/* ===========================
   ZIU Co., Ltd. — Monotone Modern
   =========================== */

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --black:       #0f0f0f;
  --dark:        #181818;
  --charcoal:    #2d2d2d;
  --mid:         #555555;
  --gray:        #888888;
  --silver:      #bbbbbb;
  --off-white:   #f2efe9;
  --white:       #ffffff;
  --border-dark: rgba(255,255,255,.12);
  --border-light:#d8d4cc;
  --transition:  .3s ease;
  --radius:      4px;
  --max-w:       1120px;

  /* Checker pattern */
  --checker-size: 18px;
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', sans-serif;
  color: var(--black);
  background: var(--off-white);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: opacity var(--transition); }
ul { list-style: none; }

.container { max-width: var(--max-w); margin: 0 auto; padding: 0 28px; }
.section { padding: 100px 0; }

/* === Checker Pattern === */
.checker-strip,
.checker-strip-top,
.checker-footer {
  height: var(--checker-size);
  background-image:
    linear-gradient(45deg, var(--white) 25%, transparent 25%),
    linear-gradient(-45deg, var(--white) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, var(--white) 75%),
    linear-gradient(-45deg, transparent 75%, var(--white) 75%);
  background-size: var(--checker-size) var(--checker-size);
  background-position: 0 0, 0 calc(var(--checker-size)/2), calc(var(--checker-size)/2) calc(-1 * var(--checker-size)/2), calc(-1 * var(--checker-size)/2) 0;
  background-color: var(--charcoal);
}

.checker-strip-top {
  background-color: var(--off-white);
  background-image:
    linear-gradient(45deg, var(--charcoal) 25%, transparent 25%),
    linear-gradient(-45deg, var(--charcoal) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, var(--charcoal) 75%),
    linear-gradient(-45deg, transparent 75%, var(--charcoal) 75%);
}

.checker-footer {
  margin: 32px 0 0;
  background-color: var(--charcoal);
  opacity: .5;
}

/* === Header === */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: transparent;
  padding: 16px 0;
  transition: background var(--transition), padding var(--transition);
}

.site-header.scrolled {
  background: rgba(15, 15, 15, .95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-dark);
  padding: 10px 0;
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-emblem {
  width: 38px;
  height: 38px;
  object-fit: contain;
  border-radius: 2px;
}

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

.logo-jp {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--white);
  line-height: 1.1;
}

.logo-en {
  font-size: .62rem;
  letter-spacing: .12em;
  color: rgba(255,255,255,.55);
  line-height: 1;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-links a {
  color: rgba(255,255,255,.8);
  font-size: .85rem;
  font-weight: 500;
  letter-spacing: .1em;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0; right: 0;
  height: 1px;
  background: var(--white);
  transform: scaleX(0);
  transition: transform var(--transition);
}

.nav-links a:hover::after { transform: scaleX(1); }

.nav-cta {
  border: 1px solid rgba(255,255,255,.6) !important;
  padding: 7px 20px !important;
  border-radius: 2px !important;
  color: var(--white) !important;
}
.nav-cta::after { display: none !important; }
.nav-cta:hover { background: rgba(255,255,255,.1) !important; }

.nav-toggle { display: none; }

/* === Hero === */
.hero {
  background: var(--black);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  text-align: center;
  overflow: hidden;
}

/* subtle noise texture */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  opacity: .4;
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 2;
  padding: 120px 28px 80px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
}

.hero-logo {
  width: min(260px, 50vw);
  height: auto;
  margin-bottom: 32px;
  filter: brightness(1);
}

.hero-label {
  font-size: .72rem;
  letter-spacing: .22em;
  color: var(--silver);
  margin-bottom: 20px;
}

.hero-catch {
  font-family: 'Noto Serif JP', serif;
  font-size: clamp(1.9rem, 5vw, 3.2rem);
  font-weight: 700;
  color: var(--white);
  line-height: 1.6;
  letter-spacing: .08em;
  margin-bottom: 16px;
}

.hero-sub {
  font-family: 'Noto Serif JP', serif;
  font-size: clamp(.95rem, 2vw, 1.15rem);
  color: var(--silver);
  letter-spacing: .12em;
  margin-bottom: 44px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 13px 32px;
  border-radius: 2px;
  font-size: .85rem;
  font-weight: 700;
  letter-spacing: .1em;
  transition: all var(--transition);
  border: 1px solid transparent;
}

.btn-white {
  background: var(--white);
  color: var(--black);
  border-color: var(--white);
}
.btn-white:hover { background: var(--off-white); }

