:root {
  color-scheme: light;
  --green: #25dc73;
  --green-dark: #11984f;
  --green-soft: #7cffaa;
  --yellow: #ffc400;
  --cream: #fffbe7;
  --paper: #ffffff;
  --ink: #171712;
  --muted: #3d3a30;
  --line: #171712;
  --shadow-hard: 8px 8px 0 var(--ink);
  --shadow-small: 4px 4px 0 var(--ink);
  --radius-lg: 30px;
  font-family: "DM Sans", "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  min-height: 100vh;
  background: linear-gradient(180deg, #39e984 0%, var(--green) 58%, #1fc765 100%);
  -webkit-font-smoothing: antialiased;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  opacity: 0.18;
  background-image:
    linear-gradient(rgba(23, 23, 18, 0.24) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 23, 18, 0.24) 1px, transparent 1px);
  background-size: 42px 42px;
}
a { color: inherit; text-decoration: none; }

.siteHeader {
  position: sticky;
  top: 12px;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: min(1160px, calc(100% - 28px));
  margin: 12px auto 0;
  padding: 10px 12px;
  border: 3px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 251, 231, 0.94);
  box-shadow: var(--shadow-small);
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 1.1rem; font-weight: 900; letter-spacing: -0.04em; }
.brandMark { width: 42px; height: 42px; border: 3px solid var(--line); border-radius: 50%; object-fit: cover; background: var(--green); }
nav { display: flex; align-items: center; gap: 8px; }
nav a { padding: 10px 14px; border: 2px solid var(--line); border-radius: 999px; background: var(--paper); font-size: 0.84rem; font-weight: 900; }
nav a:hover { background: var(--yellow); }

.hero, .friendBanner, .featureGrid, .sceneGrid, .appExplanation, .section, .download { width: min(1160px, calc(100% - 28px)); margin: 0 auto; }
.card { border: 3px solid var(--line); border-radius: var(--radius-lg); box-shadow: var(--shadow-hard); }
.creamCard { background: var(--cream); }
.whiteCard { background: var(--paper); }
.yellowCard { background: var(--yellow); }

.hero { display: grid; grid-template-columns: minmax(0, 0.95fr) minmax(360px, 1.05fr); gap: clamp(26px, 5vw, 72px); align-items: center; padding: 64px 0 62px; }
.heroCopy { padding: clamp(24px, 4.5vw, 52px); }
.eyebrow { display: inline-flex; width: fit-content; margin: 0 0 16px; padding: 7px 12px; border: 2px solid var(--line); border-radius: 999px; color: var(--green-soft); background: var(--ink); font-size: 0.78rem; font-weight: 900; letter-spacing: 0.04em; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 20px; font-family: "Noto Sans JP", "DM Sans", sans-serif; font-size: clamp(2.8rem, 5vw, 4.25rem); font-weight: 900; line-height: 1.06; letter-spacing: -0.08em; }
h2 { margin-bottom: 14px; font-family: "Noto Sans JP", "DM Sans", sans-serif; font-size: clamp(2rem, 4vw, 3.7rem); font-weight: 900; line-height: 1.06; letter-spacing: -0.075em; }
h3 { margin-bottom: 8px; font-size: 1.28rem; font-weight: 900; letter-spacing: -0.04em; }
.lead, .quietNote, .friendBanner p, .featureGrid p, .sceneGrid p, .appExplanation p, .sectionCopy p, .steps p, .captionCard p, .download p { color: var(--muted); font-family: "Noto Sans JP", "DM Sans", sans-serif; font-weight: 800; line-height: 1.78; }
.lead { max-width: 660px; margin-bottom: 0; font-size: clamp(1.04rem, 2vw, 1.3rem); }
.quietNote { font-size: 0.9rem; }
.heroActions, .storeButtons { display: flex; flex-wrap: wrap; gap: 12px; margin: 28px 0 18px; }
.primaryButton, .secondaryButton, .storeButtons span { display: inline-flex; align-items: center; justify-content: center; min-height: 54px; padding: 0 24px; border: 3px solid var(--line); border-radius: 999px; font-weight: 900; box-shadow: var(--shadow-small); }
.primaryButton { background: var(--yellow); }
.secondaryButton, .storeButtons span { background: var(--paper); }
.primaryButton:hover, .secondaryButton:hover { transform: translate(2px, 2px); box-shadow: 2px 2px 0 var(--ink); }

.heroVisual { margin: 0; padding: 18px; }
.phonePoster { display: grid; gap: 12px; padding: 16px; border: 3px solid var(--line); border-radius: 28px; background: var(--green); }
.phonePane { min-height: 176px; padding: 22px; border: 3px solid var(--line); border-radius: 24px; }
.otherSide { background: #101010; color: var(--paper); }
.mySide { background: var(--paper); }
.phonePane p { margin-bottom: 10px; opacity: 0.76; }
.phonePane strong { display: block; font-family: "Noto Sans JP", "DM Sans", sans-serif; font-size: clamp(1.55rem, 3vw, 2.35rem); font-weight: 900; line-height: 1.14; letter-spacing: -0.05em; }
.chip { display: inline-flex; width: fit-content; margin-bottom: 12px; padding: 6px 10px; border: 2px solid currentColor; border-radius: 999px; font-size: 0.75rem; font-weight: 900; }
.darkChip { color: var(--green-soft); }
.greenChip { color: var(--ink); background: var(--green); }
.micBadge { display: grid; place-items: center; width: 78px; height: 78px; margin: -18px auto; border: 3px solid var(--line); border-radius: 50%; background: var(--yellow); font-weight: 900; box-shadow: var(--shadow-small); z-index: 1; }
.heroVisual figcaption { display: grid; gap: 8px; margin-top: 16px; padding: 14px; border: 3px solid var(--line); border-radius: 22px; background: var(--paper); }
.heroVisual figcaption strong { font-family: "Noto Sans JP", "DM Sans", sans-serif; font-size: 1.18rem; font-weight: 900; }
.heroVisual figcaption span { color: var(--muted); font-weight: 800; line-height: 1.65; }

