:root {
  --ink: #0b2841;
  --ink-soft: #163552;
  --paper: #f7f5f1;
  --paper-2: #efece6;
  --text: #0b2841;
  --text-muted: #5a6b7a;
  --line: rgba(11, 40, 65, 0.12);
  --line-brand: #06c755;
  --line-brand-hover: #05b34c;
  --line-ink: #ffffff;
  --on-dark: #f7f5f1;
  --on-dark-muted: rgba(247, 245, 241, 0.78);
  --font-display: "Zen Old Mincho", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --font-body: "Zen Kaku Gothic New", "Hiragino Sans", "Yu Gothic", sans-serif;
  --space: clamp(1.4rem, 4vw, 2.75rem);
  --section-y: clamp(5.5rem, 14vw, 9.5rem);
  --max: 40rem;
  --header-h: 4.25rem;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--text);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

h1,
h2 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: 0.04em;
  margin: 0;
}

h1 {
  font-size: clamp(2.1rem, 6.8vw, 4rem);
}

h2 {
  font-size: clamp(1.65rem, 4.4vw, 2.5rem);
}

p {
  margin: 0;
}

.line-icon {
  flex-shrink: 0;
  display: block;
}

/* Header */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space);
  mix-blend-mode: normal;
  pointer-events: none;
}

.site-header .logo,
.site-header .header-cta {
  pointer-events: auto;
}

.logo {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  color: var(--on-dark);
}

.logo-ja {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  line-height: 1.1;
}

.logo-en {
  font-size: 0.65rem;
  letter-spacing: 0.28em;
  text-transform: lowercase;
  opacity: 0.75;
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 0.55rem 0.95rem;
  border-radius: 999px;
  background: var(--line-brand);
  color: var(--line-ink);
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.header-cta:hover {
  background: var(--line-brand-hover);
  transform: translateY(-1px);
}

/* Hero */
.hero {
  position: relative;
  min-height: 100svh;
  display: grid;
  align-items: end;
  overflow: hidden;
  color: var(--on-dark);
  background: var(--ink);
}

.hero-media {
  position: absolute;
  inset: 0;
  background: url("assets/hero-site.jpg") center / cover no-repeat;
  transform: scale(1.04);
  animation: hero-ken 20s var(--ease) both;
  filter: saturate(0.85) contrast(1.05);
}

.hero-veil {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(11, 40, 65, 0.28) 0%, rgba(11, 40, 65, 0.45) 40%, rgba(11, 40, 65, 0.92) 100%),
    linear-gradient(90deg, rgba(11, 40, 65, 0.78) 0%, rgba(11, 40, 65, 0.2) 60%, rgba(11, 40, 65, 0.5) 100%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(100%, 48rem);
  padding: calc(var(--header-h) + 2.5rem) var(--space) clamp(3.5rem, 10vw, 6rem);
}

.brand,
.brand-mark {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin: 0 0 1.25rem;
}

.brand-ja {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.9rem, 5.5vw, 3rem);
  letter-spacing: 0.1em;
  line-height: 1;
}

.brand-en {
  font-size: 0.72rem;
  letter-spacing: 0.32em;
  text-transform: lowercase;
  opacity: 0.72;
}

.lede {
  margin-top: 1.5rem;
  max-width: 26rem;
  color: var(--on-dark-muted);
  font-size: clamp(1rem, 2.1vw, 1.125rem);
  line-height: 1.8;
}

.cta-row {
  margin-top: 2.25rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  line-height: 1.3;
  padding: 1.05rem 1.4rem;
  border: none;
  border-radius: 999px;
  cursor: pointer;
  transition: transform 0.25s var(--ease), background 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.btn-line {
  background: var(--line-brand);
  color: var(--line-ink);
  box-shadow: 0 10px 30px rgba(6, 199, 85, 0.28);
}

.btn-line:hover {
  background: var(--line-brand-hover);
  transform: translateY(-2px);
  box-shadow: 0 14px 34px rgba(6, 199, 85, 0.35);
}

.btn-line:active {
  transform: translateY(0);
}

.btn-lg {
  padding: 1.2rem 1.7rem;
  font-size: 1rem;
}

/* Sections — airy editorial */
.section {
  padding: var(--section-y) var(--space);
}

.section-inner {
  width: min(100%, var(--max));
  margin: 0 auto;
}

.section-label {
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: lowercase;
  color: var(--text-muted);
  margin-bottom: 1.35rem;
}

.section-body {
  margin-top: 1.5rem;
  color: var(--text-muted);
  max-width: 36rem;
  font-size: 1.02rem;
}

.section-problem,
.section-offer,
.section-trust {
  background: var(--paper);
}

.section-approach,
.section-flow {
  background: var(--paper-2);
}

.section-final {
  background: var(--ink);
  color: var(--on-dark);
  text-align: center;
}

