/* ==========================================================================
   ArchCet Academy (始鯨學院) Design System - Comprehensive Responsive System
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design Tokens & Color Palette
   -------------------------------------------------------------------------- */
:root {
  /* Fonts */
  --font-sans: 'Outfit', 'Noto Sans TC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-heading: 'Outfit', 'Noto Sans TC', sans-serif;

  /* Light Mode Palette - Fresh Aqua Breeze & Ocean Pastels */
  --bg-primary: #f5fbfc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #eaf5f7;
  --bg-card: rgba(255, 255, 255, 0.92);
  --bg-glass: rgba(255, 255, 255, 0.86);

  --text-primary: #152538;
  --text-secondary: #486178;
  --text-muted: #6f8a9f;
  --text-inverse: #ffffff;

  /* Brand Accents derived from Logo (Mint Teal, Bubble Blue, Lavender, Rose Pink) */
  --accent-logo: #17bfa6;          /* Logo Teal / Aqua */
  --accent-easymath: #8572ea;      /* Easy Math Lavender Purple */
  --accent-hanzi: #ec6ebd;         /* Hanzi & BPMF Rose Pink */
  --accent-bubble: #38bdf8;        /* Bubble Cyan Blue */

  --accent-primary: #17bfa6;
  --accent-primary-hover: #10a38d;
  --accent-secondary: #8572ea;

  --accent-gradient: linear-gradient(135deg, #17bfa6 0%, #38bdf8 45%, #9d7df3 100%);
  --accent-glow: rgba(23, 191, 166, 0.28);

  --border-color: rgba(198, 226, 233, 0.85);
  --border-focus: #17bfa6;

  /* Shadows */
  --shadow-sm: 0 2px 5px rgba(21, 37, 56, 0.04);
  --shadow-md: 0 6px 20px rgba(21, 37, 56, 0.07);
  --shadow-lg: 0 16px 36px rgba(21, 37, 56, 0.1);
  --shadow-hover: 0 20px 40px rgba(23, 191, 166, 0.24);

  /* Layout & Spacing */
  --nav-height: 72px;
  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 26px;
  --radius-full: 9999px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Mode Tokens - Midnight Deep Ocean Atmosphere */
[data-theme="dark"] {
  --bg-primary: #0a1120;
  --bg-secondary: #0f1b2f;
  --bg-tertiary: #172740;
  --bg-card: rgba(15, 27, 47, 0.88);
  --bg-glass: rgba(15, 27, 47, 0.82);

  --text-primary: #f0f7ff;
  --text-secondary: #a4c2de;
  --text-muted: #7496b6;
  --text-inverse: #0a1120;

  --accent-logo: #34e0c4;
  --accent-easymath: #9d8ff3;
  --accent-hanzi: #f197d8;
  --accent-bubble: #60d0ff;

  --accent-primary: #34e0c4;
  --accent-primary-hover: #62eed7;
  --accent-secondary: #9d8ff3;

  --accent-gradient: linear-gradient(135deg, #34e0c4 0%, #38bdf8 45%, #c084fc 100%);
  --accent-glow: rgba(52, 224, 196, 0.35);

  --border-color: rgba(255, 255, 255, 0.12);
  --border-focus: #34e0c4;

  --shadow-sm: 0 2px 5px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 6px 18px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 16px 36px rgba(0, 0, 0, 0.55);
  --shadow-hover: 0 20px 40px rgba(52, 224, 196, 0.26);
}

/* --------------------------------------------------------------------------
   2. Reset & Base Styles
   -------------------------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 1.5rem);
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  padding-bottom: env(safe-area-inset-bottom, 0);
}

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

a {
  color: inherit;
  text-decoration: none;
}

button, input, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* Global Focus Visible Accessibility */
:focus-visible {
  outline: 2.5px solid var(--accent-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* Container */
.container {
  width: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Section Common */
.section {
  padding: 6rem 0;
  position: relative;
}

.section-title-wrap {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-tag {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-primary);
  background: rgba(23, 191, 166, 0.12);
  padding: 0.35rem 1.1rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
  border: 1px solid var(--border-color);
}

.section-title {
  font-size: clamp(1.85rem, 3.5vw, 2.35rem);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.25;
}

.section-subtitle {
  font-size: clamp(0.975rem, 1.8vw, 1.125rem);
  color: var(--text-secondary);
  margin-top: 0.75rem;
  max-width: 620px;
  margin-left: auto;
  margin-right: auto;
}

