/* ===== Design Tokens ===== */

:root {
  --color-text: #1d1d1f;
  --color-white: #ffffff;
  --color-brand: #016499;
  --color-heading-dark: #0b1a52;
  --color-bg-gray: #f8f8f8;
  --color-bg-blue: #d4eaf1;
  --color-accent-red: #d64655;
  --color-footer-bg: #0b1a52;
  --color-footer-text: #ffffff;
  --color-mobile-menu-bg: #4E93B8;
  --color-border: rgba(29, 29, 31, 0.24);
  --color-divider: rgba(29, 29, 31, 0.16);

  --font-base: "Roboto", Arial, sans-serif;
  --page-width: 1440px;
  --content-width: 1200px;
  --gutter: 120px;
  --header-gutter: 40px;
}

/* ===== Base ===== */

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-base);
  font-size: 18px;
  font-weight: 400;
  line-height: 1.4;
  letter-spacing: 0.9px;
  color: var(--color-text);
  background: var(--color-white);
}

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

ul,
ol {
  margin: 0;
  padding: 0;
}

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

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

h2 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.48px;
  color: var(--color-heading-dark);
}

h3 {
  font-weight: 700;
  color: var(--color-heading-dark);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.section-inner {
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
}

/* ===== Header ===== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-white);
  border-bottom: 1px solid transparent;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--page-width);
  height: 76px;
  margin-inline: auto;
  padding: 14px var(--header-gutter);
}

.site-header__logo img {
  width: 399px;
  height: 48px;
  object-fit: contain;
}

.site-header__logo-img--sp {
  display: none;
}

.site-header__menu-btn {
  display: none;
}

.site-header__mobile-panel {
  display: none;
}

.site-header__nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.site-header__nav-list a {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.9px;
  line-height: 1.4;
  transition: color 0.2s;
}

.site-header__nav-list a:hover {
  color: var(--color-brand);
}

.site-header__contact-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 60px;
  background: var(--color-brand);
  color: var(--color-white);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.8px;
  line-height: 1.4;
  transition: opacity 0.2s;
}

.site-header__contact-btn:hover {
  opacity: 0.88;
}

.site-header__contact-btn img {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

/* ===== Hero ===== */

.hero {
  position: relative;
  overflow: hidden;
  min-height: 600px;
  background: linear-gradient(135deg, #e8f4f8 0%, #f5fafc 50%, #ffffff 100%);
}

.hero__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
}

.hero__inner {
  position: relative;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 40px;
  max-width: var(--page-width);
  min-height: 520px;
  margin-inline: auto;
  padding: 300px var(--gutter) 56px;
}

/*.hero__content {
  flex: 0 1 550px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}*/
.hero__content {
  flex: 0 1 1000px;
  max-width: 100%;
  position: relative;
  z-index: 2; /* 画像より前面に */
}

.hero h1 {
  font-size: 56px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.56px;
  color: var(--color-heading-dark);
}

.hero__lead {
  font-size: 20px;
  line-height: 1.6;
  letter-spacing: 0.6px;
}

.hero__illustration {
  position: absolute;
  top: 64px;
  right: var(--gutter);
  width: 730px;
  max-width: 50%;
  height: auto;
  object-fit: contain;
  z-index: 1;
}

/* ===== Key Points ===== */

.key-points {
  max-width: var(--page-width);
  margin-inline: auto;
  padding: 80px var(--gutter) 0;
  background: var(--color-white);
}

.key-points__list {
  display: flex;
  justify-content: center;
  gap: 48px;
  list-style: none;
}

.key-points__item {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 368px;
  padding: 40px 8px 24px;
  text-align: center;
  overflow: hidden;
}

.key-points__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.6;
  pointer-events: none;
  z-index: 0;
}

.key-points__title,
.key-points__text {
  position: relative;
  z-index: 1;
}

.key-points__title {
  margin-bottom: 16px;
  font-size: 24px;
  line-height: 1.4;
  letter-spacing: 0.72px;
  color: var(--color-heading-dark);
}

.key-points__text {
  font-size: 18px;
  letter-spacing: 0.9px;
}

/* ===== Technical Summary ===== */

.technical-summary {
  max-width: var(--page-width);
  margin-inline: auto;
  padding: 56px var(--gutter) 80px;
  background: var(--color-white);
}

.technical-summary .section-inner {
  padding: 56px 40px;
  background: var(--color-bg-gray);
}

