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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Roboto', 'Noto Sans JP', sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: #0f172a;
  background: #fff;
  -webkit-font-smoothing: antialiased;
}

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

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

/* ===== Layout ===== */
.container {
  width: min(100%, 1040px);
  margin-inline: auto;
  padding-inline: 24px;
}

/* ===== Hero ===== */
.hero {
  position: relative;
  overflow: hidden;
  background: #f9fafb;
  padding: 100px 0 120px;
  text-align: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse 80% 60% at 50% 0%,
    rgba(0, 122, 255, 0.07) 0%,
    transparent 70%
  );
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.app-icon {
  line-height: 1;
}

.app-icon img {
  width: 120px;
  height: 120px;
  border-radius: 27.5%;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  margin-bottom: 16px;
}

.hero-title {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 800;
  letter-spacing: 0.06em;
  color: #0f172a;
}

.hero-copy {
  font-size: clamp(1.1rem, 3vw, 1.5rem);
  font-weight: 500;
  color: #475569;
  line-height: 1.8;
}

/* App Store ボタン */
.btn-store {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  background: #000;
  color: #fff;
  padding: 13px 28px 13px 22px;
  border-radius: 16px;
  margin-top: 8px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.18);
  transition:
    transform 0.18s ease,
    box-shadow 0.18s ease,
    opacity 0.15s;
  min-width: 210px;
}

.btn-store:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 32px rgba(0, 0, 0, 0.28);
  opacity: 0.92;
}

.btn-store:active {
  transform: translateY(0);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.store-icon {
  width: 28px;
  height: 28px;
  fill: #fff;
  flex-shrink: 0;
}

.store-label {
  display: flex;
  flex-direction: column;
  text-align: left;
  gap: 1px;
}

.store-sub {
  font-size: 10px;
  font-weight: 400;
  opacity: 0.72;
  letter-spacing: 0.04em;
  line-height: 1;
}

.store-main {
  font-size: 21px;
  font-weight: 700;
  letter-spacing: 0em;
  line-height: 1;
}

/* Coming Soon バッジ */
.hero-badge {
  display: inline-block;
  background: rgba(15, 23, 42, 0.06);
  color: #64748b;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 6px 16px;
  border-radius: 100px;
  border: 1px solid rgba(15, 23, 42, 0.1);
  margin-top: 8px;
}

/* ===== Use Cases ===== */
.usecases {
  padding: 80px 0;
  background: #fff;
}

.usecase-list {
  list-style: none;
  max-width: 680px;
  margin-inline: auto;
  border-top: 1px solid #e2e8f0;
}

.usecase-item {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 22px 8px 22px 20px;
  border-bottom: 1px solid #e2e8f0;
  position: relative;
  transition: padding-left 0.25s ease;
}

.usecase-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 12px;
  bottom: 12px;
  width: 3px;
  background: linear-gradient(180deg, #3b82f6, #8b5cf6);
  border-radius: 2px;
  transform: scaleY(0);
  transform-origin: center;
  transition: transform 0.25s ease;
}

.usecase-item:hover {
  padding-left: 28px;
}

.usecase-item:hover::before {
  transform: scaleY(1);
}

.usecase-emoji {
  font-size: 1.6rem;
  line-height: 1;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #f8fafc;
  border-radius: 14px;
  flex-shrink: 0;
  border: 1px solid #e2e8f0;
  transition:
    background 0.25s ease,
    transform 0.25s ease;
}

.usecase-item:hover .usecase-emoji {
  background: #eff6ff;
  transform: scale(1.06);
}

.usecase-text {
  font-size: clamp(1.05rem, 2.5vw, 1.35rem);
  font-weight: 700;
  color: #0f172a;
  letter-spacing: -0.01em;
}

/* ===== Section common ===== */
.section-title {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  text-align: center;
  color: #0f172a;
}

.section-sub {
  text-align: center;
  color: #64748b;
  margin-top: 8px;
  font-size: 0.95rem;
}

/* ===== Features ===== */
.features {
  padding: 100px 0;
  background: #fff;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-top: 48px;
}

.feature-card {
  background: #f9fafb;
  border: 1px solid #e2e8f0;
  border-radius: 20px;
  padding: 32px 24px;
  transition:
    box-shadow 0.2s,
    transform 0.2s;
}

