:root {
  --paper: #f7f3ea;
  --paper-strong: #ece2d2;
  --ink: #16130e;
  --muted: #665d50;
  --line: rgba(22, 19, 14, 0.16);
  --red: #a8322d;
  --green: #2f5a48;
  --gold: #b47a27;
  --blue: #244b5d;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Noto Serif SC", "Songti SC", "Microsoft YaHei", serif;
}

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

.site-header {
  position: fixed;
  z-index: 30;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px clamp(18px, 4vw, 52px);
  color: white;
  background: linear-gradient(180deg, rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0));
}

.brand,
.site-header nav {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand {
  font-weight: 800;
  letter-spacing: 0.08em;
}

.brand-mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.65);
  background: rgba(255, 255, 255, 0.12);
}

.site-header nav a {
  font-size: 14px;
  opacity: 0.88;
}

.home-hero {
  display: none;
  min-height: 78vh;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 360px);
  align-items: end;
  gap: clamp(28px, 6vw, 90px);
  padding: 140px clamp(22px, 7vw, 96px) 70px;
  color: white;
  background:
    linear-gradient(90deg, rgba(0, 0, 0, 0.72), rgba(0, 0, 0, 0.2)),
    linear-gradient(180deg, rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0.74)),
    url("https://bonus-track.net/wp-content/uploads/2020/05/li_5-scaled.jpg") center/cover;
}

.hero-panel {
  max-width: 1030px;
}

.eyebrow,
.section-kicker,
.back-link,
.case-accent {
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  font-weight: 800;
}

.eyebrow,
.case-accent {
  color: #f2cf87;
}

.home-hero h1,
.hero-copy h1 {
  margin: 0;
  max-width: 9.6em;
  font-size: clamp(46px, 8vw, 108px);
  line-height: 0.98;
  letter-spacing: 0;
}

.home-hero p,
.hero-copy span {
  display: block;
  max-width: 860px;
  margin-top: 28px;
  font-size: clamp(18px, 1.8vw, 24px);
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.86);
}

.hero-index {
  padding: 28px;
  border-left: 3px solid #f2cf87;
  background: rgba(0, 0, 0, 0.22);
  backdrop-filter: blur(10px);
}

.hero-index strong {
  display: block;
  font-size: clamp(34px, 4vw, 58px);
  line-height: 1;
  color: #f2cf87;
}

.hero-index span {
  display: block;
  margin-top: 18px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.78);
}

.case-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  grid-auto-rows: minmax(430px, 50vh);
  min-height: 100vh;
  gap: 1px;
  background: var(--ink);
}

.case-card {
  position: relative;
  min-height: 430px;
  overflow: hidden;
  display: grid;
  grid-template-rows: auto 1fr auto minmax(72px, auto) auto;
  align-items: end;
  padding: 28px;
  color: white;
  isolation: isolate;
}

.case-card:nth-child(-n + 5) {
  padding-top: 86px;
}

.case-card img,
.project-hero > img {
  position: absolute;
  inset: 0;
  z-index: -2;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.03);
  transition: transform 700ms ease, filter 700ms ease;
}

.case-card::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(180deg, rgba(0, 0, 0, 0.02), rgba(0, 0, 0, 0.82)),
    linear-gradient(90deg, rgba(0, 0, 0, 0.36), rgba(0, 0, 0, 0));
}

.case-card:hover img {
  transform: scale(1.09);
  filter: saturate(1.08) contrast(1.05);
}

.case-number {
  align-self: start;
  color: rgba(255, 255, 255, 0.72);
  font-weight: 800;
}

.case-accent {
  align-self: end;
  min-height: 18px;
}

.case-card h2 {
  margin: 14px 0 12px;
  font-size: clamp(30px, 2.8vw, 54px);
  line-height: 1.02;
  min-height: 3.12em;
  display: flex;
  align-items: flex-start;
}

.case-card p {
  margin: 0;
  line-height: 1.55;
  color: rgba(255, 255, 255, 0.82);
  min-height: 4.65em;
}

.case-card small {
  width: fit-content;
  margin-top: 22px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.62);
  padding-bottom: 7px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 13px;
}

.project-hero {
  position: relative;
  min-height: 88vh;
  display: grid;
  align-items: end;
  color: white;
  background: #111;
  overflow: hidden;
}

.project-hero > img {
  opacity: 0.78;
}

.project-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(0, 0, 0, 0.72), rgba(0, 0, 0, 0.12)),
    linear-gradient(180deg, rgba(0, 0, 0, 0.16), rgba(0, 0, 0, 0.72));
}

.project-cover-visual {
  position: absolute;
  z-index: 2;
  top: 118px;
  right: clamp(22px, 7vw, 96px);
  width: min(34vw, 520px);
  margin: 0;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.26);
  background: rgba(255, 255, 255, 0.08);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.36);
}

.project-cover-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-copy {
  position: relative;
  z-index: 2;
  max-width: 1040px;
  padding: 130px clamp(22px, 7vw, 96px) 80px;
}