.technical-summary h2 {
  margin-bottom: 24px;
  font-size: 24px;
  letter-spacing: 0.72px;
  line-height: 1.4;
}

.technical-summary p {
  max-width: 1120px;
  font-size: 18px;
  line-height: 1.4;
  letter-spacing: 0.9px;
}

/* ===== Problem ===== */

.problem {
  background: var(--color-bg-gray);
}

.problem .section-inner {
  max-width: var(--page-width);
  padding: 80px var(--gutter);
}

.problem h2 {
  margin-bottom: 24px;
}

.problem .section-inner > p {
  max-width: 1200px;
  margin-bottom: 32px;
}

.problem__highlight {
  margin: 0 0 40px;
  padding: 12px 32px;
  background: var(--color-white);
  text-align: center;
}

.problem__highlight p {
  font-size: 20px;
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: 0.6px;
  color: var(--color-brand);
}

/* problem__term: edit span text in index.html when replacing "source-term" */

.problem__flow {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.problem__flow-row {
  margin: 0;
  padding: 0;
}

.problem__flow-step {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 0 0 auto;
}

.problem__flow-step-label {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 70px;
  padding: 16px 28px;
  border: 2px solid var(--color-heading-dark);
  border-radius: 100px;
  background: var(--color-white);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: 0.6px;
  color: var(--color-heading-dark);
  white-space: nowrap;
}

.problem__flow-step--highlight .problem__flow-step-label {
  border-color: var(--color-accent-red);
  color: var(--color-accent-red);
}

.problem__flow-step::after {
  content: "";
  display: block;
  width: 30px;
  height: 23px;
  flex-shrink: 0;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='30' height='23' viewBox='0 0 30 23' fill='none'%3E%3Cpath d='M0 11.5H28M28 11.5L17 1M28 11.5L17 21' stroke='%231D1D1F' stroke-width='2'/%3E%3C/svg%3E") center / contain no-repeat;
}

.problem__flow-row:last-child .problem__flow-step:last-child::after {
  display: none;
}

/* 1200px+: single horizontal row via display: contents on div rows */
@media (min-width: 1200px) {
  .problem__flow-row {
    display: contents;
  }
}

/* 1200px–1439px: horizontal row with gradual scaling */
@media (max-width: 1439px) and (min-width: 1200px) {
  .problem__flow-step-label {
    padding: clamp(10px, 1.1vw, 16px) clamp(14px, 2vw, 28px);
    font-size: clamp(13px, 1.25vw, 20px);
    letter-spacing: clamp(0.4px, 0.04vw, 0.6px);
    min-height: clamp(48px, 4.9vw, 70px);
  }

  .problem__flow,
  .problem__flow-step {
    gap: clamp(2px, 0.28vw, 4px);
  }

  .problem__flow-step::after {
    width: clamp(20px, 2.1vw, 30px);
    height: clamp(15px, 1.6vw, 23px);
  }
}

/* 769px–1199px: 3+2 two-row layout (no arrow between rows) */
@media (max-width: 1199px) and (min-width: 769px) {
  .problem__flow {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 8px;
  }

  .problem__flow-row {
    display: flex;
    flex-wrap: nowrap;
    align-items: center;
    justify-content: center;
    gap: 4px;
  }

  .problem__flow-row:first-child .problem__flow-step:last-child::after {
    display: none;
  }

  .problem__flow-row:last-child .problem__flow-step:first-child::before {
    content: "";
    display: block;
    width: 30px;
    height: 23px;
    flex-shrink: 0;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='30' height='23' viewBox='0 0 30 23' fill='none'%3E%3Cpath d='M0 11.5H28M28 11.5L17 1M28 11.5L17 21' stroke='%231D1D1F' stroke-width='2'/%3E%3C/svg%3E") center / contain no-repeat;
  }
}

/* ===== Technology ===== */

.technology {
  background: var(--color-white);
}

.technology .section-inner {
  display: flex;
  flex-direction: column;
  gap: 32px;
  max-width: var(--page-width);
  padding: 80px var(--gutter) 0;
}

.technology__intro {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.technology__figure {
  margin: 0;
  align-self: center;
}

.technology__figure img {
  display: block;
  width: 100%;
  max-width: 1100px;
  height: auto;
}

/* ===== Advantages ===== */

.advantages {
  background: var(--color-white);
}

.advantages .section-inner {
  max-width: var(--page-width);
  padding: 80px var(--gutter) 0;
}

