/* ============================================================
   Fox Lab — iOS App Developer Portal
   Design System & Stylesheet
   ============================================================ */

/* --- 1. Custom Properties --------------------------------- */
:root {
  /* Colors */
  --color-bg: #f5f5f7;
  --color-card-bg: #ffffff;
  --color-text-primary: #1d1d1f;
  --color-text-secondary: #6e6e73;
  --color-text-tertiary: #aeaeb2;
  --color-accent: #e85d04;
  --color-accent-hover: #f0701f;
  --color-accent-light: #fff4e6;
  --color-accent-muted: #ffe8d6;
  --color-border: #d2d2d7;
  --color-border-light: #e8e8ed;
  --color-success: #30d158;
  --color-star: #f5a623;
  --color-nav-bg: rgba(245, 245, 247, 0.8);

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text',
               'Helvetica Neue', Helvetica, Arial, 'PingFang SC',
               'Microsoft YaHei', sans-serif;
  --font-mono: 'SF Mono', SFMono-Regular, ui-monospace, 'Menlo', monospace;

  --text-xs: 0.75rem;     /* 12px */
  --text-sm: 0.875rem;    /* 14px */
  --text-base: 1rem;      /* 16px */
  --text-lg: 1.125rem;    /* 18px */
  --text-xl: 1.25rem;     /* 20px */
  --text-2xl: 1.5rem;     /* 24px */
  --text-3xl: 2rem;       /* 32px */
  --text-4xl: 3rem;       /* 48px */
  --text-5xl: 4rem;       /* 64px */

  --font-regular: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  --leading-tight: 1.15;
  --leading-snug: 1.3;
  --leading-normal: 1.5;
  --leading-relaxed: 1.7;

  --tracking-tight: -0.02em;
  --tracking-normal: -0.01em;
  --tracking-wide: 0.02em;

  /* Spacing (4px grid) */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;
  --radius-2xl: 24px;
  --radius-full: 9999px;
  --radius-icon: 22.5%;   /* iOS app icon rounding */

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.08);
  --shadow-xl: 0 24px 60px rgba(0, 0, 0, 0.12);
  --shadow-card-hover: 0 8px 30px rgba(0, 0, 0, 0.10);

  /* Transitions */
  --ease-out: cubic-bezier(0.25, 0.1, 0.25, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Layout */
  --max-width: 1200px;
  --nav-height: 52px;
}

/* --- 2. Reset & Base -------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: var(--font-regular);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  letter-spacing: var(--tracking-normal);
  overflow-x: hidden;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s var(--ease-out);
}

a:hover { color: var(--color-accent-hover); }

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  font-size: inherit;
}

ul, ol { list-style: none; }

/* --- 3. Typography ---------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-semibold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text-primary);
}

.section-title {
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  text-align: center;
  margin-bottom: var(--space-2);
}

.section-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  text-align: center;
  margin-bottom: var(--space-12);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* --- 4. Layout -------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

section {
  padding: var(--space-20) 0;
}

/* --- 5. Navbar -------------------------------------------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--color-nav-bg);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid transparent;
  z-index: 1000;
  transition: border-color 0.3s var(--ease-out);
}

.navbar.scrolled {
  border-bottom-color: var(--color-border-light);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-lg);
  font-weight: var(--font-bold);
  color: var(--color-text-primary);
  letter-spacing: var(--tracking-tight);
  text-decoration: none;
}

.nav-logo svg { width: 32px; height: 32px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  border-radius: var(--radius-full);
  transition: all 0.2s var(--ease-out);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text-primary);
  background: rgba(0, 0, 0, 0.04);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.lang-toggle {
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  color: var(--color-text-secondary);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  transition: all 0.2s var(--ease-out);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
}

.lang-toggle:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* --- 6. Hero Section -------------------------------------- */
.hero {
  padding: calc(var(--nav-height) + var(--space-20)) 0 var(--space-16);
  text-align: center;
  background: linear-gradient(180deg,
    rgba(232, 93, 4, 0.04) 0%,
    rgba(232, 93, 4, 0.01) 40%,
    var(--color-bg) 100%);
}

.hero-logo {
  display: inline-block;
  margin-bottom: var(--space-8);
  animation: float 6s ease-in-out infinite;
}

.hero-logo svg { width: 96px; height: 96px; }

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-12px); }
}

.hero-title {
  font-size: var(--text-5xl);
  font-weight: var(--font-bold);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text-primary);
  margin-bottom: var(--space-4);
  line-height: var(--leading-tight);
}

.hero-title .accent { color: var(--color-accent); }

.hero-tagline {
  font-size: var(--text-xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-10);
  font-weight: var(--font-regular);
  line-height: var(--leading-relaxed);
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-8);
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  color: #fff;
  background: var(--color-accent);
  border-radius: var(--radius-full);
  transition: all 0.2s var(--ease-out);
  box-shadow: 0 4px 16px rgba(232, 93, 4, 0.3);
}

