/* リセット & ベース */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --deep-night: #0B1020;
  --aurora-cyan: #6EF3D6;
  --soft-violet: #8A7CFF;
  --mist-white: #E6E9F0;
  --muted-gray: #9AA0B5;
  --dark-surface: rgba(15, 23, 42, 0.8);
  --card-bg: rgba(20, 28, 50, 0.7);
  --card-bg-hover: rgba(25, 35, 60, 0.85);
  --card-border: rgba(110, 243, 214, 0.2);
  --section-bg: rgba(11, 16, 32, 0.3);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", "Meiryo", sans-serif;
  background-color: var(--deep-night);
  color: var(--mist-white);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

/* Language Switcher */
.language-switcher {
  position: fixed;
  top: 32px;
  right: 32px;
  z-index: 1000;
}

.lang-link {
  display: inline-block;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 500;
  color: var(--mist-white);
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: all 0.3s ease;
}

.lang-link:hover {
  background: rgba(15, 23, 42, 0.6);
  border-color: rgba(110, 243, 214, 0.3);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(110, 243, 214, 0.2);
}

/* ヒーローセクション */
.hero {
  position: relative;
  height: 100vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  background: radial-gradient(ellipse at center, rgba(110, 243, 214, 0.05) 0%, var(--deep-night) 70%);
}

.particles {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  pointer-events: none;
}

.particle {
  position: absolute;
  width: 3px;
  height: 3px;
  background: var(--aurora-cyan);
  border-radius: 50%;
  opacity: 0.4;
  animation: float 20s infinite ease-in-out;
  box-shadow: 0 0 6px rgba(110, 243, 214, 0.5);
}

.particle:nth-child(2n) {
  background: var(--soft-violet);
  animation-duration: 25s;
  box-shadow: 0 0 6px rgba(138, 124, 255, 0.5);
}

.particle:nth-child(3n) {
  animation-duration: 30s;
  opacity: 0.25;
  width: 2px;
  height: 2px;
}

@keyframes float {
  0%, 100% {
    transform: translate(0, 0) scale(1);
    opacity: 0.3;
  }
  50% {
    transform: translate(150px, -150px) scale(1.8);
    opacity: 0.7;
  }
}

.hero-content {
  position: relative;
  z-index: 2;
  padding: 0 32px;
  max-width: 900px;
}

.hero-logo {
  width: 120px;
  height: auto;
  margin-bottom: 32px;
  opacity: 0;
  animation: fadeInUp 1s ease-out 0.3s forwards;
  filter: drop-shadow(0 4px 12px rgba(110, 243, 214, 0.2));
}

.hero-title {
  font-size: clamp(40px, 7vw, 72px);
  font-weight: 400;
  letter-spacing: 0.02em;
  line-height: 1.3;
  margin-bottom: 32px;
  color: var(--mist-white);
  animation: fadeInUp 1.2s ease-out;
  text-shadow: 0 2px 20px rgba(110, 243, 214, 0.1);
}

.hero-subtitle {
  font-size: clamp(18px, 2.8vw, 28px);
  font-weight: 300;
  color: var(--muted-gray);
  letter-spacing: 0.05em;
  animation: fadeInUp 1.4s ease-out;
  line-height: 1.6;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
}

.scroll-indicator span {
  display: block;
  width: 2px;
  height: 40px;
  background: linear-gradient(to bottom, transparent, var(--aurora-cyan));
  animation: scrollPulse 2s infinite;
}

@keyframes scrollPulse {
  0%, 100% {
    opacity: 0.3;
    transform: translateY(0);
  }
  50% {
    opacity: 1;
    transform: translateY(10px);
  }
}

/* セクション共通 */
section {
  padding: 140px 0;
  position: relative;
}

.section-title {
  font-size: clamp(32px, 5vw, 56px);
  font-weight: 400;
  text-align: center;
  letter-spacing: 0.02em;
  margin-bottom: 100px;
  color: var(--mist-white);
  line-height: 1.5;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

/* 哲学セクション */
.philosophy {
  background: linear-gradient(180deg, var(--deep-night) 0%, var(--section-bg) 100%);
  position: relative;
}

.philosophy::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--card-border), transparent);
}

.philosophy-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 32px;
  margin-top: 60px;
}

.philosophy-item {
  text-align: center;
  padding: 48px 32px;
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.philosophy-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--aurora-cyan), transparent);
  opacity: 0;
  transition: opacity 0.4s ease;
}

.philosophy-item:hover {
  transform: translateY(-8px);
  border-color: rgba(110, 243, 214, 0.4);
  background: var(--card-bg-hover);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 30px rgba(110, 243, 214, 0.15);
}

.philosophy-item:hover::before {
  opacity: 1;
}

.philosophy-icon {
  font-size: 56px;
  margin-bottom: 28px;
  opacity: 0.9;
  filter: drop-shadow(0 4px 8px rgba(110, 243, 214, 0.2));
  transition: transform 0.3s ease;
}

.philosophy-item:hover .philosophy-icon {
  transform: scale(1.1);
}

.philosophy-heading {
  font-size: 26px;
  font-weight: 500;
  margin-bottom: 20px;
  color: var(--mist-white);
  letter-spacing: 0.03em;
}

.philosophy-text {
  font-size: 17px;
  line-height: 1.9;
  color: var(--muted-gray);
  letter-spacing: 0.01em;
}

/* ユースケースセクション */
.usecases {
  background: var(--section-bg);
  position: relative;
}

.usecase-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
  margin-top: 60px;
}

.usecase-item {
  padding: 48px 32px;
  text-align: center;
  border: 1px solid var(--card-border);
  border-radius: 16px;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.usecase-item::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--aurora-cyan), var(--soft-violet));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}