.advantages h2 {
  margin-bottom: 32px;
}

.advantages__list {
  display: flex;
  gap: 24px;
  list-style: none;
}

.advantages__item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 40px 16px;
  border: 1px solid var(--color-text);
  background: var(--color-white);
  text-align: center;
}

.advantages__item img {
  width: 80px;
  height: 80px;
  object-fit: contain;
}

.advantages__item h3 {
  font-size: 20px;
  line-height: 1.6;
  letter-spacing: 0.6px;
}

.advantages__item p {
  font-size: 18px;
  line-height: 1.4;
  letter-spacing: 0.9px;
}

/* ===== Evidence ===== */

.evidence {
  background: var(--color-white);
}

.evidence .section-inner {
  max-width: var(--page-width);
  padding: 80px var(--gutter) 0;
}

.evidence h2 {
  margin-bottom: 24px;
}

.evidence__lead {
  margin-bottom: 32px;
}

.evidence__list {
  display: flex;
  gap: 24px;
  list-style: none;
}

.evidence__item {
  flex: 1;
  padding: 40px 16px;
  border: 1px solid var(--color-text);
  background: var(--color-bg-blue);
  text-align: center;
}

.evidence__item h3 {
  font-size: 20px;
  line-height: 1.6;
  letter-spacing: 0.6px;
}

.evidence__item p {
  margin-top: 8px;
  font-size: 18px;
  line-height: 1.4;
  letter-spacing: 0.9px;
}

/* ===== Roadmap ===== */

.roadmap {
  background: var(--color-white);
}

.roadmap .section-inner {
  max-width: var(--page-width);
  padding: 80px var(--gutter) 0;
}

.roadmap h2 {
  margin-bottom: 32px;
}

.roadmap__list {
  display: flex;
  align-items: stretch;
  gap: 0;
  list-style: none;
}

.roadmap__item {
  flex: 0 0 220px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 24px 16px;
  border: 1px solid var(--color-text);
  background: var(--color-white);
  text-align: center;
}

.roadmap__item:not(:last-child) {
  position: relative;
  margin-right: 25px;
}

.roadmap__item:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 50%;
  right: -25px;
  width: 25px;
  height: 2px;
  background: var(--color-text);
  transform: translateY(-50%);
}

.roadmap__step-label {
  display: inline-block;
  padding: 6px 24px;
  border: 2px solid var(--color-brand);
  border-radius: 100px;
  background: var(--color-bg-blue);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.9px;
  line-height: 1.4;
}

.roadmap__item h3 {
  font-size: 20px;
  line-height: 1.6;
  letter-spacing: 0.6px;
}

/* ===== Collaborative Development Framework ===== */

.dev-framework {
  background: var(--color-white);
}

.dev-framework .section-inner {
  max-width: var(--page-width);
  padding: 80px var(--gutter);
}

.dev-framework h2 {
  margin-bottom: 32px;
}

.dev-framework__figure {
  margin: 0;
}

.dev-framework__figure img {
  width: 100%;
  max-width: 1193px;
  height: auto;
}

/* ===== Collaboration ===== */

.collaboration {
  position: relative;
  overflow: hidden;
  background: var(--color-bg-blue);
}

.collaboration::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(232, 244, 248, 0.9) 0%, rgba(212, 234, 241, 0.95) 100%);
  pointer-events: none;
}

.collaboration .section-inner {
  position: relative;
  max-width: var(--page-width);
  padding: 80px var(--gutter);
}

.collaboration__inner {
  display: flex;
  align-items: center;
  gap: 160px;
}

.collaboration__content {
  flex: 1;
  max-width: 640px;
}

.collaboration__content h2 {
  margin-bottom: 24px;
}

.collaboration__content p {
  margin-bottom: 16px;
}

.collaboration__content ul {
  margin: 0 0 24px 27px;
  list-style: disc;
}

.collaboration__content li {
  margin-bottom: 4px;
}

.collaboration__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 70px;
  padding: 16px 32px;
  border-radius: 100px;
  background: var(--color-brand);
  color: var(--color-white);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: 0.6px;
  transition: opacity 0.2s;
}

.collaboration__cta:hover {
  opacity: 0.88;
}

.collaboration__flow {
  flex: 0 0 399px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.collaboration__flow li {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 56px;
  padding: 16px 32px;
  border-radius: 100px;
  background: var(--color-white);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: 0.6px;
  color: var(--color-heading-dark);
  text-align: center;
}

