/* =========================================================
   LTrin (엘트린) 공식 홈페이지 — 공통 스타일시트
   테마: 딥 테크 네이비 + 시그니처 시안(Sub-100nm 정밀도를 상징)
   ========================================================= */

:root {
  --navy-950: #060b16;
  --navy-900: #0a1425;
  --navy-800: #0f1c33;
  --navy-700: #16294a;
  --navy-600: #203a63;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.16);
  --text-0: #f4f7fb;
  --text-1: #c4cede;
  --text-2: #8a97b3;
  --cyan: #22d3ee;
  --cyan-strong: #06b6d4;
  --amber: #f0b429;
  --ok: #34d399;
  --radius: 14px;
  --maxw: 1180px;
  --shadow-card: 0 10px 30px rgba(2, 8, 20, 0.35);
  font-size: 16px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--navy-950);
  color: var(--text-1);
  font-family: "Pretendard", "Noto Sans KR", -apple-system, BlinkMacSystemFont,
    "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; margin: 0; padding: 0; }

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 배경 그리드 텍스처 (반도체/정밀 이미지) ---------- */
.grid-bg {
  position: relative;
  background-image:
    linear-gradient(rgba(34, 211, 238, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(34, 211, 238, 0.06) 1px, transparent 1px);
  background-size: 42px 42px;
  background-position: center top;
}
.grid-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 60% 50% at 50% 0%, rgba(34,211,238,0.10), transparent 70%);
  pointer-events: none;
}

/* ---------- 헤더 / 네비게이션 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(6, 11, 22, 0.86);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 1.28rem;
  letter-spacing: 0.02em;
  color: var(--text-0);
}
.logo .logo-img {
  height: 30px;
  width: auto;
  display: block;
}
.logo small {
  display: block;
  font-size: 0.62rem;
  font-weight: 600;
  color: var(--cyan);
  letter-spacing: 0.16em;
}

.main-nav { display: flex; align-items: center; gap: 6px; }
.main-nav a {
  padding: 10px 16px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-1);
  border-radius: 8px;
  transition: color .15s ease, background .15s ease;
}
.main-nav a:hover { color: var(--text-0); background: rgba(255,255,255,0.05); }
.main-nav a.active { color: var(--navy-950); background: var(--cyan); }

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: 8px;
  background: transparent;
  border: 1px solid var(--line-strong);
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-0);
  transition: border-color .15s ease, background .15s ease;
}
.nav-cta:hover { border-color: var(--cyan); background: rgba(34,211,238,0.08); }

.nav-toggle {
  display: none;
  width: 40px; height: 40px;
  border-radius: 8px;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--text-0);
  font-size: 1.2rem;
  cursor: pointer;
}

/* ---------- 히어로 ---------- */
.hero {
  padding: 96px 0 76px;
  border-bottom: 1px solid var(--line);
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  color: var(--cyan);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 24px;
}
.eyebrow .dot {
  width: 7px; height: 7px; border-radius: 999px; background: var(--cyan);
  box-shadow: 0 0 10px var(--cyan);
}
.hero h1 {
  font-size: clamp(2.1rem, 4.4vw, 3.4rem);
  line-height: 1.22;
  color: var(--text-0);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 22px;
  max-width: 780px;
}
.hero h1 em {
  font-style: normal;
  background: linear-gradient(90deg, var(--cyan), #67e8f9);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p.lead {
  font-size: 1.08rem;
  color: var(--text-1);
  max-width: 620px;
  margin: 0 0 34px;
}
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 56px; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 26px;
  border-radius: 10px;
  font-weight: 700;
  font-size: 0.98rem;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform .15s ease, box-shadow .15s ease, opacity .15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(90deg, var(--cyan-strong), var(--cyan));
  color: var(--navy-950);
  box-shadow: 0 8px 24px rgba(34, 211, 238, 0.25);
}
.btn-ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--text-0);
}
.btn-ghost:hover { border-color: var(--cyan); }

.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.stat-row .stat {
  padding: 22px 20px;
  border-right: 1px solid var(--line);
  background: rgba(255,255,255,0.02);
}
.stat-row .stat:last-child { border-right: none; }
.stat .num {
  font-size: 1.7rem;
  font-weight: 800;
  color: var(--text-0);
  letter-spacing: -0.01em;
}
.stat .num span { color: var(--cyan); }
.stat .label { font-size: 0.82rem; color: var(--text-2); margin-top: 6px; }

/* ---------- 섹션 공통 ---------- */
.section { padding: 84px 0; border-bottom: 1px solid var(--line); }
.section:last-of-type { border-bottom: none; }
.section-head { max-width: 680px; margin: 0 0 46px; }
.section-tag {
  color: var(--cyan);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 12px;
  display: block;
}
.section-head h2 {
  font-size: clamp(1.6rem, 2.6vw, 2.2rem);
  color: var(--text-0);
  font-weight: 800;
  margin: 0 0 14px;
  letter-spacing: -0.01em;
}
.section-head p { color: var(--text-2); font-size: 1rem; margin: 0; }