.hero-cta:hover {
  background: var(--color-accent-hover);
  box-shadow: 0 6px 24px rgba(232, 93, 4, 0.4);
  transform: translateY(-1px);
  color: #fff;
}

.hero-cta svg { width: 18px; height: 18px; }

/* --- 7. Stats Bar ----------------------------------------- */
.stats-bar {
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-border-light);
  border-bottom: 1px solid var(--color-border-light);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
  text-align: center;
}

.stat-item {
  padding: var(--space-4);
}

.stat-number {
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  color: var(--color-accent);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
}

.stat-label {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-top: var(--space-2);
}

/* --- 8. Apps Section -------------------------------------- */
.apps-section {
  background: var(--color-bg);
}

.app-filter {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-12);
}

.filter-btn {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  background: var(--color-card-bg);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-full);
  transition: all 0.2s var(--ease-out);
}

.filter-btn:hover,
.filter-btn.active {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background: var(--color-accent-light);
}

.apps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-6);
}

/* --- 9. App Card ------------------------------------------ */
.app-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
  cursor: pointer;
  transition: all 0.3s var(--ease-out);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.app-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-card-hover);
  opacity: 0;
  transition: opacity 0.3s var(--ease-out);
}

.app-card:hover {
  transform: translateY(-4px);
  border-color: transparent;
}

.app-card:hover::before { opacity: 1; }

.app-card-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
  position: relative;
  z-index: 1;
}

.app-icon {
  width: 72px;
  height: 72px;
  border-radius: var(--radius-icon);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  flex-shrink: 0;
  background: #f0f0f0;
}

.app-meta {
  flex: 1;
  min-width: 0;
}

.app-name {
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  color: var(--color-text-primary);
  line-height: var(--leading-snug);
  margin-bottom: var(--space-1);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.app-category {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  margin-bottom: var(--space-2);
}

.app-rating {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.stars {
  display: flex;
  gap: 1px;
}

.star {
  width: 14px;
  height: 14px;
  color: var(--color-star);
  fill: currentColor;
}

.star.empty { color: var(--color-border); }

.rating-count {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  margin-left: var(--space-1);
}

.app-price-badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  border-radius: var(--radius-sm);
  background: var(--color-accent-light);
  color: var(--color-accent);
  flex-shrink: 0;
  position: relative;
  z-index: 1;
}

.app-price-badge.free {
  background: #e8f8ee;
  color: #1a7f3f;
}

.app-desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-4);
  flex: 1;
  position: relative;
  z-index: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.app-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  z-index: 1;
}

.app-version {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.app-store-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-accent);
  transition: all 0.2s var(--ease-out);
}

.app-store-link:hover { gap: var(--space-2); }

.app-store-link svg { width: 16px; height: 16px; }

/* --- 10. Legacy Apps -------------------------------------- */
.legacy-section { background: #fafafa; }

.legacy-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-4);
}

.legacy-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  border: 1px dashed var(--color-border);
  opacity: 0.6;
  transition: opacity 0.2s var(--ease-out);
}

.legacy-card:hover { opacity: 0.85; }

.legacy-card-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-2);
}

.legacy-icon-placeholder {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--color-border-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-tertiary);
}

.legacy-name {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-text-secondary);
}

.legacy-badge {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  background: var(--color-border-light);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-full);
}

/* --- 11. App Detail View ---------------------------------- */
.detail-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  z-index: 2000;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s var(--ease-out);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.detail-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.detail-panel {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 100%;
  max-width: 520px;
  background: var(--color-card-bg);
  z-index: 2001;
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform 0.4s cubic-bezier(0.32, 0.72, 0, 1);
  box-shadow: var(--shadow-xl);
  border-left: 1px solid var(--color-border-light);
}

.detail-panel.active { transform: translateX(0); }

.detail-content { padding: var(--space-6) var(--space-8); }

.detail-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: rgba(0, 0, 0, 0.05);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s var(--ease-out);
  z-index: 10;
}

.detail-close:hover { background: rgba(0, 0, 0, 0.1); }

.detail-icon {
  width: 100px;
  height: 100px;
  border-radius: var(--radius-2xl);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
  margin-bottom: var(--space-6);
}

.detail-name {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--space-2);
}

.detail-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
  flex-wrap: wrap;
}

.detail-category {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
}

.detail-price {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-accent);
  padding: var(--space-1) var(--space-3);
  background: var(--color-accent-light);
  border-radius: var(--radius-full);
}

.detail-rating {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.detail-description {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-8);
  white-space: pre-line;
}

.detail-features { margin-bottom: var(--space-8); }

.detail-features h3 {
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-3);
}

.detail-features ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.detail-features li {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  padding-left: var(--space-6);
  position: relative;
  line-height: var(--leading-relaxed);
}

.detail-features li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 7px;
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background: var(--color-accent);
}

.detail-actions { margin-bottom: var(--space-8); }

.btn-appstore {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-4);
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  color: #fff;
  background: #0071e3;
  border-radius: var(--radius-full);
  transition: all 0.2s var(--ease-out);
}

