/* =========================================================
   강태호 포트폴리오 · 스타일 (Clean Light Theme)
   면접관/제3자가 한눈에 파악할 수 있는 가독성 우선 디자인
   ========================================================= */
:root {
  --bg: #ffffff;
  --bg-soft: #f5f7fa;      /* 섹션 교차 배경 */
  --card: #ffffff;
  --border: #e6e9ef;
  --border-strong: #d5dae3;
  --ink: #17202e;          /* 제목 */
  --text: #46536a;         /* 본문 */
  --muted: #8b95a7;        /* 보조/날짜 */
  --accent: #2563eb;       /* 포인트 (신뢰감 있는 블루) */
  --accent-soft: #eef3ff;
  --accent-ink: #1d4ed8;
  --font: "Pretendard", "Apple SD Gothic Neo", "Segoe UI", system-ui, sans-serif;
  --mono: "SFMono-Regular", "Consolas", monospace;
  --maxw: 1080px;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(16,32,58,.04), 0 6px 20px rgba(16,32,58,.06);
  --shadow-hover: 0 8px 30px rgba(37,99,235,.14);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.65;
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent-ink); text-decoration: none; transition: color .18s; }
a:hover { color: var(--accent); }
b { font-weight: 700; color: var(--ink); }

/* ---------------- NAV ---------------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.82);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s, box-shadow .25s;
}
.nav.is-scrolled { border-color: var(--border); box-shadow: 0 2px 12px rgba(16,32,58,.05); }
.nav__inner {
  max-width: var(--maxw); margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 15px 24px;
}
.nav__logo { font-size: 1.3rem; font-weight: 800; color: var(--ink); letter-spacing: .5px; }
.nav__logo span { color: var(--accent); }
.nav__links { display: flex; align-items: center; gap: 30px; }
.nav__links a { color: var(--text); font-size: .95rem; font-weight: 500; }
.nav__links a:hover { color: var(--accent); }
.nav__github {
  color: #fff !important; background: var(--accent);
  padding: 8px 16px; border-radius: 8px; font-weight: 600;
}
.nav__github:hover { background: var(--accent-ink); }
.nav__toggle { display: none; background: none; border: none; color: var(--ink); font-size: 1.5rem; cursor: pointer; line-height: 1; }

/* ---------------- HERO / PROFILE ---------------- */
.hero { max-width: var(--maxw); margin: 0 auto; padding: 80px 24px 72px; }
.hero__inner { display: grid; grid-template-columns: 1.15fr .95fr; gap: 60px; align-items: center; }
.hero__hi { color: var(--accent); font-family: var(--mono); font-size: .9rem; font-weight: 600; margin-bottom: 14px; }
.hero__name { font-size: clamp(2.8rem, 7vw, 4.4rem); color: var(--ink); font-weight: 800; line-height: 1.04; letter-spacing: -0.03em; }
.accent { color: var(--accent); }
.hero__role { font-size: clamp(1.35rem, 3.6vw, 2rem); color: var(--ink); font-weight: 700; margin-top: 10px; }
.hero__sub { color: var(--muted); font-size: .62em; font-weight: 500; }
.hero__tagline { margin-top: 20px; max-width: 500px; font-size: 1.05rem; color: var(--text); }
.hero__cta { margin-top: 34px; display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  display: inline-block; padding: 13px 26px; border-radius: 10px;
  font-weight: 600; font-size: .95rem; transition: all .18s;
}
.btn--primary { background: var(--accent); color: #fff !important; box-shadow: 0 4px 14px rgba(37,99,235,.28); }
.btn--primary:hover { background: var(--accent-ink); transform: translateY(-1px); }
.btn--ghost { border: 1.5px solid var(--border-strong); color: var(--ink) !important; }
.btn--ghost:hover { border-color: var(--accent); color: var(--accent) !important; }

/* profile card */
.profile-card {
  list-style: none; background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 10px 26px; box-shadow: var(--shadow);
}
.profile-card li { display: flex; gap: 18px; padding: 16px 0; border-bottom: 1px solid var(--border); }
.profile-card li:last-child { border-bottom: none; }
.profile-card__k {
  flex: 0 0 58px; color: var(--accent); font-size: .82rem; font-weight: 700;
  padding-top: 2px;
}
.profile-card__v { color: var(--ink); font-size: .95rem; }
.profile-card__v em { font-style: normal; color: var(--accent); font-weight: 600; font-size: .9em; }
.profile-card__v small { display: block; color: var(--muted); font-size: .8rem; font-weight: 500; letter-spacing: 0; margin-top: 1px; }
.profile-card__v .cert { display: block; }
.profile-card__v .cert + .cert { margin-top: 10px; }
.profile-card__v a { font-weight: 600; }

