/* ============================================================
   ResearchTECH — style.css
   Dark modern. Ink black base, gold→cyan ribbon signature.
   ============================================================ */

:root{
  --ink:        #0A0B0D;
  --ink-2:      #0E1014;
  --card:       #15181D;
  --card-2:     #1A1E25;
  --line:       rgba(255,255,255,.08);
  --line-2:     rgba(255,255,255,.14);
  --gold:       #D4A437;
  --gold-lt:    #E8C56B;
  --cyan:       #39CFE0;
  --cyan-lt:    #7FE3EE;
  --text:       #F3F5F7;
  --text-2:     #A3ABB5;
  --text-3:     #6B7480;

  --grad: linear-gradient(105deg, var(--gold) 0%, #C9C065 42%, var(--cyan) 100%);

  --maxw: 1180px;
  --pad: 24px;
  --r: 16px;
  --ease: cubic-bezier(.22,.61,.36,1);

  --f-display: 'Poppins', 'Pretendard Variable', sans-serif;
  --f-body: 'Pretendard Variable', 'Poppins', sans-serif;
  --f-mono: 'Michroma', 'Poppins', sans-serif;
}

*{ box-sizing:border-box; margin:0; padding:0; }
html{ scroll-behavior:smooth; -webkit-text-size-adjust:100%; }
body{
  font-family:var(--f-body);
  background:var(--ink);
  color:var(--text);
  line-height:1.6;
  letter-spacing:-.01em;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
a{ color:inherit; text-decoration:none; }
ul{ list-style:none; }
img{ max-width:100%; display:block; }

.container{ width:100%; max-width:var(--maxw); margin:0 auto; padding:0 var(--pad); }

.grad{
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  -webkit-text-fill-color:transparent;
  color:transparent;
}

/* ---------- eyebrow / section heads ---------- */
.eyebrow{
  font-family:var(--f-mono);
  font-size:.72rem;
  letter-spacing:.22em;
  color:var(--text-3);
  text-transform:uppercase;
  margin-bottom:18px;
}
.section{ padding:120px 0; position:relative; }
.section-head{ max-width:760px; margin-bottom:64px; }
.section-title{
  font-family:var(--f-display);
  font-weight:600;
  font-size:clamp(1.8rem, 4.2vw, 2.9rem);
  line-height:1.22;
  letter-spacing:-.02em;
}
.section-lead{
  margin-top:18px;
  font-size:1.15rem;
  color:var(--text-2);
  font-weight:500;
}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex; align-items:center; justify-content:center;
  font-family:var(--f-display); font-weight:600; font-size:.98rem;
  padding:14px 28px; border-radius:999px;
  transition:transform .25s var(--ease), box-shadow .25s var(--ease), background .25s var(--ease), color .25s var(--ease);
  cursor:pointer; border:1px solid transparent; white-space:nowrap;
}
.btn-primary{
  background:var(--grad); color:#0A0B0D;
  box-shadow:0 6px 24px -8px rgba(57,207,224,.5);
}
.btn-primary:hover{ transform:translateY(-2px); box-shadow:0 12px 34px -8px rgba(57,207,224,.65); }
.btn-ghost{
  background:transparent; color:var(--text); border-color:var(--line-2);
}
.btn-ghost:hover{ border-color:var(--cyan); color:var(--cyan); transform:translateY(-2px); }
.btn-lg{ padding:17px 38px; font-size:1.05rem; }