.back-link {
  display: inline-block;
  margin-bottom: 42px;
  color: rgba(255, 255, 255, 0.76);
}

.hero-copy p {
  margin: 0 0 18px;
  color: #f1d493;
  font-size: 15px;
  letter-spacing: 0.18em;
}

.metric-band {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-bottom: 1px solid var(--line);
  background: var(--ink);
  color: white;
}

.metric-band div {
  min-height: 190px;
  padding: 34px;
  border-right: 1px solid rgba(255, 255, 255, 0.14);
}

.metric-band strong {
  display: block;
  color: #f4d99d;
  font-size: 22px;
}

.metric-band span {
  display: block;
  margin-top: 16px;
  color: rgba(255, 255, 255, 0.76);
  line-height: 1.65;
}

.story-section,
.timeline-section,
.link-section,
.consult-section {
  padding: clamp(64px, 9vw, 120px) clamp(22px, 7vw, 96px);
}

.story-section {
  max-width: 1220px;
}

.section-kicker {
  color: var(--red);
}

h2 {
  margin: 14px 0 24px;
  font-size: clamp(30px, 4vw, 58px);
  line-height: 1.08;
  letter-spacing: 0;
}

.story-section p,
.link-section p,
.consult-section p {
  max-width: 920px;
  font-size: clamp(18px, 1.7vw, 23px);
  line-height: 1.9;
  color: var(--muted);
}

.detail-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(36px, 6vw, 86px);
  padding: clamp(70px, 10vw, 130px) clamp(22px, 7vw, 96px);
  background: var(--paper-strong);
}

.partner-list,
.timeline,
.link-grid {
  margin: 0;
  padding: 0;
  list-style: none;
}

.partner-list li {
  display: grid;
  grid-template-columns: minmax(180px, 0.45fr) minmax(0, 1fr);
  gap: 18px;
  padding: 22px 0;
  border-top: 1px solid var(--line);
}

.partner-list a {
  color: var(--green);
  font-size: 20px;
  font-weight: 800;
  text-decoration: underline;
  text-underline-offset: 5px;
}

.partner-list span {
  color: var(--muted);
  line-height: 1.7;
}

.timeline-section {
  background: #fffaf0;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.timeline div {
  min-height: 250px;
  padding: 30px;
  background: #fffaf0;
}

.timeline span {
  display: inline-grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border: 1px solid var(--line);
  color: var(--red);
  font-weight: 800;
}

.timeline p {
  margin: 30px 0 0;
  font-size: 17px;
  line-height: 1.75;
  color: var(--muted);
}

.link-section {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(320px, 1fr);
  gap: clamp(36px, 6vw, 90px);
  background: var(--ink);
  color: white;
}

.link-section .section-kicker {
  color: #f4d99d;
}

.link-section p {
  color: rgba(255, 255, 255, 0.75);
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.text-link {
  display: flex;
  min-height: 68px;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  padding: 18px 20px;
  background: rgba(255, 255, 255, 0.06);
  color: white;
  line-height: 1.45;
}

.text-link::after {
  content: "↗";
  color: #f4d99d;
}

.consult-section {
  display: block;
  background: var(--green);
  color: white;
}

.consult-section .section-kicker,
.consult-section p {
  color: rgba(255, 255, 255, 0.78);
}

.copyright-section {
  padding: 24px clamp(22px, 7vw, 96px);
  background: #0f0e0b;
  color: rgba(255, 255, 255, 0.7);
}

.copyright-section p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
}

@media (max-width: 1180px) {
  .case-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 900px) {
  .home-hero,
  .detail-grid,
  .link-section,
  .consult-section {
    grid-template-columns: 1fr;
  }

  .metric-band,
  .timeline,
  .link-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .site-header {
    padding: 14px 16px;
  }

  .site-header nav {
    display: none;
  }

  .home-hero {
    min-height: 88vh;
    padding: 112px 20px 44px;
  }

  .case-grid,
  .metric-band,
  .timeline,
  .link-grid {
    grid-template-columns: 1fr;
  }

  .metric-band div {
    min-height: 95px;
    padding: 24px 28px;
  }

  .metric-band span {
    margin-top: 8px;
  }

  .case-card {
    min-height: 360px;
  }

  .hero-copy {
    padding: 22px 20px 56px;
  }

  .project-hero {
    min-height: auto;
    display: block;
    padding-top: 96px;
  }

  .project-hero > img {
    opacity: 0.34;
  }

  .project-cover-visual {
    position: relative;
    top: auto;
    right: auto;
    width: auto;
    margin: 0 20px 24px;
    aspect-ratio: 16 / 10;
  }

  .story-section,
  .timeline-section,
  .link-section,
  .consult-section,
  .detail-grid {
    padding: 54px 20px;
  }

  .partner-list li {
    grid-template-columns: 1fr;
  }
}

.home-hero {
  display: none !important;
}