/* ============================================
   CSS Variables
   ============================================ */
:root {
  --black: #0d0d0d;
  --gray-900: #1a1a1a;
  --gray-800: #2d2d2d;
  --gray-700: #404040;
  --gray-600: #525252;
  --gray-500: #737373;
  --gray-400: #a3a3a3;
  --gray-300: #d4d4d4;
  --gray-200: #e5e5e5;
  --gray-100: #f5f5f5;
  --white: #fafafa;

  --accent: #2563eb;
  --accent-light: #3b82f6;

  --font-sans: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;

  --container: 1200px;
  --radius: 12px;
  --radius-sm: 8px;

  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-weight: 400;
  line-height: 1.7;
  color: var(--gray-800);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

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

ul {
  list-style: none;
}

/* ============================================
   Layout
   ============================================ */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.section-title {
  font-size: clamp(12px, 1.5vw, 14px);
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gray-500);
  margin-bottom: 48px;
}

.section-desc {
  font-size: 1.125rem;
  color: var(--gray-600);
  margin-top: -32px;
  margin-bottom: 48px;
}

/* ============================================
   Language Nav
   ============================================ */
.lang-nav {
  position: fixed;
  top: 24px;
  right: 24px;
  z-index: 1000;
  display: flex;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-radius: 100px;
  padding: 4px;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
}

.lang-btn {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 600;
  padding: 8px 16px;
  border: none;
  border-radius: 100px;
  background: transparent;
  color: var(--gray-500);
  cursor: pointer;
  transition: var(--transition);
}

.lang-btn:hover {
  color: var(--gray-800);
}

.lang-btn.active {
  background: var(--black);
  color: var(--white);
}

/* ============================================
   Hero
   ============================================ */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  align-items: center;
  position: relative;
  padding: 120px 24px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(37, 99, 235, 0.08) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 100% 100%, rgba(37, 99, 235, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  text-align: center;
  max-width: 900px;
}

.hero-label {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 24px;
}

.hero-title {
  font-size: clamp(1.75rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: 0;
  color: var(--black);
  margin-bottom: 40px;
}

.hero-title span {
  display: block;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 100px;
  transition: var(--transition);
}

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

.btn-primary:hover {
  background: var(--gray-800);
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
  background: var(--white);
  color: var(--black);
  border: 1.5px solid var(--gray-300);
}

.btn-secondary:hover {
  border-color: var(--gray-400);
  transform: translateY(-2px);
}

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

.scroll-indicator span {
  display: block;
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, var(--gray-400), transparent);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

/* ============================================
   About
   ============================================ */
.about {
  padding: 120px 0;
  background: var(--gray-100);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 80px;
  align-items: center;
}

.about-image {
  position: relative;
}

.about-image img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: var(--radius);
}

.image-placeholder {
  aspect-ratio: 1;
  background: linear-gradient(135deg, var(--gray-200) 0%, var(--gray-300) 100%);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--gray-500);
  position: relative;
  overflow: hidden;
}

.image-placeholder::before {
  content: '';
  position: absolute;
  inset: 0;
  border: 1px dashed var(--gray-400);
  border-radius: var(--radius);
  margin: 16px;
}

.image-placeholder.dark {
  background: linear-gradient(135deg, var(--gray-800) 0%, var(--gray-900) 100%);
  color: var(--gray-500);
}

.image-placeholder.dark::before {
  border-color: var(--gray-700);
}


.about-name {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 700;
  color: var(--black);
  line-height: 1.4;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
}

.about-title {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--gray-600);
  margin-bottom: 32px;
}

.about-text h2 {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--black);
  margin-bottom: 24px;
}

.about-text p:not(.about-name):not(.about-title) {
  font-size: 1.0625rem;
  color: var(--gray-600);
  margin-bottom: 32px;
}

.about-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.about-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--gray-600);
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: var(--transition);
}

.about-links a:hover {
  color: var(--black);
  border-bottom-color: var(--black);
}

/* ============================================
   Projects
   ============================================ */
.projects {
  padding: 120px 0;
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.project-card {
  display: block;
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--gray-600);
  transition: var(--transition);
}

.project-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
  border-color: var(--gray-700);
}

.project-image {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--gray-600);
}

.project-image img {
  width: 100%;
  aspect-ratio: 16/10;
  object-fit: cover;
  transition: transform var(--transition);
}

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

.project-image .image-placeholder {
  aspect-ratio: 16/10;
  border-radius: 0;
}

.project-info {
  padding: 28px;
}

.project-info h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--black);
  margin-bottom: 8px;
}

.project-info p {
  font-size: 0.9375rem;
  color: var(--gray-600);
  margin-bottom: 16px;
  line-height: 1.6;
}

.project-link {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  transition: var(--transition);
}

.project-card:hover .project-link {
  color: var(--accent-light);
}

/* ============================================
   Numbers
   ============================================ */
.numbers {
  padding: 100px 0;
  background: var(--black);
}