.collaboration__flow li:not(:last-child) {
  margin-bottom: 38px;
}

.collaboration__flow li:not(:last-child)::after {
  content: "";
  position: absolute;
  bottom: -30px;
  left: 50%;
  width: 30px;
  height: 23px;
  transform: translateX(-50%);
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='30' height='23' viewBox='0 0 30 23' fill='none'%3E%3Cpath d='M15 0V20M15 20L8 13M15 20L22 13' stroke='%231D1D1F' stroke-width='2'/%3E%3C/svg%3E") center / contain no-repeat;
}

/* ===== Potential Applications ===== */

.applications {
  background: var(--color-white);
}

.applications .section-inner {
  max-width: var(--page-width);
  margin-inline: auto;
  padding: 80px var(--gutter);
}

.applications__box {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: fit-content;
  margin-inline: auto;
  padding: 40px 48px;
  background: var(--color-bg-blue);
}

.applications__box h2 {
  font-size: 36px;
  letter-spacing: 0.36px;
}

.applications__row {
  display: flex;
  align-items: flex-start;
  gap: 48px;
}

.applications__row > p {
  flex-shrink: 0;
  white-space: nowrap;
}

.applications__row ul {
  margin: 0;
  padding-left: 27px;
  list-style: disc;
  flex-shrink: 0;
}

.applications__box li {
  margin-bottom: 4px;
  white-space: nowrap;
}

/* 1200px+: horizontal layout, centered blue box */
@media (min-width: 1200px) {
  .applications__row {
    flex-direction: row;
  }

  .applications__box {
    max-width: none;
  }
}

/* 1440px+: Figma spacing — section 348px padding, box 48px padding, centered */
@media (min-width: 1440px) {
  .applications .section-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 80px 348px;
  }

  .applications__box {
    margin-inline: auto;
  }
}

/* 769px–1199px: vertical row layout */
@media (max-width: 1199px) {
  .applications .section-inner {
    padding: 80px var(--gutter);
  }

  .applications__box {
    width: 100%;
    max-width: 100%;
  }

  .applications__row {
    flex-direction: column;
    gap: 24px;
  }

  .applications__row > p {
    white-space: normal;
  }
}

/* ===== FAQ ===== */

.faq {
  background: var(--color-bg-gray);
}

.faq .section-inner {
  max-width: var(--page-width);
  padding: 80px var(--gutter);
}

.faq h2 {
  margin-bottom: 24px;
}

.faq__lead {
  max-width: 560px;
  margin-bottom: 32px;
}

.faq__list {
  width: 100%;
  max-width: 1200px;
}

.faq__item {
  border-top: 1px solid var(--color-divider);
}

.faq__item:last-child {
  border-bottom: 1px solid var(--color-divider);
}

.faq__question {
  margin: 0;
}

.faq__toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: 100%;
  padding: 20px 0;
  border: none;
  background: none;
  font: inherit;
  font-size: 24px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.72px;
  text-align: left;
  color: var(--color-heading-dark);
  cursor: pointer;
}

.faq__toggle img {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  transition: transform 0.2s ease;
}

.faq__toggle[aria-expanded="false"] img {
  transform: rotate(180deg);
}

.faq__answer[hidden] {
  display: none;
}

.faq__answer {
  max-width: 800px;
  padding-bottom: 24px;
  font-size: 18px;
  line-height: 1.4;
  letter-spacing: 0.9px;
}

.faq__answer p + p {
  margin-top: 8px;
}

/* ===== Publications & Patents ===== */

.publications {
  background: var(--color-white);
}

.publications .section-inner {
  max-width: var(--page-width);
  padding: 80px var(--gutter) 0;
}

.publications h2 {
  max-width: 560px;
  margin-bottom: 24px;
}

.publications ul {
  max-width: 560px;
  margin-left: 27px;
  list-style: disc;
}

.publications li {
  margin-bottom: 8px;
}

.publications li:last-child {
  margin-bottom: 0;
}

/* ===== Research Team ===== */

.team {
  background: var(--color-white);
}

.team .section-inner {
  max-width: var(--page-width);
  padding: 80px var(--gutter);
}

.team h2 {
  max-width: 560px;
  margin-bottom: 24px;
}

.team p {
  max-width: 560px;
  line-height: 1.4;
}

/* ===== Contact ===== */

.contact {
  position: relative;
  overflow: hidden;
  background: var(--color-bg-blue);
}

.contact__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
}

.contact .section-inner {
  position: relative;
  max-width: var(--page-width);
  padding: 80px var(--gutter);
}

