:root {
  --ink: #142026;
  --ink-soft: #3a4b54;
  --teal-900: #0f3a44;
  --teal-700: #1c5a66;
  --teal-500: #2f8a99;
  --teal-300: #7fc0cb;
  --gold: #c9a23a;
  --gold-soft: #e3c987;
  --paper: #fbfcfc;
  --surface: #ffffff;
  --surface-alt: #f1f5f6;
  --border: #dde5e7;
  --shadow: 0 1px 2px rgba(20, 32, 38, 0.05), 0 8px 24px rgba(20, 32, 38, 0.06);
  --radius: 8px;
  --maxw: 1100px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, "Yu Gothic",
    "Noto Sans JP", system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3 {
  line-height: 1.35;
  margin: 0;
  font-weight: 700;
}

p {
  margin: 0;
}

a {
  color: var(--teal-700);
  text-decoration: none;
}

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

.mono {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.95em;
  color: var(--teal-700);
  word-break: break-all;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -48px;
  z-index: 100;
  background: var(--teal-900);
  color: #fff;
  padding: 10px 16px;
  border-radius: var(--radius);
  transition: top 0.2s var(--ease);
}
.skip-link:focus {
  top: 16px;
}

:focus-visible {
  outline: 3px solid var(--teal-500);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(251, 252, 252, 0.88);
  backdrop-filter: saturate(160%) blur(8px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 68px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
}
.brand-mark {
  display: inline-flex;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.brand-text {
  display: flex;
  flex-direction: column;
}
.brand-name {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.04em;
}
.brand-sub {
  font-size: 0.74rem;
  color: var(--ink-soft);
}
.site-nav {
  display: flex;
  gap: 22px;
  font-size: 0.92rem;
}
.site-nav a {
  color: var(--ink-soft);
  padding: 6px 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.site-nav a:hover {
  color: var(--teal-700);
  border-color: var(--gold);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: clamp(540px, 84vh, 760px);
  display: flex;
  align-items: center;
  overflow: hidden;
  isolation: isolate;
}
.hero-media {
  position: absolute;
  inset: 0;
  z-index: -3;
  background-image: url("assets/sereneflow-hero-calm-growth.png");
  background-size: cover;
  background-position: 64% center;
  overflow: hidden;
  animation: hero-water-pan 24s var(--ease) infinite alternate;
}
.hero-media::before,
.hero-media::after {
  content: "";
  position: absolute;
  inset: -18%;
  pointer-events: none;
}
.hero-media::before {
  background:
    repeating-linear-gradient(
      104deg,
      rgba(255, 255, 255, 0) 0 56px,
      rgba(127, 192, 203, 0.16) 64px,
      rgba(255, 255, 255, 0) 86px
    ),
    radial-gradient(circle at 78% 62%, rgba(255, 255, 255, 0.28), transparent 28%),
    radial-gradient(circle at 65% 78%, rgba(74, 163, 179, 0.22), transparent 34%);
  mix-blend-mode: screen;
  opacity: 0.72;
  animation: water-drift 18s linear infinite;
}
.hero-media::after {
  background:
    linear-gradient(
      112deg,
      transparent 0 38%,
      rgba(255, 255, 255, 0.28) 45%,
      transparent 52% 100%
    ),
    repeating-linear-gradient(
      172deg,
      transparent 0 22px,
      rgba(255, 255, 255, 0.13) 24px,
      transparent 31px
    );
  opacity: 0.45;
  animation: water-shimmer 11s var(--ease) infinite alternate;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(
      100deg,
      rgba(251, 252, 252, 0.96) 0%,
      rgba(251, 252, 252, 0.82) 34%,
      rgba(251, 252, 252, 0.32) 60%,
      rgba(251, 252, 252, 0) 82%
    );
}
.hero-water-flow {
  position: absolute;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  overflow: hidden;
  opacity: 0.74;