.feature-card:hover {
  box-shadow: 0 8px 32px rgba(15, 23, 42, 0.07);
  transform: translateY(-3px);
}

.feature-icon {
  font-size: 36px;
  line-height: 1;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 0.88rem;
  color: #64748b;
  line-height: 1.75;
}

/* ===== Screenshots ===== */
.screenshots {
  padding: 80px 0 120px;
  background: #fff;
}

.screenshots-track {
  display: flex;
  justify-content: center;
  gap: 28px;
  margin-top: 48px;
  flex-wrap: wrap;
  align-items: flex-start;
}

.screenshot-frame {
  width: 210px;
  overflow: hidden;
  background: transparent;
  flex-shrink: 0;
}

.screenshot-frame img {
  width: 100%;
  height: auto;
  display: block;
  box-sizing: border-box;
  border: 4px solid #000;
  border-radius: 32px;
}

/* 画像が読み込めない場合のプレースホルダー */
.screenshot-frame.placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #eff6ff 0%, #f0fdf4 100%);
}

.screenshot-frame.placeholder::after {
  content: '📱';
  font-size: 48px;
  opacity: 0.4;
}

.screenshots-note {
  text-align: center;
  margin-top: 24px;
  font-size: 0.8rem;
  color: #94a3b8;
}

/* ===== Footer ===== */
.footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 48px 0;
  text-align: center;
}

.footer-brand {
  font-size: 1rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.footer-links {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
  font-size: 0.85rem;
  margin-bottom: 20px;
}

.footer-links a {
  color: #94a3b8;
  transition: color 0.15s;
}

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

.footer-copy {
  font-size: 0.8rem;
  color: #475569;
}

/* ===== Lightbox ===== */
.screenshot-frame {
  cursor: zoom-in;
  transition: transform 0.28s ease;
}

.screenshot-frame:hover {
  transform: translateY(-8px);
}

.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
  z-index: 1000;
  padding: 24px;
}

.lightbox.is-open {
  opacity: 1;
  pointer-events: auto;
}

.lightbox-img {
  max-width: min(320px, 85vw);
  max-height: 85vh;
  box-shadow: 0 32px 80px rgba(0, 0, 0, 0.6);
  transform: scale(0.92);
  transition: transform 0.25s ease;
  object-fit: contain;
}

.lightbox.is-open .lightbox-img {
  transform: scale(1);
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 20px;
  background: rgba(255, 255, 255, 0.15);
  border: none;
  color: #fff;
  font-size: 24px;
  line-height: 1;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
  backdrop-filter: blur(4px);
}

.lightbox-close:hover {
  background: rgba(255, 255, 255, 0.28);
}

/* ===== Legal Pages ===== */
.legal-header {
  background: #0f172a;
  padding: 20px 0;
}

.legal-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.legal-brand {
  font-size: 1rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: 0.08em;
}

.legal-brand:hover {
  opacity: 0.8;
}

.lang-toggle--dark {
  border-color: rgba(255, 255, 255, 0.25);
  color: rgba(255, 255, 255, 0.7);
}

.lang-toggle--dark:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.4);
}

.legal-main {
  padding: 72px 0 96px;
  min-height: calc(100vh - 200px);
}

.legal-content {
  max-width: 680px;
  margin-inline: auto;
}

.legal-title {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 8px;
}

.version-date {
  font-size: 0.75rem;
  font-weight: 400;
  color: #94a3b8;
  margin-left: 8px;
}

.legal-content h2 {
  font-size: 1.05rem;
  font-weight: 700;
  color: #0f172a;
  margin-top: 40px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid #e2e8f0;
}

.legal-content h3 {
  font-size: 0.93rem;
  font-weight: 600;
  color: #334155;
  margin-top: 20px;
  margin-bottom: 8px;
}

.legal-content p {
  font-size: 0.93rem;
  color: #475569;
  line-height: 1.85;
  margin-bottom: 12px;
}

.legal-content ul {
  padding-left: 1.5em;
  margin-bottom: 12px;
}

.legal-content li {
  font-size: 0.93rem;
  color: #475569;
  line-height: 1.85;
  margin-bottom: 4px;
}

