/* =============================================
   UPCYCLE MATERIAL — style.css
   Dark Industrial Design
   ============================================= */

/* ---- Variables ---- */
:root {
  --clr-bg:        #0a0a0a;
  --clr-bg-alt:    #111111;
  --clr-bg-card:   #1a1a1a;
  --clr-border:    #2e2e2e;
  --clr-border-lt: #3d3d3d;
  --clr-text:      #f4f1ec;
  --clr-text-muted:#cdc6bc;
  --clr-text-light:#9a9088;
  --clr-accent:    #c4622d;
  --clr-accent-lt: #d97840;
  --clr-accent-dim:#5a2a14;
  --clr-stone:     #8a7d6e;

  --font: 'Noto Sans JP', sans-serif;
  --radius: 2px;
  --gutter: clamp(1.25rem, 5vw, 3rem);
  --section-gap: clamp(5rem, 10vw, 9rem);
  --header-h: 64px;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 112.5%; }
body {
  font-family: var(--font);
  background: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.9;
  font-size: 1rem;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { font-family: var(--font); cursor: pointer; border: none; background: none; }
input, textarea, select { font-family: var(--font); }

/* ---- Container ---- */
.container {
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---- Typography ---- */
.eyebrow {
  display: block;
  font-size: 0.6875rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--clr-accent);
  margin-bottom: 1.25rem;
  font-weight: 500;
}
.section-title {
  font-size: clamp(2rem, 4.5vw, 3.25rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--clr-text);
  margin-bottom: 1.5rem;
}
.section-lead {
  font-size: 1rem;
  color: var(--clr-text-muted);
  line-height: 2.0;
  max-width: 52ch;
}
.section-header {
  margin-bottom: clamp(3rem, 6vw, 5rem);
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  border-radius: var(--radius);
  transition: background 0.2s, color 0.2s, border-color 0.2s;
  cursor: pointer;
}
.btn-primary {
  background: var(--clr-accent);
  color: #fff;
  border: 1px solid var(--clr-accent);
}
.btn-primary:hover { background: var(--clr-accent-lt); border-color: var(--clr-accent-lt); }
.btn-ghost {
  background: transparent;
  color: var(--clr-text);
  border: 1px solid var(--clr-border-lt);
}
.btn-ghost:hover { border-color: var(--clr-text-muted); }