  mix-blend-mode: screen;
}
.water-band {
  position: absolute;
  left: -28%;
  width: 156%;
  height: 15%;
  border-radius: 999px;
  background:
    linear-gradient(
      90deg,
      transparent 0%,
      rgba(255, 255, 255, 0.08) 16%,
      rgba(127, 192, 203, 0.32) 34%,
      rgba(255, 255, 255, 0.18) 50%,
      rgba(74, 163, 179, 0.26) 66%,
      transparent 100%
    ),
    repeating-linear-gradient(
      100deg,
      transparent 0 44px,
      rgba(255, 255, 255, 0.22) 52px,
      transparent 72px
    );
  filter: blur(1px);
  transform: rotate(-7deg) translate3d(-12%, 0, 0);
  animation: water-band-flow 7.2s linear infinite;
}
.water-band-1 {
  top: 35%;
}
.water-band-2 {
  top: 50%;
  opacity: 0.68;
  animation-duration: 9.4s;
  animation-delay: -2.6s;
}
.water-band-3 {
  top: 66%;
  opacity: 0.52;
  animation-duration: 11.2s;
  animation-delay: -5s;
}
.hero-circuit {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
  opacity: 0.82;
}
.circuit-trace {
  position: absolute;
  background: linear-gradient(90deg, transparent, rgba(74, 163, 179, 0.4), rgba(201, 162, 58, 0.24), transparent);
  opacity: 0.7;
}
.circuit-trace::before,
.circuit-trace::after {
  content: "";
  position: absolute;
  background: rgba(74, 163, 179, 0.35);
}
.trace-top,
.trace-bottom {
  height: 1px;
}
.trace-left,
.trace-right {
  width: 1px;
  background: linear-gradient(180deg, transparent, rgba(74, 163, 179, 0.4), rgba(201, 162, 58, 0.24), transparent);
}
.trace-top-1 {
  top: 76px;
  left: 48%;
  width: 42%;
}
.trace-top-1::before {
  left: 28%;
  top: 0;
  width: 1px;
  height: 28px;
}
.trace-top-1::after {
  left: 68%;
  top: 0;
  width: 1px;
  height: 20px;
}
.trace-top-2 {
  top: 112px;
  left: 62%;
  width: 28%;
  opacity: 0.52;
}
.trace-right-1 {
  top: 14%;
  right: 62px;
  height: 58%;
}
.trace-right-1::before {
  right: 0;
  top: 34%;
  width: 36px;
  height: 1px;
}
.trace-right-1::after {
  right: 0;
  top: 68%;
  width: 26px;
  height: 1px;
}
.trace-right-2 {
  top: 28%;
  right: 112px;
  height: 34%;
  opacity: 0.46;
}
.trace-bottom-1 {
  bottom: 92px;
  left: 42%;
  width: 47%;
}
.trace-bottom-1::before {
  left: 18%;
  bottom: 0;
  width: 1px;
  height: 24px;
}
.trace-bottom-1::after {
  left: 58%;
  bottom: 0;
  width: 1px;
  height: 30px;
}
.trace-bottom-2 {
  bottom: 56px;
  left: 55%;
  width: 35%;
  opacity: 0.48;
}
.trace-left-1 {
  top: 21%;
  left: 70px;
  height: 42%;
  opacity: 0.34;
}
.trace-left-2 {
  top: 36%;
  left: 116px;
  height: 34%;
  opacity: 0.28;
}
.circuit-node {
  position: absolute;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: rgba(251, 252, 252, 0.9);
  box-shadow: 0 0 0 1px rgba(74, 163, 179, 0.46), 0 0 8px rgba(74, 163, 179, 0.38);
}
.node-1 { top: 74px; left: 67%; }
.node-2 { top: 110px; left: 80%; }
.node-3 { right: 60px; top: 48%; }
.node-4 { bottom: 90px; left: 66%; }
.signal-streak {
  position: absolute;
  border-radius: 999px;
  opacity: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.96), var(--gold), transparent);
  box-shadow: 0 0 10px rgba(255, 255, 255, 0.72), 0 0 18px rgba(201, 162, 58, 0.55);
}
.signal-x {
  width: 112px;
  height: 2px;
  animation: signal-x 3.8s linear infinite;
}
.signal-y {
  width: 2px;
  height: 112px;
  background: linear-gradient(180deg, transparent, rgba(255, 255, 255, 0.96), var(--gold), transparent);
  animation: signal-y 4.4s linear infinite;
}
.signal-x-1 {
  top: 75px;
  left: 50%;
}
.signal-x-2 {
  bottom: 91px;
  left: 74%;
  animation-delay: -1.9s;
}
.signal-x-reverse {
  top: 111px;
  left: 86%;
  animation-name: signal-x-reverse;
  animation-duration: 5.1s;
  animation-delay: -3.4s;
}
.signal-y-1 {