.section-final .section-label,
.section-final .section-body {
  color: var(--on-dark-muted);
}

.section-final .section-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.section-final .section-body {
  margin-bottom: 2.25rem;
}

.section-final .brand-mark .brand-ja {
  font-size: 1.6rem;
  color: var(--on-dark);
}

.section-final .brand-mark .brand-en {
  color: var(--on-dark-muted);
}

/* Lists */
.offer-list,
.flow-list {
  list-style: none;
  margin: 3rem 0 0;
  padding: 0;
}

.offer-list li,
.flow-list li {
  padding: 1.65rem 0;
  border-bottom: 1px solid var(--line);
}

.offer-list li:first-child,
.flow-list li:first-child {
  border-top: 1px solid var(--line);
}

.offer-list li {
  display: grid;
  gap: 0.4rem 1.75rem;
}

@media (min-width: 640px) {
  .offer-list li {
    grid-template-columns: 9.5rem 1fr;
    align-items: baseline;
  }
}

.offer-name {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.offer-desc {
  color: var(--text-muted);
  font-size: 0.98rem;
}

.flow-list li {
  display: grid;
  grid-template-columns: 3.75rem 1fr;
  gap: 1.1rem;
  align-items: start;
}

.flow-num {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--ink);
  line-height: 1.45;
}

.flow-text {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  font-weight: 500;
}

.flow-sub {
  font-weight: 400;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Footer */
.site-footer {
  padding: 3.5rem var(--space) 5.5rem;
  background: var(--paper);
  border-top: 1px solid var(--line);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--ink);
  margin-bottom: 0.25rem;
}

.footer-en {
  font-size: 0.68rem;
  letter-spacing: 0.24em;
  text-transform: lowercase;
  margin-bottom: 1rem;
  opacity: 0.7;
}

.footer-meta {
  margin-bottom: 1rem;
}

.footer-note {
  max-width: 28rem;
  margin: 0 auto;
  line-height: 1.7;
  opacity: 0.85;
}

/* Floating LINE — icon, expands on hover */
.fab-line {
  position: fixed;
  right: 1.1rem;
  bottom: 1.1rem;
  z-index: 60;
  display: inline-flex;
  align-items: center;
  gap: 0;
  height: 3.5rem;
  padding: 0 1rem;
  border-radius: 999px;
  background: var(--line-brand);
  color: var(--line-ink);
  box-shadow: 0 12px 32px rgba(6, 199, 85, 0.35);
  overflow: hidden;
  max-width: 3.5rem;
  transition: max-width 0.35s var(--ease), padding 0.35s var(--ease), background 0.25s var(--ease), transform 0.25s var(--ease);
}

.fab-line .line-icon {
  margin: 0 auto;
}

.fab-label {
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  white-space: nowrap;
  opacity: 0;
  max-width: 0;
  margin-left: 0;
  transition: opacity 0.25s var(--ease), max-width 0.35s var(--ease), margin-left 0.35s var(--ease);
}

.fab-line:hover,
.fab-line:focus-visible {
  max-width: 12rem;
  padding: 0 1.25rem 0 1rem;
  background: var(--line-brand-hover);
  transform: translateY(-2px);
}

.fab-line:hover .fab-label,
.fab-line:focus-visible .fab-label {
  opacity: 1;
  max-width: 8rem;
  margin-left: 0.55rem;
}

/* Motion */
.reveal {
  opacity: 0;
  transform: translateY(1rem);
  animation: rise 1s var(--ease) forwards;
  animation-delay: var(--d, 0ms);
}

@keyframes rise {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes hero-ken {
  from { transform: scale(1.08); }
  to { transform: scale(1.02); }
}

.reveal-on-scroll {
  opacity: 0;
  transform: translateY(1.75rem);
  transition: opacity 0.95s var(--ease), transform 0.95s var(--ease);
}

.reveal-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

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

  .reveal,
  .reveal-on-scroll,
  .hero-media,
  .fab-line,
  .fab-label {
    animation: none !important;
    transition: none !important;
    opacity: 1 !important;
    transform: none !important;
  }

  .fab-line {
    max-width: 12rem;
    padding: 0 1.25rem 0 1rem;
  }

  .fab-label {
    opacity: 1;
    max-width: 8rem;
    margin-left: 0.55rem;
  }
}

@media (max-width: 480px) {
  .btn,
  .btn-lg {
    width: 100%;
  }

  .hero-content {
    padding-bottom: 3rem;
  }

  .header-cta span {
    display: none;
  }

  .header-cta {
    padding: 0.65rem;
    border-radius: 50%;
  }

  .fab-line {
    right: 0.85rem;
    bottom: 0.85rem;
  }
}