/* ==========================================
   style.css — NEXUS CRAFT Demo Site
   ========================================== */

/* ------------------------------------------
   CSS Variables
   ------------------------------------------ */
:root {
  /* Colors */
  --color-bg:          #0d1b2a;
  --color-bg-alt:      #112240;
  --color-bg-card:     #0f2035;
  --color-accent:      #00d4ff;
  --color-accent-dim:  rgba(0, 212, 255, 0.15);
  --color-accent-glow: rgba(0, 212, 255, 0.4);
  --color-text:        #e8eaf0;
  --color-text-sub:    #8892b0;
  --color-border:      #1e3a5f;
  --color-white:       #ffffff;

  /* Fonts */
  --font-en:   'Orbitron', 'Space Grotesk', sans-serif;
  --font-base: 'Space Grotesk', 'Noto Sans JP', sans-serif;
  --font-jp:   'Noto Sans JP', sans-serif;

  /* Spacing */
  --space-xs:  0.5rem;
  --space-sm:  1rem;
  --space-md:  2rem;
  --space-lg:  4rem;
  --space-xl:  6rem;
  --space-2xl: 8rem;

  /* Transitions */
  --transition-fast:   0.2s ease;
  --transition-base:   0.3s ease;
  --transition-slow:   0.6s ease;

  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;

  /* Container */
  --container-max: 1200px;
  --container-px:  clamp(1.25rem, 5vw, 3rem);
}

/* ------------------------------------------
   Base
   ------------------------------------------ */
html {
  scroll-padding-top: 80px;
  scrollbar-gutter: stable;
}

body {
  font-family: var(--font-base);
  background-color: var(--color-bg);
  color: var(--color-text);
  font-size: clamp(0.9rem, 2vw, 1rem);
  overflow-x: hidden;
}

::selection {
  background: var(--color-accent);
  color: var(--color-bg);
}

/* ------------------------------------------
   Utilities
   ------------------------------------------ */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-px);
}

.section {
  padding-block: var(--space-xl);
}

.section--alt {
  background-color: var(--color-bg-alt);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-lg);
}

.section-label {
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.25em;
  color: var(--color-accent);
  text-transform: uppercase;
  margin-bottom: var(--space-xs);
}

.section-title {
  font-family: var(--font-jp);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.section-desc {
  font-family: var(--font-jp);
  font-size: clamp(0.875rem, 2vw, 1rem);
  color: var(--color-text-sub);
  line-height: 1.9;
}

/* ------------------------------------------
   Buttons
   ------------------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  font-family: var(--font-base);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.btn--primary {
  background-color: var(--color-accent);
  color: var(--color-bg);
}

.btn--primary::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0.2);
  transform: translateX(-100%);
  transition: transform 0.4s ease;
}

.btn--primary:hover::before {
  transform: translateX(0);
}

.btn--primary:hover {
  box-shadow: 0 0 20px var(--color-accent-glow), 0 0 40px rgba(0, 212, 255, 0.2);
  transform: translateY(-2px);
}

.btn--outline {
  border: 1px solid var(--color-accent);
  color: var(--color-accent);
}

.btn--outline:hover {
  background-color: var(--color-accent-dim);
  box-shadow: 0 0 16px var(--color-accent-glow);
  transform: translateY(-2px);
}

.btn--wide {
  min-width: 220px;
  padding-block: 1rem;
}

/* ------------------------------------------
   Fade-in animations
   ------------------------------------------ */
.fade-in,
.fade-in-left,
.fade-in-right {
  opacity: 0;
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in {
  transform: translateY(30px);
}

.fade-in-left {
  transform: translateX(-40px);
}

.fade-in-right {
  transform: translateX(40px);
}

.fade-in.visible,
.fade-in-left.visible,
.fade-in-right.visible {
  opacity: 1;
  transform: translate(0);
}

/* ------------------------------------------
   HEADER
   ------------------------------------------ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding-block: 1.25rem;
  transition: background var(--transition-base), box-shadow var(--transition-base), padding var(--transition-base);
}

.header.scrolled {
  background-color: rgba(13, 27, 42, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 var(--color-border);
  padding-block: 0.875rem;
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.header__logo {
  font-family: var(--font-en);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-text);
  white-space: nowrap;
}

