:root {
  --bg: oklch(14% 0.008 60);
  --bg-2: oklch(17% 0.01 60);
  --surface: oklch(19.5% 0.012 60);
  --line: oklch(27% 0.012 60);
  --line-strong: oklch(38% 0.015 60);
  --text: oklch(94% 0.012 60);
  --text-2: oklch(78% 0.014 60);
  --text-3: oklch(63% 0.014 60);
  --accent: oklch(74% 0.11 72);
  --accent-strong: oklch(82% 0.09 72);

  --font-display: "Noto Serif SC", "Songti SC", "SimSun", serif;
  --font-body: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;

  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;

  --max: 1240px;
  --gutter: clamp(20px, 5vw, 64px);
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

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

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

button {
  font-family: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

::selection {
  background: var(--accent);
  color: oklch(16% 0.01 60);
}

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

/* ---------- Header ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px var(--gutter);
  transition: background-color 0.4s var(--ease), padding 0.4s var(--ease), border-color 0.4s var(--ease);
  border-bottom: 1px solid transparent;
}

.site-header.is-scrolled {
  background: oklch(14% 0.008 60 / 0.86);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
  padding-block: 12px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.brand__cn {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.brand__en {
  font-size: 0.7rem;
  letter-spacing: 0.28em;
  color: var(--text-3);
}

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

.site-nav a {
  position: relative;
  font-size: 0.95rem;
  color: var(--text-2);
  transition: color 0.25s var(--ease);
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 100%;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.35s var(--ease);
}

.site-nav a:hover {
  color: var(--text);
}

.site-nav a:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

.nav-cta {
  color: var(--text) !important;
  padding: 8px 16px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  transition: border-color 0.25s var(--ease), background-color 0.25s var(--ease) !important;
}

.nav-cta:hover {
  border-color: var(--accent);
  background: oklch(74% 0.11 72 / 0.08);
}

.nav-cta::after {
  display: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 44px;
  height: 44px;
  padding: 10px;
}

.nav-toggle span {
  display: block;
  height: 1.5px;
  width: 100%;
  background: var(--text);
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}

.nav-toggle.is-open span:nth-child(1) {
  transform: translateY(3.75px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
  transform: translateY(-3.75px) rotate(-45deg);
}

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

.hero__img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  transform: scale(1.06);
}

.hero__scrim {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(to top, oklch(14% 0.008 60 / 0.92) 0%, oklch(14% 0.008 60 / 0.35) 45%, oklch(14% 0.008 60 / 0.25) 100%),
    linear-gradient(to right, oklch(14% 0.008 60 / 0.45), transparent 60%);
}

.hero__inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter) clamp(72px, 14vh, 160px);
}

.hero__eyebrow {
  font-size: 0.85rem;
  letter-spacing: 0.32em;
  color: var(--accent-strong);
  margin-bottom: var(--space-lg);
}

.hero__title {
  font-family: var(--font-display);
  font-size: clamp(4rem, 13vw, 10rem);
  font-weight: 600;
  line-height: 1.02;
  letter-spacing: 0.06em;
  margin-left: -0.06em;
}

.hero__lead {
  max-width: 34ch;
  font-size: clamp(1rem, 2vw, 1.25rem);
  line-height: 1.9;
  color: var(--text-2);
  margin-top: var(--space-lg);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-top: var(--space-xl);
}

.hero__scroll {
  position: absolute;
  right: var(--gutter);
  bottom: 48px;
  z-index: 1;
  font-size: 0.72rem;
  letter-spacing: 0.3em;
  color: var(--text-3);
  writing-mode: vertical-rl;
}

.hero__scroll::after {
  content: "";
  display: block;
  width: 1px;
  height: 56px;
  margin-top: 12px;
  background: var(--line-strong);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 28px;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  border-radius: 999px;
  transition: transform 0.25s var(--ease), background-color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.btn--primary {
  background: var(--accent);
  color: oklch(16% 0.01 60);
  font-weight: 500;
}

.btn--primary:hover {
  background: var(--accent-strong);
  transform: translateY(-1px);
}

.btn--ghost {
  border: 1px solid oklch(94% 0.012 60 / 0.4);
  color: var(--text);
}

.btn--ghost:hover {
  border-color: var(--text);
  transform: translateY(-1px);
}

/* ---------- Section shell ---------- */
.work,
.about,
.inquiry {
  padding: var(--space-4xl) var(--gutter);
  max-width: var(--max);
  margin: 0 auto;
}