  top: 18%;
  right: 61px;
  animation-delay: -1.2s;
}
.signal-y-2 {
  bottom: 11%;
  left: 69px;
  animation-name: signal-y-reverse;
  animation-delay: -2.8s;
  opacity: 0;
}
.hero-content {
  position: relative;
  z-index: 1;
  padding-top: 64px;
  padding-bottom: 120px;
  max-width: 680px;
}
.hero-eyebrow {
  font-size: 0.82rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--teal-700);
  font-weight: 600;
  margin-bottom: 18px;
}
.hero-title {
  font-size: 3rem;
  color: var(--teal-900);
  margin-bottom: 22px;
}
.hero-lead {
  font-size: 1.08rem;
  color: var(--ink-soft);
  max-width: 40em;
  margin-bottom: 32px;
  overflow-wrap: anywhere;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 26px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.98rem;
  border: 1px solid transparent;
  transition: transform 0.18s var(--ease), background 0.2s var(--ease),
    border-color 0.2s var(--ease), color 0.2s var(--ease);
}
.btn-primary {
  background: var(--teal-900);
  color: #fff;
}
.btn-primary:hover {
  background: var(--teal-700);
  transform: translateY(-1px);
}
.btn-ghost {
  background: rgba(255, 255, 255, 0.7);
  color: var(--teal-900);
  border-color: var(--teal-700);
}
.btn-ghost:hover {
  background: #fff;
  border-color: var(--gold);
  transform: translateY(-1px);
}
.hero-scroll {
  position: absolute;
  z-index: 1;
  left: 50%;
  bottom: 26px;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--ink-soft);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
}
.hero-scroll-arrow {
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--gold);
  border-bottom: 2px solid var(--gold);
  transform: rotate(45deg);
  animation: nudge 1.8s var(--ease) infinite;
}
@keyframes nudge {
  0%, 100% { transform: rotate(45deg) translate(0, 0); opacity: 0.5; }
  50% { transform: rotate(45deg) translate(3px, 3px); opacity: 1; }
}
@keyframes hero-water-pan {
  0% {
    transform: scale(1.015) translate3d(0, 0, 0);
  }
  100% {
    transform: scale(1.045) translate3d(-1.2%, 0.8%, 0);
  }
}
@keyframes water-drift {
  0% {
    transform: translate3d(-4%, 0, 0) rotate(0.001deg);
  }
  100% {
    transform: translate3d(4%, -2%, 0) rotate(0.001deg);
  }
}
@keyframes water-shimmer {
  0% {
    transform: translate3d(-8%, 3%, 0);
    opacity: 0.28;
  }
  50% {
    opacity: 0.54;
  }
  100% {
    transform: translate3d(8%, -2%, 0);
    opacity: 0.42;
  }
}
@keyframes water-band-flow {
  0% {
    background-position: 0 0, 0 0;
    transform: rotate(-7deg) translate3d(-14%, 0, 0);
  }
  100% {
    background-position: 260px 0, 340px 0;
    transform: rotate(-7deg) translate3d(12%, 0, 0);
  }
}
@keyframes signal-x {
  0% {
    opacity: 0;
    transform: translate3d(-140px, 0, 0) scaleX(0.55);
  }
  8% {
    opacity: 0.95;
  }
  22% {
    opacity: 0.7;
  }
  30%, 100% {
    opacity: 0;
    transform: translate3d(430px, 0, 0) scaleX(1.15);
  }
}
@keyframes signal-x-reverse {
  0% {
    opacity: 0;
    transform: translate3d(170px, 0, 0) scaleX(0.55);
  }
  7% {
    opacity: 0.9;
  }
  20% {
    opacity: 0.62;
  }
  28%, 100% {
    opacity: 0;
    transform: translate3d(-360px, 0, 0) scaleX(1.1);
  }
}
@keyframes signal-y {
  0% {
    opacity: 0;
    transform: translate3d(0, -120px, 0) scaleY(0.55);
  }
  8% {
    opacity: 0.9;
  }
  21% {
    opacity: 0.62;
  }
  29%, 100% {
    opacity: 0;
    transform: translate3d(0, 360px, 0) scaleY(1.12);
  }
}
@keyframes signal-y-reverse {
  0% {
    opacity: 0;
    transform: translate3d(0, 160px, 0) scaleY(0.55);
  }
  8% {
    opacity: 0.9;
  }
  21% {
    opacity: 0.62;
  }
  29%, 100% {
    opacity: 0;
    transform: translate3d(0, -340px, 0) scaleY(1.12);
  }
}

