:root {
  --bg: #0d1117;
  --bg-card: #161b22;
  --bg-card2: #1c2333;
  --accent: #00d4ff;
  --accent2: #7c3aed;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --border: #30363d;
  --radius: 12px;
  --nav-h: 64px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* ── NAV ── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(13,17,23,.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center;
  padding: 0 2rem;
  gap: 2rem;
}
.nav-brand {
  font-weight: 700; font-size: 1.1rem;
  color: var(--text); text-decoration: none;
  margin-right: auto;
}
.nav-brand span { color: var(--accent); }
nav a {
  color: var(--text-muted); text-decoration: none;
  font-size: .9rem; font-weight: 500;
  transition: color .2s;
}
nav a:hover, nav a.active { color: var(--accent); }
.nav-contact {
  color: var(--accent) !important;
  border: 1px solid var(--accent);
  padding: .35rem .9rem;
  border-radius: 6px;
  font-size: .85rem !important;
}
.nav-contact:hover { background: var(--accent); color: var(--bg) !important; }

main { padding-top: var(--nav-h); }

/* ── SECTIONS ── */
section { padding: 5rem 2rem; max-width: 1100px; margin: 0 auto; }

.section-label {
  font-size: .75rem; font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase; color: var(--accent);
  margin-bottom: .75rem;
}
h1, h2 { line-height: 1.2; }

/* ── HERO ── */
.hero {
  min-height: calc(100vh - var(--nav-h));
  display: flex; align-items: center;
  max-width: 100%; padding: 4rem 2rem;
  position: relative; overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute; top: -200px; right: -200px;
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(124,58,237,.15) 0%, transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: '';
  position: absolute; bottom: -100px; left: -100px;
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(0,212,255,.08) 0%, transparent 70%);
  pointer-events: none;
}
.hero-inner { max-width: 1100px; margin: 0 auto; width: 100%; }
.hero-tag {
  display: inline-flex; align-items: center; gap: .5rem;
  background: rgba(124,58,237,.15);
  border: 1px solid rgba(124,58,237,.4);
  border-radius: 999px;
  padding: .35rem 1rem;
  font-size: .8rem; font-weight: 600;
  color: #a78bfa;
  margin-bottom: 1.5rem;
}
.hero-tag::before { content: '◆'; font-size: .6rem; }
.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 800;
  margin-bottom: 1rem;
}
.hero h1 .name { color: var(--accent); }
.hero h1 .role { display: block; color: var(--text-muted); font-weight: 400; font-size: 60%; margin-top: .25rem; }
.hero-desc {
  font-size: 1.1rem; color: var(--text-muted);
  max-width: 600px;
  margin-bottom: 2rem;
}
.hero-cta { display: flex; gap: 1rem; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: .75rem 1.75rem;
  border-radius: 8px; font-weight: 600; font-size: .95rem;
  text-decoration: none; transition: all .2s;
  cursor: pointer; border: none;
}
.btn-primary {
  background: var(--accent); color: #0d1117;
}
.btn-primary:hover { background: #33ddff; transform: translateY(-1px); }
.btn-secondary {
  background: transparent; color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }

/* ── AI SERVICES ── */
.ai-section { background: var(--bg-card); border-radius: 0; padding: 5rem 2rem; }
.ai-inner { max-width: 1100px; margin: 0 auto; }
.ai-section h2 { font-size: clamp(1.6rem, 3vw, 2.4rem); margin-bottom: .75rem; }
.ai-section .intro { color: var(--text-muted); max-width: 650px; margin-bottom: 3rem; }
.ai-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; }
.ai-card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 2rem;
  transition: border-color .2s, transform .2s;
}
.ai-card:hover { border-color: var(--accent); transform: translateY(-3px); }
.ai-card-icon {
  font-size: 2rem; margin-bottom: 1rem;
  display: block;
}
.ai-card h3 { font-size: 1.1rem; margin-bottom: .75rem; color: var(--text); }
.ai-card p { color: var(--text-muted); font-size: .9rem; }
.ai-card .tag {
  display: inline-block; margin-top: 1rem;
  font-size: .75rem; font-weight: 600;
  color: var(--accent2); background: rgba(124,58,237,.12);
  border: 1px solid rgba(124,58,237,.3);
  padding: .2rem .6rem; border-radius: 4px;
}