.btn-outline {
  background: transparent;
  border-color: rgba(255,255,255,.5);
  color: var(--white);
}
.btn-outline:hover { background: rgba(255,255,255,.08); border-color: var(--white); }

.checker-strip {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  z-index: 2;
}

.hero-scroll {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  width: 28px;
  height: 46px;
  border: 1px solid rgba(255,255,255,.3);
  border-radius: 100px;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 8px;
}

.hero-scroll span {
  display: block;
  width: 5px; height: 5px;
  background: var(--white);
  border-radius: 50%;
  animation: scroll-dot 2s ease-in-out infinite;
}

@keyframes scroll-dot {
  0%   { opacity: 0; transform: translateY(0); }
  50%  { opacity: 1; }
  100% { opacity: 0; transform: translateY(18px); }
}

/* === Section Labels === */
.section-eyebrow {
  font-size: .65rem;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--mid);
  margin-bottom: 10px;
}

.section-title {
  font-family: 'Noto Serif JP', serif;
  font-size: clamp(1.55rem, 3vw, 2.1rem);
  font-weight: 700;
  color: var(--black);
  margin-bottom: 52px;
  letter-spacing: .06em;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--black);
  display: inline-block;
}

.section-desc {
  color: var(--mid);
  margin-top: -36px;
  margin-bottom: 48px;
  font-size: .9rem;
  display: block;
}

/* === Concept === */
.concept {
  background: var(--white);
}

.concept-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
  margin-top: 8px;
}

.concept-lead {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.1rem;
  color: var(--black);
  line-height: 2;
  margin-bottom: 24px;
  font-weight: 600;
}

.concept-text p:last-child {
  color: var(--mid);
  font-size: .9rem;
  line-height: 2;
}

.concept-cards {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.concept-card {
  border: 1px solid var(--border-light);
  border-top: 3px solid var(--black);
  padding: 24px 24px 24px 20px;
  display: grid;
  grid-template-columns: 36px 1fr;
  grid-template-rows: auto auto;
  gap: 2px 16px;
  background: var(--off-white);
  transition: background var(--transition);
}

.concept-card:hover { background: var(--white); }

.concept-card-num {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--charcoal);
  grid-row: 1 / 3;
  align-self: center;
  text-align: center;
  opacity: .4;
}

.concept-card h3 {
  font-size: .92rem;
  font-weight: 700;
  color: var(--black);
  letter-spacing: .04em;
}

.concept-card p {
  font-size: .83rem;
  color: var(--mid);
  line-height: 1.7;
}

/* === Services === */
.services {
  background: var(--dark);
}

.services .section-eyebrow { color: var(--gray); }
.services .section-title { color: var(--white); border-bottom-color: var(--white); }
.services .section-desc { color: var(--gray); }

.service-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--charcoal);
  border: 1px solid var(--charcoal);
}

.service-card {
  background: var(--dark);
  padding: 40px 36px;
  transition: background var(--transition);
}

.service-card:hover { background: var(--charcoal); }

.service-num {
  font-family: 'Noto Serif JP', serif;
  font-size: 2rem;
  font-weight: 700;
  color: rgba(255,255,255,.08);
  letter-spacing: .05em;
  margin-bottom: 12px;
  line-height: 1;
}

.service-card h3 {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 10px;
  letter-spacing: .04em;
  line-height: 1.5;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-dark);
}

.service-tag {
  display: inline-block;
  border: 1px solid var(--gray);
  color: var(--silver);
  font-size: .68rem;
  letter-spacing: .1em;
  padding: 3px 10px;
  margin-bottom: 12px;
}

.service-card > p:not(.service-tag) {
  color: var(--gray);
  font-size: .87rem;
  margin-bottom: 16px;
}

.service-card ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.service-card ul li {
  font-size: .85rem;
  color: var(--silver);
  padding-left: 14px;
  position: relative;
  line-height: 1.7;
}

.service-card ul li::before {
  content: '';
  position: absolute;
  left: 0; top: .7em;
  width: 5px; height: 1px;
  background: var(--gray);
}

.service-card ul li small {
  display: block;
  font-size: .78rem;
  color: var(--mid);
  margin-top: 2px;
}

/* === Company === */
.company {
  background: var(--off-white);
}

.company-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.company-table {
  width: 100%;
  border-collapse: collapse;
}

.company-table tr {
  border-bottom: 1px solid var(--border-light);
}

.company-table th,
.company-table td {
  padding: 16px 12px;
  text-align: left;
  font-size: .88rem;
  vertical-align: top;
}

.company-table th {
  width: 130px;
  color: var(--black);
  font-weight: 700;
  white-space: nowrap;
  letter-spacing: .04em;
}

