/* lack × Keychron ティザー
   本文は 17px 以上、補足も 14px 以上（スマホで読める大きさ） */
:root {
  --bg: #16171b;
  --bg-alt: #1e2026;
  --panel: #262830;
  --line: #3a3d47;
  --text: #f2f2f4;
  --muted: #b4b7c1;
  --accent: #ff6a2b;
  --accent-ink: #1a0f08;
  --radius: 10px;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family:
    "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo,
    sans-serif;
  font-size: 17px;
  line-height: 1.85;
  -webkit-text-size-adjust: 100%;
}
img {
  max-width: 100%;
  height: auto;
  display: block;
}
a {
  color: inherit;
}
.wrap {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 20px;
}
.narrow {
  max-width: 760px;
}
.center {
  text-align: center;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  border: 0;
  white-space: nowrap;
}

/* 日英切り替え（html の data-lang で出し分け） */
html[data-lang="ja"] [data-l="en"],
html[data-lang="en"] [data-l="ja"] {
  display: none !important;
}
.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}
.lang-switch {
  display: flex;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.lang-switch button {
  min-width: 56px;
  min-height: 44px;
  padding: 0 10px;
  white-space: nowrap;
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
}
html[data-lang="ja"] [data-set-lang="ja"],
html[data-lang="en"] [data-set-lang="en"] {
  background: var(--text);
  color: var(--bg);
}

/* ボタン */
.btn {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 12px 26px;
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  background: var(--accent);
  color: var(--accent-ink);
  font: inherit;
  font-weight: 700;
  font-size: 17px;
  line-height: 1.3;
  text-decoration: none;
  cursor: pointer;
  box-shadow: 0 4px 0 #b8461a;
  transition:
    transform 0.08s,
    box-shadow 0.08s;
}
.btn:active {
  transform: translateY(3px);
  box-shadow: 0 1px 0 #b8461a;
}
.btn small {
  font-size: 13px;
  font-weight: 600;
  opacity: 0.8;
}
.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line);
  box-shadow: 0 4px 0 #0c0d10;
}
.btn-sm {
  white-space: nowrap;
  min-height: 44px;
  padding: 8px 16px;
  font-size: 15px;
}
.btn-lg {
  min-width: 300px;
  padding: 16px 32px;
  font-size: 20px;
}

/* ヘッダー */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(22, 23, 27, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  gap: 12px;
}
.wordmark {
  white-space: nowrap;
  font-weight: 800;
  font-size: 19px;
  letter-spacing: 0.02em;
}
.wordmark i {
  font-style: normal;
  color: var(--accent);
  margin: 0 4px;
}

/* ヒーロー */
.hero {
  position: relative;
  overflow: hidden;
  padding: 56px 0 72px;
  text-align: center;
}
.keys {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, 64px);
  gap: 10px;
  padding: 10px;
  justify-content: center;
  opacity: 0.35;
  mask-image: radial-gradient(ellipse at 50% 30%, #000 10%, transparent 70%);
  -webkit-mask-image: radial-gradient(
    ellipse at 50% 30%,
    #000 10%,
    transparent 70%
  );
  pointer-events: none;
}
.keys span {
  height: 64px;
  border-radius: 8px;
  background: var(--panel);
  box-shadow:
    inset 0 -6px 0 #1b1c22,
    0 1px 0 var(--line);
  transition:
    background 0.4s,
    transform 0.15s;
}
.keys span.on {
  background: var(--accent);
  box-shadow: inset 0 -6px 0 #b8461a;
  transform: translateY(2px);
}
.hero .wrap {
  position: relative;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 16px;
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(22, 23, 27, 0.7);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
}
.dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
  animation: blink 1.4s infinite;
}
@keyframes blink {
  50% {
    opacity: 0.25;
  }
}
h1 {
  margin: 0;
  font-size: clamp(32px, 6vw, 58px);
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: 0.01em;
}
h1 em {
  font-style: normal;
  color: var(--accent);
}
.collab {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin: 32px 0;
}
.collab-logo {
  width: 200px;
}
.collab-x {
  font-size: 34px;
  color: var(--accent);
  font-weight: 300;
}
.collab-icon {
  width: 88px;
  height: 88px;
  border-radius: 50%;
  border: 3px solid var(--line);
  object-fit: cover;
}
.hero-visual {
  margin: 0 auto;
  max-width: 960px;
  background: #ccc4c1;
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.5);
}
.hero-cta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  margin-top: 36px;
}

/* セクション共通 */
.block {
  padding: 80px 0;
}
.alt {
  background: var(--bg-alt);
}
.label {
  display: block;
  color: var(--accent);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.2em;
}
h1,
h2,
.lead {
  word-break: auto-phrase;
  text-wrap: balance;
}
h2 {
  margin: 6px 0 24px;
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1.4;
}
.h-sm {
  font-size: 20px;
  margin-top: 40px;
}
.h-sm:first-child {
  margin-top: 0;
}
.lead {
  font-size: 20px;
  font-weight: 700;
  line-height: 1.75;
}