.logo-bracket {
  color: var(--color-accent);
  opacity: 0.7;
}

.logo-accent {
  color: var(--color-accent);
}

.nav__list {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav__link {
  padding: 0.5rem 0.875rem;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: var(--color-text-sub);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.nav__link:hover {
  color: var(--color-text);
  background: rgba(255, 255, 255, 0.05);
}

.nav__link--cta {
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
  padding: 0.4rem 1rem;
}

.nav__link--cta:hover {
  background: var(--color-accent-dim);
  color: var(--color-accent);
}

/* Close button (SP only — hidden on desktop) */
.nav__close {
  display: none;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 6px;
  border-radius: var(--radius-sm);
}

.hamburger__bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.hamburger.open .hamburger__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.hamburger.open .hamburger__bar:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.hamburger.open .hamburger__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ------------------------------------------
   HERO
   ------------------------------------------ */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero__canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero__content {
  position: relative;
  z-index: 1;
  padding-top: 80px;
}

.hero__label {
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.3em;
  color: var(--color-accent);
  text-transform: uppercase;
  margin-bottom: 1.5rem;
  opacity: 0;
  animation: heroFadeIn 0.8s ease 0.3s forwards;
}

.hero__title {
  font-family: var(--font-en);
  font-size: clamp(2rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text);
  margin-bottom: 1.5rem;
  min-height: 1.2em;
  opacity: 0;
  animation: heroFadeIn 0.8s ease 0.5s forwards;
}

.hero__cursor {
  display: inline-block;
  color: var(--color-accent);
  animation: blink 1s step-end infinite;
  font-weight: 300;
}

.hero__sub {
  font-family: var(--font-jp);
  font-size: clamp(0.9375rem, 2vw, 1.125rem);
  color: var(--color-text-sub);
  line-height: 1.9;
  margin-bottom: 2.5rem;
  max-width: 540px;
  opacity: 0;
  animation: heroFadeIn 0.8s ease 0.7s forwards;
}

.hero__actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  opacity: 0;
  animation: heroFadeIn 0.8s ease 0.9s forwards;
}

.hero__scroll {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  opacity: 0;
  animation: heroFadeIn 0.8s ease 1.2s forwards;
}

.hero__scroll-text {
  font-family: var(--font-en);
  font-size: 0.625rem;
  letter-spacing: 0.25em;
  color: var(--color-text-sub);
}

.hero__scroll-line {
  display: block;
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, var(--color-accent), transparent);
  animation: scrollLine 2s ease infinite;
}

/* ------------------------------------------
   ABOUT
   ------------------------------------------ */
.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
  margin-bottom: 4rem;
}

.about__subtitle {
  font-family: var(--font-en);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--color-accent);
  margin-bottom: 0.75rem;
  margin-top: 2rem;
}

.about__subtitle:first-child {
  margin-top: 0;
}

.about__body {
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  color: var(--color-text-sub);
  line-height: 1.9;
}

.about__strengths {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.strength-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.strength-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.1);
}

.strength-card__icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-dim);
  border-radius: var(--radius-sm);
}

.strength-card__title {
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.375rem;
}

.strength-card__text {
  font-family: var(--font-jp);
  font-size: 0.875rem;
  color: var(--color-text-sub);
  line-height: 1.7;
}

/* Stats */
.about__stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--color-border);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.stat-item {
  background: var(--color-bg-card);
  padding: 2.5rem 1.5rem;
  text-align: center;
  transition: background var(--transition-base);
}

.stat-item:hover {
  background: rgba(0, 212, 255, 0.05);
}

.stat-item__num {
  font-family: var(--font-en);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  display: inline;
}

.stat-item__unit {
  font-family: var(--font-en);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-accent);
}

.stat-item__label {
  font-family: var(--font-jp);
  font-size: 0.8125rem;
  color: var(--color-text-sub);
  margin-top: 0.5rem;
}

/* ------------------------------------------
   SERVICES
   ------------------------------------------ */
.services__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.service-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2rem;
  position: relative;
  overflow: hidden;
  transition: border-color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.service-card:hover {
  border-color: rgba(0, 212, 255, 0.5);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3), 0 0 20px rgba(0, 212, 255, 0.1);
}

.service-card:hover::before {
  opacity: 1;
}

.service-card__num {
  font-family: var(--font-en);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--color-accent);
  opacity: 0.5;
  margin-bottom: 1.25rem;
}