/* ---------- 특허기술 카드 ---------- */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.tech-card {
  background: linear-gradient(180deg, var(--navy-800), var(--navy-900));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 26px;
  box-shadow: var(--shadow-card);
  transition: border-color .15s ease, transform .15s ease;
}
.tech-card:hover { border-color: rgba(34,211,238,0.4); transform: translateY(-3px); }
.tech-card .idx {
  font-size: 0.78rem;
  font-weight: 800;
  color: var(--cyan);
  letter-spacing: 0.1em;
  margin-bottom: 14px;
}
.tech-card h3 {
  color: var(--text-0);
  font-size: 1.15rem;
  margin: 0 0 12px;
  font-weight: 800;
}
.tech-card p { color: var(--text-2); font-size: 0.92rem; margin: 0 0 16px; }
.tech-card .kv { display: flex; flex-direction: column; gap: 8px; }
.tech-card .kv div {
  display: flex; justify-content: space-between; gap: 10px;
  font-size: 0.85rem; padding: 8px 0; border-top: 1px solid var(--line);
}
.tech-card .kv div b { color: var(--text-0); font-weight: 700; }
.tech-card .kv div span.badge {
  color: var(--ok); font-weight: 700;
}

/* ---------- 비교 테이블 ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
table.compare {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
  font-size: 0.92rem;
}
table.compare th, table.compare td {
  padding: 14px 18px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}
table.compare thead th {
  background: rgba(255,255,255,0.03);
  color: var(--text-0);
  font-weight: 800;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
table.compare tbody tr:last-child td { border-bottom: none; }
table.compare td.hl { color: var(--cyan); font-weight: 800; }
table.compare th:first-child, table.compare td:first-child { position: sticky; left: 0; background: var(--navy-900); }

/* ---------- 응용처 / 타겟 마켓 ---------- */
.app-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 14px;
}
.app-chip {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px 16px;
  background: rgba(255,255,255,0.02);
  text-align: center;
}
.app-chip .year { color: var(--cyan); font-size: 0.76rem; font-weight: 800; }
.app-chip .name { color: var(--text-0); font-weight: 700; font-size: 0.95rem; margin-top: 6px; }

/* ---------- 파트너 / 레퍼런스 ---------- */
.partner-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}
.partner-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  background: rgba(255,255,255,0.02);
}
.partner-card .tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--navy-950);
  background: var(--cyan);
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 12px;
}
.partner-card .tag.alt { background: var(--amber); }
.partner-card h4 { color: var(--text-0); margin: 0 0 8px; font-size: 1.02rem; }
.partner-card p { margin: 0; color: var(--text-2); font-size: 0.88rem; }

/* ---------- 비디오 섹션 ---------- */
.video-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.video-card h4 {
  color: var(--text-0);
  font-size: 0.98rem;
  font-weight: 700;
  margin: 14px 0 0;
  line-height: 1.4;
}
.video-frame {
  position: relative;
  display: block;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--navy-800);
  aspect-ratio: 16 / 9;
  box-shadow: var(--shadow-card);
}
.video-frame iframe, .video-frame video {
  width: 100%; height: 100%; border: 0; display: block;
}
.video-frame img {
  width: 100%; height: 100%; object-fit: cover; display: block;
  transition: transform .25s ease;
}
.video-frame:hover img { transform: scale(1.04); }
.video-frame .play-btn {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 58px; height: 58px;
  border-radius: 999px;
  background: rgba(6, 11, 22, 0.72);
  border: 1px solid rgba(255,255,255,0.35);
  display: flex; align-items: center; justify-content: center;
  color: var(--cyan);
  font-size: 1.1rem;
  backdrop-filter: blur(2px);
  transition: background .2s ease, transform .2s ease;
}
.video-frame:hover .play-btn {
  background: var(--cyan);
  color: var(--navy-950);
  transform: translate(-50%, -50%) scale(1.08);
}
@media (max-width: 900px) {
  .video-grid { grid-template-columns: 1fr; }
}

