/* ----- CSS Variables (Design System) ----- */
:root {
  --color-primary: #5c7c50; /* アースグリーン */
  --color-primary-dark: #3e5a33;
  --color-accent: #d2a65f; /* バガス由来の暖かみのあるイエローブラウン */
  --color-text: #333333;
  --color-text-light: #666666;
  --color-bg-light: #f9f7f0; /* ナチュラルなオフホワイト */
  --color-white: #ffffff;
  
  --font-base: 'Noto Sans JP', 'Inter', sans-serif;
  --font-heading: 'Noto Sans JP', serif;
  
  --spacing-sm: 0.5rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 3rem;
  --spacing-xl: 6rem;
  
  --radius: 8px;
  --transition: all 0.3s ease;
}

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

body {
  font-family: var(--font-base);
  color: var(--color-text);
  line-height: 1.6;
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
}

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

ul {
  list-style: none;
}

img {
  max-width: 100%;
  border-radius: var(--radius);
  display: block;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 5%;
}

.text-center { text-align: center; }

/* ----- Buttons ----- */
.btn {
  display: inline-block;
  padding: 0.8rem 1.8rem;
  border-radius: 30px;
  font-weight: 500;
  transition: var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  box-shadow: 0 4px 12px rgba(92, 124, 80, 0.3);
  transform: translateY(-2px);
}

.btn-outline {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: transparent;
}

.btn-outline:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.btn-lg {
  padding: 1rem 2.5rem;
  font-size: 1.1rem;
}

/* ----- Header ----- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: 1rem 0;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  box-shadow: 0 2px 15px rgba(0,0,0,0.05);
  transition: var(--transition);
}

.header.scrolled {
  padding: 0.5rem 0;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 1px;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-list a:not(.btn) {
  position: relative;
  font-weight: 500;
  color: var(--color-text);
  transition: color 0.3s;
}

.nav-list a:not(.btn):hover {
  color: var(--color-primary);
}

.nav-list a:not(.btn)::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0%;
  height: 2px;
  background-color: var(--color-primary);
  transition: width 0.3s;
}

.nav-list a:not(.btn):hover::after {
  width: 100%;
}

/* ----- Hero Section ----- */
.hero {
  position: relative;
  height: 100vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: linear-gradient(rgba(0,0,0,0.4), rgba(0,0,0,0.2)), url('../images/bagasse_hero_bg_1773284068709.png');
  background-size: cover;
  background-position: center;
  z-index: -1;
  transform: scale(1.05);
  animation: slowZoom 20s infinite alternate;
}

.hero-content {
  color: var(--color-white);
  padding-top: 80px;
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  line-height: 1.2;
  margin-bottom: 1.5rem;
  font-weight: 700;
  text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.highlight {
  color: var(--color-accent);
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  margin-bottom: 2.5rem;
  line-height: 1.8;
  max-width: 600px;
  text-shadow: 0 2px 5px rgba(0,0,0,0.5);
}

/* ----- Sections Common ----- */
.section {
  padding: var(--spacing-xl) 0;
}

.bg-light {
  background-color: var(--color-bg-light);
}

.section-tag {
  display: inline-block;
  color: var(--color-primary);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  color: var(--color-text);
}

.section-desc {
  font-size: 1.1rem;
  color: var(--color-text-light);
  margin-bottom: var(--spacing-lg);
}

/* ----- About Section ----- */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.image-wrapper {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.image-wrapper img {
  transition: transform 0.5s ease;
}

.image-wrapper:hover img {
  transform: scale(1.05);
}

/* ----- Benefits Section ----- */
.benefits-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.benefit-card {
  background: var(--color-white);
  padding: 2.5rem 2rem;
  border-radius: var(--radius);
  box-shadow: 0 10px 30px rgba(0,0,0,0.05);
  text-align: center;
  transition: var(--transition);
}

.benefit-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 40px rgba(0,0,0,0.1);
}

.icon-circle {
  width: 80px;
  height: 80px;
  background-color: var(--color-bg-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin: 0 auto 1.5rem;
  color: var(--color-primary);
}

.benefit-card h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
}

.benefit-card p {
  color: var(--color-text-light);
  font-size: 0.95rem;
}

/* ----- CTA Section ----- */
.cta {
  padding: 5rem 0;
  background-color: var(--color-primary);
  color: var(--color-white);
  position: relative;
  overflow: hidden;
}

.cta::before {
  content: '';
  position: absolute;
  top: -50px;
  right: -50px;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: rgba(255,255,255,0.1);
}

.cta-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.cta-desc {
  font-size: 1.1rem;
  opacity: 0.9;
  margin-bottom: 2rem;
}

.cta .btn-primary {
  background-color: var(--color-white);
  color: var(--color-primary);
}

.cta .btn-primary:hover {
  background-color: var(--color-bg-light);
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

/* ----- Footer ----- */
.footer {
  background-color: #222;
  color: #fff;
  padding: 3rem 0;
  text-align: center;
}

.footer-logo {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--color-primary);
}

.footer-copy {
  color: rgba(255,255,255,0.5);
  font-size: 0.9rem;
}

/* ----- Animations ----- */
@keyframes slowZoom {
  0% { transform: scale(1); }
  100% { transform: scale(1.1); }
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeIn 0.8s forwards;
}

.slide-up {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.slide-in-left {
  opacity: 0;
  transform: translateX(-40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.slide-in-right {
  opacity: 0;
  transform: translateX(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.visible {
  opacity: 1;
  transform: translate(0);
}

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

@keyframes fadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ----- Responsive ----- */
@media (max-width: 768px) {
  .nav-list { display: none; }
  
  .hero-title { font-size: 2.5rem; }
  
  .about-grid { grid-template-columns: 1fr; gap: 2rem; }
  
  .about-text { order: 2; }
  .about-image { order: 1; }
  
  .section { padding: 4rem 0; }
  .section-title, .cta-title { font-size: 2rem; }
}