/* ==============================
   Custom Properties
   ============================== */
:root {
  --color-text: #0f172a;
  --color-text-muted: #64748b;
  --color-bg: #ffffff;
  --color-surface: #f0f5ff;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-dark: #0f172a;
  --color-white: #ffffff;
  --color-border: #e2e8f0;
  --font-sans: "Noto Sans JP", "Hiragino Sans", "Yu Gothic", sans-serif;
  --font-en: "Inter", sans-serif;
}

/* ==============================
   Base
   ============================== */
html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

/* ==============================
   Utility
   ============================== */
.container {
  width: min(calc(100% - 2.5rem), 75rem);
  margin-inline: auto;
}

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

/* ==============================
   Button
   ============================== */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3rem;
  padding-inline: 1.5rem;
  border: 1.5px solid transparent;
  border-radius: 0.375rem;
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.button--primary {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

.button--primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
}

.button--outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.button--outline:hover {
  background: var(--color-primary);
  color: var(--color-white);
}

.button--white {
  background: var(--color-white);
  color: var(--color-primary);
  border-color: var(--color-white);
}

.button--white:hover {
  background: transparent;
  color: var(--color-white);
  border-color: var(--color-white);
}

/* ==============================
   Site Header
   ============================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(0.75rem);
}

.site-header__inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 4.5rem;
}

.site-header__logo {
  font-family: var(--font-en);
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.site-header__logo span {
  color: var(--color-primary);
}

/* Hamburger */
.site-header__menu-button {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.3125rem;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0.625rem;
  cursor: pointer;
}

.hamburger-line {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--color-text);
  border-radius: 9999px;
  transition: transform 0.25s ease, opacity 0.25s ease;
  transform-origin: center;
}

.site-header__menu-button[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: translateY(0.40625rem) rotate(45deg);
}

.site-header__menu-button[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}

.site-header__menu-button[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: translateY(-0.40625rem) rotate(-45deg);
}

@media screen and (min-width: 48rem) {
  .site-header__menu-button {
    display: none;
  }
}

/* Site Nav */
.site-nav {
  display: none;
  position: absolute;
  top: calc(100% + 1px);
  left: 0;
  width: 100%;
  padding-block: 1.25rem;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 0.5rem 1.5rem rgba(0, 0, 0, 0.06);
}

.site-nav.is-open {
  display: block;
}

.site-nav__list {
  display: flex;
  flex-direction: column;
}

.site-nav__link {
  display: block;
  padding: 0.625rem 1.25rem;
  font-family: var(--font-en);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--color-text);
  transition: color 0.2s ease;
}

.site-nav__link:hover {
  color: var(--color-primary);
}

.site-nav__cta {
  display: none;
}

@media screen and (min-width: 48rem) {
  .site-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
    position: static;
    width: auto;
    padding: 0;
    background: transparent;
    border-bottom: 0;
    box-shadow: none;
  }

  .site-nav__list {
    flex-direction: row;
    align-items: center;
    gap: 2rem;
  }

  .site-nav__link {
    padding: 0;
  }

  .site-nav__cta {
    display: inline-flex;
  }
}

/* ==============================
   Hero
   ============================== */
.hero {
  padding-block: 5rem 4rem;
  overflow: hidden;
}

.hero__inner {
  display: grid;
  gap: 3rem;
  align-items: center;
}

.hero__label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-en);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.hero__label::before {
  content: '';
  display: block;
  width: 2rem;
  height: 1.5px;
  background: var(--color-primary);
}

.hero__title {
  margin-top: 1rem;
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.hero__text {
  margin-top: 1rem;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--color-text-muted);
}

.hero__actions {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 2rem;
}

.hero__visual {
  position: relative;
}

.hero__visual-img {
  width: 100%;
  border-radius: 0.75rem;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  box-shadow: 0 1.5rem 4rem rgba(37, 99, 235, 0.15);
}

.hero__visual-decoration {
  position: absolute;
  inset: -0.75rem;
  border: 1.5px solid var(--color-primary);
  border-radius: 1rem;
  opacity: 0.2;
  pointer-events: none;
  z-index: -1;
}

@media screen and (min-width: 48rem) {
  .hero {
    padding-block: 6rem 5rem;
  }

  .hero__inner {
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
  }

  .hero__title {
    font-size: 3.5rem;
  }

  .hero__actions {
    flex-direction: row;
  }
}

/* ==============================
   Section Common
   ============================== */
.section {
  padding-block: 5rem;
}

.section__header {
  display: grid;
  gap: 0.75rem;
  margin-bottom: 3rem;
}

.section__label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-en);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.section__label::before {
  content: '';
  display: block;
  width: 1.5rem;
  height: 1.5px;
  background: var(--color-primary);
}

.section__title {
  font-size: 1.875rem;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: #374151;
}

.section__text {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-text-muted);
  max-width: 40rem;
}

@media screen and (min-width: 48rem) {
  .section {
    padding-block: 6rem;
  }

  .section__title {
    font-size: 2.25rem;
  }
}

/* ==============================
   Works Grid
   ============================== */
.works-grid {
  display: grid;
  gap: 1.5rem;
}

.works-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 0.75rem;
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.works-card:hover {
  transform: translateY(-0.25rem);
  box-shadow: 0 1rem 3rem rgba(37, 99, 235, 0.12);
}