/* --------------------------------------------------------------------------
   3. Background Decorative Effects & Floating Animations
   -------------------------------------------------------------------------- */
.bg-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(105px);
  z-index: 0;
  pointer-events: none;
  opacity: 0.65;
}

.bg-glow-1 {
  width: 500px;
  height: 500px;
  background: var(--accent-logo);
  top: -120px;
  right: -100px;
  opacity: 0.18;
}

.bg-glow-2 {
  width: 540px;
  height: 540px;
  background: var(--accent-secondary);
  bottom: 8%;
  left: -160px;
  opacity: 0.16;
}

@keyframes gentleFloat {
  0%, 100% {
    transform: translateY(0px) rotate(0deg);
  }
  50% {
    transform: translateY(-8px) rotate(2deg);
  }
}

/* --------------------------------------------------------------------------
   4. Navigation Bar
   -------------------------------------------------------------------------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--bg-glass);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: background var(--transition-normal), border-color var(--transition-normal);
  padding-top: env(safe-area-inset-top, 0);
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.brand-logo img {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  object-fit: cover;
  box-shadow: var(--shadow-sm);
  border: 1.5px solid var(--border-color);
  transition: transform var(--transition-fast);
}

.brand-logo:hover img {
  transform: rotate(-6deg) scale(1.08);
}

.brand-title {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  position: relative;
  padding: 0.25rem 0;
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent-primary);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2.5px;
  background: var(--accent-gradient);
  border-radius: var(--radius-full);
  transition: width var(--transition-fast);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Control Buttons (Theme, Lang) */
.btn-icon {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  min-width: 40px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-icon:hover {
  background: var(--bg-secondary);
  border-color: var(--accent-primary);
  color: var(--accent-primary);
  transform: translateY(-1px);
}

.btn-icon:active {
  transform: scale(0.95);
}

.btn-lang {
  padding: 0 0.9rem;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-weight: 600;
  font-size: 0.85rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: all var(--transition-fast);
}

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

.btn-lang:active {
  transform: scale(0.96);
}

/* Mobile Menu Toggle (Animated 3-Bar Hamburger) */
.mobile-toggle {
  display: none;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  width: 42px;
  height: 42px;
  min-width: 42px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  padding: 9px;
  flex-direction: column;
  justify-content: space-around;
  align-items: center;
  transition: all var(--transition-fast);
}

.mobile-toggle .hamburger-bar {
  display: block;
  width: 22px;
  height: 2.2px;
  background: var(--text-primary);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}

.mobile-toggle.active .hamburger-bar:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

.mobile-toggle.active .hamburger-bar:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.mobile-toggle.active .hamburger-bar:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   5. Hero Section
   -------------------------------------------------------------------------- */
.hero-section {
  padding-top: calc(var(--nav-height) + 4.5rem);
  padding-bottom: 5.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-content {
  max-width: 820px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 1.35rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(10px);
}

.hero-badge-dot {
  width: 8px;
  height: 8px;
  background: var(--accent-logo);
  border-radius: 50%;
  display: inline-block;
  box-shadow: 0 0 10px var(--accent-logo);
}

.hero-title {
  font-size: clamp(2.35rem, 5vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.18;
  margin-bottom: 1.25rem;
}

.hero-title-gradient {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-slogan {
  font-size: clamp(1.15rem, 2.5vw, 1.4rem);
  font-weight: 600;
  color: var(--accent-primary);
  letter-spacing: 0.02em;
  margin-bottom: 1.25rem;
  font-style: italic;
}

.hero-desc {
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--text-secondary);
  max-width: 660px;
  margin: 0 auto 2.5rem auto;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

/* Primary Button */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.9rem 2.2rem;
  background: var(--accent-gradient);
  color: #ffffff;
  font-weight: 700;
  font-size: 1rem;
  border-radius: var(--radius-full);
  border: none;
  cursor: pointer;
  box-shadow: var(--shadow-md), 0 4px 18px var(--accent-glow);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), 0 8px 28px var(--accent-glow);
}

.btn-primary:active {
  transform: scale(0.97);
}

/* Secondary Button */
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.9rem 2.2rem;
  background: var(--bg-card);
  color: var(--text-primary);
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  cursor: pointer;
  backdrop-filter: blur(10px);
  transition: transform var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast);
}

.btn-secondary:hover {
  transform: translateY(-2px);
  border-color: var(--accent-primary);
  background: var(--bg-secondary);
}

