:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: rgba(37, 99, 235, 0.1);
  --primary-lighter: rgba(37, 99, 235, 0.05);
  --text: #171717;
  --text-secondary: #6b7280;
  --border: #e5e7eb;
  --surface: #ffffff;
  --muted: #f9fafb;
  --green: #22c55e;
  --blue: #3b82f6;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    sans-serif;
  color: var(--text);
  scroll-behavior: smooth;
}

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

body {
  margin: 0;
  background: var(--surface);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

button {
  font: inherit;
}

ul {
  margin: 0;
  padding-left: 18px;
}

li {
  color: var(--text-secondary);
  line-height: 1.75;
}

code {
  background: var(--muted);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85em;
}

/* ============ Container ============ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ============ Header ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 64px;
  padding: 0 clamp(1rem, 4vw, 3rem);
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  white-space: nowrap;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 14px;
  color: var(--text-secondary);
}

.nav-links a {
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--primary);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 16px;
  border-radius: var(--radius-sm);
  background: var(--primary);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  transition: all 0.2s;
  white-space: nowrap;
}

.header-cta:hover {
  background: var(--primary-hover);
  transform: scale(1.02);
}

/* ============ Buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 24px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 15px;
  transition: all 0.3s;
  cursor: pointer;
  border: none;
  touch-action: manipulation;
  white-space: nowrap;
}

.btn-lg {
  min-height: 52px;
  padding: 0 32px;
  font-size: 16px;
  border-radius: var(--radius);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
  background: var(--primary-hover);
  box-shadow: var(--shadow-xl);
  transform: scale(1.03);
}

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

.btn-outline {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  background: var(--muted);
  border-color: var(--primary);
  color: var(--primary);
}

.btn.disabled {
  pointer-events: none;
  opacity: 0.5;
}

/* ============ Badges ============ */
.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 4px 12px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
}

.badge-primary {
  background: var(--primary-light);
  color: var(--primary);
}

.badge-secondary {
  background: var(--muted);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

/* ============ Dots ============ */
.dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

.dot-green {
  background: var(--green);
}

.dot-blue {
  background: var(--blue);
}

/* ============ Hero ============ */
.hero {
  position: relative;
  min-height: calc(100vh - 64px);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: linear-gradient(
    135deg,
    var(--primary-lighter),
    var(--surface),
    rgba(147, 197, 253, 0.05)
  );
}

.hero-decoration {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.hero-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
  animation: pulse 8s ease-in-out infinite;
}

.hero-blob-1 {
  width: 400px;
  height: 400px;
  top: -100px;
  right: -50px;
  background: rgba(37, 99, 235, 0.15);
}

.hero-blob-2 {
  width: 300px;
  height: 300px;
  bottom: -80px;
  left: -40px;
  background: rgba(147, 197, 253, 0.2);
  animation-delay: 2s;
}

@keyframes pulse {
  0%,
  100% {
    transform: scale(1);
    opacity: 0.4;
  }
  50% {
    transform: scale(1.15);
    opacity: 0.25;
  }
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
  padding: 80px 1.5rem 120px;
  text-align: center;
}

.hero h1 {
  margin: 16px 0 0;
  font-size: clamp(48px, 8vw, 80px);
  font-weight: 800;
  line-height: 1;
  background: linear-gradient(135deg, var(--primary), rgba(37, 99, 235, 0.75));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.hero-desc {
  margin: 24px auto 0;
  max-width: 600px;
  color: var(--text-secondary);
  font-size: 18px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  margin-top: 36px;
}

.hero-indicators {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
  margin-top: 32px;
  font-size: 14px;
  color: var(--text-secondary);
}

.indicator {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
}

.scroll-pill {
  width: 28px;
  height: 44px;
  border-radius: 14px;
  border: 2px solid var(--border);
  display: flex;
  justify-content: center;
  padding-top: 8px;
}

.scroll-dot {
  width: 4px;
  height: 8px;
  border-radius: 2px;
  background: var(--primary);
  animation: bounce-dot 2s ease-in-out infinite;
}