.contact__content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  max-width: 1200px;
  margin-inline: auto;
  text-align: center;
}

.contact__content h2 {
  width: 100%;
  color: var(--color-heading-dark);
}

.contact__text {
  width: 100%;
  font-size: 18px;
  letter-spacing: 0.9px;
  line-height: 1.4;
}

.contact__text p + p {
  margin-top: 0;
}

.contact__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 70px;
  padding: 16px 32px;
  border-radius: 100px;
  background: var(--color-brand);
  color: var(--color-white);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: 0.6px;
  transition: opacity 0.2s;
}

.contact__cta:hover {
  opacity: 0.88;
}

.contact__privacy {
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 0.8px;
  line-height: 1.4;
  text-decoration: underline;
  color: var(--color-text);
}

.contact__privacy:hover {
  opacity: 0.75;
}

/* ===== Footer ===== */

.site-footer {
  background: var(--color-footer-bg);
  color: var(--color-footer-text);
}

.site-footer__inner {
  max-width: var(--page-width);
  margin-inline: auto;
  padding: 40px var(--gutter);
}

.site-footer__brand {
  max-width: 700px;
  padding-bottom: 56px;
}

.site-footer__brand img {
  width: 399px;
  height: 48px;
  margin-bottom: 2px;
  object-fit: contain;
}

.site-footer__logo--sp {
  display: none;
}

.site-footer__brand p {
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 0.8px;
  line-height: 1.4;
}

.site-footer__nav {
  display: flex;
  gap: 0;
  padding-bottom: 64px;
}

.site-footer__nav ul {
  width: 300px;
  list-style: none;
}

.site-footer__nav li + li {
  margin-top: 12px;
}

.site-footer__nav a {
  color: var(--color-footer-text);
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 0.8px;
  line-height: 1.4;
  transition: opacity 0.2s;
}

.site-footer__nav a:hover {
  opacity: 0.75;
}

.site-footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-footer__bottom a {
  color: var(--color-footer-text);
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 0.8px;
  text-decoration: underline;
}

.site-footer__bottom small {
  color: var(--color-footer-text);
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 0.8px;
}

/* ===== Privacy Policy Page ===== */

.privacy-hero {
  position: relative;
  overflow: hidden;
  min-height: 240px;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, #e8f4f8 0%, #f5fafc 50%, #ffffff 100%);
}

.privacy-hero__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
}

.privacy-hero__inner {
  position: relative;
  width: 100%;
  max-width: var(--page-width);
  margin-inline: auto;
  padding: 86px var(--gutter);
}

.privacy-hero h1 {
  font-size: 56px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.56px;
  color: var(--color-heading-dark);
}

.privacy-breadcrumb {
  max-width: var(--page-width);
  margin-inline: auto;
  padding: 8px var(--gutter);
  background: var(--color-white);
}

.privacy-breadcrumb__list {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 16px;
  list-style: none;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.6px;
  line-height: 1.8;
}

.privacy-breadcrumb__list a {
  text-decoration: underline;
  transition: opacity 0.2s;
}

.privacy-breadcrumb__list a:hover {
  opacity: 0.75;
}

.privacy-breadcrumb__sep {
  flex-shrink: 0;
}

.privacy-content {
  background: var(--color-white);
}

.privacy-content__inner {
  max-width: var(--content-width);
  margin-inline: auto;
  padding: 80px var(--gutter);
}

.privacy__intro {
  max-width: 1198px;
  margin-bottom: 56px;
  font-size: 18px;
  letter-spacing: 0.9px;
  line-height: 1.4;
}

.privacy__sections {
  display: flex;
  flex-direction: column;
  gap: 56px;
}

.privacy__section h2 {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 24px;
  font-size: 36px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.36px;
  color: var(--color-text);
}

.privacy__section-num {
  flex-shrink: 0;
  color: var(--color-brand);
}

.privacy__section-body {
  max-width: 1198px;
  font-size: 18px;
  letter-spacing: 0.9px;
  line-height: 1.4;
}

.privacy__section-body p + p,
.privacy__section-body p + ul,
.privacy__section-body ul + p {
  margin-top: 0;
}

.privacy__section-body ul {
  margin: 0;
  padding-left: 27px;
  list-style: disc;
}

.privacy__section-body li + li {
  margin-top: 0;
}

.privacy__updated {
  margin-top: 0;
}

/* ===== Responsive — 1024px and below (tablet) ===== */

@media (max-width: 1024px) {
  :root {
    --gutter: 40px;
    --header-gutter: 24px;
  }