.company-table td {
  color: var(--mid);
  line-height: 1.9;
}

.company-table td a {
  color: var(--black);
  border-bottom: 1px solid var(--border-light);
  transition: border-color var(--transition);
}

.company-table td a:hover { border-color: var(--black); }

.company-map {
  overflow: hidden;
  border: 1px solid var(--border-light);
  filter: grayscale(100%);
  transition: filter var(--transition);
}

.company-map:hover { filter: grayscale(30%); }
.company-map iframe { display: block; }

/* === Contact === */
.contact {
  background: var(--black);
  position: relative;
}

.contact .section-eyebrow { color: var(--gray); }
.contact .section-title { color: var(--white); border-bottom-color: var(--white); }

.contact-desc {
  color: var(--gray);
  margin-top: -36px;
  margin-bottom: 48px;
  font-size: .9rem;
  line-height: 2;
  display: block;
}

.contact-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  background: var(--charcoal);
  border: 1px solid var(--charcoal);
}

.contact-card {
  background: var(--dark);
  padding: 44px 40px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: background var(--transition);
  cursor: pointer;
}

.contact-card:hover { background: var(--charcoal); }

.contact-card-label {
  font-size: .65rem;
  letter-spacing: .28em;
  color: var(--gray);
  font-weight: 700;
}

.contact-card-value {
  font-family: 'Noto Serif JP', serif;
  font-size: clamp(1rem, 2.5vw, 1.4rem);
  font-weight: 700;
  color: var(--white);
  letter-spacing: .04em;
  word-break: break-all;
  line-height: 1.4;
}

.contact-card-note {
  font-size: .75rem;
  color: var(--mid);
}

/* === Footer === */
.site-footer {
  background: var(--black);
  border-top: 1px solid var(--charcoal);
  padding: 48px 0 28px;
  color: var(--gray);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding-bottom: 0;
  flex-wrap: wrap;
}

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

.footer-logo {
  width: 44px;
  height: 44px;
  object-fit: contain;
}

.footer-name {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 4px;
}

.footer-name .logo-jp {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--white);
}

.footer-name .logo-en {
  font-size: .62rem;
  letter-spacing: .1em;
  color: var(--mid);
}

.footer-brand p {
  font-size: .78rem;
  color: var(--mid);
}

.footer-nav {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
}

.footer-nav a {
  font-size: .8rem;
  letter-spacing: .06em;
  color: var(--gray);
  transition: color var(--transition);
}

.footer-nav a:hover { color: var(--white); }

.footer-bottom {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--charcoal);
  text-align: center;
  font-size: .72rem;
  color: var(--mid);
  letter-spacing: .06em;
}

/* === Fade-in === */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .65s ease, transform .65s ease;
}

.fade-in.visible { opacity: 1; transform: translateY(0); }

.service-card.fade-in:nth-child(2) { transition-delay: .08s; }
.service-card.fade-in:nth-child(3) { transition-delay: .16s; }
.service-card.fade-in:nth-child(4) { transition-delay: .24s; }
.concept-card.fade-in:nth-child(2) { transition-delay: .08s; }
.concept-card.fade-in:nth-child(3) { transition-delay: .16s; }
.contact-card.fade-in:nth-child(2) { transition-delay: .08s; }

/* === Responsive === */
@media (max-width: 860px) {
  .concept-body,
  .company-inner,
  .contact-cards { grid-template-columns: 1fr; }

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

@media (max-width: 600px) {
  .section { padding: 72px 0; }

  .nav-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 101;
  }

  .nav-toggle span {
    display: block;
    width: 24px; height: 2px;
    background: var(--white);
    border-radius: 1px;
    transition: all .3s;
  }

  .nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle.open span:nth-child(2) { opacity: 0; }
  .nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .nav-links {
    position: fixed;
    inset: 0;
    background: var(--black);
    flex-direction: column;
    justify-content: center;
    gap: 40px;
    opacity: 0;
    pointer-events: none;
    transition: opacity .3s;
  }

  .nav-links.open { opacity: 1; pointer-events: auto; }
  .nav-links a { font-size: 1.1rem; }

  .hero-catch { letter-spacing: .04em; }
  .hero-actions { flex-direction: column; align-items: center; }

  .service-card { padding: 32px 24px; }
  .contact-card { padding: 32px 24px; }

  .footer-inner { flex-direction: column; align-items: flex-start; }
  .footer-nav { gap: 16px; }

  .company-table th { width: 90px; font-size: .82rem; }
  .company-table td { font-size: .82rem; }
}