@keyframes bounce-dot {
  0%,
  100% {
    transform: translateY(0);
    opacity: 1;
  }
  50% {
    transform: translateY(12px);
    opacity: 0.3;
  }
}

/* ============ Sections ============ */
.section {
  padding: 96px 0;
}

.section-muted {
  background: var(--muted);
}

.section-gradient-down {
  background: linear-gradient(180deg, var(--surface), rgba(249, 250, 251, 0.3));
}

.section-gradient-up {
  background: linear-gradient(180deg, rgba(249, 250, 251, 0.3), var(--surface));
}

.section-heading {
  max-width: 700px;
  margin: 0 auto 48px;
  text-align: center;
}

.section-heading .badge {
  margin-bottom: 16px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 800;
  line-height: 1.2;
}

.section-heading p {
  margin: 12px 0 0;
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.75;
}

/* ============ Cards ============ */
.card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 28px;
  transition: all 0.3s ease;
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.card:active {
  transform: scale(0.98);
}

.card-featured {
  border-color: rgba(37, 99, 235, 0.2);
  background: linear-gradient(135deg, var(--primary-lighter), var(--surface));
}

.card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.card-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--muted);
  color: var(--text-secondary);
  transition: all 0.3s;
}

.card:hover .card-icon {
  background: var(--primary-light);
  color: var(--primary);
}

.icon-primary {
  background: var(--primary-light);
  color: var(--primary);
}

.card h3 {
  margin: 0;
  font-size: 20px;
  font-weight: 700;
  line-height: 1.3;
}

.card p {
  margin: 10px 0 0;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.75;
}

/* ============ Feature Grid ============ */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

/* ============ Platform Grid ============ */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 12px;
}

.platform-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  text-align: center;
  transition: all 0.3s;
  cursor: default;
}

.platform-icon {
  width: 40px;
  height: 40px;
  margin-bottom: 10px;
  object-fit: contain;
}

.platform-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
  border-color: var(--primary);
}

.platform-name {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-weight: 600;
  font-size: 14px;
}

.platform-types {
  margin-top: 6px;
  color: var(--text-secondary);
  font-size: 12px;
}

/* ============ Download ============ */
.download-layout {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 20px;
  margin-bottom: 48px;
}

.download-panel {
  padding: 32px;
  align-self: start;
}

.download-panel:hover {
  transform: none;
}

.download-kicker {
  margin: 0 0 4px;
  color: var(--primary);
  font-weight: 700;
  font-size: 14px;
}

.download-panel h3 {
  margin: 0;
}

.download-panel p {
  margin: 8px 0 0;
}

.download-panel .btn {
  margin-top: 20px;
  width: 100%;
}

.download-note {
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-secondary);
}

.download-note a {
  color: var(--primary);
  font-weight: 600;
  transition: color 0.2s;
}

.download-note a:hover {
  color: var(--primary-hover);
  text-decoration: underline;
}

.download-list {
  display: grid;
  gap: 10px;
}

.download-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 16px;
  align-items: center;
  padding: 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  transition: all 0.2s;
}

.download-item:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.download-item h3 {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
}

.download-item p {
  margin: 4px 0 0;
  font-size: 13px;
  color: var(--text-secondary);
}

.download-item a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 14px;
  white-space: nowrap;
  transition: all 0.2s;
}

.download-item a:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-lighter);
}

.download-empty {
  min-height: 140px;
  display: grid;
  place-items: center;
  border: 1px dashed var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
}

.download-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.download-feature-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  transition: all 0.3s;
}

.download-feature-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.download-feature-card h4 {
  margin: 12px 0 4px;
  font-size: 16px;
  font-weight: 700;
}

.download-feature-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 14px;
}

/* ============ Guide ============ */
.guide-tabs {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 28px;
}

.guide-tab {
  min-height: 40px;
  padding: 0 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  color: var(--text-secondary);
  transition: all 0.2s;
}