.service-card__icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-dim);
  border-radius: var(--radius-md);
  margin-bottom: 1.25rem;
}

.service-card__title {
  font-family: var(--font-jp);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.75rem;
}

.service-card__text {
  font-family: var(--font-jp);
  font-size: 0.875rem;
  color: var(--color-text-sub);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

.service-card__link {
  font-family: var(--font-base);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.05em;
  transition: gap var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
}

.service-card__link:hover {
  gap: 0.625rem;
}

/* ------------------------------------------
   WORKS
   ------------------------------------------ */
.works__filter {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 2.5rem;
}

.filter-btn {
  padding: 0.5rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-sub);
  border: 1px solid var(--color-border);
  border-radius: 9999px;
  transition: all var(--transition-fast);
}

.filter-btn:hover,
.filter-btn--active {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-dim);
}

.works__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.work-card {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-bg-card);
  transition: transform var(--transition-base), box-shadow var(--transition-base), opacity 0.3s ease;
}

.work-card.hidden {
  display: none;
}

.work-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4), 0 0 24px rgba(0, 212, 255, 0.1);
}

.work-card__img {
  aspect-ratio: 16 / 10;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.work-card__placeholder {
  opacity: 0.6;
  transition: opacity var(--transition-base), transform var(--transition-base);
}

.work-card:hover .work-card__placeholder {
  opacity: 1;
  transform: scale(1.1);
}

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

.work-card__tag {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  background: var(--color-accent-dim);
  padding: 0.25rem 0.625rem;
  border-radius: 9999px;
  margin-bottom: 0.75rem;
}

.work-card__title {
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.5;
  margin-bottom: 0.5rem;
}

.work-card__desc {
  font-family: var(--font-jp);
  font-size: 0.8125rem;
  color: var(--color-text-sub);
  line-height: 1.7;
}

/* ------------------------------------------
   HISTORY / TIMELINE
   ------------------------------------------ */
.timeline {
  position: relative;
  max-width: 860px;
  margin-inline: auto;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 1px;
  background: linear-gradient(to bottom, transparent, var(--color-border) 10%, var(--color-border) 90%, transparent);
  transform: translateX(-50%);
}

.timeline__item {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
  position: relative;
}

.timeline__item:last-child {
  margin-bottom: 0;
}

/* Left items: card on left, dot on right side of center */
.timeline__item .timeline__card {
  grid-column: 1;
  text-align: right;
}

.timeline__item .timeline__dot {
  position: absolute;
  left: 50%;
  top: 1.25rem;
  transform: translateX(-50%);
  width: 14px;
  height: 14px;
  background: var(--color-accent);
  border-radius: 50%;
  box-shadow: 0 0 12px var(--color-accent-glow);
  z-index: 1;
}

/* Right items */
.timeline__item--right .timeline__card {
  grid-column: 2;
  text-align: left;
}

.timeline__card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: border-color var(--transition-base);
}

.timeline__card:hover {
  border-color: rgba(0, 212, 255, 0.4);
}

.timeline__year {
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--color-accent);
  display: block;
  margin-bottom: 0.5rem;
}

.timeline__title {
  font-family: var(--font-jp);
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

.timeline__text {
  font-family: var(--font-jp);
  font-size: 0.875rem;
  color: var(--color-text-sub);
  line-height: 1.7;
}

/* ------------------------------------------
   FAQ
   ------------------------------------------ */
.faq__list {
  max-width: 780px;
  margin-inline: auto;
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
}

.faq-item:first-child {
  border-top: 1px solid var(--color-border);
}

.faq-item__q {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1.375rem 0;
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-text);
  text-align: left;
  background: none;
  transition: color var(--transition-fast);
}

.faq-item__q:hover {
  color: var(--color-accent);
}

.faq-item__icon {
  flex-shrink: 0;
  font-size: 1.25rem;
  font-weight: 300;
  color: var(--color-accent);
  line-height: 1;
  transition: transform var(--transition-base);
}

.faq-item__q[aria-expanded="true"] .faq-item__icon {
  transform: rotate(45deg);
}

.faq-item__a {
  padding-bottom: 1.375rem;
}

.faq-item__a p {
  font-family: var(--font-jp);
  font-size: 0.9rem;
  color: var(--color-text-sub);
  line-height: 1.9;
  padding-right: 2.5rem;
}

