/**
 * ========================================================================
 * XYZ.CHEAP - Global Styles (macOS Design Language)
 * ========================================================================
 *
 * 採用 Apple Human Interface Guidelines 的設計系統
 * 支持明亮/黑暗主題、流暢動畫、玻璃態效果
 *
 * @version 1.0.0
 * @date 2025-12-16
 */

/* ========================================================================
   CSS Custom Properties - Design Tokens
   ======================================================================== */

:root {
    /* macOS System Colors - Light Mode */
    --color-system-blue: #007AFF;
    --color-system-green: #34C759;
    --color-system-indigo: #5856D6;
    --color-system-orange: #FF9500;
    --color-system-pink: #FF2D55;
    --color-system-purple: #AF52DE;
    --color-system-red: #FF3B30;
    --color-system-teal: #5AC8FA;
    --color-system-yellow: #FFCC00;
    --color-system-gray: #8E8E93;

    /* Label Colors - Light Mode */
    --color-label-primary: rgba(0, 0, 0, 0.85);
    --color-label-secondary: rgba(0, 0, 0, 0.55);
    --color-label-tertiary: rgba(0, 0, 0, 0.30);
    --color-label-quaternary: rgba(0, 0, 0, 0.18);

    /* Fill Colors - Light Mode */
    --color-fill-primary: rgba(120, 120, 128, 0.20);
    --color-fill-secondary: rgba(120, 120, 128, 0.16);
    --color-fill-tertiary: rgba(118, 118, 128, 0.12);
    --color-fill-quaternary: rgba(116, 116, 128, 0.08);

    /* Background Colors - Light Mode */
    --color-background-primary: #FFFFFF;
    --color-background-secondary: #F2F2F7;
    --color-background-tertiary: #FFFFFF;
    --color-background-elevated: #FFFFFF;

    /* Separator Colors - Light Mode */
    --color-separator-opaque: rgba(60, 60, 67, 0.29);
    --color-separator-non-opaque: rgba(60, 60, 67, 0.12);

    /* Grouped Background - Light Mode */
    --color-grouped-background-primary: #F2F2F7;
    --color-grouped-background-secondary: #FFFFFF;
    --color-grouped-background-tertiary: #F2F2F7;

    /* Glassmorphism */
    --glass-background: rgba(255, 255, 255, 0.72);
    --glass-border: rgba(255, 255, 255, 0.18);
    --glass-shadow: rgba(0, 0, 0, 0.10);

    /* Typography */
    --font-family-system: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
    --font-family-mono: "SF Mono", Monaco, Menlo, Consolas, "Courier New", monospace;

    /* Font Sizes - SF Pro Scale */
    --font-size-large-title: 34px;
    --font-size-title-1: 28px;
    --font-size-title-2: 22px;
    --font-size-title-3: 20px;
    --font-size-headline: 17px;
    --font-size-body: 17px;
    --font-size-callout: 16px;
    --font-size-subheadline: 15px;
    --font-size-footnote: 13px;
    --font-size-caption-1: 12px;
    --font-size-caption-2: 11px;

    /* Font Weights */
    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    /* Spacing Scale */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 20px;
    --spacing-2xl: 24px;
    --spacing-3xl: 32px;
    --spacing-4xl: 40px;
    --spacing-5xl: 48px;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.10), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.10), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.10), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Z-Index Scale */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* Dark Mode Overrides */
[data-theme="dark"] {
    /* Label Colors - Dark Mode */
    --color-label-primary: rgba(255, 255, 255, 0.85);
    --color-label-secondary: rgba(255, 255, 255, 0.55);
    --color-label-tertiary: rgba(255, 255, 255, 0.30);
    --color-label-quaternary: rgba(255, 255, 255, 0.18);

    /* Fill Colors - Dark Mode */
    --color-fill-primary: rgba(120, 120, 128, 0.36);
    --color-fill-secondary: rgba(120, 120, 128, 0.32);
    --color-fill-tertiary: rgba(118, 118, 128, 0.24);
    --color-fill-quaternary: rgba(116, 116, 128, 0.18);

