/* ==============================================
   效能優化版 - 圖片壓縮工具 CSS
   設計原則：
   1. 移除不必要的漸變和動畫
   2. 精簡配色系統
   3. 強化視覺層級
   4. 優化手機體驗
============================================== */

/* CSS Variables */
:root {
    /* 精簡後的配色 */
    --primary: #6C63FF;
    --primary-light: #8B80FF;
    --primary-dark: #5A54D9;
    --success: #00D68F;
    --danger: #FF4757;
    --warning: #FFA502;

    /* 文字顏色 */
    --text-primary: #2E3338;
    --text-secondary: #6C757D;
    --text-disabled: #ADB5BD;

    /* 背景顏色 */
    --bg-primary: #F8F9FA;
    --bg-secondary: #E9ECEF;
    --card-bg: #FFFFFF;

    /* 邊框與陰影 */
    --border-color: #DEE2E6;
    --border-radius: 8px;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.15);

    /* 動畫 - 統一時長 */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.2s ease;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans TC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    padding: 20px;
    -webkit-font-smoothing: antialiased;
}

/* Container */
.app-container {
    max-width: 1000px;
    margin: 0 auto;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 40px;
    position: relative;
}

/* 主題切換按鈕 */
.theme-toggle {
    position: absolute;
    top: 0;
    right: 0;
    width: 44px;
    height: 44px;
    border: none;
    border-radius: 50%;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1.2rem;
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-sm);
}

.theme-toggle:hover {
    background: var(--primary);
    color: white;
    transform: rotate(15deg);
}

h1 {
    color: var(--primary);
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

h1 i {
    font-size: 2.2rem;
}

.tagline {
    color: var(--text-secondary);
    font-size: 1.1rem;
    font-weight: 400;
}

/* ============================================
   步驟式工作流程
============================================ */

.workflow {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.workflow-step {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: var(--transition-normal);
}

.workflow-step.active {
    box-shadow: var(--shadow-md);
    border: 2px solid var(--primary);
}

.workflow-step[data-step="1"].completed,
.workflow-step[data-step="2"].completed {
    opacity: 0.7;
}

/* 步驟標題 */
.step-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 24px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
}

.step-indicator {
    display: flex;
    align-items: center;
    gap: 16px;
}

.step-number {
    width: 40px;
    height: 40px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    font-weight: 700;
    flex-shrink: 0;
}

.workflow-step:not(.active) .step-number {
    background: var(--border-color);
    color: var(--text-disabled);
}

.workflow-step.completed .step-number {
    background: var(--success);
}

.step-info h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.step-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin: 0;
}

.step-status {
    font-size: 1.5rem;
    color: var(--border-color);
}

.workflow-step.completed .step-status {
    color: var(--success);
}

/* 步驟內容 */
.step-content {
    padding: 24px;
}

.workflow-step:not(.active) .step-content {
    display: none;
}

/* ============================================
   步驟 1: 上傳區域
============================================ */

.upload-zone {
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius);
    padding: 60px 20px;
    text-align: center;
    background: var(--bg-primary);
    transition: var(--transition-normal);
    cursor: pointer;
}

.upload-zone:hover,
.upload-zone.drag-over {
    border-color: var(--primary);
    background: rgba(108, 99, 255, 0.05);
}

.upload-icon {
    font-size: 4rem;
    color: var(--primary);
    margin-bottom: 16px;
    display: block;
}

.upload-zone h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.upload-zone > p {
    color: var(--text-secondary);
    margin: 8px 0;
}

.upload-btn {
    display: inline-block;
    padding: 12px 32px;
    background: var(--primary);
    color: white;
    border-radius: var(--border-radius);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-normal);
    margin: 16px 0;
}

.upload-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.upload-btn i {
    margin-right: 8px;
}

.upload-hint {
    font-size: 0.85rem;
    color: var(--text-disabled);
    margin-top: 8px;
}

/* 已上傳圖片預覽 */
.uploaded-preview {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
}

.file-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.file-info i {
    font-size: 2rem;
    color: var(--primary);
}

.file-name {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.file-size {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin: 0;
}

.preview-image-container {
    padding: 24px;
    background: var(--bg-secondary);
    display: flex;
    justify-content: center;
    align-items: center;
}

.preview-image-container img {
    max-width: 100%;
    max-height: 300px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

/* ============================================
   步驟 2: 設定面板
============================================ */

/* 模式選擇標籤 */
.mode-selector {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 24px;
}

.mode-tab {
    padding: 16px;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.mode-tab i {
    font-size: 1.2rem;
}