  /* ----- Header ----- */

  .site-header__logo-img--pc {
    width: 300px;
    height: auto;
  }

  .site-header__nav {
    gap: 20px;
  }

  .site-header__nav-list {
    gap: 16px;
  }

  .site-header__nav-list a {
    font-size: 16px;
    letter-spacing: 0.8px;
  }

  .site-header__contact-btn {
    padding: 10px 20px;
    font-size: 14px;
  }

  /* ----- Roadmap ----- */

  .roadmap__list {
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px 25px;
  }

  .roadmap__item {
    flex: 0 1 calc(33.333% - 20px);
    min-width: 180px;
    max-width: 220px;
  }

  .roadmap__item:not(:last-child) {
    margin-right: 0;
  }

  .roadmap__item:not(:last-child)::after {
    display: none;
  }

  /* ----- Collaboration ----- */

  .collaboration__inner {
    flex-wrap: wrap;
    justify-content: center;
    gap: 64px;
  }

  .collaboration__content {
    flex: 1 1 400px;
    max-width: none;
  }

  .collaboration__flow {
    flex: 0 1 320px;
  }

  .collaboration__flow li {
    font-size: 18px;
    padding: 12px 24px;
  }
}

/* ===== Responsive — 768px and below ===== */

@media (max-width: 768px) {
  :root {
    --gutter: 20px;
  }

  body {
    font-size: 16px;
    letter-spacing: 0.8px;
  }

  h2 {
    font-size: 36px;
    letter-spacing: 0.36px;
  }

  /* ----- Header & Mobile Menu ----- */

  .site-header__inner {
    height: 64px;
    padding: 0 12px;
  }

  .site-header__logo-img--pc {
    display: none;
  }

  .site-header__logo-img--sp {
    display: block;
    width: 300px;
    height: 16px;
    object-fit: contain;
  }

  .site-header__nav {
    display: none;
  }

  .site-header__menu-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    padding: 0;
    border: none;
    background: none;
    cursor: pointer;
  }

  .site-header__menu-icon {
    width: 24px;
    height: 24px;
  }

  .site-header__menu-icon--close {
    display: none;
  }

  .site-header.is-menu-open .site-header__menu-icon--open {
    display: none;
  }

  .site-header.is-menu-open .site-header__menu-icon--close {
    display: block;
  }

  .site-header.is-menu-open .site-header__inner {
    background: transparent;
  }

  .site-header.is-menu-open {
    background: var(--color-mobile-menu-bg);
  }

  .site-header__mobile-panel {
    display: none;
    position: fixed;
    inset: 64px 0 0;
    z-index: 99;
    padding: 16px 20px 160px;
    overflow-y: auto;
    background: var(--color-mobile-menu-bg);
  }

  .site-header.is-menu-open .site-header__mobile-panel {
    display: block;
  }

  .site-header__mobile-nav {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
  }

  .site-header__mobile-nav ul {
    align-self: stretch;
    list-style: none;
    margin: 0 0 24px;
    padding: 0;
  }

  .site-header__mobile-nav li + li {
    margin-top: 0;
  }

  .site-header__mobile-nav a {
    display: block;
    padding: 12px 0;
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 0.9px;
    line-height: 1.4;
  }

  .site-header__mobile-nav .site-header__mobile-contact {
    display: flex;
    align-items: center;
    justify-content: center;
    box-sizing: border-box;
    width: 100%;
    max-width: 335px;
    margin-inline: auto;
    padding: 12px 32px;
    border-radius: 100px;
    background: var(--color-brand);
    color: var(--color-white);
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 0.9px;
    line-height: 1.4;
    text-align: center;
  }

  body.is-menu-open {
    overflow: hidden;
  }

  /* ----- Hero ----- */

  .hero {
    min-height: auto;
  }

  .hero__inner {
    flex-direction: column;
    align-items: center;
    min-height: auto;
    padding: 56px var(--gutter) 32px;
    text-align: center;
  }

  .hero__content {
    flex: none;
    width: 100%;
    align-items: center;
  }

  .hero h1 {
    font-size: 36px;
    letter-spacing: 0.36px;
  }

  .hero__lead {
    font-size: 14px;
    letter-spacing: 0.7px;
  }

  .hero__illustration {
    position: static;
    width: 100%;
    max-width: 335px;
    margin-top: 24px;
  }