.btn-secondary:active {
  transform: scale(0.97);
}

/* --------------------------------------------------------------------------
   6. Apps Showcase Section - Color Matched Cards
   -------------------------------------------------------------------------- */
.apps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2.25rem;
  position: relative;
  z-index: 1;
}

.app-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
  position: relative;
  overflow: hidden;
}

/* Top Color Accent Line on each card */
.app-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  opacity: 0.9;
  transition: opacity var(--transition-fast);
}

#cardEasyMath::before {
  background: var(--accent-easymath);
}

#cardHanzi::before {
  background: var(--accent-hanzi);
}

#cardBpmf::before {
  background: var(--accent-logo);
}

.app-card:hover {
  transform: translateY(-6px);
}

#cardEasyMath:hover {
  box-shadow: 0 20px 36px rgba(133, 114, 234, 0.25);
  border-color: var(--accent-easymath);
}

#cardHanzi:hover {
  box-shadow: 0 20px 36px rgba(236, 110, 189, 0.25);
  border-color: var(--accent-hanzi);
}

#cardBpmf:hover {
  box-shadow: 0 20px 36px rgba(23, 191, 166, 0.25);
  border-color: var(--accent-logo);
}

.app-header {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  margin-bottom: 1.25rem;
}

.app-icon {
  width: 76px;
  height: 76px;
  border-radius: var(--radius-md);
  object-fit: cover;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color);
  flex-shrink: 0;
}

.app-title-wrap {
  flex-grow: 1;
}

.app-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.app-subtitle {
  font-size: 0.925rem;
  font-weight: 600;
}

#cardEasyMath .app-subtitle { color: var(--accent-easymath); }
#cardHanzi .app-subtitle { color: var(--accent-hanzi); }
#cardBpmf .app-subtitle { color: var(--accent-logo); }

.app-desc {
  font-size: 0.975rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  flex-grow: 1;
  line-height: 1.65;
}

.app-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.app-tag {
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

#cardEasyMath .app-tag {
  background: rgba(133, 114, 234, 0.12);
  color: var(--accent-easymath);
}

#cardHanzi .app-tag {
  background: rgba(236, 110, 189, 0.12);
  color: var(--accent-hanzi);
}

#cardBpmf .app-tag {
  background: rgba(23, 191, 166, 0.12);
  color: var(--accent-logo);
}

.app-card[data-app-card] {
  cursor: pointer;
}

.app-footer {
  margin-top: auto;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.btn-detail {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.65rem 1.15rem;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: inherit;
}

.btn-detail:hover {
  background: var(--bg-secondary);
  border-color: var(--accent-primary);
  color: var(--accent-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn-detail:active {
  transform: scale(0.97);
}

.btn-detail svg {
  flex-shrink: 0;
}

.btn-appstore {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.7rem 1.4rem;
  background: var(--text-primary);
  color: var(--bg-primary);
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.btn-appstore:hover {
  opacity: 0.92;
  transform: translateY(-2px);
}

.btn-appstore:active {
  transform: scale(0.97);
}

.btn-appstore svg {
  fill: currentColor;
  width: 18px;
  height: 18px;
}

/* --------------------------------------------------------------------------
   6.1 App Detail Modal Dialog - Glassmorphism Showcase
   -------------------------------------------------------------------------- */
body.modal-open {
  overflow: hidden;
}

.app-modal {
  border: none;
  padding: 0;
  margin: 0;
  background: transparent;
  max-width: 100vw;
  max-height: 100vh;
  width: 100vw;
  height: 100vh;
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  transition: opacity 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.app-modal.is-active {
  display: flex;
  opacity: 1;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(10, 17, 32, 0.72);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  cursor: pointer;
}

.modal-card {
  position: relative;
  width: 92%;
  max-width: 860px;
  max-height: 88vh;
  background: var(--bg-card);
  backdrop-filter: blur(28px);
  -webkit-backdrop-filter: blur(28px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.38);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  z-index: 10;
  transform: translateY(20px) scale(0.97);
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.app-modal.is-active .modal-card {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 20;
  transition: all var(--transition-fast);
}

.modal-close:hover {
  color: var(--text-primary);
  border-color: var(--accent-primary);
  transform: rotate(90deg) scale(1.08);
}

.modal-scroll-body {
  overflow-y: auto;
  padding: 2.5rem;
  max-height: 88vh;
  scrollbar-width: thin;
  scrollbar-color: var(--accent-primary) transparent;
}