/* =============================================
   HEADER
   ============================================= */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  z-index: 100;
  background: rgba(12,12,12,0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s;
}
.site-header.scrolled { border-bottom-color: var(--clr-border); }
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
}
.header-logo {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--clr-text);
}
.site-nav ul {
  display: flex;
  align-items: center;
  gap: 2.5rem;
}
.site-nav ul li a {
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--clr-text-muted);
  transition: color 0.2s;
}
.site-nav ul li a:hover { color: var(--clr-text); }
.site-nav ul li a.nav-cta {
  color: var(--clr-accent);
  border: 1px solid var(--clr-accent-dim);
  padding: 0.4rem 1rem;
  border-radius: var(--radius);
  transition: background 0.2s, color 0.2s;
}
.site-nav ul li a.nav-cta:hover { background: var(--clr-accent); color: #fff; }
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 28px;
  cursor: pointer;
}
.hamburger span {
  display: block;
  height: 1px;
  background: var(--clr-text);
  transition: transform 0.3s, opacity 0.3s;
}
.hamburger.open span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* =============================================
   HERO
   ============================================= */
.hero {
  min-height: 100svh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--header-h);
  background: var(--clr-bg);
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 70% 50%, rgba(196,98,45,0.07) 0%, transparent 70%),
    radial-gradient(ellipse 40% 60% at 20% 80%, rgba(138,125,110,0.05) 0%, transparent 60%);
  pointer-events: none;
}
.hero-noise {
  position: absolute;
  inset: 0;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  background-size: 200px;
  pointer-events: none;
}
.hero-content {
  position: relative;
  z-index: 1;
  padding-inline: var(--gutter);
  max-width: 1200px;
  margin-inline: auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 5vw, 5rem);
  align-items: center;
}
.hero-text {
  min-width: 0;
}
.hero-img-wrap {
  aspect-ratio: 3 / 4;
  overflow: hidden;
  border: 1px solid var(--clr-border);
}
.hero-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.hero-eyebrow {
  font-size: 1rem;
  letter-spacing: 0.12em;
  color: var(--clr-accent);
  margin-bottom: 1.5rem;
  font-weight: 500;
}
.hero-title {
  font-size: clamp(4rem, 12vw, 9rem);
  font-weight: 900;
  line-height: 1.0;
  letter-spacing: -0.03em;
  color: #fff;
  margin-bottom: 2rem;
}
.hero-sub {
  font-size: clamp(1.125rem, 2vw, 1.375rem);
  font-weight: 500;
  color: var(--clr-text-muted);
  line-height: 2.0;
  margin-bottom: 2.5rem;
  max-width: 44ch;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}
.hero-scroll-hint {
  position: absolute;
  bottom: 2.5rem;
  left: var(--gutter);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}
.hero-scroll-hint span {
  font-size: 0.5625rem;
  letter-spacing: 0.25em;
  color: var(--clr-text-light);
  writing-mode: vertical-rl;
}
.hero-scroll-line {
  width: 1px;
  height: 60px;
  background: linear-gradient(to bottom, var(--clr-text-light), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
  0%, 100% { opacity: 0.4; transform: scaleY(1); }
  50% { opacity: 1; transform: scaleY(0.6); }
}

/* =============================================
   CONCEPT
   ============================================= */
.concept-section {
  padding-block: var(--section-gap);
  border-top: 1px solid var(--clr-border);
}
.concept-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(3rem, 6vw, 6rem);
  align-items: center;
}
.concept-text p {
  font-weight: 500;
  color: var(--clr-text-muted);
  margin-bottom: 1rem;
  line-height: 2.0;
}
.concept-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--clr-border);
}
.concept-stat { display: flex; flex-direction: column; gap: 0.25rem; }
.stat-num {
  font-size: 2.25rem;
  font-weight: 900;
  color: var(--clr-accent);
  line-height: 1;
  letter-spacing: -0.02em;
}
.stat-num small { font-size: 1rem; }
.stat-label {
  font-size: 0.75rem;
  color: var(--clr-text-muted);
  letter-spacing: 0.04em;
  line-height: 1.4;
}
.concept-visual {
  position: relative;
}
.concept-img-placeholder {
  aspect-ratio: 4 / 5;
  background: var(--clr-bg-card);
  border: 1px solid var(--clr-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-text-light);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
}
.concept-img-placeholder img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.concept-img-wrap {
  aspect-ratio: 4 / 5;
  overflow: hidden;
}
.concept-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.concept-tag {
  position: absolute;
  bottom: -1rem;
  right: -1rem;
  background: var(--clr-accent);
  color: #fff;
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.5rem 1rem;
}

/* =============================================
   WHY
   ============================================= */
.why-section {
  padding-block: clamp(3rem, 6vw, 5rem);
  border-top: 1px solid var(--clr-border);
  background: var(--clr-bg-alt);
}
.why-inner {
  max-width: 720px;
  padding-left: 2rem;
  border-left: 3px solid var(--clr-accent);
}
.why-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 900;
  color: var(--clr-text);
  margin-bottom: 1.25rem;
  letter-spacing: -0.01em;
}
.why-text {
  font-size: 1rem;
  font-weight: 500;
  color: var(--clr-text-muted);
  line-height: 2.0;
}
.why-text a {
  color: var(--clr-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s;
}
.why-text a:hover { color: var(--clr-accent-lt); }

