:root {
  --nav-height: 52px;
  --primary-color: #007aff;
  --primary-hover: #0066d6;
  --background-dark: #000000;
  --background-light: #1c1c1e;
  --text-color: #ffffff;
  --text-secondary: #aeaeb2;
  --text-muted: #6e6e73;
  --glass-bg: rgba(28, 28, 30, 0.72);
  --glass-border: rgba(255, 255, 255, 0.12);
  --glass-highlight: rgba(255, 255, 255, 0.06);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
  --segment-track: rgba(255, 255, 255, 0.05);
  --segment-active: rgba(255, 255, 255, 0.18);
  --segment-active-shadow:
    0 2px 8px rgba(0, 0, 0, 0.35),
    inset 0 1px 0 rgba(255, 255, 255, 0.14);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

[data-section] {
  scroll-margin-top: var(--nav-height);
}

body {
  min-height: 100vh;
  min-height: 100dvh;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, "PingFang SC", "Hiragino Sans GB", sans-serif;
  background-color: var(--background-dark);
  background-image: radial-gradient(circle at 50% 10%, #1a1a1a 0%, #000000 100%);
  color: var(--text-color);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(0, 0, 0, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.site-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  max-width: 1068px;
  height: 100%;
  margin: 0 auto;
  padding: 0 20px;
}

.site-nav__brand {
  display: inline-flex;
  flex-shrink: 0;
  align-items: center;
  gap: 10px;
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-color);
  text-decoration: none;
  transition: opacity 0.2s ease;
}

.site-nav__brand:hover {
  opacity: 0.85;
}

.site-nav__brand-icon {
  display: block;
  width: 28px;
  height: 28px;
  border-radius: 22%;
  object-fit: cover;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.35);
}

.site-nav__links {
  display: none;
  align-items: center;
  gap: 28px;
}

.site-nav__link {
  font-size: 0.8125rem;
  font-weight: 400;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.25s ease, opacity 0.25s ease;
}

.site-nav__link:hover {
  color: var(--text-secondary);
}

.site-nav__link.is-active {
  color: var(--text-color);
  font-weight: 500;
}

.site-nav__cta {
  flex-shrink: 0;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--primary-color);
  color: var(--text-color);
  font-size: 0.8125rem;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.site-nav__cta:hover {
  background: var(--primary-hover);
  transform: scale(1.04);
}

.page {
  max-width: 1068px;
  margin: 0 auto;
  padding: calc(24px + var(--nav-height)) 20px 48px;
  display: flex;
  flex-direction: column;
  gap: 48px;
  text-align: center;
}

.hero-download {
  margin: 0;
  scroll-margin-top: var(--nav-height);
}

#download {
  scroll-margin-top: var(--nav-height);
}

.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  padding: 24px 8px 8px;
  text-align: center;
  overflow-x: clip;
}

.app-icon {
  display: block;
  width: 120px;
  height: 120px;
  margin-bottom: 24px;
}

.app-icon__img {
  width: 100%;
  height: 100%;
  display: block;
  border-radius: 22%;
  object-fit: cover;
  box-shadow:
    0 12px 40px rgba(0, 0, 0, 0.55),
    0 0 0 1px rgba(255, 255, 255, 0.06);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.badge__label {
  display: inline-block;
  padding: 5px 12px;
  border-radius: 999px;
  background: rgba(0, 122, 255, 0.22);
  color: #64b5ff;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.title {
  width: 100%;
  max-width: 100%;
  margin: 0 auto 28px;
  padding: 0 4px;
  font-size: clamp(0.8125rem, 4.65vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: #f5f5f7;
  white-space: nowrap;
}

.cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 200px;
  padding: 14px 36px;
  border-radius: 999px;
  background-color: var(--primary-color);
  color: var(--text-color);
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  box-shadow:
    0 0 0 1px rgba(0, 122, 255, 0.5),
    0 8px 28px rgba(0, 122, 255, 0.45);
  transition: transform 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
}

.cta:hover {
  transform: scale(1.05);
  background-color: var(--primary-hover);
  box-shadow:
    0 6px 20px rgba(0, 122, 255, 0.4),
    inset 0 1px 0 rgba(255, 255, 255, 0.22);
}

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

.showcase {
  padding: 8px 0 16px;
  text-align: center;
}

.showcase-header {
  max-width: 680px;
  margin: 0 auto 28px;
  padding: 0 8px;
}

.showcase-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 12px;
  background: linear-gradient(135deg, #fff 0%, #a5a5a5 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.showcase-subtitle {
  font-size: clamp(1.0625rem, 2.2vw, 1.3125rem);
  line-height: 1.45;
  color: var(--text-secondary);
  font-weight: 400;
}

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

.preview {
  position: relative;
  margin-bottom: 48px;
}

.preview-tabs {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  margin: 0 auto 28px;
  border-radius: 999px;
  background: var(--segment-track);
  backdrop-filter: blur(24px) saturate(1.15);
  -webkit-backdrop-filter: blur(24px) saturate(1.15);
  border: 1px solid var(--glass-border);
  box-shadow:
    inset 0 1px 0 var(--glass-highlight),
    0 8px 24px rgba(0, 0, 0, 0.28);
}

