        flex-direction: column;
        align-items: stretch;
   }
   .search-container {
        max-width: 100%;
   }
   .header-top {
       flex-direction: column;
       gap: 1rem;
       align-items: center;
   }

   /* --- 手機版分類導覽列最終優化 --- */
   .category-nav {
       /* 恢復黏貼效果 (移除 position: relative) */
       -webkit-overflow-scrolling: touch;
   }

   /* 右側漸層，提示可以水平滾動 */
   .category-nav::after {
       content: '';
       position: absolute;
       top: 0;
       right: 0;
       width: 40px;
       height: 100%;
       /* 使用導覽列的背景變數，確保無縫融合 */
       background: linear-gradient(to left, var(--category-nav-background), transparent);
       pointer-events: none; /* 確保不會阻擋點擊 */
       z-index: 1; /* 確保漸層在內容之上 */
   }

   .category-list {
       flex-wrap: nowrap;
       justify-content: flex-start;
       overflow-x: auto;
       padding: 0.5rem 1rem;
       gap: 0.5rem; /* 縮小間距 */
       -ms-overflow-style: none;
       scrollbar-width: none;
   }

   .category-list::-webkit-scrollbar {
       display: none;
   }

   .category-link {
       flex-shrink: 0;
       padding: 0.4rem 0.8rem; /* 縮小內邊距 */
       white-space: nowrap;
       font-size: 0.9rem; /* 縮小字體 */
   }
}

/* --- Skeleton Loader Styles --- */
@keyframes pulse-light {
    0% { background-color: var(--skeleton-base-color); }
    50% { background-color: var(--skeleton-pulse-color); }
    100% { background-color: var(--skeleton-base-color); }
}
@keyframes pulse-dark {
    0% { background-color: var(--skeleton-base-color); }
    50% { background-color: var(--skeleton-pulse-color); }
    100% { background-color: var(--skeleton-base-color); }
}
.skeleton-card {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--card-border-radius);
    padding: 1.5rem;
}
.skeleton-card .skeleton-item {
    background-color: var(--skeleton-base-color);
    border-radius: 4px;
}
body.light-theme .skeleton-card .skeleton-item {
    animation: pulse-light 1.5s infinite ease-in-out;
}
body.dark-theme .skeleton-card .skeleton-item {
    animation: pulse-dark 1.5s infinite ease-in-out;
}
.skeleton-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}
.skeleton-logo {
    width: 48px;
    height: 48px;
    border-radius: 8px;
}
.skeleton-title {
    height: 24px;
    width: 70%;
}
.skeleton-description {
    height: 16px;
    margin-bottom: 0.5rem;
}
.skeleton-description:nth-child(2) { width: 90%; }
.skeleton-description:nth-child(3) { width: 80%; }
.skeleton-offer {
    height: 32px;
    width: 50%;
    margin-top: 1.5rem;
    border-radius: 6px;
}


/* --- 回到頂部按鈕 --- */
#scroll-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--accent-color);
    color: var(--background-color);
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 1.5rem;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: opacity var(--transition-smooth), visibility var(--transition-smooth), transform var(--transition-smooth), background-color var(--transition-fast);
    z-index: 1000;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}
#scroll-to-top:hover {
    background-color: var(--accent-color-hover);
    transform: translateY(15px) scale(1.05);
}
#scroll-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}


/* --- 搜尋欄清除按鈕 --- */
.search-clear-button {
    position: absolute;
    right: 0.5rem;
    top: 50%;
    transform: translateY(-50%) scale(0.8);
    background: transparent;
    border: none;
    color: var(--secondary-text-color);
    cursor: pointer;
    font-size: 1.5rem;
    padding: 0.25rem;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}
#search-bar:not(:placeholder-shown) + .search-clear-button {
    opacity: 0.7;
    pointer-events: auto;
    transform: translateY(-50%) scale(1);
}
#search-bar:not(:placeholder-shown) + .search-clear-button:hover {
    opacity: 1;
    color: var(--primary-text-color);
}

/* 禁用瀏覽器原生的搜尋輸入框清除按鈕 */
input[type="search"]::-webkit-search-cancel-button {
    -webkit-appearance: none; /* 移除 WebKit 瀏覽器的默認樣式 */
    appearance: none; /* 標準屬性 */
    display: none; /* 確保完全隱藏 */
}