/* =============================================
   MATERIALS
   ============================================= */
.materials-section {
  padding-block: var(--section-gap);
  border-top: 1px solid var(--clr-border);
  background: var(--clr-bg-alt);
}
.materials-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--clr-border);
  border: 1px solid var(--clr-border);
  margin-bottom: 2rem;
}
.material-card {
  background: var(--clr-bg-card);
  padding: 2.5rem 1.75rem;
  transition: background 0.25s;
}
.material-card:hover { background: #1e1e1e; }
.material-icon {
  width: 48px;
  height: 48px;
  color: var(--clr-accent);
  margin-bottom: 1.5rem;
}
.material-icon svg { width: 100%; height: 100%; }
.material-img {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  margin: -2.5rem -1.75rem 1.75rem;
}
.material-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.4s ease;
}
.material-card:hover .material-img img { transform: scale(1.04); }
.material-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--clr-text);
  letter-spacing: 0.02em;
}
.material-card p {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--clr-text-muted);
  line-height: 2.0;
  margin-bottom: 1.25rem;
}
.material-tag {
  font-size: 0.625rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--clr-accent);
  border: 1px solid var(--clr-accent-dim);
  display: inline-block;
  padding: 0.25rem 0.625rem;
}
.materials-note {
  font-size: 0.8125rem;
  color: var(--clr-text-muted);
  border-left: 2px solid var(--clr-accent-dim);
  padding-left: 1rem;
}

/* =============================================
   PROCESS
   ============================================= */
.process-section {
  padding-block: var(--section-gap);
  border-top: 1px solid var(--clr-border);
}
.process-steps {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.process-step {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 2rem;
  padding-block: 2.5rem;
  border-bottom: 1px solid var(--clr-border);
  transition: background 0.2s;
}
.process-step:first-of-type { border-top: 1px solid var(--clr-border); }
.process-step:hover { background: rgba(196,98,45,0.03); }
.process-num {
  font-size: 3.5rem;
  font-weight: 900;
  color: var(--clr-border-lt);
  line-height: 1;
  letter-spacing: -0.02em;
  transition: color 0.2s;
}
.process-step:hover .process-num { color: var(--clr-accent-dim); }
.process-body h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--clr-text);
}
.process-body p {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--clr-text-muted);
  line-height: 2.0;
  max-width: 60ch;
}

/* =============================================
   WORKS
   ============================================= */
.works-section {
  padding-block: var(--section-gap);
  border-top: 1px solid var(--clr-border);
  background: var(--clr-bg-alt);
}
.works-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: auto auto;
  gap: 1px;
  background: var(--clr-border);
  border: 1px solid var(--clr-border);
  margin-bottom: 1.5rem;
}
.work-item {
  background: var(--clr-bg-card);
  overflow: hidden;
}
.work-item--large {
  grid-column: 1 / 2;
  grid-row: 1 / 3;
}
.work-placeholder {
  background: var(--clr-bg-alt);
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-text-light);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  transition: background 0.2s;
}
.work-item--large .work-placeholder { aspect-ratio: 1 / 2.04; }
.work-item:hover .work-placeholder { background: #1a1a1a; }
.work-placeholder img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.work-img {
  aspect-ratio: 1 / 1;
  overflow: hidden;
}
.work-item--large .work-img { aspect-ratio: 1 / 2.04; }
.work-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.4s ease;
}
.work-item:hover .work-img img { transform: scale(1.04); }
.work-caption {
  padding: 1rem 1.25rem;
  border-top: 1px solid var(--clr-border);
}
.work-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--clr-text);
  letter-spacing: 0.04em;
  margin-bottom: 0.2rem;
}
.work-desc {
  font-size: 0.75rem;
  color: var(--clr-text-muted);
  letter-spacing: 0.04em;
}
.works-note {
  font-size: 0.8125rem;
  color: var(--clr-text-light);
  font-style: italic;
}

