/**
 * Tad Carousel v1.0.0
 * 現代化、無障礙輪播元件
 * WCAG 2.3 AAA 相容
 */

/* ===== CSS 變數定義 ===== */
:root {
    --tad-carousel-transition: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --tad-carousel-gap: 1rem;
    --tad-carousel-nav-size: 3rem;
    --tad-carousel-nav-bg: rgba(0, 0, 0, 0.8);
    --tad-carousel-nav-bg-hover: rgba(0, 0, 0, 1);
    --tad-carousel-nav-color: #ffffff;
    --tad-carousel-dot-size: 0.75rem;
    --tad-carousel-dot-color: rgba(0, 0, 0, 0.3);
    --tad-carousel-dot-active: #000000;
    --tad-carousel-focus-outline: 3px solid #005fcc;
    --tad-carousel-focus-offset: 2px;
}

/* ===== 主容器 ===== */
.tad-carousel {
    position: relative;
    width: 100%;
    overflow: hidden;
}

.tad-carousel[aria-busy="true"] {
    cursor: wait;
}

/* ===== 軌道容器 ===== */
.tad-carousel__track-container {
    overflow: hidden;
    margin: 0;
    padding: 0;
}

.tad-carousel__track {
    display: flex;
    gap: var(--tad-carousel-gap);
    transition: transform var(--tad-carousel-transition);
    will-change: transform;
    list-style: none;
    margin: 0;
    padding: 0;
}

/* 減少動態效果偏好 */
@media (prefers-reduced-motion: reduce) {
    .tad-carousel__track {
        transition: none;
    }
}

/* ===== 項目 ===== */
.tad-carousel__item {
    flex: 0 0 auto;
    min-width: 0;
}

.tad-carousel__item>* {
    max-width: 100%;
    height: auto;
}

/* ===== 導航按鈕 ===== */
.tad-carousel__nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
    width: var(--tad-carousel-nav-size);
    height: var(--tad-carousel-nav-size);
    padding: 0;
    border: none;
    border-radius: 50%;
    background: var(--tad-carousel-nav-bg);
    color: var(--tad-carousel-nav-color);
    font-size: 1.25rem;
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.tad-carousel__nav:hover {
    background: var(--tad-carousel-nav-bg-hover);
}

.tad-carousel__nav:focus-visible {
    outline: var(--tad-carousel-focus-outline);
    outline-offset: var(--tad-carousel-focus-offset);
}

.tad-carousel__nav:active {
    transform: translateY(-50%) scale(0.95);
}

.tad-carousel__nav:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.tad-carousel__nav--prev {
    left: 0.5rem;
}

.tad-carousel__nav--next {
    right: 0.5rem;
}

/* 導航圖示 */
.tad-carousel__nav-icon {
    display: block;
    width: 1em;
    height: 1em;
    fill: currentColor;
}

/* ===== 分頁指示器 ===== */
.tad-carousel__dots {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
    padding: 0;
    list-style: none;
}

.tad-carousel__dot {
    width: var(--tad-carousel-dot-size);
    height: var(--tad-carousel-dot-size);
    padding: 0;
    border: 2px solid var(--tad-carousel-dot-active);
    border-radius: 50%;
    background: var(--tad-carousel-dot-color);
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.tad-carousel__dot:hover {
    transform: scale(1.2);
}

.tad-carousel__dot:focus-visible {
    outline: var(--tad-carousel-focus-outline);
    outline-offset: var(--tad-carousel-focus-offset);
}

.tad-carousel__dot[aria-selected="true"],
.tad-carousel__dot.is-active {
    background: var(--tad-carousel-dot-active);
}

/* ===== 即時區域（螢幕閱讀器） ===== */
.tad-carousel__live-region {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ===== 暫停/播放按鈕 ===== */
.tad-carousel__autoplay-toggle {
    position: absolute;
    bottom: 0.5rem;
    right: 0.5rem;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    padding: 0;
    border: none;
    border-radius: 50%;
    background: var(--tad-carousel-nav-bg);
    color: var(--tad-carousel-nav-color);
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.tad-carousel__autoplay-toggle:hover {
    background: var(--tad-carousel-nav-bg-hover);
}

.tad-carousel__autoplay-toggle:focus-visible {
    outline: var(--tad-carousel-focus-outline);
    outline-offset: var(--tad-carousel-focus-offset);
}

/* ===== 響應式設計 ===== */
@media (max-width: 768px) {
    :root {
        --tad-carousel-nav-size: 2.5rem;
        --tad-carousel-gap: 0.5rem;
    }

    .tad-carousel__nav--prev {
        left: 0.25rem;
    }

    .tad-carousel__nav--next {
        right: 0.25rem;
    }
}

@media (max-width: 480px) {
    .tad-carousel__nav {
        --tad-carousel-nav-size: 2rem;
        font-size: 1rem;
    }
}

/* ===== 高對比模式支援 ===== */
@media (prefers-contrast: high) {
    :root {
        --tad-carousel-nav-bg: #000000;
        --tad-carousel-nav-color: #ffffff;
        --tad-carousel-dot-color: transparent;
        --tad-carousel-dot-active: #000000;
        --tad-carousel-focus-outline: 3px solid #ffffff;
    }
}

/* ===== 深色模式支援 ===== */
@media (prefers-color-scheme: dark) {
    :root {
        --tad-carousel-nav-bg: rgba(255, 255, 255, 0.9);
        --tad-carousel-nav-bg-hover: rgba(255, 255, 255, 1);
        --tad-carousel-nav-color: #000000;
        --tad-carousel-dot-color: rgba(255, 255, 255, 0.3);
        --tad-carousel-dot-active: #ffffff;
    }
}