/* ---------- 제품 카드 (장비소개) ---------- */
.product-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px;
  background: linear-gradient(180deg, rgba(255,255,255,0.02), transparent);
  margin-bottom: 26px;
}
.product-card .head {
  display: flex; align-items: flex-start; justify-content: space-between; gap: 20px;
  flex-wrap: wrap; margin-bottom: 20px;
}
.product-card h3 { color: var(--text-0); font-size: 1.5rem; margin: 0 0 6px; font-weight: 800; }
.product-card .sub { color: var(--cyan); font-size: 0.9rem; font-weight: 700; }
.product-card .desc { color: var(--text-2); font-size: 0.95rem; max-width: 720px; margin: 14px 0 22px; }
.spec-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
}
.spec-grid .spec {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px 16px;
  background: rgba(255,255,255,0.02);
}
.spec-grid .spec .k { font-size: 0.76rem; color: var(--text-2); margin-bottom: 6px; }
.spec-grid .spec .v { font-size: 1.02rem; color: var(--text-0); font-weight: 800; }
.pill {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--text-1);
  margin: 0 6px 6px 0;
}
.pill.on { border-color: var(--cyan); color: var(--cyan); }

/* ---------- 게시판 ---------- */
.board-tabs { display: flex; gap: 8px; margin-bottom: 24px; flex-wrap: wrap; }
.board-tab {
  padding: 9px 18px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--text-1);
  cursor: pointer;
  background: transparent;
}
.board-tab.active { background: var(--cyan); border-color: var(--cyan); color: var(--navy-950); }

.board-list { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.board-row {
  display: grid;
  grid-template-columns: 96px 1fr 130px;
  gap: 16px;
  align-items: center;
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
  cursor: pointer;
  transition: background .15s ease;
}
.board-row:last-child { border-bottom: none; }
.board-row:hover { background: rgba(255,255,255,0.03); }
.board-row .cat {
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--cyan);
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  padding: 4px 8px;
  text-align: center;
}
.board-row .title { color: var(--text-0); font-weight: 700; font-size: 0.98rem; }
.board-row .title .new {
  display: inline-block; color: var(--amber); font-weight: 800; font-size: 0.76rem; margin-left: 8px;
}
.board-row .excerpt { color: var(--text-2); font-size: 0.84rem; margin-top: 4px; }
.board-row .date { color: var(--text-2); font-size: 0.84rem; text-align: right; }
.board-empty { padding: 60px 20px; text-align: center; color: var(--text-2); }

.board-detail {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px;
  display: none;
}
.board-detail.open { display: block; }
.board-detail .back {
  display: inline-flex; align-items: center; gap: 6px;
  color: var(--cyan); font-weight: 700; font-size: 0.88rem; margin-bottom: 22px; cursor: pointer;
}
.board-detail h2 { color: var(--text-0); font-size: 1.4rem; margin: 0 0 10px; }
.board-detail .meta { color: var(--text-2); font-size: 0.84rem; margin-bottom: 24px; }
.board-detail .body { color: var(--text-1); font-size: 0.96rem; line-height: 1.8; white-space: pre-line; }

.notice-banner {
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  padding: 18px 20px;
  color: var(--text-2);
  font-size: 0.86rem;
  margin-bottom: 28px;
  background: rgba(34,211,238,0.04);
}
.notice-banner b { color: var(--cyan); }

/* ---------- CTA 섹션 ---------- */
.cta-band {
  padding: 70px 0;
  text-align: center;
  background: radial-gradient(ellipse 70% 100% at 50% 0%, rgba(34,211,238,0.10), transparent 70%);
}
.cta-band h2 { color: var(--text-0); font-size: clamp(1.5rem, 2.6vw, 2rem); margin: 0 0 14px; font-weight: 800; }
.cta-band p { color: var(--text-2); margin: 0 0 30px; }

/* ---------- 푸터 ---------- */
.site-footer { background: var(--navy-900); border-top: 1px solid var(--line); padding: 56px 0 30px; }
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
.footer-grid h5 { color: var(--text-0); font-size: 0.9rem; margin: 0 0 16px; }
.footer-grid p, .footer-grid li { color: var(--text-2); font-size: 0.88rem; }
.footer-grid li { margin-bottom: 10px; }
.footer-grid li a:hover { color: var(--cyan); }
.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: 24px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px;
  color: var(--text-2); font-size: 0.82rem;
}

/* ---------- 반응형 ---------- */
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr; }
  .tech-grid { grid-template-columns: 1fr; }
  .stat-row { grid-template-columns: repeat(2, 1fr); }
  .stat-row .stat:nth-child(2) { border-right: none; }
}

@media (max-width: 760px) {
  .main-nav, .nav-cta { display: none; }
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
  .site-header.open .main-nav {
    display: flex; flex-direction: column; align-items: stretch;
    position: absolute; top: 72px; left: 0; right: 0;
    background: var(--navy-900); border-bottom: 1px solid var(--line);
    padding: 12px 24px 20px;
  }
  .site-header.open .nav-cta { display: inline-flex; margin: 4px 24px 20px; }
  .hero { padding: 56px 0 48px; }
  .section { padding: 56px 0; }
  .board-row { grid-template-columns: 1fr; gap: 6px; }
  .board-row .date { text-align: left; }
}