.modal-scroll-body::-webkit-scrollbar {
  width: 6px;
}
.modal-scroll-body::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

/* Modal Hero Header */
.modal-hero {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  padding-bottom: 1.75rem;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 1.75rem;
}

.modal-app-icon {
  width: 96px;
  height: 96px;
  border-radius: 22px;
  object-fit: cover;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  flex-shrink: 0;
}

.modal-hero-info {
  flex-grow: 1;
}

.modal-hero-title {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.modal-hero-subtitle {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.modal-meta-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.modal-meta-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.775rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

/* Modal Sections */
.modal-section {
  margin-bottom: 2rem;
}

.modal-section-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.modal-desc-text {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}

/* Features Grid inside Modal */
.modal-features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin-bottom: 1.5rem;
}

.modal-feature-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.modal-feature-card:hover {
  border-color: var(--accent-primary);
  transform: translateY(-2px);
}

.modal-feature-icon {
  font-size: 1.75rem;
  margin-bottom: 0.65rem;
  display: inline-block;
}

.modal-feature-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.modal-feature-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* Modal Tables */
.modal-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  margin-bottom: 1.5rem;
  background: var(--bg-secondary);
}

.modal-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  text-align: left;
}

.modal-table th,
.modal-table td {
  padding: 0.85rem 1.15rem;
  border-bottom: 1px solid var(--border-color);
}

.modal-table th {
  background: var(--bg-tertiary);
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
}

.modal-table td {
  color: var(--text-secondary);
  line-height: 1.5;
}

.modal-table tr:last-child td {
  border-bottom: none;
}

/* Emoji Catalogue Showcase Grid */
.emoji-showcase-wrap {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.emoji-series-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  text-align: center;
}

.emoji-series-icons {
  font-size: 1.4rem;
  letter-spacing: 2px;
  margin-bottom: 0.35rem;
}

.emoji-series-name {
  font-size: 0.825rem;
  font-weight: 700;
  color: var(--text-primary);
}

.emoji-series-tag {
  font-size: 0.7rem;
  color: var(--text-muted);
}

/* Modal Footer Actions */
.modal-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
  margin-top: 1.5rem;
}

.modal-footer .btn-appstore {
  padding: 0.85rem 2rem;
  font-size: 1rem;
}

/* --------------------------------------------------------------------------
   7. Academy / Vision Section
   -------------------------------------------------------------------------- */
.academy-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3.25rem;
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 3.5rem;
  align-items: center;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-lg);
}

.academy-img-wrap {
  text-align: center;
}

.academy-img {
  width: 220px;
  height: 220px;
  border-radius: var(--radius-lg);
  object-fit: cover;
  box-shadow: var(--shadow-md), 0 8px 24px var(--accent-glow);
  margin: 0 auto;
  border: 2px solid var(--border-color);
  animation: gentleFloat 5s ease-in-out infinite;
}

.academy-content h3 {
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  font-weight: 800;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.academy-content p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 1.5rem;
}

.academy-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.academy-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  text-align: left;
}

.feature-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: rgba(23, 191, 166, 0.15);
  color: var(--accent-logo);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.15rem;
  font-weight: 700;
}

.feature-text h4 {
  font-size: 0.975rem;
  font-weight: 700;
  color: var(--text-primary);
}

.feature-text p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0;
}

/* --------------------------------------------------------------------------
   8. Contact Us Section
   -------------------------------------------------------------------------- */
.contact-wrap {
  max-width: 680px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem 2.5rem;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-lg);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-label {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.form-label span {
  color: #ef4444;
  margin-left: 0.25rem;
}

.form-control {
  width: 100%;
  padding: 0.85rem 1.15rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 1rem;
  -webkit-appearance: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3.5px var(--accent-glow);
}

textarea.form-control {
  resize: vertical;
  min-height: 140px;
}

.form-status {
  padding: 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  display: none;
}

.form-status.success {
  display: block;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid #10b981;
  color: #10b981;
}

.form-status.error {
  display: block;
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid #ef4444;
  color: #ef4444;
}

/* --------------------------------------------------------------------------
   9. Footer Section
   -------------------------------------------------------------------------- */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 3.5rem 0 2.5rem 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--text-primary);
}

.footer-brand img {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.75rem;
  list-style: none;
}