/* ============================================================
   HEADER
   ============================================================ */
.site-header{
  position:fixed; top:0; left:0; right:0; z-index:100;
  transition:background .3s var(--ease), border-color .3s var(--ease), backdrop-filter .3s var(--ease);
  border-bottom:1px solid transparent;
}
.site-header.scrolled{
  background:rgba(10,11,13,.72);
  backdrop-filter:blur(14px) saturate(140%);
  -webkit-backdrop-filter:blur(14px) saturate(140%);
  border-bottom-color:var(--line);
}
.header-inner{ display:flex; align-items:center; justify-content:space-between; height:72px; }
.brand-logo{ height:40px; width:auto; }
.nav{ display:flex; align-items:center; gap:34px; }
.nav a{
  font-size:.95rem; color:var(--text-2); font-weight:500;
  transition:color .2s var(--ease); position:relative;
}
.nav a:not(.nav-cta):hover{ color:var(--text); }
.nav a:not(.nav-cta)::after{
  content:''; position:absolute; left:0; bottom:-6px; height:1.5px; width:0;
  background:var(--grad); transition:width .25s var(--ease);
}
.nav a:not(.nav-cta):hover::after{ width:100%; }
.nav-cta{
  padding:9px 20px; border:1px solid var(--line-2); border-radius:999px;
  color:var(--text)!important; font-weight:600;
  transition:border-color .2s var(--ease), color .2s var(--ease), background .2s var(--ease);
}
.nav-cta:hover{ border-color:var(--cyan); color:var(--cyan)!important; }

.nav-toggle{
  display:none; flex-direction:column; gap:5px; background:none; border:0; cursor:pointer; padding:8px;
}
.nav-toggle span{ width:24px; height:2px; background:var(--text); border-radius:2px; transition:transform .3s var(--ease), opacity .3s var(--ease); }
.nav-toggle.open span:nth-child(1){ transform:translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2){ opacity:0; }
.nav-toggle.open span:nth-child(3){ transform:translateY(-7px) rotate(-45deg); }

/* ============================================================
   HERO
   ============================================================ */
.hero{
  position:relative; min-height:100vh; display:flex; align-items:center;
  padding:120px 0 80px; overflow:hidden;
}
.hero-bg{ position:absolute; inset:0; z-index:0; }
.hero-bg::before{
  /* radial glow */
  content:''; position:absolute; inset:0;
  background:
    radial-gradient(60% 50% at 18% 30%, rgba(212,164,55,.10), transparent 70%),
    radial-gradient(55% 50% at 82% 70%, rgba(57,207,224,.12), transparent 72%);
}
.hero-bg::after{
  /* bottom fade into next section */
  content:''; position:absolute; inset:0;
  background:linear-gradient(180deg, transparent 55%, var(--ink) 100%);
}
.ribbon-flow{ position:absolute; inset:0; width:100%; height:100%; opacity:.5; }
.flow{ stroke-linecap:round; }
.flow-1{ opacity:.7; }
.flow-2{ opacity:.45; }
.flow-3{ opacity:.3; }

.hero-inner{ position:relative; z-index:1; }
.hero-title{
  font-family:var(--f-display); font-weight:700;
  font-size:clamp(2.6rem, 8vw, 5.4rem);
  line-height:1.04; letter-spacing:-.03em; margin-bottom:28px;
}
.hero-sub{
  font-size:clamp(1rem, 2.1vw, 1.28rem); color:var(--text-2);
  max-width:620px; margin-bottom:34px; font-weight:400;
}
.hero-keywords{
  display:flex; flex-wrap:wrap; gap:10px; margin-bottom:42px;
}
.hero-keywords li{
  font-family:var(--f-display); font-size:.86rem; font-weight:500;
  color:var(--text-2);
  padding:8px 16px; border:1px solid var(--line); border-radius:999px;
  background:rgba(255,255,255,.02);
}
.hero-actions{ display:flex; gap:14px; flex-wrap:wrap; }

.scroll-cue{
  position:absolute; bottom:34px; left:50%; transform:translateX(-50%); z-index:1;
  width:26px; height:42px; border:1.5px solid var(--line-2); border-radius:999px;
  display:flex; justify-content:center; padding-top:8px;
}
.scroll-cue span{ width:3px; height:8px; border-radius:3px; background:var(--cyan); animation:scrollcue 1.8s var(--ease) infinite; }
@keyframes scrollcue{ 0%{opacity:0; transform:translateY(0);} 30%{opacity:1;} 100%{opacity:0; transform:translateY(14px);} }

