@charset "utf-8";
 /* =========================================
       1. 基礎與深色主題設定
       ========================================= */
    :root {
        --theme-color: #ff004d; /* 桃紅色重點色 */
        --bg-color: #121212;
        --card-bg: #1e1e1e;
    }

    body {
        background-color: var(--bg-color);
    }

    /* =========================================
       2. Hero 區塊 (左影片/右資訊)
       ========================================= */
    .course-hero-section {
        background-color: #000;
        padding: 40px 0 60px 0;
        color: #fff;
    }

    .hero-grid {
        display: grid;
        grid-template-columns: 1.6fr 1fr;
        gap: 40px;
        align-items: start;
        max-width: 1200px;
        margin: 0 auto;
        padding: 0 20px;
    }

    .video-container {
        position: relative;
        padding-bottom: 56.25%; /* 16:9 */
        height: 0;
        overflow: hidden;
        border-radius: 8px;
        background: #000;
    }

    .video-container iframe {
        position: absolute;
        top: 0; left: 0;
        width: 100%; height: 100%;
    }

    .course-info-card {
        background: var(--card-bg);
        padding: 25px;
        border-radius: 10px;
        border: 1px solid #333;
    }

    .info-stat-joined { color: #ccc; font-size: 14px; margin-bottom: 15px; display: block; }
    
    .info-list { list-style: none; padding: 0; margin: 0 0 20px 0; }
    .info-list li { margin-bottom: 12px; font-size: 15px; color: #ddd; display: flex; align-items: center; }
    .info-list li i { width: 24px; margin-right: 8px; color: #999; text-align: center; }

    .installment-plan { border-top: 1px solid #444; padding-top: 15px; margin-top: 15px; color: #aaa; font-size: 14px; display: flex; align-items: center; }
    .installment-plan i { color: #28a745; margin-right: 8px; }

    .price-area { margin-top: 25px; display: flex; align-items: baseline; gap: 12px; }
    .price-sale { font-size: 32px; font-weight: bold; color: var(--theme-color); }
    .price-original { font-size: 16px; text-decoration: line-through; color: #777; }

    .btn-buy-large { display: block; width: 100%; background-color: var(--theme-color); color: #fff; text-align: center; padding: 14px; border-radius: 6px; font-weight: bold; font-size: 18px; margin-top: 20px; text-decoration: none; transition: 0.3s; }
    .btn-buy-large:hover { filter: brightness(1.1); }

    /* =========================================
       3. 頁籤導航 (Fixed 模擬 Sticky)
       ========================================= */
    .course-nav-bar {
        width: 100%;
        background-color: #000;
        border-bottom: 1px solid #333;
        z-index: 900;
        height: 60px; /* 固定高度 */
        transition: top 0.2s; /* 定位切換順暢 */
    }

    /* ★ JS 控制：當變成 Fixed 時的樣式 ★ */
    .course-nav-bar.is-fixed {
        position: fixed;
        left: 0;
        box-shadow: 0 5px 15px rgba(0,0,0,0.5);
    }

    .tabs-inner {
        max-width: 1200px;
        margin: 0 auto;
        padding: 0 20px;
        display: flex;
        gap: 40px;
        height: 100%;
        align-items: center;
    }

    .tab-item {
        color: #aaa;
        text-decoration: none;
        font-size: 16px;
        height: 100%;
        display: flex;
        align-items: center;
        position: relative;
        cursor: pointer;
        font-weight: 500;
    }

    .tab-item:hover, .tab-item.active { color: #fff; }

    .tab-item.active::after {
        content: '';
        position: absolute;
        bottom: 0; left: 0; width: 100%; height: 3px;
        background-color: var(--theme-color);
    }

    /* =========================================
       4. 內容區塊
       ========================================= */
    .content-area { 
        max-width: var(--container-width); 
        margin: 0 auto; 
        padding:0 var(--container-padding-x); 
    }

    .course-section {
        padding: 60px 0;
        border-bottom: 1px solid #222;
    }

    .section-title { font-size: 28px; margin-bottom: 30px; color: #fff; padding-left: 15px; border-left: 4px solid var(--theme-color); }
    .text-highlight { font-size: 24px; line-height: 1.5; margin-bottom: 20px; color: #eebb99; }
    .text-highlight b { color: #eebb99; }
    .course-body p, .course-body li { font-size: 18px; line-height: 1.8; color: #ccc; margin-bottom: 15px; }

    /* =========================================
       5. FAQ 手風琴樣式 (配合 script.js 邏輯)
       ========================================= */
    .faq-list {
        display: flex;
        flex-direction: column;
        gap: 15px;
    }

    .faq-item {
        background-color: #1e1e1e;
        border: 1px solid #333;
        border-radius: 8px;
        overflow: hidden;
        transition: border-color 0.3s;
    }

    .faq-item:hover { border-color: #555; }

    /* 題目 */
    .faq-question {
        padding: 20px;
        cursor: pointer;
        display: flex;
        justify-content: space-between;
        align-items: center;
        font-weight: bold;
        font-size: 18px;
        color: #fff;
        background-color: #1e1e1e;
        transition: background-color 0.3s;
    }

    .faq-question:hover { background-color: #2a2a2a; }

    .faq-question .icon {
        color: var(--theme-color);
        transition: transform 0.3s;
    }

    /* 答案 (關鍵：動畫與隱藏) */
    .faq-answer {
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease-out;
        background-color: #181818;
    }

    .answer-content {
        padding: 20px;
        border-top: 1px solid #333;
        color: #ccc;
        line-height: 1.6;
        font-size: 16px;
    }

    /* 當 script.js 加上 active class 時 */
    .faq-item.active .faq-question .icon {
        transform: rotate(45deg); 
    }

    /* RWD */
    @media (max-width: 900px) {
        .hero-grid { grid-template-columns: 1fr; }
        .tabs-inner { overflow-x: auto; white-space: nowrap; padding: 0 15px; gap: 25px; }
    }