  /* ----- Key Points ----- */

  .key-points {
    padding: 40px var(--gutter) 0;
  }

  .key-points__list {
    flex-direction: column;
    align-items: center;
    gap: 24px;
  }

  .key-points__item {
    width: 100%;
    max-width: 335px;
    padding: 32px 8px 24px;
  }

  .key-points__title {
    font-size: 20px;
    letter-spacing: 0.6px;
    line-height: 1.6;
  }

  .key-points__text {
    font-size: 16px;
    letter-spacing: 0.8px;
  }

  /* ----- Technical Summary ----- */

  .technical-summary {
    padding: 40px var(--gutter);
  }

  .technical-summary .section-inner {
    padding: 40px 24px;
  }

  .technical-summary h2 {
    font-size: 24px;
    letter-spacing: 0.72px;
  }

  .technical-summary p {
    font-size: 18px;
  }

  /* ----- Problem ----- */

  .problem .section-inner {
    padding: 64px var(--gutter);
  }

  .problem .section-inner > p {
    margin-bottom: 24px;
    font-size: 16px;
  }

  .problem__highlight {
    margin-bottom: 24px;
    padding: 12px 16px;
  }

  .problem__highlight p {
    font-size: 18px;
    letter-spacing: 0.9px;
    line-height: 1.4;
    white-space: normal;
  }

  .problem__flow {
    flex-direction: column;
    align-items: center;
    gap: 4px;
  }

  .problem__flow-row {
    display: contents;
  }

  .problem__flow-step {
    flex-direction: column;
    align-items: center;
    gap: 4px;
  }

  .problem__flow-step-label {
    min-height: auto;
    padding: 12px 24px;
    border-width: 1px;
    font-size: 18px;
    letter-spacing: 0.9px;
    line-height: 1.4;
    white-space: normal;
    text-align: center;
  }

  .problem__flow-step::after {
    width: 30px;
    height: 30px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='30' height='23' viewBox='0 0 30 23' fill='none'%3E%3Cpath d='M15 0V20M15 20L8 13M15 20L22 13' stroke='%231D1D1F' stroke-width='2'/%3E%3C/svg%3E");
  }

  .problem__flow-row:first-child .problem__flow-step::after,
  .problem__flow-row:last-child .problem__flow-step:not(:last-child)::after {
    display: block;
  }

  .problem__flow-row:last-child .problem__flow-step:last-child::after {
    display: none;
  }

  /* ----- Technology ----- */

  .technology .section-inner {
    padding: 64px var(--gutter) 0;
  }

  .technology__figure {
    align-self: stretch;
  }

  /* ----- Advantages ----- */

  .advantages .section-inner {
    padding: 64px var(--gutter) 0;
  }

  .advantages h2 {
    margin-bottom: 24px;
  }

  .advantages__list {
    flex-direction: column;
    gap: 24px;
  }

  .advantages__item {
    width: 100%;
    max-width: 335px;
    margin-inline: auto;
    padding: 24px 16px;
  }

  .advantages__item img {
    width: 64px;
    height: 64px;
  }

  .advantages__item h3 {
    font-size: 18px;
    letter-spacing: 0.9px;
    line-height: 1.4;
  }

  .advantages__item p {
    font-size: 16px;
    letter-spacing: 0.8px;
  }

  /* ----- Evidence ----- */

  .evidence .section-inner {
    padding: 64px var(--gutter) 0;
  }

  .evidence__lead {
    font-size: 16px;
    margin-bottom: 32px;
  }

  .evidence__list {
    flex-direction: column;
    align-items: center;
    gap: 24px;
  }

  .evidence__item {
    width: 100%;
    max-width: 335px;
    padding: 24px 16px;
  }

  .evidence__item h3 {
    font-size: 18px;
    letter-spacing: 0.9px;
    line-height: 1.4;
  }

  .evidence__item p {
    font-size: 16px;
  }

  /* ----- Roadmap ----- */

  .roadmap .section-inner {
    padding: 64px var(--gutter) 0;
  }

  .roadmap__list {
    flex-direction: column;
    align-items: center;
  }

  .roadmap__item {
    flex: none;
    width: 220px;
  }

  .roadmap__item:not(:last-child) {
    margin-right: 0;
    margin-bottom: 25px;
  }

  .roadmap__item:not(:last-child)::after {
    top: auto;
    right: auto;
    bottom: -25px;
    left: 50%;
    width: 2px;
    height: 25px;
    transform: translateX(-50%);
  }