.legal-content a {
  color: #3b82f6;
  text-decoration: underline;
}

.legal-content a:hover {
  color: #1d4ed8;
}

/* ===== Sticky Nav ===== */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.65);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(15, 23, 42, 0.08);
  box-shadow: 0 1px 16px rgba(15, 23, 42, 0.05);
  transform: translateY(-100%);
  opacity: 0;
  transition:
    transform 0.3s ease,
    opacity 0.3s ease;
}

.site-nav.is-visible {
  transform: translateY(0);
  opacity: 1;
}

.site-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  gap: 24px;
  flex-wrap: nowrap;
}

.site-nav-brand {
  font-size: 0.88rem;
  font-weight: 800;
  color: #0f172a;
  letter-spacing: 0.04em;
  white-space: nowrap;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 6px;
}

.site-nav-brand:hover {
  opacity: 0.65;
}

.site-nav-brand-icon {
  width: 24px;
  height: 24px;
  border-radius: 27.5%;
  vertical-align: middle;
}

.site-nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: nowrap;
  flex-shrink: 1;
  min-width: 0;
}

.site-nav-links a {
  font-size: 0.8rem;
  color: #64748b;
  white-space: nowrap;
  padding: 5px 10px;
  border-radius: 6px;
  transition:
    color 0.15s,
    background 0.15s;
}

.site-nav-links a:hover {
  color: #0f172a;
  background: rgba(15, 23, 42, 0.05);
}

/* ===== Language Toggle (page top) ===== */
.lang-toggle-fixed {
  padding: 16px 20px;
  text-align: left;
}

/* ===== Language Toggle ===== */
.lang-toggle {
  background: none;
  border: 1px solid rgba(15, 23, 42, 0.18);
  color: #64748b;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 4px 10px;
  border-radius: 6px;
  cursor: pointer;
  flex-shrink: 0;
  transition:
    color 0.15s,
    background 0.15s,
    border-color 0.15s;
  font-family: inherit;
}

.lang-toggle:hover {
  color: #0f172a;
  background: rgba(15, 23, 42, 0.05);
  border-color: rgba(15, 23, 42, 0.3);
}

/* ===== Hamburger Button ===== */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  border-radius: 8px;
  flex-shrink: 0;
  transition: background 0.15s;
  -webkit-tap-highlight-color: transparent;
}

.nav-hamburger:hover {
  background: rgba(15, 23, 42, 0.06);
}

.nav-hamburger-line {
  display: block;
  width: 20px;
  height: 2px;
  background: #0f172a;
  border-radius: 1px;
  transition:
    transform 0.25s ease,
    opacity 0.2s ease;
}

.nav-hamburger.is-open .nav-hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-hamburger.is-open .nav-hamburger-line:nth-child(2) {
  opacity: 0;
}

.nav-hamburger.is-open .nav-hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===== Mobile Menu Overlay ===== */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.3);
  z-index: 99;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.nav-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .nav-hamburger {
    display: flex;
  }

  .site-nav-links {
    position: fixed;
    top: 56px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(15, 23, 42, 0.08);
    box-shadow: 0 8px 32px rgba(15, 23, 42, 0.1);
    padding: 8px 0;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition:
      transform 0.3s ease,
      opacity 0.25s ease;
    z-index: 100;
  }

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

  .site-nav-links a {
    font-size: 0.9rem;
    padding: 14px 24px;
    border-radius: 0;
    color: #0f172a;
  }

  .site-nav-links a:hover,
  .site-nav-links a:active {
    background: rgba(15, 23, 42, 0.05);
  }

  .nav-overlay {
    display: block;
  }

  .hero {
    padding: 120px 0 88px;
  }

  .usecases {
    padding: 56px 0;
  }

  .usecase-item {
    padding: 18px 8px 18px 16px;
  }

  .usecase-emoji {
    width: 44px;
    height: 44px;
    font-size: 1.4rem;
  }

  .features {
    padding: 72px 0;
  }

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

  .screenshots {
    padding: 56px 0 80px;
  }

  .screenshots-track {
    gap: 16px;
  }

  .screenshot-frame {
    width: 155px;
  }

  .footer-links {
    flex-wrap: wrap;
    gap: 4px 12px;
  }

  .footer-links span[aria-hidden='true'] {
    display: none;
  }

  .footer-links a {
    padding: 4px 8px;
  }
}