:root {
  color-scheme: light;
  --ink: #172033;
  --muted: #5b667a;
  --line: #dce3ed;
  --surface: #f4f7fb;
  --accent: #f06d2f;
  --accent-dark: #c94e18;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", sans-serif;
  line-height: 1.75;
}

.introduction-overlay {
  position: fixed;
  z-index: 10;
  inset: 0;
  display: grid;
  place-items: center;
  overflow-y: auto;
  padding: 28px 20px;
  background: rgba(17, 27, 45, .94);
  color: #f8fbff;
  opacity: 1;
  transition: opacity .48s ease, visibility .48s ease;
}

.introduction-overlay::before,
.introduction-overlay::after {
  position: fixed;
  width: min(55vw, 620px);
  aspect-ratio: 1;
  border-radius: 50%;
  content: "";
  filter: blur(2px);
  pointer-events: none;
}

.introduction-overlay::before {
  top: -30%;
  right: -12%;
  background: radial-gradient(circle, rgba(240, 109, 47, .42), transparent 68%);
}

.introduction-overlay::after {
  bottom: -38%;
  left: -14%;
  background: radial-gradient(circle, rgba(88, 148, 230, .31), transparent 70%);
}

.introduction-panel {
  position: relative;
  z-index: 1;
  width: min(760px, 100%);
  padding: clamp(34px, 6vw, 68px);
  border: 1px solid rgba(255, 255, 255, .2);
  border-radius: 20px;
  background: rgba(23, 32, 51, .72);
  box-shadow: 0 24px 80px rgba(0, 0, 0, .28);
  animation: introduction-enter .7s cubic-bezier(.22, 1, .36, 1) both;
}

.introduction-panel .eyebrow { color: #ffad82; }

.introduction-panel h1 {
  max-width: none;
  margin-bottom: 18px;
  color: #fff;
  font-size: clamp(2rem, 4vw, 3.25rem);
}

.mobile-title-break { display: none; }

.introduction-copy {
  max-width: 650px;
  height: min(54vh, 420px);
  position: relative;
  color: #dae4f1;
}

.introduction-step {
  display: flex;
  align-items: center;
  min-height: 100%;
  padding: 12px 22px 12px 0;
}

.introduction-heading { align-items: flex-start; flex-direction: column; justify-content: center; }

.introduction-step > p:not(.eyebrow):not(.introduction-scroll-hint) {
  margin: 0;
  font-size: clamp(1rem, 1.8vw, 1.14rem);
}

.introduction-scroll-hint {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin: 18px 0 0;
  padding: 7px 10px;
  border: 1px solid rgba(255, 255, 255, .16);
  border-radius: 999px;
  background: rgba(255, 255, 255, .06);
  color: rgba(238, 245, 255, .88);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .08em;
}

.scroll-chevron {
  display: inline-block;
  font-size: 1.25rem;
  line-height: .7;
  animation: scroll-chevron-bounce 1.4s ease-in-out infinite;
}

.introduction-heading.has-scroll-cue .introduction-scroll-hint {
  animation: introduction-hint-nudge 1.1s ease-in-out .55s 2;
}

body.introduction-slides-ready .introduction-step {
  position: absolute;
  inset: 0;
  min-height: 0;
  visibility: hidden;
  opacity: 0;
  transform: translateY(30px) scale(.98);
  pointer-events: none;
  transition: opacity .75s ease, transform .75s cubic-bezier(.22, 1, .36, 1);
}

body.introduction-slides-ready .introduction-step.is-entering-from-top {
  transform: translateY(-30px) scale(.98);
}

body.introduction-slides-ready .introduction-step.is-active {
  visibility: visible;
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

body.introduction-slides-ready .introduction-step.is-leaving {
  visibility: visible;
  opacity: 0;
  transform: translateY(-30px) scale(.98);
  pointer-events: none;
  transition: opacity .62s ease, transform .62s cubic-bezier(.22, 1, .36, 1);
}

body.introduction-slides-ready .introduction-step.is-leaving.is-leaving-down {
  transform: translateY(30px) scale(.98);
}

.introduction-actions {
  display: flex;
  align-items: center;
  gap: 18px 24px;
  margin-top: 28px;
}

.introduction-navigation {
  display: flex;
  justify-content: flex-end;
  margin-top: 10px;
  color: rgba(218, 228, 241, .72);
  font-size: .76rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: .08em;
}

.introduction-navigation span {
  min-width: 42px;
  text-align: right;
}

.introduction-actions p {
  margin: 0;
  color: #b7c5d9;
  font-size: .88rem;
  line-height: 1.6;
}