.mode-tab:hover {
    border-color: var(--primary);
    background: rgba(108, 99, 255, 0.05);
}

.mode-tab.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

/* 模式面板 */
.mode-panel {
    display: none;
}

.mode-panel.active {
    display: block;
}

/* 設定群組 */
.setting-group {
    margin-bottom: 32px;
}

.setting-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.setting-label i {
    color: var(--primary);
}

/* 預設按鈕組 */
.preset-buttons {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-bottom: 20px;
}

.preset-btn {
    padding: 16px 12px;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition-normal);
    text-align: center;
}

.preset-btn:hover {
    border-color: var(--primary);
    background: rgba(108, 99, 255, 0.05);
}

.preset-btn.active {
    border-color: var(--primary);
    background: rgba(108, 99, 255, 0.1);
}

.preset-name {
    display: block;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.preset-desc {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* 品質滑桿 */
.quality-slider-container {
    display: flex;
    align-items: center;
    gap: 16px;
}

.quality-slider {
    flex: 1;
    height: 8px;
    border-radius: 4px;
    background: var(--border-color);
    outline: none;
    -webkit-appearance: none;
    cursor: pointer;
}

.quality-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    transition: var(--transition-fast);
}

.quality-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.quality-slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    border: none;
    cursor: pointer;
}

.quality-value-display {
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 60px;
    text-align: center;
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--primary);
}

.quality-hint {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 2px 8px;
    background: var(--bg-secondary);
    border-radius: 4px;
    white-space: nowrap;
}

/* 進階設定 */
.advanced-settings {
    margin-top: 24px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
}

.advanced-settings summary {
    padding: 16px;
    cursor: pointer;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
    user-select: none;
}

.advanced-settings summary:hover {
    background: var(--bg-primary);
}

.advanced-settings summary i {
    color: var(--primary);
}

.advanced-content {
    padding: 16px;
    border-top: 1px solid var(--border-color);
}

.setting-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 0;
}

.setting-row label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
}

.setting-row i {
    color: var(--primary);
}

/* 輸入控制項 */
.select-input {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background: white;
    font-size: 1rem;
    cursor: pointer;
    min-width: 150px;
}

.text-input {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    flex: 1;
}

.text-input:disabled {
    background: var(--bg-secondary);
    color: var(--text-disabled);
}

/* 浮水印開關 */
.watermark-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.switch {
    position: relative;
    display: inline-block;
    width: 48px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.switch .slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--border-color);
    transition: var(--transition-normal);
    border-radius: 24px;
}

.switch .slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: var(--transition-normal);
    border-radius: 50%;
}

.switch input:checked + .slider {
    background-color: var(--primary);
}

.switch input:checked + .slider:before {
    transform: translateX(24px);
}

/* 裁切設定區 */
.crop-settings {
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
}

.crop-settings summary {
    padding: 16px;
    cursor: pointer;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
    user-select: none;
}

.crop-settings summary:hover {
    background: var(--bg-primary);
}

.crop-settings summary i {
    color: var(--primary);
}

.crop-content {
    padding: 16px;
    border-top: 1px solid var(--border-color);
}

/* 裁切容器 */
.crop-container {
    margin-bottom: 16px;
}

.cropper-wrapper {
    max-height: 400px;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.cropper-wrapper img {
    max-width: 100%;
    display: block;
}

.crop-actions {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
    margin-top: 16px;
}

/* ============================================
   步驟 3: 結果展示
============================================ */

/* 壓縮統計 */
.compression-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
}

.stat-card.highlight {
    background: rgba(0, 214, 143, 0.1);
    border-color: var(--success);
}

.stat-icon {
    width: 48px;
    height: 48px;
    background: var(--success);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.stat-content {
    flex: 1;
}

.stat-number {
    display: block;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--success);
    line-height: 1.2;
    margin-bottom: 4px;
}

.stat-card:not(.highlight) .stat-number {
    color: var(--text-primary);
    font-size: 1.2rem;
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* 圖片對比 */
.comparison-view {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 24px;
    align-items: start;
    margin-bottom: 32px;
}

.comparison-image {
    position: relative;
}

.image-label {
    position: absolute;
    top: 12px;
    left: 12px;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 6px 12px;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 600;
    z-index: 10;
}

.image-label.success {
    background: var(--success);
}

.image-container {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 400px;
    height: 400px;
}

.image-container img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 4px;
    box-shadow: var(--shadow-sm);
}

.image-info {
    margin-top: 12px;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.comparison-divider {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-disabled);
    font-size: 1.5rem;
    padding-top: 150px;
}

/* 下載操作 */
.download-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
}

/* ============================================
   按鈕樣式
============================================ */