.section-head {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  margin-bottom: var(--space-2xl);
}

.section-head__index {
  font-size: 0.85rem;
  color: var(--accent);
  letter-spacing: 0.1em;
  padding-top: 8px;
}

.section-head__title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: 0.02em;
}

.section-head__en {
  font-size: 0.8rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-top: var(--space-xs);
}

/* ---------- Filters ---------- */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
  border-bottom: 1px solid var(--line);
  padding-bottom: var(--space-md);
}

.filter {
  padding: 8px 18px;
  font-size: 0.92rem;
  color: var(--text-3);
  border-radius: 999px;
  border: 1px solid transparent;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease), background-color 0.25s var(--ease);
}

.filter:hover {
  color: var(--text);
}

.filter.is-active {
  color: var(--text);
  border-color: var(--line-strong);
  background: var(--surface);
}

/* ---------- Grid ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  grid-auto-flow: dense;
  gap: var(--space-lg);
}

.project {
  grid-column: span 4;
}

.g-span-4 { grid-column: span 4; }
.g-span-5 { grid-column: span 5; }
.g-span-7 { grid-column: span 7; }
.g-span-8 { grid-column: span 8; }

.project.is-hidden {
  display: none;
}

.project__media {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border-radius: 2px;
  background: var(--bg-2);
}

.r-34 .project__media { aspect-ratio: 3 / 4; }
.r-169 .project__media { aspect-ratio: 16 / 9; }
.r-1610 .project__media { aspect-ratio: 16 / 10; }

.project__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.9s var(--ease), filter 0.9s var(--ease);
  filter: saturate(0.94) brightness(0.92);
}

.project__media:hover img {
  transform: scale(1.05);
  filter: saturate(1) brightness(1);
}

.project__meta {
  padding-top: var(--space-md);
}

.project__cat {
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  color: var(--accent);
  text-transform: uppercase;
}

.project__title {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 600;
  line-height: 1.35;
  margin-top: 6px;
}

.project__en {
  font-size: 0.85rem;
  color: var(--text-3);
  margin-top: 2px;
}

.project__date {
  font-size: 0.78rem;
  color: var(--text-3);
  margin-top: 10px;
}

.work__note {
  margin-top: var(--space-xl);
  font-size: 0.85rem;
  color: var(--text-3);
  text-align: center;
}

/* ---------- About ---------- */
.about__inner {
  border-top: 1px solid var(--line);
  padding-top: var(--space-2xl);
}

.about__body {
  max-width: 880px;
  margin-left: auto;
}

.about__lead {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 600;
  line-height: 1.6;
}

.about__text {
  color: var(--text-2);
  margin-top: var(--space-lg);
  max-width: 62ch;
}

.about__list {
  list-style: none;
  margin-top: var(--space-2xl);
  display: grid;
  gap: 0;
}

.about__list li {
  display: flex;
  align-items: baseline;
  gap: var(--space-lg);
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--line);
  font-size: 1rem;
}

.about__list span {
  font-size: 0.8rem;
  color: var(--accent);
  letter-spacing: 0.1em;
}

/* ---------- Inquiry ---------- */
.inquiry__lead {
  color: var(--text-2);
  max-width: 60ch;
  margin-bottom: var(--space-2xl);
}

.inquiry__layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: var(--space-3xl);
  align-items: start;
}

.inquiry__form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
}

.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.field--full {
  grid-column: 1 / -1;
}

.field label {
  font-size: 0.85rem;
  color: var(--text-2);
}

.field input,
.field select,
.field textarea {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 2px;
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
  padding: 12px 14px;
  transition: border-color 0.25s var(--ease);
}

.field textarea {
  resize: vertical;
  min-height: 100px;
}

.field input::placeholder,
.field textarea::placeholder {
  color: var(--text-3);
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.form-status {
  font-size: 0.9rem;
  color: var(--accent-strong);
}

.inquiry__aside {
  position: sticky;
  top: 100px;
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: var(--space-lg);
  background: var(--bg-2);
}

.inquiry__aside h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
}

.aside-email {
  display: inline-block;
  margin-top: var(--space-md);
  color: var(--accent-strong);
  font-size: 0.95rem;
  border-bottom: 1px solid oklch(74% 0.11 72 / 0.4);
  padding-bottom: 2px;
}

.aside-meta {
  margin-top: var(--space-lg);
  display: grid;
  gap: var(--space-md);
}