.works-card__link {
  display: block;
}

.works-card__thumbnail {
  aspect-ratio: 16 / 10;
  overflow: hidden;
}

.works-card__thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.works-card:hover .works-card__thumbnail img {
  transform: scale(1.04);
}

.works-card__body {
  padding: 1.25rem 1.5rem;
}

.works-card__category {
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 0.375rem;
}

.works-card__title {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--color-text);
}

.works-card__arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  margin-top: 0.75rem;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-primary);
}

@media screen and (min-width: 48rem) {
  .works-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ==============================
   About
   ============================== */
.about {
  background: var(--color-surface);
}

.about__inner {
  display: grid;
  gap: 3rem;
  align-items: start;
}

.about__lead {
  margin-top: 1rem;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--color-text-muted);
}

.about__strengths {
  display: grid;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.about__strength-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  font-size: 0.9375rem;
  line-height: 1.6;
}

.about__strength-item::before {
  content: '';
  flex-shrink: 0;
  display: block;
  width: 0.1875rem;
  height: 1.25rem;
  margin-top: 0.1875rem;
  background: var(--color-primary);
  border-radius: 9999px;
}

.about__stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.stat-card {
  padding: 1.5rem 1.25rem;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 0.75rem;
  text-align: center;
}

.stat-card__num {
  display: block;
  font-family: var(--font-en);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.1;
}

.stat-card__num small {
  font-size: 1.25rem;
}

.stat-card__label {
  display: block;
  margin-top: 0.375rem;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

@media screen and (min-width: 48rem) {
  .about__inner {
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
  }
}

/* ==============================
   CTA Section
   ============================== */
.cta-section {
  padding-block: 6rem;
  background: #0f172a;
  text-align: center;
  color: var(--color-white);
}

.cta-section__label {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-en);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #93c5fd;
  margin-bottom: 1.25rem;
}

.cta-section__label::before {
  content: '';
  display: block;
  width: 1.5rem;
  height: 1.5px;
  background: #93c5fd;
}

.cta-section__title {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.02em;
}

.cta-section__text {
  margin-top: 1rem;
  margin-inline: auto;
  font-size: 1rem;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.65);
  max-width: 30rem;
}

.cta-section__action {
  margin-top: 2.5rem;
}

@media screen and (min-width: 48rem) {
  .cta-section__title {
    font-size: 2.75rem;
  }
}

/* ==============================
   Site Footer
   ============================== */
.site-footer {
  padding-block: 2.5rem;
  border-top: 1px solid var(--color-border);
  background: var(--color-white);
}

.site-footer__inner {
  display: grid;
  gap: 1.25rem;
}

.site-footer__logo {
  font-family: var(--font-en);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.site-footer__logo span {
  color: var(--color-primary);
}

.footer-nav__list {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-nav__link {
  font-family: var(--font-en);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-muted);
  transition: color 0.2s ease;
}

.footer-nav__link:hover {
  color: var(--color-primary);
}

.site-footer__copy {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

@media screen and (min-width: 48rem) {
  .site-footer__inner {
    grid-template-columns: auto 1fr auto;
    align-items: center;
  }

  .footer-nav__list {
    justify-content: center;
  }
}

/* ==============================
   Works Detail Page
   ============================== */
.page-hero {
  padding-block: 4rem 3rem;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.page-hero__breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.page-hero__breadcrumb a {
  color: var(--color-primary);
  transition: opacity 0.2s ease;
}

.page-hero__breadcrumb a:hover {
  opacity: 0.7;
}

.page-hero__label {
  font-family: var(--font-en);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 0.75rem;
}

.page-hero__title {
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.3;
  color: #374151;
}

.works-detail {
  padding-block: 4rem 6rem;
}

.works-detail__grid {
  display: grid;
  gap: 3rem;
}

.works-detail__images {
  display: grid;
  gap: 1rem;
}

.works-detail__image {
  width: 100%;
  border-radius: 0.5rem;
  border: 1px solid var(--color-border);
}

.works-detail__heading {
  font-size: 1.25rem;
  font-weight: 700;
  color: #374151;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--color-primary);
  margin-bottom: 1rem;
  margin-top: 2.5rem;
}

.works-detail__heading:first-child {
  margin-top: 0;
}

.works-detail__text {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--color-text-muted);
}

.works-detail__sidebar {
  position: sticky;
  top: 6rem;
}

.works-info {
  padding: 1.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 0.75rem;
}

.works-info__title {
  font-family: var(--font-en);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 1.25rem;
}

.works-info__list {
  display: grid;
  gap: 1rem;
}

.works-info__item {
  display: grid;
  gap: 0.25rem;
}

.works-info__label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-text-muted);
}

.works-info__value {
  font-size: 0.9375rem;
  color: var(--color-text);
}

.works-detail__back {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  margin-top: 3rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-primary);
  transition: gap 0.2s ease;
}

.works-detail__back:hover {
  gap: 0.625rem;
}

@media screen and (min-width: 48rem) {
  .page-hero__title {
    font-size: 2.5rem;
  }
}

@media screen and (min-width: 64rem) {
  .works-detail__grid {
    grid-template-columns: 1fr 18.75rem;
    gap: 4rem;
    align-items: start;
  }
}

/* ==============================
   Reduced Motion
   ============================== */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .button,
  .works-card,
  .hamburger-line,
  .footer-nav__link,
  .works-card__thumbnail img,
  .works-detail__back {
    transition: none;
  }
}