.footer-link {
  color: var(--text-secondary);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: var(--accent-primary);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* --------------------------------------------------------------------------
   9.1 Legal / Privacy Policy Page Styles
   -------------------------------------------------------------------------- */
.legal-page-section {
  padding-top: calc(var(--nav-height) + 2.5rem);
  padding-bottom: 5rem;
}

.legal-header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.legal-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-top: 0.75rem;
  margin-bottom: 0.5rem;
}

.legal-updated {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.legal-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3.5rem;
  box-shadow: var(--shadow-lg);
  max-width: 920px;
  margin: 0 auto;
}

.legal-content {
  color: var(--text-secondary);
  line-height: 1.8;
  font-size: 1.025rem;
}

.legal-block {
  margin-bottom: 2.5rem;
}

.legal-block:last-child {
  margin-bottom: 0;
}

.legal-block-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.legal-block p {
  margin-bottom: 1rem;
}

.legal-list {
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
}

.legal-list li {
  margin-bottom: 0.5rem;
}

.legal-highlight-box {
  background: var(--bg-tertiary);
  border-left: 4px solid var(--accent-primary);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  margin: 1.25rem 0;
}

.legal-highlight-box p {
  margin-bottom: 0;
  color: var(--text-primary);
  font-weight: 500;
}

.legal-eula-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.25rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-weight: 600;
  margin-top: 0.75rem;
  text-decoration: none;
  transition: all var(--transition-fast);
}

.legal-eula-badge:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.legal-eula-badge svg {
  color: var(--accent-primary);
}

@media (max-width: 768px) {
  .legal-card {
    padding: 2rem 1.5rem;
  }
  .legal-title {
    font-size: 1.75rem;
  }
}

/* --------------------------------------------------------------------------
   10. Scroll Animations & Utilities
   -------------------------------------------------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.2, 0.8, 0.2, 1), transform 0.7s cubic-bezier(0.2, 0.8, 0.2, 1);
  will-change: opacity, transform;
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* --------------------------------------------------------------------------
   11. Responsive Media Queries
   -------------------------------------------------------------------------- */
@media (max-width: 900px) {
  .academy-card {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 2.25rem;
    padding: 2.5rem 1.75rem;
  }

  .academy-features {
    justify-content: center;
  }

  .academy-feature-item {
    background: var(--bg-tertiary);
    padding: 1rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
  }
}

@media (max-width: 768px) {
  .section {
    padding: 4.5rem 0;
  }

  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    flex-direction: column;
    padding: 1.75rem 1.5rem;
    gap: 1.25rem;
    transform: translateY(-160%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition-normal), opacity var(--transition-fast);
    box-shadow: var(--shadow-lg);
    z-index: 999;
  }

  .nav-links.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-link {
    font-size: 1.1rem;
    padding: 0.4rem 0;
    width: 100%;
    text-align: center;
  }

  .mobile-toggle {
    display: flex;
  }

  .apps-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .app-card {
    padding: 1.75rem;
  }

  .app-footer {
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
  }

  .btn-detail,
  .btn-appstore {
    width: 100%;
    justify-content: center;
  }

  .modal-card {
    width: 95%;
    max-height: 92vh;
    border-radius: var(--radius-md);
  }

  .modal-scroll-body {
    padding: 1.5rem;
  }

  .modal-hero {
    flex-direction: column;
    text-align: center;
    gap: 1rem;
  }

  .modal-meta-pills {
    justify-content: center;
  }

  .modal-footer {
    flex-direction: column;
  }

  .modal-footer .btn-appstore {
    width: 100%;
  }

  .contact-wrap {
    padding: 2.25rem 1.5rem;
  }

  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }

  .hero-buttons .btn-primary,
  .hero-buttons .btn-secondary {
    width: 100%;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
    gap: 1.75rem;
  }

  .footer-links {
    justify-content: center;
    gap: 1.25rem;
  }
}

@media (max-width: 420px) {
  .container {
    padding: 0 1.15rem;
  }

  .brand-title {
    font-size: 1.1rem;
  }

  .nav-actions {
    gap: 0.45rem;
  }

  .btn-lang {
    padding: 0 0.65rem;
    font-size: 0.8rem;
  }
}

/* ==========================================================================
   Smart Install Prompt Component (PWA Installation Card & iOS Guide)
   ========================================================================== */
.install-prompt-card {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 1100;
  width: 380px;
  max-width: calc(100vw - 2.5rem);
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 45px rgba(21, 37, 56, 0.16), 0 0 0 1px rgba(23, 191, 166, 0.15);
  padding: 1.35rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
  opacity: 0;
  transform: translateY(30px) scale(0.96);
  pointer-events: none;
  transition: opacity 0.4s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
              box-shadow var(--transition-fast);
}