.guide-tab:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.guide-tab.is-active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.guide-panel {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  max-width: 1200px;
  margin: 0 auto;
}

.guide-panel.is-hidden {
  display: none;
}

.guide-step {
  padding: 24px;
}

.guide-step:hover {
  transform: none;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--primary);
  color: #fff;
  font-weight: 800;
  font-size: 15px;
}

.guide-step h3 {
  margin: 14px 0 10px;
  font-size: 18px;
  font-weight: 700;
}

/* ============ About ============ */
.about-layout {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.about-copy .badge {
  margin-bottom: 16px;
}

.about-copy h2 {
  margin: 0;
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  line-height: 1.2;
}

.about-copy p {
  margin: 16px 0 0;
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.8;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.stat-card {
  padding: 28px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  text-align: center;
  transition: all 0.3s;
}

.stat-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.stat-card strong {
  display: block;
  font-size: 32px;
  line-height: 1;
  color: var(--primary);
}

.stat-card span {
  display: block;
  margin-top: 8px;
  color: var(--text-secondary);
  font-size: 13px;
}

/* ============ Footer ============ */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--text);
  color: #fff;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 24px 1.5rem;
}

.footer-brand img {
  width: 28px;
  height: 28px;
}

.footer-brand span {
  color: #fff;
}

.footer-copy {
  color: #a1a1aa;
  font-size: 14px;
  margin: 0;
}

.footer-links {
  display: flex;
  gap: 16px;
}

.footer-links a {
  color: #a1a1aa;
  font-size: 14px;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: #fff;
}

/* ============ Mobile Notice ============ */
.mobile-notice {
  display: none;
}

/* ============ Responsive ============ */
@media (max-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .platform-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

@media (max-width: 768px) {
  .mobile-notice {
    display: flex;
    position: fixed;
    inset: 0;
    z-index: 9999;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #eff6ff, #ffffff, #eff6ff);
  }

  .mobile-notice-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 0 2rem;
    animation: fade-in 0.5s ease;
  }

  .mobile-notice-icon {
    width: 72px;
    height: 72px;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 24px;
  }

  .mobile-notice h2 {
    margin: 0;
    font-size: 22px;
    font-weight: 800;
    color: var(--text);
  }

  .mobile-notice p {
    margin: 10px 0 0;
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.6;
  }

  .mobile-notice-url {
    margin-top: 20px;
    padding: 10px 24px;
    border-radius: var(--radius-sm);
    background: var(--primary);
    color: #fff;
    font-weight: 700;
    font-size: 16px;
    letter-spacing: 0.5px;
  }

  .mobile-notice-platforms {
    display: flex;
    gap: 12px;
    margin-top: 24px;
  }

  .mobile-notice-platforms span {
    padding: 4px 14px;
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 13px;
    color: var(--text-secondary);
    background: var(--surface);
  }

  .site-header,
  main,
  .site-footer {
    display: none;
  }
}

@media (max-width: 480px) {
  .guide-panel {
    grid-template-columns: 1fr;
  }

  .platform-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .about-stats {
    grid-template-columns: 1fr;
  }

  .download-item {
    grid-template-columns: 1fr;
  }

  .download-item a {
    width: 100%;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}

/* ============ Animations ============ */
@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.platform-card {
  animation: fade-in 0.4s ease both;
}

.platform-card:nth-child(1) { animation-delay: 0ms; }
.platform-card:nth-child(2) { animation-delay: 30ms; }
.platform-card:nth-child(3) { animation-delay: 60ms; }
.platform-card:nth-child(4) { animation-delay: 90ms; }
.platform-card:nth-child(5) { animation-delay: 120ms; }
.platform-card:nth-child(6) { animation-delay: 150ms; }
.platform-card:nth-child(7) { animation-delay: 180ms; }
.platform-card:nth-child(8) { animation-delay: 210ms; }
.platform-card:nth-child(9) { animation-delay: 240ms; }
.platform-card:nth-child(10) { animation-delay: 270ms; }
.platform-card:nth-child(n + 11) { animation-delay: 300ms; }