  .roadmap__item h3 {
    font-size: 18px;
    letter-spacing: 0.9px;
  }

  /* ----- Collaborative Development Framework ----- */

  .dev-framework .section-inner {
    padding: 64px var(--gutter);
  }

  .dev-framework h2 {
    margin-bottom: 32px;
    font-size: 36px;
    letter-spacing: 0.36px;
    line-height: 1.2;
  }

  .dev-framework__figure img {
    max-width: 335px;
    margin-inline: auto;
  }

  /* ----- Collaboration ----- */

  .collaboration .section-inner {
    padding: 64px var(--gutter);
  }

  .collaboration__inner {
    flex-direction: column;
    gap: 64px;
  }

  .collaboration__content {
    max-width: none;
  }

  .collaboration__content p,
  .collaboration__content li {
    font-size: 16px;
  }

  .collaboration__cta {
    width: 100%;
    max-width: 335px;
    min-height: auto;
    padding: 12px 32px;
    font-size: 18px;
    letter-spacing: 0.9px;
    line-height: 1.4;
    text-align: center;
  }

  .collaboration__flow {
    flex: none;
    width: 100%;
    max-width: 335px;
    margin-inline: auto;
  }

  .collaboration__flow li {
    width: 100%;
    padding: 12px 24px;
    font-size: 18px;
    letter-spacing: 0.9px;
    line-height: 1.4;
  }

  /* ----- Potential Applications ----- */

  .applications .section-inner {
    padding: 64px var(--gutter);
  }

  .applications__box {
    padding: 32px 16px;
  }

  .applications__box h2 {
    font-size: 28px;
    letter-spacing: 0.56px;
    line-height: 1.4;
  }

  /* ----- FAQ ----- */

  .faq .section-inner {
    padding: 64px var(--gutter);
  }

  .faq__lead {
    font-size: 16px;
    max-width: none;
  }

  .faq__toggle {
    gap: 8px;
    font-size: 20px;
    letter-spacing: 0.6px;
    line-height: 1.6;
  }

  .faq__answer {
    max-width: none;
    font-size: 16px;
    letter-spacing: 0.8px;
  }

  /* ----- Publications & Patents ----- */

  .publications .section-inner {
    padding: 64px var(--gutter) 0;
  }

  .publications h2,
  .publications ul {
    max-width: none;
  }

  .publications li {
    font-size: 16px;
  }

  /* ----- Research Team ----- */

  .team .section-inner {
    padding: 64px var(--gutter);
  }

  .team h2,
  .team p {
    max-width: none;
  }

  .team p {
    font-size: 16px;
  }

  /* ----- Contact ----- */

  .contact .section-inner {
    padding: 64px var(--gutter);
  }

  .contact__content h2 {
    font-size: 36px;
    letter-spacing: 0.36px;
  }

  .contact__text {
    font-size: 16px;
    letter-spacing: 0.8px;
  }

  .contact__cta {
    width: 100%;
    max-width: 335px;
    min-height: auto;
    padding: 12px 32px;
    font-size: 18px;
    letter-spacing: 0.9px;
    line-height: 1.4;
  }

  /* ----- Footer ----- */

  .site-footer__inner {
    padding: 64px var(--gutter);
  }

  .site-footer__logo--pc {
    display: none;
  }

  .site-footer__logo--sp {
    display: block;
    width: 300px;
    height: 48px;
    margin-bottom: 8px;
    object-fit: contain;
  }

  .site-footer__brand p {
    font-size: 14px;
    letter-spacing: 0.7px;
  }

  .site-footer__nav {
    flex-direction: column;
    padding-bottom: 64px;
  }

  .site-footer__nav ul {
    width: 100%;
  }

  .site-footer__nav ul + ul {
    margin-top: 12px;
  }

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 24px;
  }

  /* ----- Privacy Policy ----- */

  .privacy-hero {
    min-height: auto;
  }

  .privacy-hero__inner {
    padding: 56px var(--gutter);
  }

  .privacy-hero h1 {
    font-size: 36px;
    letter-spacing: 0.36px;
  }

  .privacy-content__inner {
    padding: 64px var(--gutter);
  }

  .privacy__intro {
    margin-bottom: 40px;
    font-size: 16px;
    letter-spacing: 0.8px;
  }

  .privacy__sections {
    gap: 40px;
  }

  .privacy__section h2 {
    font-size: 24px;
    letter-spacing: 0.24px;
  }

  .privacy__section-body {
    font-size: 16px;
    letter-spacing: 0.8px;
  }
}