.aside-meta div {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.aside-meta dt {
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--text-3);
}

.aside-meta dd {
  font-size: 0.95rem;
  color: var(--text-2);
}

/* ---------- Footer ---------- */
.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
  max-width: var(--max);
  margin: 0 auto;
  padding: var(--space-2xl) var(--gutter) var(--space-2xl);
  border-top: 1px solid var(--line);
  color: var(--text-3);
  font-size: 0.85rem;
}

.site-footer a {
  color: var(--text-2);
  transition: color 0.25s var(--ease);
}

.site-footer a:hover {
  color: var(--accent-strong);
}

/* ---------- Lightbox ---------- */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 60;
  background: oklch(12% 0.008 60 / 0.98);
  display: grid;
  grid-template-columns: 1fr;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.35s var(--ease), visibility 0.35s var(--ease);
}

.lightbox.is-open {
  opacity: 1;
  visibility: visible;
}

.lightbox__figure {
  display: grid;
  grid-template-columns: 1fr 360px;
  grid-template-rows: 1fr;
  height: 100%;
}

.lightbox__img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: clamp(40px, 6vw, 96px) clamp(40px, 6vw, 96px) 72px;
}

.lightbox__caption {
  align-self: end;
  padding: var(--space-2xl) var(--space-xl) var(--space-2xl) var(--space-xl);
  border-left: 1px solid var(--line);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.lightbox__cat {
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  color: var(--accent);
}

.lightbox__caption h3 {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 600;
  line-height: 1.3;
}

.lightbox__en {
  color: var(--text-3);
  font-size: 0.9rem;
}

.lightbox__meta {
  color: var(--text-3);
  font-size: 0.8rem;
}

.lightbox__desc {
  color: var(--text-2);
  margin-top: var(--space-sm);
  max-width: 40ch;
}

.lightbox__close {
  position: absolute;
  top: 16px;
  right: 20px;
  z-index: 2;
  width: 48px;
  height: 48px;
  font-size: 2.2rem;
  line-height: 1;
  color: var(--text-2);
  transition: color 0.25s var(--ease);
}

.lightbox__close:hover {
  color: var(--text);
}

.lightbox__nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 2;
  width: 56px;
  height: 56px;
  font-size: 2.4rem;
  line-height: 1;
  color: var(--text-2);
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: oklch(14% 0.008 60 / 0.5);
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

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

.lightbox__nav--prev { left: 20px; }
.lightbox__nav--next { right: 20px; }

.lightbox__count {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  color: var(--text-3);
}

/* ---------- Reveal (fail-open: hidden only when JS present) ---------- */
.js .reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.js .reveal.in-view {
  opacity: 1;
  transform: none;
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .grid {
    grid-template-columns: repeat(6, 1fr);
  }

  .g-span-4, .g-span-5, .g-span-7, .g-span-8 {
    grid-column: span 3;
  }

  .inquiry__layout {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .inquiry__aside {
    position: static;
  }

  .lightbox__figure {
    grid-template-columns: 1fr;
    grid-template-rows: 1fr auto;
  }

  .lightbox__img {
    padding: 64px 40px 16px;
  }

  .lightbox__caption {
    border-left: none;
    border-top: 1px solid var(--line);
    padding: var(--space-lg) var(--gutter) var(--space-3xl);
    max-height: 42vh;
  }
}

@media (max-width: 640px) {
  .site-nav {
    position: fixed;
    inset: 0;
    z-index: -1;
    flex-direction: column;
    justify-content: center;
    gap: 32px;
    background: oklch(14% 0.008 60 / 0.98);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s var(--ease), visibility 0.3s var(--ease);
  }

  .site-nav.is-open {
    opacity: 1;
    visibility: visible;
  }

  .site-nav a {
    font-size: 1.4rem;
    color: var(--text);
  }

  .nav-cta {
    font-size: 1rem !important;
  }

  .nav-toggle {
    display: flex;
    position: relative;
    z-index: 2;
  }

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

  .g-span-4, .g-span-5, .g-span-7, .g-span-8 {
    grid-column: span 1;
  }

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

  .hero__scroll {
    display: none;
  }

  .lightbox__nav {
    top: auto;
    bottom: 20px;
    transform: none;
  }

  .lightbox__nav--prev { left: 20px; }
  .lightbox__nav--next { right: 20px; }

  .lightbox__count {
    bottom: 38px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .js .reveal {
    opacity: 1;
    transform: none;
  }

  .hero__img {
    transform: none;
  }
}