/* ============================================
   Water Environmental Analysis - Aqua Lab Design
   ============================================ */

:root {
  /* Color Palette */
  --deep-blue: #0369a1;
  --deep-blue-dark: #075985;
  --aqua-green: #059669;
  --aqua-green-dark: #047857;
  --clear-cyan: #06b6d4;
  --sky-light: #e0f2fe;
  --mint-light: #d1fae5;
  --bg-light: #f8fafc;
  --bg-white: #ffffff;
  --text-dark: #0f172a;
  --text-gray: #475569;
  --text-light: #f8fafc;
  
  /* Typography */
  --font-main: 'Noto Sans JP', sans-serif;
  
  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-dark);
  background: var(--bg-light);
}

a {
  color: var(--deep-blue);
  text-decoration: none;
  transition: var(--transition-fast);
}

a:hover {
  color: var(--aqua-green);
}

img {
  max-width: 100%;
  height: auto;
}

/* ============================================
   Header
   ============================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: linear-gradient(135deg, var(--deep-blue) 0%, var(--deep-blue-dark) 100%);
  box-shadow: 0 2px 20px rgba(3, 105, 161, 0.2);
}

.header-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.logo-icon {
  width: 45px;
  height: 45px;
  background: linear-gradient(135deg, var(--clear-cyan), var(--aqua-green));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
}

.logo-text {
  color: var(--text-light);
  font-weight: 700;
  font-size: 1.2rem;
  line-height: 1.2;
}

.logo-text span {
  display: block;
  font-size: 0.75rem;
  font-weight: 400;
  opacity: 0.85;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--space-xs);
}

.nav-menu a {
  display: block;
  padding: var(--space-xs) var(--space-sm);
  color: rgba(255,255,255,0.85);
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: 6px;
  transition: var(--transition-fast);
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--text-light);
  background: rgba(255,255,255,0.15);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 10px;
}

.hamburger span {
  width: 25px;
  height: 3px;
  background: var(--text-light);
  border-radius: 2px;
  transition: var(--transition-normal);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(6px, 6px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  margin-top: 70px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: none;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(3, 105, 161, 0.9) 0%,
    rgba(5, 150, 105, 0.7) 50%,
    rgba(6, 182, 212, 0.5) 100%
  );
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-md);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  background: rgba(255,255,255,0.2);
  border: 1px solid rgba(255,255,255,0.4);
  color: var(--text-light);
  padding: var(--space-xs) var(--space-sm);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: var(--space-md);
  backdrop-filter: blur(10px);
}

.hero h1 {
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 900;
  color: #ffffff;
  line-height: 1.2;
  margin-bottom: var(--space-md);
  text-shadow: 
    2px 2px 0 rgba(0,0,0,0.3),
    -2px 2px 0 rgba(0,0,0,0.3),
    2px -2px 0 rgba(0,0,0,0.3),
    -2px -2px 0 rgba(0,0,0,0.3),
    0 4px 12px rgba(0,0,0,0.3);
}

.hero h1 span {
  color: var(--clear-cyan);
  text-shadow: none;
  background: linear-gradient(135deg, #67e8f9, #a5f3fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  font-size: 1.15rem;
  color: rgba(255,255,255,0.95);
  max-width: 650px;
  margin-bottom: var(--space-lg);
  line-height: 1.8;
}

.hero-cta {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-lg);
  border-radius: 8px;
  font-weight: 600;
  font-size: 1rem;
  transition: var(--transition-normal);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--aqua-green);
  color: var(--text-light);
}

.btn-primary:hover {
  background: var(--aqua-green-dark);
  color: var(--text-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(5, 150, 105, 0.4);
}

.btn-outline {
  background: transparent;
  color: var(--text-light);
  border: 2px solid rgba(255,255,255,0.5);
}

.btn-outline:hover {
  border-color: var(--text-light);
  background: rgba(255,255,255,0.1);
  color: var(--text-light);
}

/* ============================================
   Stats Section
   ============================================ */
.stats {
  background: var(--bg-white);
  padding: var(--space-xl) 0;
  border-bottom: 1px solid #e2e8f0;
}

.stats-grid {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-md);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

.stat-item {
  text-align: center;
  padding: var(--space-md);
}

.stat-icon {
  font-size: 2.5rem;
  margin-bottom: var(--space-xs);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--deep-blue), var(--aqua-green));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.stat-label {
  color: var(--text-gray);
  font-size: 0.9rem;
  margin-top: var(--space-xs);
}

/* ============================================
   Section Common
   ============================================ */
.section {
  padding: var(--space-2xl) var(--space-md);
}

.section-alt {
  background: var(--bg-white);
}

.section-dark {
  background: linear-gradient(135deg, var(--deep-blue) 0%, var(--deep-blue-dark) 100%);
  color: var(--text-light);
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--space-xs);
  color: var(--text-dark);
}

.section-dark .section-title {
  color: var(--text-light);
}

.section-subtitle {
  color: var(--text-gray);
  font-size: 1.05rem;
  margin-bottom: var(--space-xl);
}