/* はじまり（X 投稿） */
.origin {
  background: var(--bg-alt);
}
.tweet {
  display: flex;
  justify-content: center;
  margin: 28px 0 8px;
}
.tweet .twitter-tweet {
  margin: 0 auto !important;
}
/* 埋め込みが読み込まれる前・読み込めない場合の表示 */
blockquote.twitter-tweet {
  max-width: 520px;
  margin: 0;
  padding: 20px 24px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--bg);
  text-align: left;
}
blockquote.twitter-tweet p {
  margin: 0 0 12px;
  font-size: 18px;
}
blockquote.twitter-tweet a {
  color: var(--muted);
}

/* 想定ユーザー（キーキャップ風） */
.users {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin: 36px 0 0;
  padding: 0;
  list-style: none;
  text-align: center;
}
.users li {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
kbd {
  display: block;
  padding: 18px 6px;
  border-radius: 10px;
  background: var(--panel);
  box-shadow:
    inset 0 -6px 0 #1b1c22,
    0 0 0 1px var(--line);
  font-family: inherit;
  font-size: 16px;
  font-weight: 700;
}

/* 紹介 */
.profiles {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 16px;
}
.profile {
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--bg);
}
.profile-icon {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  object-fit: cover;
}
.profile-logo {
  display: flex;
  align-items: center;
  height: 96px;
}
.profile-logo img {
  width: 200px;
}
.profile h3 {
  margin: 18px 0 10px;
  font-size: 24px;
}
.profile h3 small {
  display: block;
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
}
.profile p {
  margin: 0 0 12px;
}

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}
.links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
}
.links a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* アンケート */
.survey {
  background:
    radial-gradient(circle at 50% 0, rgba(255, 106, 43, 0.18), transparent 60%),
    var(--bg);
}
.survey .btn-lg {
  margin-top: 16px;
}

/* メール登録 */
.signup {
  display: flex;
  gap: 12px;
  max-width: 560px;
  margin: 28px auto 0;
}
.signup input {
  flex: 1;
  min-width: 0;
  min-height: 56px;
  padding: 0 16px;
  border: 2px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  font: inherit;
  font-size: 18px;
}
.signup input:focus {
  outline: none;
  border-color: var(--accent);
}
.form-msg {
  min-height: 1.8em;
  margin: 14px 0 0;
  font-weight: 700;
}
.form-msg.ok {
  color: #7be0a1;
}
.form-msg.ng {
  color: #ff9b8a;
}
.note {
  color: var(--muted);
  font-size: 15px;
}
/* 登録欄の下の注意書き（ページ下部の利用目的と同じく控えめに） */
.note-sm {
  margin-top: 4px;
  font-size: 14px;
  line-height: 1.7;
  opacity: 0.85;
}
.note-sm a {
  color: inherit;
}

/* 利用目的 */
/* 注意書きなので控えめに（スマホで読める 14px は下回らない） */
.block.privacy {
  padding: 40px 0 48px;
  border-top: 1px solid var(--line);
}
.privacy {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}
.privacy .h-sm {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 15px;
}
.privacy p,
.privacy ul {
  margin: 0 0 8px;
}
.privacy ul {
  padding-left: 1.4em;
}

/* フッター */
.site-footer {
  padding: 40px 0;
  border-top: 1px solid var(--line);
  text-align: center;
}
.site-footer p {
  margin: 0;
  font-weight: 700;
}
.site-footer .small {
  color: var(--muted);
  font-size: 14px;
  font-weight: 400;
}

.pc-hide {
  display: none;
}

@media (max-width: 720px) {
  body {
    font-size: 17px;
  }
  .pc-hide {
    display: inline;
  }
  .sp-hide {
    display: none;
  }
  .hero {
    padding: 36px 0 56px;
  }
  .keys {
    grid-template-columns: repeat(auto-fill, 48px);
  }
  .keys span {
    height: 48px;
  }
  .collab {
    gap: 14px;
  }
  .collab-logo {
    width: 150px;
  }
  .collab-icon {
    width: 72px;
    height: 72px;
  }
  .hero-cta .btn {
    width: 100%;
  }
  .block {
    padding: 60px 0;
  }
  .users {
    grid-template-columns: 1fr 1fr;
  }
  .profiles {
    grid-template-columns: 1fr;
  }
  .profile {
    padding: 24px;
  }
  .signup {
    flex-direction: column;
  }
  .btn-lg {
    width: 100%;
    min-width: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .dot {
    animation: none;
  }
}