/* ------------------------------------------
   ACCESS
   ------------------------------------------ */
.access__grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 3rem;
  align-items: start;
  min-width: 0;
}

.access__grid > * {
  min-width: 0;
}

.access__dl {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.access__dl-item {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 1rem;
  padding-block: 1rem;
  border-bottom: 1px solid var(--color-border);
}

.access__dl-item:first-child {
  border-top: 1px solid var(--color-border);
}

.access__dl-item dt {
  font-family: var(--font-jp);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-text-sub);
  padding-top: 0.125rem;
}

.access__dl-item dd {
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  color: var(--color-text);
  line-height: 1.7;
}

.access__map {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  aspect-ratio: 4 / 3;
  min-height: 300px;
  min-width: 0;      /* グリッド内でのはみ出し防止 */
  width: 100%;
}

.access__map iframe {
  display: block;
  width: 100%;
  max-width: 100%;
  height: 100%;
}

.map-placeholder {
  width: 100%;
  height: 100%;
  background: var(--color-bg-card);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  color: var(--color-text-sub);
}

.map-placeholder p {
  font-family: var(--font-en);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-sub);
}

.map-placeholder span {
  font-family: var(--font-jp);
  font-size: 0.75rem;
  opacity: 0.6;
}

/* ------------------------------------------
   CONTACT
   ------------------------------------------ */
.contact__form {
  max-width: 700px;
  margin-inline: auto;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.form-group--center {
  align-items: center;
  margin-top: 0.5rem;
}

.form-label {
  font-family: var(--font-jp);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-text);
}

.form-required {
  color: var(--color-accent);
  margin-left: 0.25rem;
}

.form-input {
  width: 100%;
  padding: 0.875rem 1rem;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input::placeholder {
  color: rgba(136, 146, 176, 0.5);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.12);
}

.form-input.error {
  border-color: #ff6b6b;
}

.form-textarea {
  resize: vertical;
  min-height: 140px;
}

.form-error {
  font-family: var(--font-jp);
  font-size: 0.8125rem;
  color: #ff6b6b;
  min-height: 1.2em;
}

/* Thanks */
.contact__thanks {
  max-width: 500px;
  margin-inline: auto;
  text-align: center;
  padding: 4rem 2rem;
}

.thanks-icon {
  margin-bottom: 1.5rem;
  display: flex;
  justify-content: center;
}

.contact__thanks h3 {
  font-family: var(--font-jp);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.75rem;
}

.contact__thanks p {
  font-family: var(--font-jp);
  font-size: 0.9375rem;
  color: var(--color-text-sub);
  line-height: 1.9;
}

/* ------------------------------------------
   FOOTER
   ------------------------------------------ */
.footer {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  padding-block: 3rem 1.5rem;
}

.footer__inner {
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 3rem;
  align-items: center;
  padding-bottom: 2rem;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--color-border);
}

.footer__logo {
  font-family: var(--font-en);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: 0.5rem;
}

.footer__tagline {
  font-family: var(--font-en);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--color-text-sub);
}

.footer__nav-list {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.footer__nav-list a {
  font-size: 0.875rem;
  color: var(--color-text-sub);
  transition: color var(--transition-fast);
}

.footer__nav-list a:hover {
  color: var(--color-accent);
}

.footer__social {
  display: flex;
  gap: 0.75rem;
}

.social-link {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-sub);
  transition: all var(--transition-fast);
}

.social-link:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-dim);
}

.footer__bottom {
  text-align: center;
}

.footer__copy {
  font-family: var(--font-en);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--color-text-sub);
  opacity: 0.6;
}

/* ------------------------------------------
   BACK TO TOP
   ------------------------------------------ */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 500;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-accent);
  transition: all var(--transition-base);
  opacity: 0;
  pointer-events: none;
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--color-accent-dim);
  border-color: var(--color-accent);
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0, 212, 255, 0.2);
}

/* ------------------------------------------
   Keyframes
   ------------------------------------------ */
@keyframes heroFadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0; }
}

@keyframes scrollLine {
  0%   { transform: scaleY(0); transform-origin: top; }
  50%  { transform: scaleY(1); transform-origin: top; }
  51%  { transform: scaleY(1); transform-origin: bottom; }
  100% { transform: scaleY(0); transform-origin: bottom; }
}