.section-dark .section-subtitle {
  color: rgba(255,255,255,0.8);
}

.container {
  max-width: 1400px;
  margin: 0 auto;
}

/* ============================================
   Feature Cards
   ============================================ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.feature-card {
  background: var(--bg-white);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0,0,0,0.06);
  transition: var(--transition-normal);
  border: 1px solid #e2e8f0;
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 40px rgba(3, 105, 161, 0.15);
  border-color: var(--deep-blue);
}

.feature-image {
  position: relative;
  height: 200px;
  overflow: hidden;
}

.feature-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition-normal);
}

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

.feature-tag {
  position: absolute;
  top: var(--space-sm);
  left: var(--space-sm);
  background: var(--aqua-green);
  color: var(--text-light);
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
}

.feature-content {
  padding: var(--space-md);
}

.feature-content h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: var(--space-xs);
  color: var(--text-dark);
}

.feature-content p {
  color: var(--text-gray);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: var(--space-sm);
}

.feature-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--deep-blue);
  font-weight: 600;
  font-size: 0.9rem;
}

.feature-link:hover {
  color: var(--aqua-green);
  gap: 10px;
}

/* ============================================
   Topics Grid
   ============================================ */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md);
}

.topic-card {
  background: rgba(255,255,255,0.1);
  border-radius: 12px;
  padding: var(--space-md);
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  transition: var(--transition-normal);
  border: 1px solid rgba(255,255,255,0.2);
}

.topic-card:hover {
  background: rgba(255,255,255,0.2);
  transform: translateX(8px);
  color: var(--text-light);
}

.topic-icon {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--clear-cyan), var(--aqua-green));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}

.topic-content h4 {
  color: var(--text-light);
  font-size: 1.05rem;
  margin-bottom: 4px;
}

.topic-content p {
  color: rgba(255,255,255,0.75);
  font-size: 0.85rem;
  line-height: 1.5;
}

/* ============================================
   News Section
   ============================================ */
.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.news-card {
  background: var(--bg-white);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 15px rgba(0,0,0,0.05);
  transition: var(--transition-normal);
  border: 1px solid #e2e8f0;
}

.news-card:hover {
  box-shadow: 0 8px 30px rgba(0,0,0,0.1);
}

.news-image {
  height: 160px;
  overflow: hidden;
  background: linear-gradient(135deg, var(--sky-light), var(--mint-light));
  display: flex;
  align-items: center;
  justify-content: center;
}

.news-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.news-content {
  padding: var(--space-md);
}

.news-date {
  color: var(--deep-blue);
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.news-content h4 {
  font-size: 1.05rem;
  margin-bottom: var(--space-xs);
  color: var(--text-dark);
  line-height: 1.4;
}

.news-content p {
  color: var(--text-gray);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ============================================
   CTA Section
   ============================================ */
.cta-section {
  background: linear-gradient(135deg, var(--aqua-green) 0%, var(--deep-blue) 100%);
  padding: var(--space-2xl) var(--space-md);
  text-align: center;
}

.cta-content {
  max-width: 700px;
  margin: 0 auto;
}

.cta-content h2 {
  font-size: 2rem;
  color: var(--text-light);
  margin-bottom: var(--space-sm);
}

.cta-content p {
  color: rgba(255,255,255,0.9);
  margin-bottom: var(--space-lg);
  font-size: 1.1rem;
}

.cta-content .btn-primary {
  background: var(--bg-white);
  color: var(--deep-blue);
}

.cta-content .btn-primary:hover {
  background: var(--sky-light);
  color: var(--deep-blue-dark);
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background: var(--deep-blue-dark);
  color: rgba(255,255,255,0.8);
  padding: var(--space-2xl) var(--space-md) var(--space-lg);
}

.footer-grid {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer-brand p {
  margin-top: var(--space-sm);
  line-height: 1.7;
  font-size: 0.9rem;
}

.footer-title {
  color: var(--text-light);
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--space-xs);
}

.footer-links a {
  color: rgba(255,255,255,0.7);
  font-size: 0.9rem;
  transition: var(--transition-fast);
}

.footer-links a:hover {
  color: var(--clear-cyan);
}

.footer-bottom {
  max-width: 1400px;
  margin: 0 auto;
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255,255,255,0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

.footer-legal a {
  color: rgba(255,255,255,0.6);
  margin-left: var(--space-md);
}

.footer-legal a:hover {
  color: var(--clear-cyan);
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 1024px) {
  .features-grid,
  .news-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--deep-blue);
    flex-direction: column;
    padding: var(--space-lg);
    gap: var(--space-xs);
    transform: translateX(-100%);
    transition: var(--transition-normal);
  }
  
  .nav-menu.active {
    transform: translateX(0);
  }
  
  .nav-menu a {
    font-size: 1.1rem;
    padding: var(--space-sm);
  }
  
  .hamburger {
    display: flex;
  }
  
  .hero {
    min-height: 70vh;
  }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .hero-description {
    font-size: 1rem;
  }
  
  .features-grid,
  .news-grid,
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .footer-bottom {
    flex-direction: column;
    gap: var(--space-sm);
    text-align: center;
  }
  
  .footer-legal a {
    margin: 0 var(--space-xs);
  }
}