/* ---------- Sections ---------- */
.section {
  padding: 92px 0;
}
.section-notice {
  background: var(--surface);
  border-top: 1px solid var(--border);
}
.section-business {
  background: var(--surface-alt);
}
.section-profile {
  background: var(--surface);
}
.section-principles {
  background: linear-gradient(180deg, var(--teal-900), #0b2c34);
  color: #eaf3f4;
}
.section-eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-weight: 600;
  color: var(--teal-500);
  margin-bottom: 12px;
}
.section-principles .section-eyebrow {
  color: var(--gold-soft);
}
.section-title {
  font-size: 2.1rem;
  color: var(--teal-900);
  position: relative;
  padding-bottom: 16px;
  margin-bottom: 18px;
}
.section-principles .section-title {
  color: #fff;
}
.section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 56px;
  height: 3px;
  border-radius: 2px;
  background: var(--gold);
}
.section-desc {
  max-width: 56em;
  color: var(--ink-soft);
  margin-bottom: 40px;
  overflow-wrap: anywhere;
}
.section-principles .section-desc {
  color: #cfe2e4;
}

/* ---------- Notice ---------- */
.notice-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--gold);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 30px;
  display: grid;
  gap: 22px;
  grid-template-columns: 1fr;
}
.notice-status {
  display: flex;
  align-items: center;
  gap: 14px;
}
.notice-dot {
  flex: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--teal-300);
  box-shadow: 0 0 0 4px rgba(127, 192, 203, 0.25);
}
.notice-message {
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--teal-900);
}
.notice-meta {
  margin: 0;
  display: grid;
  gap: 10px;
  border-top: 1px solid var(--border);
  padding-top: 20px;
}
.notice-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
}
.notice-meta dt {
  min-width: 96px;
  font-weight: 600;
  color: var(--ink-soft);
  font-size: 0.9rem;
}
.notice-meta dd {
  margin: 0;
  color: var(--ink);
  word-break: break-all;
}
.notice-fallback {
  margin-top: 24px;
  color: var(--ink-soft);
  font-size: 0.95rem;
  max-width: 60em;
}