    /* Background Colors - Dark Mode */
    --color-background-primary: #000000;
    --color-background-secondary: #1C1C1E;
    --color-background-tertiary: #2C2C2E;
    --color-background-elevated: #1C1C1E;

    /* Separator Colors - Dark Mode */
    --color-separator-opaque: rgba(84, 84, 88, 0.65);
    --color-separator-non-opaque: rgba(84, 84, 88, 0.24);

    /* Grouped Background - Dark Mode */
    --color-grouped-background-primary: #000000;
    --color-grouped-background-secondary: #1C1C1E;
    --color-grouped-background-tertiary: #2C2C2E;

    /* Glassmorphism - Dark Mode */
    --glass-background: rgba(28, 28, 30, 0.72);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-shadow: rgba(0, 0, 0, 0.30);
}

/* RTL Language Support */
[dir="rtl"] {
    direction: rtl;
}

/* ========================================================================
   Base Styles & Reset
   ======================================================================== */

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

html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    font-feature-settings: "kern" 1;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-system);
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-regular);
    line-height: 1.47059;
    letter-spacing: -0.022em;
    color: var(--color-label-primary);
    background-color: var(--color-background-secondary);
    transition: background-color var(--transition-slow), color var(--transition-slow);
    overflow-x: hidden;
    min-height: 100vh;
    padding-top: 60px; /* Header height */
    padding-bottom: 52px; /* Footer height */
}

/* ========================================================================
   Typography
   ======================================================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-bold);
    line-height: 1.2;
    letter-spacing: -0.03em;
    color: var(--color-label-primary);
}

h1 {
    font-size: var(--font-size-large-title);
    margin-bottom: var(--spacing-2xl);
}

h2 {
    font-size: var(--font-size-title-1);
    margin-bottom: var(--spacing-xl);
}

h3 {
    font-size: var(--font-size-title-2);
    margin-bottom: var(--spacing-lg);
}

h4 {
    font-size: var(--font-size-title-3);
    margin-bottom: var(--spacing-md);
}

p {
    margin-bottom: var(--spacing-lg);
    color: var(--color-label-secondary);
    line-height: 1.58824;
}

a {
    color: var(--color-system-blue);
    text-decoration: none;
    transition: opacity var(--transition-fast);
}

a:hover {
    opacity: 0.72;
}

a:active {
    opacity: 0.48;
}

code {
    font-family: var(--font-family-mono);
    font-size: 0.875em;
    padding: 2px 6px;
    background-color: var(--color-fill-tertiary);
    border-radius: var(--radius-sm);
}

/* ========================================================================
   Layout Components
   ======================================================================== */

.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-3xl) var(--spacing-lg);
    animation: fadeInUp var(--transition-slow) ease-out;
}

@media (min-width: 768px) {
    .main-content {
        padding: var(--spacing-5xl) var(--spacing-3xl);
    }
}

/* ========================================================================
   Sticky Header - Glassmorphic
   ======================================================================== */

.sticky-glassmorphic-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 60px;
    background: var(--glass-background);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 0.5px solid var(--glass-border);
    box-shadow: 0 1px 0 0 var(--glass-shadow);
    z-index: var(--z-sticky);
    transition: all var(--transition-base);
}

.navigation-container {
    max-width: 1200px;
    height: 100%;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand-logo-link {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    text-decoration: none;
    user-select: none;
}

.brand-logo-text {
    font-size: var(--font-size-title-3);
    font-weight: var(--font-weight-semibold);
    color: var(--color-label-primary);
    letter-spacing: -0.02em;
}

.brand-accent {
    color: var(--color-system-blue);
}

.header-right-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

/* ========================================================================
   Buttons
   ======================================================================== */

.icon-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: none;
    background: transparent;
    color: var(--color-label-primary);
    cursor: pointer;
    border-radius: var(--radius-full);
    transition: background-color var(--transition-fast);
    -webkit-tap-highlight-color: transparent;
}

.icon-button:hover {
    background-color: var(--color-fill-tertiary);
}

.icon-button:active {
    background-color: var(--color-fill-secondary);
    transform: scale(0.96);
}

.icon-svg {
    width: 24px;
    height: 24px;
    stroke-width: 1.5px;
    transition: transform var(--transition-fast);
}