.numbers-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 48px;
  text-align: center;
}

.number-item {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.number {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--white);
  line-height: 1;
}

.number-label {
  font-size: 14px;
  color: var(--gray-500);
  letter-spacing: 0.05em;
}

/* ============================================
   Philosophy
   ============================================ */
.philosophy {
  padding: 120px 0;
  background: var(--gray-100);
}

.philosophy-content {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.philosophy blockquote {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 500;
  line-height: 1.6;
  color: var(--gray-700);
  font-style: normal;
}

/* ============================================
   Personal
   ============================================ */
.personal {
  padding: 120px 0;
}

.personal-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 48px;
}

.personal-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  padding: 32px;
  background: var(--gray-100);
  border-radius: var(--radius);
}

.personal-image {
  width: 100%; /* Ensure image takes full width of its container */
  aspect-ratio: 1; /* Maintain aspect ratio */
  overflow: hidden; /* Hide overflowing parts for rounded corners */
  border-radius: var(--radius); /* Apply rounded corners */
  border: 1px solid var(--gray-600); /* Apply gray border */
}

.personal-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--radius); /* Apply rounded corners to the image itself */
}

.personal-info h3 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--black);
  margin-bottom: 16px;
  letter-spacing: 0.02em;
}

.personal-info ul li {
  font-size: 0.9375rem;
  color: var(--gray-600);
  padding: 6px 0;
  border-bottom: 1px solid var(--gray-200);
}

.personal-info ul li:last-child {
  border-bottom: none;
}

/* ============================================
   Contact
   ============================================ */
.contact {
  padding: 120px 0 80px;
  background: var(--gray-900);
  text-align: center;
}

.contact h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--white);
  margin-bottom: 16px;
}

.contact > .container > p {
  font-size: 1.0625rem;
  color: var(--gray-500);
  margin-bottom: 48px;
}

.contact-links {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
  margin-bottom: 80px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 24px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--gray-300);
  transition: var(--transition);
}

.contact-item:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  color: var(--white);
}

.contact-icon {
  font-size: 1.25rem;
}

.copyright {
  font-size: 13px;
  color: var(--gray-600);
}

/* ============================================
   Animations
   ============================================ */
.hero-content,
.about-grid,
.project-card,
.number-item,
.philosophy-content,
.personal-card {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.visible .hero-content,
.visible .about-grid,
.visible .project-card,
.visible .number-item,
.visible .philosophy-content,
.visible .personal-card,
.hero .hero-content {
  opacity: 1;
  transform: translateY(0);
}

.project-card:nth-child(1) { transition-delay: 0s; }
.project-card:nth-child(2) { transition-delay: 0.1s; }
.project-card:nth-child(3) { transition-delay: 0.2s; }

.number-item:nth-child(1) { transition-delay: 0s; }
.number-item:nth-child(2) { transition-delay: 0.1s; }
.number-item:nth-child(3) { transition-delay: 0.2s; }
.number-item:nth-child(4) { transition-delay: 0.3s; }

.personal-card:nth-child(1) { transition-delay: 0s; }
.personal-card:nth-child(2) { transition-delay: 0.15s; }

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 1024px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .about-image {
    max-width: 320px;
    width: 100%;
    margin: 0 auto;
  }

  .project-grid {
    grid-template-columns: 1fr;
    max-width: 500px;
    margin: 0 auto;
  }

  .numbers-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 48px 24px;
  }

  .personal-grid {
    grid-template-columns: 1fr;
    max-width: 500px;
    margin: 0 auto;
  }
}

@media (max-width: 640px) {
  .hero {
    padding: 100px 20px 60px;
  }

  .hero-title {
    font-size: 1.25rem;
    line-height: 1.7;
  }

  .about,
  .projects,
  .philosophy,
  .personal {
    padding: 80px 0;
  }

  .numbers {
    padding: 60px 0;
  }

  .numbers-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px 16px;
  }

  .number {
    font-size: 2rem;
  }

  .about-image {
    max-width: 320px;
    width: 100%;
    margin: 0 auto;
  }

  .about-image .image-placeholder {
    aspect-ratio: 1;
  }

  .personal-card {
    grid-template-columns: 1fr;
    text-align: center;
    padding: 24px;
  }

  .personal-image {
    width: 100%;
    max-width: 320px;
    margin: 0 auto;
  }

  .personal-image .image-placeholder {
    aspect-ratio: 1;
  }

  .contact {
    padding: 80px 0 60px;
  }

  .contact-links {
    flex-direction: column;
    align-items: center;
    gap: 16px;
  }

  .contact-item {
    width: 100%;
    max-width: 300px;
    justify-content: center;
  }

  .lang-nav {
    top: 16px;
    right: 16px;
  }

  .section-title {
    margin-bottom: 32px;
  }

  .section-desc {
    margin-top: -20px;
    margin-bottom: 32px;
  }
}