.btn-appstore:hover {
  background: #0077ed;
  color: #fff;
  box-shadow: 0 4px 16px rgba(0, 113, 227, 0.3);
  transform: translateY(-1px);
}

/* --- 12. Screenshots Carousel ----------------------------- */
.screenshots-section { margin-bottom: var(--space-8); }

.screenshots-section h3 {
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-3);
}

.screenshots-scroll {
  display: flex;
  gap: var(--space-3);
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  padding-bottom: var(--space-2);
}

.screenshots-scroll::-webkit-scrollbar { display: none; }

.screenshot-img {
  flex-shrink: 0;
  width: 220px;
  height: auto;
  border-radius: var(--radius-lg);
  scroll-snap-align: start;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
}

/* --- 13. About Section ------------------------------------ */
.about-section {
  background: var(--color-card-bg);
  border-top: 1px solid var(--color-border-light);
  border-bottom: 1px solid var(--color-border-light);
}

.about-content {
  max-width: 680px;
  margin: 0 auto;
  text-align: center;
}

.about-text {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-6);
}

.about-contact {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-lg);
  font-weight: var(--font-medium);
  color: var(--color-accent);
  padding: var(--space-3) var(--space-6);
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-full);
  transition: all 0.2s var(--ease-out);
}

.about-contact:hover {
  background: var(--color-accent);
  color: #fff;
}

/* --- 14. Developer Note (HZ AppTech Apps) ----------------- */
.hz-section { background: #fafafa; }

.hz-note {
  text-align: center;
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-8);
}

.hz-apps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-6);
}

/* --- 15. Footer ------------------------------------------- */
.footer {
  background: var(--color-card-bg);
  border-top: 1px solid var(--color-border-light);
  padding: var(--space-12) 0;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  text-align: center;
}

.footer-links {
  display: flex;
  gap: var(--space-6);
  flex-wrap: wrap;
  justify-content: center;
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  transition: color 0.2s var(--ease-out);
}

.footer-links a:hover { color: var(--color-accent); }

.footer-copyright {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

/* --- 16. Language Support --------------------------------- */
/*
   Two strategies:
   A. CSS visibility toggle — for elements with only ONE data-lang attribute
      (hero spans etc.) — hide/show based on <html data-lang="...">
   B. JS textContent swap — for elements with BOTH data-lang-en AND data-lang-zh
      (nav links, section titles, etc.) — no CSS hiding needed
*/

/* A. Single-attribute elements: hide non-matching language */
[data-lang-en]:not([data-lang-zh]) { display: none; }
[data-lang-zh]:not([data-lang-en]) { display: none; }

:root[data-lang="en"] [data-lang-en]:not([data-lang-zh]),
html:not([data-lang]) [data-lang-en]:not([data-lang-zh]) { display: revert; }

:root[data-lang="zh"] [data-lang-zh]:not([data-lang-en]) { display: revert; }

/* --- 17. Animations --------------------------------------- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }

/* --- 18. No Results / Empty State ------------------------- */
.no-results {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--space-16) var(--space-4);
  color: var(--color-text-tertiary);
}

.no-results svg { width: 48px; height: 48px; margin-bottom: var(--space-4); opacity: 0.4; }

.no-results p { font-size: var(--text-sm); }

/* --- 19. Responsive --------------------------------------- */

/* Tablet */
@media (max-width: 1024px) {
  :root {
    --text-5xl: 3rem;
    --text-4xl: 2.5rem;
    --text-3xl: 1.75rem;
  }

  .apps-grid { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
  .detail-panel { max-width: 440px; }
}

/* Small tablet / large phone */
@media (max-width: 768px) {
  :root {
    --text-5xl: 2.5rem;
    --text-4xl: 2rem;
    --text-3xl: 1.5rem;
    --text-xl: 1.125rem;
  }

  section { padding: var(--space-12) 0; }
  .hero { padding-top: calc(var(--nav-height) + var(--space-12)); }

  .apps-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(3, 1fr); gap: var(--space-4); }

  .detail-panel { max-width: 100%; }

  .hz-apps-grid { grid-template-columns: 1fr; }
  .legacy-grid { grid-template-columns: 1fr; }
}

/* Phone */
@media (max-width: 480px) {
  :root {
    --text-5xl: 2rem;
    --text-4xl: 1.75rem;
    --text-3xl: 1.35rem;
    --nav-height: 48px;
  }

  .container { padding: 0 var(--space-4); }

  .hero-logo svg { width: 64px; height: 64px; }

  .nav-links { display: none; }

  .app-card-header { gap: var(--space-3); }
  .app-icon { width: 56px; height: 56px; }

  .stats-grid { gap: var(--space-2); }
  .stat-number { font-size: var(--text-3xl); }

  .app-filter { gap: var(--space-1); }
  .filter-btn { padding: var(--space-1) var(--space-3); font-size: var(--text-xs); }

  .screenshot-img { width: 180px; }
}

/* --- 20. Print & Accessibility ---------------------------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media (prefers-color-scheme: dark) {
  /* Dark mode support can be added here if desired.
     For now, the light design works well across preferences. */
}

.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;
}