.primary-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md) var(--spacing-2xl);
    font-size: var(--font-size-headline);
    font-weight: var(--font-weight-semibold);
    color: #FFFFFF;
    background: var(--color-system-blue);
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: 0 1px 3px rgba(0, 122, 255, 0.24);
}

.primary-button:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 122, 255, 0.32);
}

.primary-button:active {
    transform: translateY(0);
    box-shadow: 0 1px 3px rgba(0, 122, 255, 0.24);
}

.secondary-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md) var(--spacing-2xl);
    font-size: var(--font-size-headline);
    font-weight: var(--font-weight-semibold);
    color: var(--color-system-blue);
    background: var(--color-fill-tertiary);
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.secondary-button:hover {
    background: var(--color-fill-secondary);
}

.secondary-button:active {
    background: var(--color-fill-primary);
    transform: scale(0.98);
}

/* ========================================================================
   Side Drawer
   ======================================================================== */

.side-drawer {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: var(--z-modal);
    pointer-events: none;
}

.side-drawer[aria-hidden="false"] {
    pointer-events: auto;
}

.side-drawer-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.48);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.side-drawer[aria-hidden="false"] .side-drawer-overlay {
    opacity: 1;
}

.side-drawer-content {
    position: absolute;
    top: 0;
    left: 0;
    width: min(320px, 80vw);
    height: 100%;
    background: var(--color-background-elevated);
    box-shadow: var(--shadow-xl);
    transform: translateX(-100%);
    transition: transform var(--transition-base) cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
}

.side-drawer[aria-hidden="false"] .side-drawer-content {
    transform: translateX(0);
}

.side-drawer-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    border-bottom: 0.5px solid var(--color-separator-non-opaque);
}

.side-drawer-title {
    font-size: var(--font-size-title-3);
    font-weight: var(--font-weight-semibold);
    color: var(--color-label-primary);
}

.side-drawer-nav {
    flex: 1;
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.drawer-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    color: var(--color-label-primary);
    background: transparent;
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast);
    text-decoration: none;
}

.drawer-link:hover {
    background: var(--color-fill-tertiary);
    opacity: 1;
}

.drawer-link:active {
    background: var(--color-fill-secondary);
    transform: scale(0.98);
}

.link-icon {
    width: 20px;
    height: 20px;
    stroke-width: 2px;
    color: var(--color-system-blue);
}

/* ========================================================================
   Modal
   ======================================================================== */

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.48);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: var(--z-modal-backdrop);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
}

.modal-overlay[aria-hidden="false"] {
    opacity: 1;
    pointer-events: auto;
}

.modal-container {
    width: 100%;
    max-width: 600px;
    max-height: 80vh;
    background: var(--color-background-elevated);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    display: flex;
    flex-direction: column;
    transform: scale(0.94);
    transition: transform var(--transition-base) cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-overlay[aria-hidden="false"] .modal-container {
    transform: scale(1);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xl) var(--spacing-2xl);
    border-bottom: 0.5px solid var(--color-separator-non-opaque);
}

.modal-title {
    font-size: var(--font-size-title-2);
    font-weight: var(--font-weight-bold);
    color: var(--color-label-primary);
}

/* ========================================================================
   Language Selector
   ======================================================================== */

.language-selector-modal {
    max-width: 480px;
}

.language-search-container {
    padding: var(--spacing-lg) var(--spacing-2xl) var(--spacing-md);
}

.search-input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: var(--spacing-md);
    width: 20px;
    height: 20px;
    color: var(--color-label-tertiary);
    pointer-events: none;
}

.language-search-input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-md) var(--spacing-md) 44px;
    font-family: var(--font-family-system);
    font-size: var(--font-size-body);
    color: var(--color-label-primary);
    background: var(--color-fill-tertiary);
    border: none;
    border-radius: var(--radius-md);
    outline: none;
    transition: background-color var(--transition-fast);
}

.language-search-input:focus {
    background: var(--color-fill-secondary);
}

.language-search-input::placeholder {
    color: var(--color-label-tertiary);
}

.language-options-list {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-sm) var(--spacing-lg) var(--spacing-lg);
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xs);
}

.language-option {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background-color var(--transition-fast);
    text-align: left;
}