/* =============================================
   LINEUP
   ============================================= */
.lineup-section {
  padding-block: var(--section-gap);
  border-top: 1px solid var(--clr-border);
  background: var(--clr-bg);
}
.lineup-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--clr-border);
  border: 1px solid var(--clr-border);
}
.lineup-card {
  background: var(--clr-bg-card);
  padding: 2rem 1.5rem 1.75rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  transition: background 0.25s;
}
.lineup-card:hover { background: #1e1e1e; }
.lineup-svg {
  width: 100%;
  height: auto;
  display: block;
}
.lineup-info {
  text-align: center;
  width: 100%;
  padding-top: 0.75rem;
  border-top: 1px solid var(--clr-border);
}
.lineup-size {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--clr-text);
  letter-spacing: 0.04em;
  margin-bottom: 0.4rem;
}
.lineup-finish {
  font-size: 0.8125rem;
  color: var(--clr-accent);
  letter-spacing: 0.04em;
}
.lineup-note {
  margin-top: 1.25rem;
  font-size: 0.8125rem;
  color: var(--clr-text-muted);
  text-align: center;
}
@media (max-width: 1024px) {
  .lineup-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .lineup-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ---- Surface photos ---- */
.surface-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  background: transparent;
  border: 1px solid var(--clr-border);
  margin-bottom: clamp(2rem, 4vw, 3.5rem);
}
.surface-item {
  background: var(--clr-bg-card);
  overflow: hidden;
}
.surface-img {
  aspect-ratio: 5 / 4;
  overflow: hidden;
}
.surface-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.4s ease;
}
.surface-item:hover .surface-img img { transform: scale(1.04); }
.surface-label {
  padding: 0.75rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--clr-text);
  letter-spacing: 0.04em;
  border-top: 1px solid var(--clr-border);
}
@media (max-width: 600px) {
  .surface-row { grid-template-columns: 1fr; }
}

/* =============================================
   USAGE
   ============================================= */
.usage-section {
  padding-block: var(--section-gap);
  border-top: 1px solid var(--clr-border);
  background: var(--clr-bg);
}
.usage-inner {
  max-width: 760px;
}
.usage-title {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  font-weight: 900;
  color: var(--clr-text);
  line-height: 1.3;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}
.usage-body {
  font-size: 1rem;
  font-weight: 500;
  color: var(--clr-text-muted);
  line-height: 2.0;
  margin-bottom: 2.5rem;
  max-width: 60ch;
}
.usage-cta {
  display: inline-flex;
}

/* =============================================
   ORDER
   ============================================= */
.order-section {
  padding-block: var(--section-gap);
  border-top: 1px solid var(--clr-border);
}
.order-grid {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: clamp(3rem, 6vw, 6rem);
  align-items: start;
}
.order-intro p {
  font-weight: 500;
  color: var(--clr-text-muted);
  margin-bottom: 1rem;
  line-height: 2.0;
  margin-top: 1rem;
}
.order-list {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--clr-border);
}
.order-list li {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--clr-border);
  font-size: 0.875rem;
  color: var(--clr-text-muted);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.order-list li::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 4px;
  background: var(--clr-accent);
  border-radius: 50%;
  flex-shrink: 0;
}
.order-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}
.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.form-group label {
  font-size: 0.875rem;
  letter-spacing: 0.06em;
  color: var(--clr-text-muted);
  text-transform: uppercase;
  font-weight: 500;
}
.required { color: var(--clr-accent); }
.form-group input,
.form-group textarea {
  background: var(--clr-bg-card);
  border: 1px solid var(--clr-border);
  color: var(--clr-text);
  padding: 0.875rem 1.125rem;
  font-size: 1rem;
  border-radius: var(--radius);
  transition: border-color 0.2s;
  outline: none;
  width: 100%;
}
.form-group input:focus,
.form-group textarea:focus { border-color: var(--clr-stone); }
.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--clr-text-light); }
.form-group textarea { resize: vertical; }
.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 0.25rem;
}
.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1rem;
  color: var(--clr-text-muted);
  cursor: pointer;
  text-transform: none;
  letter-spacing: 0;
  font-weight: 400;
}
.checkbox-label input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--clr-accent);
  cursor: pointer;
  flex-shrink: 0;
}
.order-contact {
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--clr-border);
  font-style: normal;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.order-contact-company {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--clr-text);
  margin-bottom: 0.25rem;
}
.order-contact p {
  font-size: 0.875rem;
  color: var(--clr-text-muted);
  line-height: 1.6;
}
.order-contact a {
  color: var(--clr-text-muted);
  transition: color 0.2s;
}
.order-contact a:hover { color: var(--clr-accent); }
.btn-submit {
  margin-top: 0.5rem;
  align-self: flex-start;
}