.preview-tab {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 76px;
  padding: 10px 20px;
  border: none;
  border-radius: 999px;
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--text-muted);
  background: transparent;
  cursor: pointer;
  transition:
    color 0.3s cubic-bezier(0.25, 0.1, 0.25, 1),
    background 0.3s cubic-bezier(0.25, 0.1, 0.25, 1),
    box-shadow 0.3s cubic-bezier(0.25, 0.1, 0.25, 1),
    transform 0.2s ease;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.preview-tab:hover {
  color: var(--text-secondary);
}

#preview-home:checked ~ .preview-tabs label[for="preview-home"],
#preview-detail:checked ~ .preview-tabs label[for="preview-detail"],
#preview-ipad:checked ~ .preview-tabs label[for="preview-ipad"] {
  color: var(--text-color);
  font-weight: 600;
  background: var(--segment-active);
  box-shadow: var(--segment-active-shadow);
}

.preview-tab:focus-visible {
  outline: 2px solid rgba(0, 122, 255, 0.6);
  outline-offset: 2px;
}

.preview-stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: min(68vh, 620px);
  padding: 24px 12px 8px;
}

.preview-glow {
  position: absolute;
  inset: 10% 8% 6%;
  border-radius: 50%;
  background: radial-gradient(
    ellipse at center,
    rgba(0, 122, 255, 0.24) 0%,
    rgba(88, 86, 214, 0.08) 35%,
    transparent 72%
  );
  pointer-events: none;
  filter: blur(8px);
}

.preview-panel {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0;
  opacity: 0;
  visibility: hidden;
  transform: scale(0.96) translateY(12px);
  transition:
    opacity 0.45s cubic-bezier(0.25, 0.1, 0.25, 1),
    transform 0.45s cubic-bezier(0.25, 0.1, 0.25, 1),
    visibility 0.45s;
  will-change: opacity, transform;
}

.preview-panel img {
  display: block;
  width: auto;
  height: auto;
  max-width: 100%;
  user-select: none;
  -webkit-user-drag: none;
  filter: drop-shadow(0 32px 64px rgba(0, 0, 0, 0.55));
}

.preview-panel--phone img {
  max-width: min(300px, 78vw);
  max-height: min(64vh, 560px);
}

.preview-panel--pad img {
  max-width: min(920px, 96vw);
  max-height: min(52vh, 440px);
}

#preview-home:checked ~ .preview-stage [data-panel="home"],
#preview-detail:checked ~ .preview-stage [data-panel="detail"],
#preview-ipad:checked ~ .preview-stage [data-panel="ipad"] {
  opacity: 1;
  visibility: visible;
  transform: scale(1) translateY(0);
  position: relative;
}

.showcase-lead {
  max-width: 720px;
  margin: 0 auto;
  padding: 20px 24px;
  font-size: 1.05em;
  line-height: 1.65;
  letter-spacing: -0.01em;
  color: var(--text-secondary);
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  box-shadow:
    inset 0 1px 0 var(--glass-highlight),
    0 4px 20px rgba(0, 0, 0, 0.2);
}

.showcase-lead strong {
  color: #e5e5e5;
  font-weight: 600;
}

.footer {
  max-width: 1068px;
  margin: 50px auto 0;
  padding: 8px 20px 32px;
  text-align: center;
  font-size: 0.9em;
  color: var(--text-muted);
  line-height: 1.8;
}

.footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

@media (prefers-reduced-motion: reduce) {
  .preview-panel,
  .cta,
  .site-nav__cta {
    transition: none;
  }
}

@media (min-width: 768px) {
  :root {
    --nav-height: 48px;
  }

  .site-nav__links {
    display: flex;
  }

  .site-nav__cta {
    display: none;
  }
}

@media (min-width: 600px) {
  .page {
    padding: calc(32px + var(--nav-height)) 24px 64px;
    gap: 56px;
  }

  .hero {
    padding: 40px 20px 16px;
  }

  .app-icon {
    width: 128px;
    height: 128px;
    margin-bottom: 28px;
  }

  .title {
    margin-bottom: 32px;
    font-size: 2.25rem;
    letter-spacing: -0.03em;
  }

  .cta {
    min-width: 220px;
    padding: 15px 40px;
    font-size: 1.125rem;
  }

  .showcase-header {
    margin-bottom: 40px;
  }

  .preview-tabs {
    margin-bottom: 36px;
  }

  .preview-tab {
    min-width: 92px;
    padding: 11px 24px;
  }

  .showcase-lead {
    padding: 24px 32px;
    font-size: 1.1em;
  }

  .preview-stage {
    min-height: min(72vh, 680px);
    padding: 32px 20px 12px;
  }

  .preview-panel--phone img {
    max-width: 320px;
    max-height: 600px;
  }

  .preview-panel--pad img {
    max-width: 100%;
    max-height: min(56vh, 480px);
  }
}