.language-option:hover {
    background: var(--color-fill-tertiary);
}

.language-option:active {
    background: var(--color-fill-secondary);
}

.language-option.selected {
    background: var(--color-system-blue);
}

.language-option.selected .language-name {
    color: #FFFFFF;
}

.language-flag {
    width: 28px;
    height: 21px;
    border-radius: 2px;
    object-fit: cover;
}

.language-name {
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-medium);
    color: var(--color-label-primary);
}

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

.sticky-glassmorphic-footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 52px;
    background: var(--glass-background);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-top: 0.5px solid var(--glass-border);
    box-shadow: 0 -1px 0 0 var(--glass-shadow);
    z-index: var(--z-sticky);
}

.footer-container {
    max-width: 1200px;
    height: 100%;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: center;
}

.footer-text {
    font-size: var(--font-size-footnote);
    color: var(--color-label-secondary);
    margin: 0;
}

/* ========================================================================
   Content Sections
   ======================================================================== */

.hero-section {
    text-align: center;
    padding: var(--spacing-5xl) 0;
}

.hero-title {
    font-size: clamp(32px, 6vw, 48px);
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.04em;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--color-system-blue), var(--color-system-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: var(--font-size-title-3);
    color: var(--color-label-secondary);
    margin-bottom: var(--spacing-3xl);
    max-width: 640px;
    margin-left: auto;
    margin-right: auto;
}

.platform-badges {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-4xl);
}

.platform-badge {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-fill-tertiary);
    border-radius: var(--radius-full);
    font-size: var(--font-size-subheadline);
    font-weight: var(--font-weight-medium);
    color: var(--color-label-secondary);
}

.platform-logo {
    width: 24px;
    height: 24px;
}

.platform-divider {
    width: 1px;
    height: 24px;
    background: var(--color-separator-opaque);
}

/* ========================================================================
   Domain Catalog
   ======================================================================== */

.catalog-controls {
    margin-bottom: var(--spacing-3xl);
}

.search-bar-container {
    margin-bottom: var(--spacing-lg);
}

.search-input-wrapper {
    max-width: 600px;
    margin: 0 auto;
}

.catalog-search-input {
    width: 100%;
    padding: var(--spacing-lg) var(--spacing-lg) var(--spacing-lg) 48px;
    font-family: var(--font-family-system);
    font-size: var(--font-size-body);
    color: var(--color-label-primary);
    background: var(--color-background-elevated);
    border: 1px solid var(--color-separator-non-opaque);
    border-radius: var(--radius-lg);
    outline: none;
    transition: all var(--transition-fast);
}

.catalog-search-input:focus {
    border-color: var(--color-system-blue);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.12);
}

.category-filters {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: var(--spacing-xl);
}

.category-chip {
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-subheadline);
    font-weight: var(--font-weight-medium);
    color: var(--color-label-primary);
    background: var(--color-fill-tertiary);
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.category-chip:hover {
    background: var(--color-fill-secondary);
}

.category-chip.active {
    color: #FFFFFF;
    background: var(--color-system-blue);
}

/* 分類和排序按鈕圖標樣式 */
.category-chip,
.sort-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.category-chip svg,
.sort-button svg {
    flex-shrink: 0;
    opacity: 0.7;
    transition: opacity var(--transition-fast);
}

.category-chip:hover svg,
.sort-button:hover svg {
    opacity: 1;
}

.category-chip.active svg {
    opacity: 1;
}

/* 排序分隔線 */
.sort-divider {
    width: 1px;
    height: 24px;
    background: var(--color-separator-opaque);
    margin: 0 var(--spacing-xs);
}

/* Available 複選框樣式 */
.available-filter-checkbox {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background-color var(--transition-fast);
    user-select: none;
    font-size: var(--font-size-subheadline);
    font-weight: var(--font-weight-medium);
    color: var(--color-label-primary);
}

.available-filter-checkbox:hover {
    background: var(--color-fill-tertiary);
}

.available-filter-checkbox input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.available-filter-checkbox .checkbox-icon {
    width: 20px;
    height: 20px;
    padding: 2px;
    border: 2px solid var(--color-separator-opaque);
    border-radius: var(--radius-sm);
    background: var(--color-background-elevated);
    transition: all var(--transition-fast);
    opacity: 0;
}

