:root {
  --cream: #f7f3ee;
  --terracotta: #c4714a;
  --terra-light: #f0ddd0;
  --moss: #4a5e3a;
  --moss-light: #e8ede3;
  --brown: #3d2b1f;
  --gray: #7a7169;
  --white: #fff;
  --font-serif: 'Noto Serif JP', serif;
  --font-sans: 'Noto Sans JP', sans-serif;
  --sidebar-w: 220px;
}

body {
  background: var(--cream);
  color: var(--brown);
  font-family: var(--font-sans);
  font-weight: 300;
  line-height: 1.8;
}

/* ============================
   SIDEBAR NAV
============================ */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  background: var(--brown);
  color: var(--cream);
  display: flex;
  flex-direction: column;
  padding: 2.5rem 1.75rem;
  z-index: 100;
  transition: transform .3s ease;
}
.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  letter-spacing: .12em;
  color: var(--cream);
  margin-bottom: .4rem;
}
.nav-logo span {
  display: block;
  font-size: .65rem;
  letter-spacing: .2em;
  color: var(--terra-light);
  margin-top: 2px;
}
.nav-divider {
  width: 32px;
  height: 1px;
  background: var(--terracotta);
  margin: 1.25rem 0;
}
.nav-links {
  display: flex;
  flex-direction: column;
  gap: .1rem;
  flex: 1;
}
.nav-links a {
  font-size: .8rem;
  letter-spacing: .15em;
  padding: .6rem 0;
  border-bottom: 1px solid rgba(247,243,238,.08);
  color: rgba(247,243,238,.7);
  transition: color .2s, padding-left .2s;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--terra-light);
}
.nav-links a:hover {
  padding-left: .5rem;
}
.nav-links a span {
  display: block;
  font-size: .6rem;
  letter-spacing: .08em;
  color: rgba(247,243,238,.35);
  margin-top: 1px;
}
.nav-sns {
  display: flex;
  gap: 12px;
  margin-top: 1.5rem;
}
.nav-sns-item {
  width: 30px;
  height: 30px;
  border: 1px solid rgba(247,243,238,.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .65rem;
  color: rgba(247,243,238,.5);
  cursor: default;
}

/* ============================
   HAMBURGER
============================ */
.ham-btn {
  display: none;
  position: fixed;
  top: 1rem;
  right: 1rem;
  z-index: 200;
  width: 44px;
  height: 44px;
  background: var(--brown);
  border: none;
  cursor: pointer;
  border-radius: 4px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}
.ham-btn span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--cream);
  transition: transform .3s, opacity .3s;
}
.ham-btn.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.ham-btn.open span:nth-child(2) { opacity: 0; }
.ham-btn.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.5);
  z-index: 90;
}

/* ============================
   LAYOUT
============================ */
.main-wrap {
  margin-left: var(--sidebar-w);
  min-height: 100vh;
}

/* ============================
   COMMON PARTS
============================ */
.btn-primary {
  display: inline-block;
  padding: .75rem 2rem;
  background: var(--terracotta);
  color: var(--white);
  font-size: .8rem;
  letter-spacing: .15em;
  border-radius: 2px;
  transition: background .2s, transform .2s;
}
.btn-primary:hover {
  background: #b5613c;
  transform: translateY(-2px);
}

.slant {
  height: 60px;
  background: var(--white);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
}
.slant.reverse {
  clip-path: polygon(0 0, 100% 100%, 0 100%);
  background: var(--cream);
}
.slant-brown {
  height: 48px;
  background: var(--cream);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
}

.section-label {
  font-size: .65rem;
  letter-spacing: .3em;
  color: var(--terracotta);
  margin-bottom: .75rem;
}
.section-heading {
  font-family: var(--font-serif);
  font-size: clamp(1.4rem, 2.5vw, 2rem);
  font-weight: 300;
  line-height: 1.5;
  margin-bottom: 2.5rem;
}

/* ============================
   FOOTER
============================ */
footer {
  background: var(--brown);
  color: rgba(247,243,238,.5);
  text-align: center;
  padding: 2rem;
  font-size: .7rem;
  letter-spacing: .1em;
}

/* ============================
   RESPONSIVE
============================ */
@media (max-width: 768px) {
  :root { --sidebar-w: 0px; }
  .site-nav {
    transform: translateX(-260px);
    width: 260px;
  }
  .site-nav.open { transform: translateX(0); }
  .ham-btn { display: flex; }
  .nav-overlay.open { display: block; }
  .main-wrap { margin-left: 0; }
}