/* ── CHI SONO + SKILLS ── */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: start; }
@media (max-width: 768px) { .about-grid { grid-template-columns: 1fr; } }
.about-text h2 { font-size: clamp(1.5rem, 2.5vw, 2rem); margin-bottom: 1rem; }
.about-text p { color: var(--text-muted); margin-bottom: 1rem; font-size: .95rem; }

.skills-list { display: flex; flex-direction: column; gap: .75rem; }
.skill-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: .9rem 1.2rem;
  display: flex; align-items: flex-start; gap: .75rem;
}
.skill-item .icon { font-size: 1.1rem; flex-shrink: 0; margin-top: .1rem; }
.skill-item .skill-text { font-size: .88rem; color: var(--text-muted); }
.skill-item .skill-text strong { color: var(--text); display: block; margin-bottom: .15rem; }

.tech-tags { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: 1.5rem; }
.tech-tag {
  font-size: .78rem; font-weight: 600;
  padding: .3rem .8rem; border-radius: 999px;
  background: rgba(0,212,255,.08);
  border: 1px solid rgba(0,212,255,.25);
  color: var(--accent);
}

/* ── PORTFOLIO PAGE ── */
.portfolio-hero {
  padding: 4rem 2rem 2rem;
  max-width: 1100px; margin: 0 auto;
  text-align: center;
}
.portfolio-hero h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); margin-bottom: .75rem; }
.portfolio-hero p { color: var(--text-muted); max-width: 550px; margin: 0 auto; }

.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 1.25rem;
  max-width: 1100px; margin: 3rem auto; padding: 0 2rem;
}
.company-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1rem;
  text-align: center;
  text-decoration: none;
  color: var(--text);
  transition: border-color .2s, transform .2s;
  display: flex; flex-direction: column; align-items: center; gap: .75rem;
}
.company-card:hover { border-color: var(--accent); transform: translateY(-3px); }
.company-card img {
  width: 80px; height: 50px;
  object-fit: contain; filter: grayscale(40%) brightness(1.1);
  transition: filter .2s;
}
.company-card:hover img { filter: grayscale(0%) brightness(1.2); }
.company-card .company-name { font-size: .85rem; font-weight: 600; }
.company-card .company-sector { font-size: .75rem; color: var(--text-muted); }

/* ── CONTACT ── */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: start; }
@media (max-width: 768px) { .contact-grid { grid-template-columns: 1fr; } }

.contact-info h2 { font-size: clamp(1.5rem, 2.5vw, 2rem); margin-bottom: 1rem; }
.contact-info p { color: var(--text-muted); margin-bottom: 2rem; }
.contact-item {
  display: flex; align-items: center; gap: 1rem;
  padding: 1rem 1.25rem;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 8px; margin-bottom: .75rem;
  text-decoration: none; color: var(--text);
  transition: border-color .2s;
}
.contact-item:hover { border-color: var(--accent); }
.contact-item .ci-icon { font-size: 1.4rem; }
.contact-item .ci-label { font-size: .75rem; color: var(--text-muted); }
.contact-item .ci-value { font-weight: 600; font-size: .95rem; }

.contact-form { display: flex; flex-direction: column; gap: 1rem; }
.form-group label { display: block; font-size: .85rem; color: var(--text-muted); margin-bottom: .4rem; }
.form-group input, .form-group textarea {
  width: 100%;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 8px; padding: .75rem 1rem;
  color: var(--text); font-size: .9rem; font-family: inherit;
  transition: border-color .2s;
  outline: none;
}
.form-group input:focus, .form-group textarea:focus { border-color: var(--accent); }
.form-group textarea { min-height: 140px; resize: vertical; }

/* ── FOOTER ── */
footer {
  border-top: 1px solid var(--border);
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: .85rem;
}
footer a { color: var(--accent); text-decoration: none; }

/* ── DIVIDER ── */
.divider { border: none; border-top: 1px solid var(--border); margin: 0; }

@media (max-width: 640px) {
  nav { gap: 1rem; padding: 0 1rem; }
  .hero { padding: 3rem 1rem; }
  section { padding: 3.5rem 1rem; }
}