.primary-btn {
    width: 100%;
    padding: 16px 24px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.primary-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.primary-btn:active {
    transform: translateY(0);
}

.btn-secondary {
    padding: 12px 24px;
    background: white;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-secondary:hover {
    border-color: var(--primary);
    background: rgba(108, 99, 255, 0.05);
}

.btn-text {
    background: none;
    border: none;
    color: var(--primary);
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 12px;
    border-radius: var(--border-radius);
    transition: var(--transition-fast);
}

.btn-text:hover {
    background: rgba(108, 99, 255, 0.1);
}

.download-btn {
    padding: 16px 32px;
    background: var(--success);
    color: white;
    border-radius: var(--border-radius);
    font-size: 1.1rem;
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition-normal);
    box-shadow: var(--shadow-md);
}

.download-btn:hover {
    background: #00B876;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ============================================
   載入提示
============================================ */

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-spinner {
    text-align: center;
    color: white;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 16px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-spinner p {
    font-size: 1.1rem;
    font-weight: 500;
}

/* ============================================
   訊息提示
============================================ */

.message {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--card-bg);
    color: var(--text-primary);
    padding: 12px 24px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--primary);
    z-index: 10000;
    display: flex;
    align-items: center;
    gap: 10px;
    max-width: 90%;
    animation: slideDown 0.3s ease;
}

.message i {
    color: var(--primary);
    font-size: 1.1rem;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

/* ============================================
   Footer
============================================ */

footer {
    text-align: center;
    padding: 32px 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 48px;
}

/* ============================================
   響應式設計
============================================ */

@media (max-width: 768px) {
    h1 {
        font-size: 1.8rem;
        flex-direction: column;
        gap: 8px;
    }

    .tagline {
        font-size: 1rem;
    }

    .step-header {
        padding: 16px;
    }

    .step-number {
        width: 36px;
        height: 36px;
        font-size: 1rem;
    }

    .step-info h3 {
        font-size: 1.1rem;
    }

    .step-desc {
        font-size: 0.85rem;
    }

    .step-content {
        padding: 16px;
    }

    /* 手機版模式選擇改為堆疊 */
    .mode-selector {
        grid-template-columns: 1fr;
    }

    /* 手機版預設按鈕改為堆疊 */
    .preset-buttons {
        grid-template-columns: 1fr;
    }

    /* 手機版統計卡片堆疊 */
    .compression-stats {
        grid-template-columns: 1fr;
    }

    .stat-card {
        padding: 16px;
    }

    /* 手機版圖片對比改為上下排列 */
    .comparison-view {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .comparison-divider {
        padding: 0;
        transform: rotate(90deg);
    }

    .image-container {
        height: 280px;
        min-height: 280px;
    }

    /* 手機版下載按鈕堆疊 */
    .download-actions {
        flex-direction: column;
    }

    .download-btn,
    .btn-secondary {
        width: 100%;
    }
}

/* ============================================
   深色模式
============================================ */

/* 深色模式 - 系統偵測 */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --primary: #8B80FF;
        --primary-dark: #A39BFF;
        --text-primary: #E9ECEF;
        --text-secondary: #ADB5BD;
        --text-disabled: #6C757D;
        --bg-primary: #1A1D23;
        --bg-secondary: #25282E;
        --card-bg: #2C2F36;
        --border-color: #3A3D44;
    }

    :root:not([data-theme="light"]) .upload-zone,
    :root:not([data-theme="light"]) .mode-tab,
    :root:not([data-theme="light"]) .preset-btn {
        background: var(--bg-secondary);
    }

    :root:not([data-theme="light"]) .select-input,
    :root:not([data-theme="light"]) .text-input {
        background: var(--bg-secondary);
        color: var(--text-primary);
    }
}

/* 深色模式 - 手動切換 */
:root[data-theme="dark"] {
    --primary: #8B80FF;
    --primary-dark: #A39BFF;
    --text-primary: #E9ECEF;
    --text-secondary: #ADB5BD;
    --text-disabled: #6C757D;
    --bg-primary: #1A1D23;
    --bg-secondary: #25282E;
    --card-bg: #2C2F36;
    --border-color: #3A3D44;
}

[data-theme="dark"] .upload-zone,
[data-theme="dark"] .mode-tab,
[data-theme="dark"] .preset-btn {
    background: var(--bg-secondary);
}

[data-theme="dark"] .select-input,
[data-theme="dark"] .text-input {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* ============================================
   輔助功能
============================================ */

/* 鍵盤焦點指示 */
*:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* 減少動畫模式 */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}