.friendBanner { padding: clamp(26px, 5vw, 46px); margin-bottom: 28px; text-align: center; }
.friendBanner h2 { max-width: 900px; margin-inline: auto; }
.friendBanner p { max-width: 760px; margin-inline: auto; margin-bottom: 0; }
.featureGrid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; padding-bottom: 58px; }
.featureGrid article { min-height: 278px; padding: 26px; }
.featureGrid h2 { margin-top: 14px; font-size: clamp(1.65rem, 2.8vw, 2.45rem); }
.sceneGrid { display: grid; grid-template-columns: 1.15fr repeat(3, minmax(0, 0.95fr)); gap: 18px; align-items: stretch; padding-bottom: 34px; }
.sceneGrid > .sectionCopy { padding: 26px; }
.sceneGrid article { padding: 24px; }
.sceneGrid article:nth-child(3) { transform: translateY(18px); }
.sceneGrid article:nth-child(4) { transform: translateY(36px); }
.sceneGrid h3 { font-family: "Noto Sans JP", "DM Sans", sans-serif; font-size: clamp(1.55rem, 2.6vw, 2.25rem); }
.appExplanation { display: grid; grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr); gap: 26px; align-items: start; padding: clamp(26px, 5vw, 44px); margin-bottom: 34px; }
.modeList { display: grid; gap: 14px; }
.modeList article { padding: 18px; border: 3px solid var(--line); border-radius: 22px; background: var(--cream); }
.modeList article:nth-child(2) { background: var(--yellow); }
.modeList p { margin-bottom: 0; }

.section { padding: 48px 0; }
.how, .splitFeature { display: grid; grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr); gap: clamp(26px, 5vw, 58px); align-items: center; }
.sectionCopy { padding: clamp(24px, 4.5vw, 42px); }
.steps { display: grid; gap: 16px; }
.steps article { display: grid; grid-template-columns: auto 1fr; column-gap: 18px; padding: 22px; }
.steps b { grid-row: span 2; display: grid; place-items: center; width: 48px; height: 48px; border: 3px solid var(--line); border-radius: 50%; background: var(--green); font-weight: 900; }
.steps p { margin-bottom: 0; }
.captionCard { padding: clamp(24px, 4.5vw, 38px); }
.captionSource { margin: 52px 0 12px; opacity: 0.74; }
.captionCard strong { display: block; margin-bottom: 18px; font-family: "Noto Sans JP", "DM Sans", sans-serif; font-size: clamp(2.2rem, 4.4vw, 3.8rem); font-weight: 900; line-height: 1.05; letter-spacing: -0.07em; }
.download { margin-top: 42px; margin-bottom: 72px; padding: clamp(34px, 7vw, 68px); text-align: center; }
.download p { max-width: 600px; margin-inline: auto; }
.storeButtons { justify-content: center; }
footer { display: flex; justify-content: center; gap: 18px; padding: 36px 16px; color: rgba(23,23,18,0.72); font-size: 0.92rem; font-weight: 900; }

@media (max-width: 900px) {
  nav { display: none; }
  .hero, .featureGrid, .sceneGrid, .appExplanation, .how, .splitFeature { grid-template-columns: 1fr; }
  .hero { padding-top: 44px; }
  .sceneGrid article:nth-child(3), .sceneGrid article:nth-child(4) { transform: none; }
  .splitFeature .captionCard { order: 2; }
}
@media (max-width: 560px) {
  .siteHeader, .hero, .friendBanner, .featureGrid, .sceneGrid, .appExplanation, .section, .download { width: min(100% - 22px, 1160px); }
  .siteHeader { top: 8px; }
  .brandMark { width: 38px; height: 38px; }
  .brand { font-size: 1rem; }
  .card, .phonePoster, .phonePane, .heroVisual figcaption, .modeList article, .steps b { border-width: 2.5px; box-shadow: 5px 5px 0 var(--ink); }
  .friendBanner { padding: 24px 18px; text-align: left; }
  .hero { padding-bottom: 44px; }
  .heroCopy, .sectionCopy, .appExplanation { padding: 22px 18px; }
  h1 { font-size: clamp(2.25rem, 11.4vw, 3.3rem); line-height: 1.08; }
  h2 { font-size: clamp(1.9rem, 10.5vw, 3.2rem); }
  .lead { line-height: 1.72; }
  .heroVisual { padding: 12px; }
  .phonePane { min-height: 152px; padding: 18px; }
  .phonePane strong { font-size: 1.34rem; }
  .micBadge { width: 64px; height: 64px; margin: -14px auto; }
  .featureGrid { padding-bottom: 34px; }
  .featureGrid article { min-height: auto; padding: 22px; }
  .section { padding: 34px 0; }
  .steps article { grid-template-columns: 1fr; }
  .steps b { margin-bottom: 16px; box-shadow: none; }
  .captionSource { margin-top: 30px; }
  footer { flex-wrap: wrap; }
}