.introduction-overlay.is-closing {
  visibility: hidden;
  opacity: 0;
}

.introduction-overlay.is-closing .introduction-panel {
  transform: translateY(-14px) scale(.985);
  transition: transform .48s ease;
}

body:has(.introduction-overlay:not(.is-closing)) { overflow: hidden; }

@keyframes introduction-enter {
  from { opacity: 0; transform: translateY(24px) scale(.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes scroll-chevron-bounce {
  0%, 100% { transform: translateY(-2px); }
  50% { transform: translateY(4px); }
}

@keyframes introduction-hint-nudge {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(5px); }
}

main { overflow: hidden; }

.hero,
.section {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.hero {
  min-height: 580px;
  padding: 112px 0 88px;
  background:
    radial-gradient(circle at 86% 18%, #fff1e9 0, #fff1e900 25rem),
    radial-gradient(circle at 70% 78%, #eef4ff 0, #eef4ff00 27rem);
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--accent-dark);
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .14em;
}

h1, h2, h3, p { margin-top: 0; }

h1 {
  max-width: 720px;
  margin-bottom: 22px;
  font-size: clamp(2.5rem, 6vw, 4.8rem);
  letter-spacing: -.04em;
  line-height: 1.17;
}

h2 {
  max-width: 680px;
  font-size: clamp(1.8rem, 3.8vw, 2.8rem);
  letter-spacing: -.03em;
  line-height: 1.35;
  text-wrap: balance;
}

.lead {
  max-width: 610px;
  margin-bottom: 30px;
  color: var(--muted);
  font-size: 1.12rem;
}

.access-options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 360px));
  gap: 16px;
}

.access-card {
  display: grid;
  gap: 4px;
  min-height: 164px;
  padding: 22px 24px;
  border: 1px solid var(--line);
  border-radius: 12px;
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  text-align: left;
  text-decoration: none;
  transition: border-color .15s ease, box-shadow .15s ease, transform .15s ease;
}

.access-card:hover {
  border-color: var(--accent);
  box-shadow: 0 10px 24px rgba(23, 32, 51, .1);
  transform: translateY(-2px);
}

.access-card-label {
  color: var(--accent-dark);
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .08em;
}

.access-card strong { font-size: 1.18rem; }
.access-card > span:nth-of-type(2) { color: var(--muted); font-size: .88rem; line-height: 1.6; }

.access-card-details {
  display: grid;
  gap: 2px;
  margin-top: 8px;
  color: var(--muted);
  font-size: .78rem;
  line-height: 1.55;
}

.access-card-details > span:first-child {
  margin-bottom: 2px;
  color: var(--ink);
  font-weight: 800;
}

.access-request-item {
  display: grid;
  gap: 1px;
  margin-top: 4px;
}

.access-request-item strong {
  color: var(--ink);
  font-size: inherit;
}

.access-request-item small {
  color: var(--muted);
  font-size: inherit;
}

.registered-use { background: var(--surface); }
.first-use { background: #fff; }

.primary-button,
.secondary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 0 24px;
  border: 1px solid var(--accent);
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-weight: 800;
  text-decoration: none;
  transition: background .15s ease, transform .15s ease;
}

.primary-button:hover,
.secondary-button:hover { background: var(--accent-dark); transform: translateY(-1px); }

.is-disabled {
  cursor: not-allowed;
  opacity: .55;
  pointer-events: none;
}

.text-link { color: var(--ink); font-weight: 700; }

.login-note { margin-top: 18px; color: var(--muted); font-size: .88rem; }
.copy-status { min-height: 1.75em; margin: 8px 0 0; color: var(--accent-dark); font-size: .88rem; font-weight: 700; }

.copy-confirmation {
  width: min(460px, calc(100% - 32px));
  padding: 0;
  border: 0;
  border-radius: 18px;
  box-shadow: 0 24px 70px rgba(17, 27, 45, .3);
  color: var(--ink);
}

.copy-confirmation::backdrop {
  background: rgba(17, 27, 45, .58);
  backdrop-filter: blur(3px);
}

.copy-confirmation[open] {
  animation: copy-confirmation-enter .24s cubic-bezier(.22, 1, .36, 1) both;
}

.copy-confirmation-content {
  padding: clamp(28px, 6vw, 40px);
  background: #fff;
}

.copy-confirmation-content .eyebrow { color: var(--accent-dark); }

.copy-confirmation-content h2 {
  margin: 0 0 14px;
  font-size: clamp(1.35rem, 4.5vw, 1.75rem);
}