/* =============================================
   FOOTER
   ============================================= */
.site-footer {
  border-top: 1px solid var(--clr-border);
  padding-top: 3rem;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: start;
  padding-bottom: 3rem;
  gap: 2rem;
}
.footer-logo {
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--clr-text);
  margin-bottom: 0.5rem;
}
.footer-tagline {
  font-size: 0.8125rem;
  color: var(--clr-text-muted);
  margin-bottom: 1rem;
}
.footer-address {
  font-style: normal;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}
.footer-address p {
  font-size: 0.8125rem;
  color: var(--clr-text-muted);
  line-height: 1.5;
}
.footer-address a {
  color: var(--clr-text-muted);
  transition: color 0.2s;
}
.footer-address a:hover { color: var(--clr-text); }
.footer-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 2rem;
}
.footer-nav ul li a {
  font-size: 0.8125rem;
  color: var(--clr-text-muted);
  transition: color 0.2s;
}
.footer-nav ul li a:hover { color: var(--clr-text); }
.footer-bottom {
  border-top: 1px solid var(--clr-border);
  padding-block: 1.5rem;
  text-align: center;
}
.footer-bottom p {
  font-size: 0.75rem;
  color: var(--clr-text-light);
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 1024px) {
  .materials-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 900px) {
  .hero-content { grid-template-columns: 1fr; }
  .hero-img-wrap { aspect-ratio: 16 / 9; order: -1; }
  .site-nav { display: none; }
  .hamburger { display: flex; }
  .site-nav.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    inset: var(--header-h) 0 0;
    background: var(--clr-bg);
    padding: 2rem var(--gutter);
    border-top: 1px solid var(--clr-border);
    z-index: 99;
  }
  .site-nav.open ul { flex-direction: column; gap: 0; }
  .site-nav.open ul li a {
    display: block;
    padding: 1rem 0;
    font-size: 1.0625rem;
    border-bottom: 1px solid var(--clr-border);
    color: var(--clr-text);
  }
  .concept-grid { grid-template-columns: 1fr; }
  .concept-visual { order: -1; }
  .concept-img-wrap { aspect-ratio: 16 / 9; }
  .order-grid { grid-template-columns: 1fr; }
  .works-grid { grid-template-columns: repeat(2, 1fr); }
  .work-item--large { grid-column: 1 / -1; grid-row: auto; }
  .work-item--large .work-img { aspect-ratio: 16 / 9; }
  .footer-inner { flex-direction: column; gap: 2rem; }
}

@media (max-width: 600px) {
  .hero-title { font-size: clamp(3.5rem, 16vw, 5rem); }
  .materials-grid { grid-template-columns: 1fr; }
  .concept-stats { grid-template-columns: repeat(3, 1fr); gap: 1rem; }
  .process-step { grid-template-columns: 64px 1fr; gap: 1rem; }
  .process-num { font-size: 2.25rem; }
  .works-grid { grid-template-columns: 1fr; }
  .footer-nav ul { flex-direction: column; gap: 0.75rem; }
}