.install-prompt-card.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.install-prompt-card.hidden {
  display: none !important;
}

/* Close button */
.install-prompt-close {
  position: absolute;
  top: 0.85rem;
  right: 0.85rem;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-full);
  border: none;
  background: var(--bg-tertiary);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.install-prompt-close:hover {
  background: rgba(236, 110, 189, 0.15);
  color: var(--accent-hanzi);
  transform: rotate(90deg);
}

/* Content */
.install-prompt-content {
  display: flex;
  align-items: center;
  gap: 0.95rem;
  padding-right: 1.5rem;
}

.install-prompt-icon {
  width: 52px;
  height: 52px;
  min-width: 52px;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 4px 14px rgba(23, 191, 166, 0.25);
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 255, 255, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
}

.install-prompt-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.install-prompt-text {
  flex: 1;
}

.install-prompt-title {
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
  line-height: 1.35;
}

.install-prompt-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.45;
  margin: 0;
}

/* Actions */
.install-prompt-actions {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  margin-top: 0.25rem;
}

.btn-install-primary {
  width: 100%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.65rem 1rem;
  border-radius: var(--radius-full);
  border: none;
  background: var(--accent-gradient);
  color: var(--text-inverse);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 4px 15px var(--accent-glow);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), filter var(--transition-fast);
}

.btn-install-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(23, 191, 166, 0.4);
  filter: brightness(1.05);
}

.btn-install-primary:active {
  transform: translateY(0) scale(0.98);
}

.install-icon-download {
  flex-shrink: 0;
}

.install-prompt-secondary-row {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  width: 100%;
}

.btn-install-secondary {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 0.75rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn-install-secondary:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-color: var(--text-muted);
}

.btn-install-never {
  color: var(--text-muted);
}

.btn-install-never:hover {
  color: var(--accent-hanzi);
  border-color: rgba(236, 110, 189, 0.4);
}

/* Inline Steps & Tip for iOS / Mac Safari */
.inline-steps {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 0.35rem;
}

.inline-step-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.45;
  flex-wrap: wrap;
}

.icon-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  min-width: 22px;
  border-radius: 6px;
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-bubble);
  border: 1px solid rgba(56, 189, 248, 0.3);
}

.inline-tip {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.45;
  margin-top: 0.25rem;
}

.inline-tip strong {
  color: var(--accent-primary);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  min-width: 18px;
  border-radius: 50%;
  background: var(--accent-primary);
  color: var(--text-inverse);
  font-size: 0.7rem;
  font-weight: 700;
}

/* Responsive adjustments for mobile screens */
@media (max-width: 640px) {
  .install-prompt-card {
    right: 1rem;
    left: 1rem;
    bottom: calc(1rem + env(safe-area-inset-bottom, 0px));
    width: auto;
    max-width: none;
    padding: 1.15rem 1.15rem;
    border-radius: var(--radius-lg);
    gap: 0.9rem;
  }

  .install-prompt-content {
    gap: 0.75rem;
    padding-right: 1.25rem;
  }

  .install-prompt-icon {
    width: 46px;
    height: 46px;
    min-width: 46px;
    border-radius: 12px;
  }

  .install-prompt-title {
    font-size: 0.96rem;
  }

  .install-prompt-desc {
    font-size: 0.8rem;
  }

  .inline-step-item {
    font-size: 0.78rem;
    gap: 0.4rem;
  }

  .icon-badge {
    width: 20px;
    height: 20px;
    min-width: 20px;
  }

  .btn-install-primary {
    font-size: 0.85rem;
    padding: 0.6rem 0.9rem;
  }

  .btn-install-secondary {
    font-size: 0.8rem;
    padding: 0.5rem 0.6rem;
  }
}

@media (max-width: 360px) {
  .install-prompt-card {
    padding: 0.95rem 0.95rem;
    right: 0.75rem;
    left: 0.75rem;
    bottom: calc(0.75rem + env(safe-area-inset-bottom, 0px));
  }

  .install-prompt-icon {
    width: 40px;
    height: 40px;
    min-width: 40px;
  }

  .install-prompt-title {
    font-size: 0.9rem;
  }

  .install-prompt-desc {
    font-size: 0.76rem;
  }
}