/* ------------------------------------------
   Responsive — Tablet (max 1024px)
   ------------------------------------------ */
@media (max-width: 1024px) {
  .about__grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

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

  .services__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .works__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .timeline::before {
    left: 1.5rem;
  }

  .timeline__item,
  .timeline__item--right {
    grid-template-columns: 1fr;
  }

  .timeline__item .timeline__card,
  .timeline__item--right .timeline__card {
    grid-column: 1;
    text-align: left;
    margin-left: 3.5rem;
  }

  .timeline__item .timeline__dot,
  .timeline__item--right .timeline__dot {
    left: 1.5rem;
    transform: translateX(-50%);
  }

  .access__grid {
    grid-template-columns: 1fr;
  }

  .footer__inner {
    grid-template-columns: 1fr;
    gap: 1.5rem;
    text-align: center;
  }

  .footer__nav-list {
    justify-content: center;
    gap: 1rem;
  }

  .footer__social {
    justify-content: center;
  }
}

/* ------------------------------------------
   Responsive — Mobile (max 768px)
   ------------------------------------------ */
@media (max-width: 768px) {
  :root {
    --space-xl: 4rem;
  }

  .header__nav {
    display: none;
    position: fixed;
    inset: 0;
    background: #0d1b2a;
    z-index: 1001; /* header(1000)より上 */
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0;
  }

  .header__nav.open {
    display: flex;
  }

  .nav__list {
    flex-direction: column;
    gap: 0;
    text-align: center;
    width: 100%;
  }

  .nav__link {
    display: block;
    padding: 1.1rem 2rem;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
    letter-spacing: 0.08em;
    border-bottom: 1px solid var(--color-border);
  }

  .nav__link:first-child,
  .nav__list li:first-child .nav__link {
    border-top: 1px solid var(--color-border);
  }

  .nav__link:hover {
    color: var(--color-accent);
    background: rgba(0, 212, 255, 0.05);
  }

  .nav__link--cta {
    margin-top: 2rem;
    border: 1px solid var(--color-accent);
    border-radius: var(--radius-sm);
    color: var(--color-accent);
    padding: 0.875rem 2.5rem;
    display: inline-block;
    width: auto;
  }

  .nav__link--cta:hover {
    background: var(--color-accent-dim);
  }

  .hamburger {
    display: flex;
    position: relative;
    z-index: 1;
  }

  /* 閉じるボタン */
  .nav__close {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    position: absolute;
    top: 1.25rem;
    right: 1.25rem;
    padding: 0.625rem 1rem;
    font-family: var(--font-jp);
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--color-text-sub);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: transparent;
    transition: color var(--transition-fast), border-color var(--transition-fast);
  }

  .nav__close:hover {
    color: var(--color-accent);
    border-color: var(--color-accent);
  }

  /* メニューオープン時: headerをnavより上に出してXボタンを見えるようにする */
  .header.menu-open {
    z-index: 1003;
    background: transparent;
    box-shadow: none;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }

  .header.menu-open .header__logo {
    opacity: 0;
    pointer-events: none;
  }

  .hero__title {
    font-size: clamp(1.75rem, 8vw, 3rem);
  }

  .hero__content {
    text-align: center;
  }

  .hero__sub {
    margin-inline: auto;
  }

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

  .hero__actions .btn {
    width: 100%;
    max-width: 280px;
  }

  .services__grid {
    grid-template-columns: 1fr;
  }

  .works__grid {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

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

  .services__grid {
    grid-template-columns: 1fr;
  }

  .access__dl-item {
    grid-template-columns: 5.5rem 1fr;
  }

  .hero__scroll {
    display: none;
  }

  .timeline__item .timeline__card,
  .timeline__item--right .timeline__card {
    margin-left: 3rem;
  }
}

/* ------------------------------------------
   Responsive — Small Mobile (max 480px)
   ------------------------------------------ */
@media (max-width: 480px) {
  .about__stats {
    grid-template-columns: 1fr 1fr;
  }

  .stat-item {
    padding: 1.5rem 1rem;
  }

  .works__filter {
    gap: 0.375rem;
  }

  .filter-btn {
    padding: 0.4rem 0.875rem;
    font-size: 0.8125rem;
  }
}