.copy-confirmation-content p:not(.eyebrow) {
  margin: 0 0 13px;
  color: var(--muted);
  font-size: .94rem;
}

.copy-confirmation-content .primary-button {
  width: 100%;
  margin-top: 8px;
}

@keyframes copy-confirmation-enter {
  from { opacity: 0; transform: translateY(12px) scale(.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.section { padding: 88px 0; }

.section + .section { border-top: 1px solid var(--line); }

[data-reveal] {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .65s ease, transform .65s cubic-bezier(.22, 1, .36, 1);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

.feature-card[data-reveal]:nth-child(2),
.privacy-grid article[data-reveal]:nth-child(2) { transition-delay: .1s; }

.feature-card[data-reveal]:nth-child(3),
.privacy-grid article[data-reveal]:nth-child(3) { transition-delay: .2s; }

.privacy-grid article[data-reveal]:nth-child(4) { transition-delay: .3s; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 36px;
}

.feature-card {
  min-height: 250px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
}

.feature-number { color: var(--accent-dark); font-weight: 800; letter-spacing: .08em; }
.feature-card h3 { margin: 22px 0 8px; font-size: 1.2rem; text-wrap: balance; }
.feature-card p,
.security > p { color: var(--muted); }

.feature-screenshot {
  margin: 20px 0 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.feature-screenshot img {
  display: block;
  width: 100%;
  height: auto;
}

.feature-screenshot figcaption {
  padding: 7px 10px;
  color: var(--muted);
  font-size: .75rem;
}

.ai-analysis-lead {
  max-width: 790px;
  color: var(--muted);
  font-size: 1.05rem;
}

.ai-flow {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 36px;
}

.ai-flow article {
  min-height: 218px;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
}

.ai-flow span {
  color: var(--accent-dark);
  font-size: .8rem;
  font-weight: 800;
  letter-spacing: .1em;
}

.ai-flow h3 { margin: 18px 0 8px; font-size: 1.18rem; }
.ai-flow p { margin-bottom: 0; color: var(--muted); font-size: .92rem; }

.ai-examples {
  max-width: 790px;
  margin-top: 28px;
  padding: 22px 24px;
  border-left: 3px solid var(--accent);
  background: var(--surface);
}

.ai-examples p { margin-bottom: 10px; font-weight: 800; }
.ai-examples ul { margin: 0; padding-left: 1.25em; color: var(--muted); }
.ai-examples li + li { margin-top: 5px; }

.ai-disclaimer {
  max-width: 790px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: .88rem;
}

.security { padding-bottom: 108px; }
.security > p { max-width: 760px; margin-bottom: 24px; }
.secondary-button { background: var(--ink); border-color: var(--ink); }
.secondary-button:hover { background: #2a3850; }

.privacy { padding-bottom: 108px; }

.privacy-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 36px;
}

.privacy-grid article {
  padding: 24px;
  border-left: 3px solid var(--accent);
  background: var(--surface);
}

.privacy-grid h3 { margin-bottom: 8px; font-size: 1rem; }
.privacy-grid p { margin-bottom: 0; color: var(--muted); font-size: .92rem; }

footer {
  display: flex;
  justify-content: space-between;
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 26px 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: .85rem;
}

@media (max-width: 720px) {
  .mobile-title-break { display: inline; }
  .introduction-overlay { align-items: start; padding: 16px; }
  .introduction-panel { margin: auto 0; border-radius: 16px; }
  .introduction-copy { height: min(51vh, 360px); }
  .introduction-step { padding-right: 12px; }
  .introduction-actions { align-items: stretch; flex-direction: column; }
  .introduction-actions .primary-button { width: 100%; }
  .hero { min-height: auto; padding: 78px 0 66px; }
  .section { padding: 62px 0; }
  .feature-grid { grid-template-columns: 1fr; }
  .ai-flow { grid-template-columns: 1fr; }
  .access-options { grid-template-columns: 1fr; }
  .privacy-grid { grid-template-columns: 1fr; }
  .feature-card { min-height: 0; }
  h2 { font-size: clamp(1.55rem, 7.2vw, 2rem); }
  footer { gap: 8px; flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .introduction-overlay,
  .introduction-overlay.is-closing .introduction-panel,
  .introduction-panel,
  .introduction-scroll-hint,
  .scroll-chevron,
  .copy-confirmation[open],
  .access-card,
  .primary-button,
  .secondary-button,
  [data-reveal],
  [data-introduction-reveal] { animation: none; transition: none; }

  [data-reveal] { opacity: 1; transform: none; }

  body.introduction-slides-ready .introduction-step { transition: none; }
}