.usecase-item:hover {
  border-color: rgba(110, 243, 214, 0.4);
  background: var(--card-bg-hover);
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 30px rgba(110, 243, 214, 0.15);
}

.usecase-item:hover::after {
  transform: scaleX(1);
}

.usecase-image {
  font-size: 56px;
  margin-bottom: 28px;
  opacity: 0.9;
  filter: drop-shadow(0 4px 8px rgba(138, 124, 255, 0.2));
  transition: transform 0.3s ease;
}

.usecase-item:hover .usecase-image {
  transform: scale(1.1) rotate(5deg);
}

.usecase-title {
  font-size: 24px;
  font-weight: 500;
  margin-bottom: 20px;
  color: var(--mist-white);
  letter-spacing: 0.03em;
}

.usecase-text {
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted-gray);
  letter-spacing: 0.01em;
}

/* CTAセクション */
.cta {
  text-align: center;
  padding: 180px 0;
  background: linear-gradient(180deg, rgba(15, 23, 42, 0.4) 0%, var(--deep-night) 100%);
  position: relative;
}

.cta::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--card-border), transparent);
}

.cta-title {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 400;
  margin-bottom: 32px;
  color: var(--mist-white);
  letter-spacing: 0.02em;
  line-height: 1.4;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.cta-description {
  font-size: clamp(18px, 2.5vw, 22px);
  color: var(--muted-gray);
  margin-bottom: 56px;
  line-height: 1.8;
  letter-spacing: 0.01em;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.cta-button {
  display: inline-block;
  padding: 18px 56px;
  font-size: 18px;
  font-weight: 500;
  color: var(--deep-night);
  background: linear-gradient(135deg, var(--aurora-cyan), var(--soft-violet));
  border: none;
  border-radius: 12px;
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(110, 243, 214, 0.3);
  position: relative;
  overflow: hidden;
}

.cta-button::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  transition: left 0.5s ease;
}

.cta-button:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(110, 243, 214, 0.4);
}

.cta-button:hover::before {
  left: 100%;
}

.cta-button:active {
  transform: translateY(-2px);
}

/* App Store Button */
.app-store-button {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 11px 20px;
  background: #ffffff;
  color: #000000;
  border-radius: 6px;
  text-decoration: none;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.08);
  border: 1px solid rgba(0, 0, 0, 0.08);
  position: relative;
  overflow: hidden;
}

.app-store-button::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0, 0, 0, 0.05), transparent);
  transition: left 0.5s ease;
}

.app-store-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15), 0 2px 4px rgba(0, 0, 0, 0.1);
  background: #fafafa;
}

.app-store-button:hover::before {
  left: 100%;
}

.app-store-button:active {
  transform: translateY(0);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
}

.app-store-icon {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  color: #000000;
}

.app-store-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  line-height: 1.1;
}

.app-store-label {
  font-size: 13px;
  font-weight: 400;
  letter-spacing: -0.01em;
  color: #000000;
  white-space: nowrap;
}

/* フッター */
.footer {
  padding: 80px 0;
  text-align: center;
  border-top: 1px solid var(--card-border);
  background: var(--deep-night);
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 200px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--aurora-cyan), transparent);
}

.footer-logo {
  width: 80px;
  height: auto;
  margin: 0 auto 24px;
  opacity: 0.9;
  filter: drop-shadow(0 2px 8px rgba(110, 243, 214, 0.15));
  transition: opacity 0.3s ease;
}

.footer-logo:hover {
  opacity: 1;
}

.footer-text {
  font-size: 28px;
  font-weight: 400;
  color: var(--mist-white);
  margin-bottom: 16px;
  letter-spacing: 0.08em;
}

.footer-subtext {
  font-size: 15px;
  color: var(--muted-gray);
  letter-spacing: 0.05em;
  line-height: 1.6;
}

/* レスポンシブ */
@media (max-width: 768px) {
  .container {
    padding: 0 24px;
  }

  .language-switcher {
    top: 24px;
    right: 24px;
  }

  .lang-link {
    padding: 8px 16px;
    font-size: 13px;
  }

  section {
    padding: 100px 0;
  }

  .philosophy-content,
  .usecase-list {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .philosophy-item,
  .usecase-item {
    padding: 40px 24px;
  }

  .hero {
    min-height: 500px;
  }

  .hero-logo {
    width: 100px;
    margin-bottom: 24px;
  }

  .hero-title {
    font-size: 40px;
    margin-bottom: 24px;
  }

  .hero-subtitle {
    font-size: 18px;
  }

  .footer-logo {
    width: 60px;
    margin-bottom: 20px;
  }

  .section-title {
    font-size: 36px;
    margin-bottom: 60px;
  }

  .cta {
    padding: 120px 0;
  }

  .cta-title {
    font-size: 36px;
  }

  .cta-description {
    font-size: 18px;
  }

  .cta-button {
    padding: 16px 48px;
    font-size: 16px;
  }

  .app-store-button {
    padding: 10px 20px;
    gap: 10px;
  }

  .app-store-icon {
    width: 20px;
    height: 20px;
  }

  .app-store-label {
    font-size: 13px;
  }
}

@media (max-width: 480px) {
  section {
    padding: 80px 0;
  }

  .hero-title {
    font-size: 32px;
  }

  .section-title {
    font-size: 28px;
  }

  .philosophy-heading,
  .usecase-title {
    font-size: 22px;
  }
}

/* スクロールアニメーション */
.fade-in {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 1s cubic-bezier(0.4, 0, 0.2, 1), transform 1s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* スムーズなスクロール */
@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}