/* ---------------- SECTIONS ---------------- */
.section { max-width: var(--maxw); margin: 0 auto; padding: 76px 24px; }
#skills { background: var(--bg-soft); max-width: none; }
#skills > * { max-width: var(--maxw); margin-left: auto; margin-right: auto; }
.section__head { margin-bottom: 44px; }
.section__num { font-family: var(--mono); color: var(--accent); font-size: .95rem; font-weight: 600; }
.section__title { color: var(--ink); font-size: clamp(1.7rem, 4vw, 2.3rem); font-weight: 800; margin: 4px 0 10px; letter-spacing: -0.02em; }
.section__desc { color: var(--text); font-size: 1.02rem; }

/* ---------------- SKILLS ---------------- */
.skills { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px; }
.skill-group {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px 24px 24px;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}
.skill-group:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: var(--accent); }
.skill-group__title {
  color: var(--muted); font-size: .78rem; font-weight: 700; letter-spacing: .06em;
  text-transform: uppercase; margin-bottom: 15px;
}
.chips { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  background: var(--accent-soft); color: var(--accent-ink);
  padding: 6px 13px; border-radius: 8px; font-size: .85rem; font-weight: 600;
}

/* ---------------- PROJECTS ---------------- */
.projects { display: grid; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); gap: 24px; }
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); overflow: hidden;
  display: flex; flex-direction: column; box-shadow: var(--shadow);
  transition: transform .22s, box-shadow .22s, border-color .22s;
}
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); border-color: var(--border-strong); }
.card__thumb { aspect-ratio: 16/10; background: var(--bg-soft); overflow: hidden; border-bottom: 1px solid var(--border); }
.card__thumb img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform .4s; }
.card:hover .card__thumb img { transform: scale(1.04); }
.card__body { padding: 22px 24px 24px; display: flex; flex-direction: column; flex: 1; }
.card__title { color: var(--ink); font-size: 1.18rem; font-weight: 700; margin-bottom: 14px; letter-spacing: -0.01em; }
.card__meta { list-style: none; margin-bottom: 15px; font-size: .85rem; color: var(--text); }
.card__meta li { display: flex; gap: 10px; padding: 3px 0; }
.card__meta span { flex: 0 0 40px; color: var(--muted); font-size: .78rem; font-weight: 600; }
.card__desc { font-size: .92rem; color: var(--text); margin-bottom: 18px; flex: 1; }
.card__tags { list-style: none; display: flex; flex-wrap: wrap; gap: 7px; margin-bottom: 16px; }
.tag { font-size: .76rem; font-weight: 600; color: var(--text); background: var(--bg-soft); border: 1px solid var(--border); padding: 4px 10px; border-radius: 6px; }
.card__links { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.card__link { font-size: .85rem; font-weight: 600; display: inline-flex; align-items: center; gap: 4px; transition: all .18s; }
.card__link--live {
  background: var(--accent); color: #fff !important;
  padding: 7px 14px; border-radius: 8px; box-shadow: 0 3px 10px rgba(37,99,235,.25);
}
.card__link--live:hover { background: var(--accent-ink); transform: translateY(-1px); }
.card__link--repo {
  color: var(--text) !important; border: 1px solid var(--border-strong);
  padding: 7px 14px; border-radius: 8px;
}
.card__link--repo:hover { border-color: var(--accent); color: var(--accent) !important; }

/* ---------------- FOOTER ---------------- */
.footer { text-align: center; padding: 48px 24px 44px; border-top: 1px solid var(--border); background: var(--bg-soft); }
.footer__links { display: flex; justify-content: center; gap: 26px; margin-bottom: 14px; }
.footer__links a { color: var(--text); font-size: .92rem; font-weight: 500; }
.footer__copy { color: var(--muted); font-size: .82rem; }

/* ---------------- RESPONSIVE ---------------- */
@media (max-width: 860px) {
  .hero__inner { grid-template-columns: 1fr; gap: 42px; }
  .hero { padding-top: 56px; padding-bottom: 56px; }
}
@media (max-width: 640px) {
  .nav__toggle { display: block; }
  .nav__links {
    position: absolute; top: 100%; right: 0; left: 0;
    flex-direction: column; align-items: flex-start; gap: 2px;
    background: #fff; padding: 0 24px;
    border-bottom: 1px solid var(--border);
    max-height: 0; overflow: hidden; transition: max-height .28s, padding .28s;
  }
  .nav__links.is-open { max-height: 320px; padding-top: 12px; padding-bottom: 18px; }
  .nav__links a { width: 100%; padding: 9px 0; }
  .section { padding: 56px 24px; }
}