html { 
  scroll-behavior: smooth;
  scroll-padding-top: 100px;
}
body {
  font-family: "Noto Sans JP", sans-serif;
  font-weight: 500;
  color: #333;
  background-color: #fff;
  overflow-x: hidden;
}

/* Navigation Hover Effect */
.nav-link {
  position: relative;
}
.nav-link::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background-color: #00A801;
  transition: width 0.3s;
}
.nav-link:hover::after {
  width: 100%;
}


/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  transition: background 0.4s, box-shadow 0.4s;
}
.site-header.scrolled {
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.06);
}

/* ===== Hamburger ===== */
.hamburger::before {
  content: "";
  width: 100%;
  height: 100%;
  position: absolute;
  background-color: #00A801;
  top: 0;
  right: 0;
  z-index: -1;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  margin: 6px 0;
  transition: 0.3s;
  border-radius: 2px;
}
.hamburger.active span:nth-child(1){ transform: rotate(45deg) translate(5px,6px); }
.hamburger.active span:nth-child(2){ opacity:0; visibility: hidden; }
.hamburger.active span:nth-child(3){ transform: rotate(-45deg) translate(5px,-6px); }

/* ===== Mobile Nav ===== */
.mobile-nav {
  position: fixed;
  top: 0; right: -100%;
  width: 100%;
  /* max-width: 360px; */
  height: 100vh;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(20px);
  z-index: 999;
  transition: right 0.45s cubic-bezier(0.4,0,0.2,1);
  padding: 100px 40px 40px;
}
.mobile-nav.open { right: 0; }
.mobile-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.3);
  z-index: 998;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s;
}
.mobile-overlay.open { opacity: 1; pointer-events: auto; }

/* ===== Marquee header ===== */
.marquee-track {
  display: flex;
  animation: marquee 30s linear infinite;
  white-space: nowrap;
}
@keyframes marquee {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}
    
/* ===== button ===== */
.btn-arrow-r {
  display: flex;
  flex-flow: row nowrap;
  justify-content: space-between;
  align-items: center;
  margin-left: auto;
}
.btn-arrow-r:after {
  content: "";
  background-image: url(../img/common/icon_arrow.svg);
  display: inline-block;
  background-repeat: no-repeat;
  background-position: center center;
  background-size: contain;
  height: 1.1rem;
  width: 1.1rem;
  margin-left: .5rem;
}

.btn-arrow-rb:after {
  content: "";
  background-image: url(../img/common/icon_arrow.svg);
  display: inline-block;
  background-repeat: no-repeat;
  background-position: center center;
  background-size: contain;
  height: 1.1rem;
  width: 1.1rem;
  margin-left: .5rem;
  transform: rotate(90deg);
}
    
/* ===== to the top ===== */
.to_top {
  position: relative;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}
.to_top:before {
  content: '';
  flex-grow: 1;
  height: 1px; 
  background-color: #BFBFBF;
}

.line:after {
  content: '';
  flex-grow: 1;
  height: 1px; 
  background-color: #333333;
}

/* ==== animation ==== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

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

.delay-1 { transition-delay: 0.2s; }
.delay-2 { transition-delay: 0.4s; }
.delay-3 { transition-delay: 0.6s; }
.delay-4 { transition-delay: 0.8s; }

/* ===== page header ===== */
#page_head:before {
  content: "";
  background-image: url(../img/index/bg-cube-pt1.webp);
  position: absolute;
  display: block;
  background-repeat: no-repeat;
  background-position: right top;
  background-size: contain;
  transform: scaleY(-1) scaleX(-1);
  height: 230px;
  width: 380px;
  top: -20px;
  right: 0;
  z-index: -1;
}
/* w-md size */
  @media(max-width:768px){
  #page_head:before { width: 50vw; height:30vw; }
}
    
/* ===== sidemenu ===== */
.sidemenu .pc-menu:before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 1rem;
  height: 1px;
  background-color: #333;
}

/* ===== background gradient ===== */
.bg_gradient {
  background: #00A801;
  background: linear-gradient(135deg,rgba(0, 168, 1, 1) 0%, rgba(12, 145, 215, 1) 100%);
}


/* ===== check icon ===== */
.check:before {
  content: "";
  background-image: url(../img/common/icon_check.svg);
  display: inline-block;
  background-repeat: no-repeat;
  background-position: center center;
  background-size: contain;
  margin-right: .5rem;
  min-height: .75rem;
  min-width: .75rem;
}


/*
 * page pholosopy
 */
.main_philosophy .big_cube:before {
  content: "";
  background-image: url(../img/index/bg-cube-pt2.webp);
  position: absolute;
  display: block;
  background-repeat: no-repeat;
  background-position: right top;
  background-size: contain;
  height: 200px;
  width: 380px;
  top: 0;
  right: 0;
  z-index: -1;
}

/* w-md size */
  @media(max-width:768px){
  .main_philosophy .big_cube:before { width: 50vw; height:30vw; }
}

/*
 * page works
 */

.main_works #oneday .flow:before {
  content: "";
  position: absolute;
  right: 0;
  top: .5rem;
  width: .5rem;
  height: .5rem;
  background-color: #00A801;
  border-radius: 1rem;
}
.main_works #oneday .flow-line:after {
  content: "";
  position: absolute;
  right: .25rem;
  top: 2rem;
  width: 1px;
  height: calc( 100% - 1rem);
  background-color: #333;
}