/* ---------- Card grids (single level, no nesting) ---------- */
.card-grid,
.principle-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 20px;
}
.card-grid {
  grid-template-columns: repeat(3, 1fr);
}
.principle-grid {
  grid-template-columns: repeat(3, 1fr);
}
.panel {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 26px;
  min-height: 168px;
  box-shadow: var(--shadow);
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease),
    border-color 0.2s var(--ease);
}
.panel:hover {
  transform: translateY(-3px);
  box-shadow: 0 2px 4px rgba(20, 32, 38, 0.06), 0 14px 32px rgba(20, 32, 38, 0.1);
  border-color: var(--teal-300);
}
.panel-index {
  display: block;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--gold);
  margin-bottom: 12px;
}
.panel-title {
  font-size: 1.12rem;
  color: var(--teal-900);
  margin-bottom: 10px;
}
.panel-body {
  color: var(--ink-soft);
  font-size: 0.96rem;
  overflow-wrap: anywhere;
}
.section-principles .panel {
  background: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.14);
  box-shadow: none;
}
.section-principles .panel:hover {
  border-color: var(--gold);
  transform: translateY(-3px);
}
.section-principles .panel-title {
  color: #fff;
}
.section-principles .panel-body {
  color: #cfe2e4;
}

/* ---------- Profile table ---------- */
.profile-table {
  margin: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.profile-row {
  display: grid;
  grid-template-columns: 200px 1fr;
}
.profile-row + .profile-row {
  border-top: 1px solid var(--border);
}
.profile-row dt {
  background: var(--surface-alt);
  padding: 18px 22px;
  font-weight: 600;
  color: var(--teal-900);
}
.profile-row dd {
  margin: 0;
  padding: 18px 22px;
  color: var(--ink);
  overflow-wrap: anywhere;
}

/* ---------- Footer ---------- */
.site-footer {
  background: #0b2228;
  color: #cfe2e4;
  padding: 40px 0;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 40px;
  align-items: center;
  justify-content: space-between;
}
.footer-brand .brand-name {
  color: #fff;
}
.footer-note {
  font-size: 0.86rem;
  color: #9fbcc0;
  margin-top: 6px;
}
.footer-copy {
  font-size: 0.85rem;
  color: #9fbcc0;
}

/* ---------- Reveal animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .card-grid,
  .principle-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-overlay {
    background: linear-gradient(
      170deg,
      rgba(251, 252, 252, 0.95) 0%,
      rgba(251, 252, 252, 0.78) 48%,
      rgba(251, 252, 252, 0.4) 100%
    );
  }
  .hero-media {
    background-position: 70% center;
  }
  .hero-water-flow {
    opacity: 0.66;
  }
  .hero-circuit {
    opacity: 0.7;
  }
}

@media (max-width: 640px) {
  .site-nav {
    display: none;
  }
  .hero-title {
    font-size: 2.1rem;
  }
  .hero-lead {
    max-width: 20rem;
    font-size: 1rem;
  }
  .section-title {
    font-size: 1.7rem;
  }
  .section {
    padding: 64px 0;
  }
  .hero-content {
    padding-bottom: 96px;
  }
  .hero-water-flow {
    opacity: 0.48;
  }
  .water-band-3,
  .trace-left-1,
  .trace-left-2 {
    display: none;
  }
  .hero-circuit {
    opacity: 0.58;
  }
  .card-grid,
  .principle-grid {
    grid-template-columns: 1fr;
  }
  .profile-row {
    grid-template-columns: 1fr;
  }
  .profile-row dt {
    padding-bottom: 4px;
  }
  .profile-row dd {
    padding-top: 8px;
  }
  .notice-panel {
    padding: 24px 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .hero-scroll-arrow {
    animation: none;
  }
  .hero-media,
  .hero-media::before,
  .hero-media::after,
  .water-band,
  .signal-streak {
    animation: none;
  }
  .hero-media {
    transform: none;
  }
  .hero-water-flow,
  .hero-circuit {
    opacity: 0.24;
  }
  .signal-streak {
    display: none;
  }
}