.available-filter-checkbox input[type="checkbox"]:checked + .checkbox-icon {
    opacity: 1;
    border-color: var(--color-system-blue);
    background: var(--color-system-blue);
    stroke: #FFFFFF;
}

.available-filter-checkbox input[type="checkbox"]:not(:checked) + .checkbox-icon {
    opacity: 1;
    stroke: transparent;
}

.available-filter-checkbox:active .checkbox-icon {
    transform: scale(0.92);
}

.sort-controls {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
}

.sort-label {
    font-size: var(--font-size-subheadline);
    color: var(--color-label-secondary);
    margin-right: var(--spacing-sm);
}

.sort-button {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-subheadline);
    font-weight: var(--font-weight-medium);
    color: var(--color-label-primary);
    background: var(--color-fill-tertiary);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.sort-button:hover {
    background: var(--color-fill-secondary);
}

.sort-button.active {
    color: var(--color-system-blue);
    background: var(--color-fill-secondary);
}

/* ========================================================================
   Domain Cards Grid
   ======================================================================== */

.domains-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(100%, 340px), 1fr));
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-5xl);
}

.domain-card {
    background: var(--color-background-elevated);
    border: 1px solid var(--color-separator-non-opaque);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    transition: all var(--transition-base);
    cursor: pointer;
}

.domain-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-system-blue);
}

.domain-card.sold {
    opacity: 0.5;
    pointer-events: none;
}

.domain-name {
    font-size: var(--font-size-title-2);
    font-weight: var(--font-weight-bold);
    color: var(--color-label-primary);
    margin-bottom: var(--spacing-md);
    word-break: break-word;
}

.domain-price {
    font-size: var(--font-size-title-3);
    font-weight: var(--font-weight-semibold);
    color: var(--color-system-green);
    margin-bottom: var(--spacing-lg);
}

.domain-tags {
    display: flex;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-lg);
}

.domain-tag {
    padding: 4px var(--spacing-sm);
    font-size: var(--font-size-caption-1);
    font-weight: var(--font-weight-medium);
    color: var(--color-system-blue);
    background: rgba(0, 122, 255, 0.12);
    border-radius: var(--radius-sm);
}

.domain-advantages {
    margin-bottom: var(--spacing-xl);
}

.advantage-item {
    font-size: var(--font-size-subheadline);
    color: var(--color-label-secondary);
    margin-bottom: var(--spacing-xs);
    padding-left: var(--spacing-lg);
    position: relative;
}

.advantage-item::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--color-system-green);
    font-weight: var(--font-weight-bold);
}

.domain-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.domain-actions .primary-button,
.domain-actions .secondary-button {
    flex: 1;
    font-size: var(--font-size-subheadline);
    padding: var(--spacing-md);
}

/* 確保 <a> 標籤作為按鈕時樣式正確 */
a.primary-button,
a.secondary-button {
    text-decoration: none;
    color: inherit;
}

a.primary-button:hover,
a.secondary-button:hover {
    opacity: 1; /* 覆蓋 a:hover 的 opacity */
}

/* ========================================================================
   Animations
   ======================================================================== */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
    }
    to {
        transform: translateX(0);
    }
}

@keyframes scaleIn {
    from {
        transform: scale(0.9);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

/* ========================================================================
   Responsive Design
   ======================================================================== */

@media (max-width: 768px) {
    :root {
        --font-size-large-title: 28px;
        --font-size-title-1: 24px;
        --font-size-title-2: 20px;
    }

    .domains-grid {
        grid-template-columns: 1fr;
    }

    .hero-section {
        padding: var(--spacing-3xl) 0;
    }

    .platform-badges {
        flex-direction: column;
    }

    .domain-actions {
        flex-direction: column;
    }
}

/* ========================================================================
   Utility Classes
   ======================================================================== */

.hidden {
    display: none !important;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

.loading-spinner {
    display: inline-block;
    width: 24px;
    height: 24px;
    border: 3px solid var(--color-fill-tertiary);
    border-top-color: var(--color-system-blue);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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