/* ============================================================
   WHY  — equation
   ============================================================ */
.why{ background:var(--ink); }
.equation{
  display:grid; grid-template-columns:1fr auto 1fr auto 1fr; gap:18px; align-items:stretch;
  margin-bottom:46px;
}
.eq-card{
  background:var(--card); border:1px solid var(--line); border-radius:var(--r);
  padding:30px 26px; display:flex; flex-direction:column; gap:12px;
}
.eq-result{ border-color:rgba(57,207,224,.35); background:linear-gradient(160deg, rgba(212,164,55,.06), rgba(57,207,224,.06)); }
.eq-tag{ font-family:var(--f-display); font-weight:600; font-size:1.12rem; }
.eq-result .eq-tag{ font-size:1.3rem; }
.eq-body{ color:var(--text-2); font-size:.96rem; }
.eq-op{
  display:flex; align-items:center; justify-content:center;
  font-family:var(--f-mono); font-size:1.6rem; color:var(--text-3);
}
.why-note{
  font-size:clamp(1rem, 1.85vw, 1.3rem); line-height:1.6; color:var(--text);
  font-weight:400; white-space:nowrap;
}
.why-note strong{ font-weight:600; color:var(--cyan-lt); }

/* ============================================================
   APPROACH — compare
   ============================================================ */
.approach{ background:var(--ink-2); border-block:1px solid var(--line); }
.compare{ display:grid; grid-template-columns:1fr 1fr; gap:22px; }
.compare-col{ border-radius:var(--r); padding:36px 32px; border:1px solid var(--line); }
.compare-them{ background:var(--card); }
.compare-us{ background:linear-gradient(160deg, rgba(212,164,55,.07), rgba(57,207,224,.07)); border-color:rgba(57,207,224,.32); }
.compare-col h3{ font-family:var(--f-display); font-weight:600; font-size:1.3rem; margin-bottom:22px; }
.compare-them h3{ color:var(--text-3); }
.compare-us h3{ color:var(--cyan-lt); }
.compare-col ul{ display:flex; flex-direction:column; gap:14px; }
.compare-col li{ position:relative; padding-left:26px; color:var(--text-2); font-size:.98rem; line-height:1.55; }
.compare-them li::before{ content:'—'; position:absolute; left:0; color:var(--text-3); }
.compare-us li{ color:var(--text); }
.compare-us li::before{
  content:''; position:absolute; left:0; top:.55em; width:13px; height:8px;
  border-left:2px solid var(--cyan); border-bottom:2px solid var(--cyan);
  transform:rotate(-45deg);
}

/* ============================================================
   SERVICES
   ============================================================ */
.services{ background:var(--ink); }
.svc-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:18px; }
.svc-card{
  background:var(--card); border:1px solid var(--line); border-radius:var(--r);
  padding:30px 28px; position:relative; overflow:hidden;
  transition:transform .3s var(--ease), border-color .3s var(--ease), background .3s var(--ease);
}
.svc-card::before{
  content:''; position:absolute; left:0; top:0; height:100%; width:3px;
  background:var(--grad); transform:scaleY(0); transform-origin:top; transition:transform .35s var(--ease);
}
.svc-card:hover{ transform:translateY(-4px); border-color:var(--line-2); background:var(--card-2); }
.svc-card:hover::before{ transform:scaleY(1); }
.svc-num{
  font-family:var(--f-mono); font-size:.92rem; color:var(--text-3); letter-spacing:.05em;
  display:block; margin-bottom:14px;
}
.svc-card h3{ font-family:var(--f-display); font-weight:600; font-size:1.2rem; margin-bottom:18px; letter-spacing:-.01em; }
.svc-card ul{ display:flex; flex-direction:column; gap:9px; }
.svc-card li{ color:var(--text-2); font-size:.92rem; padding-left:15px; position:relative; }
.svc-card li::before{
  content:''; position:absolute; left:0; top:.62em; width:5px; height:5px; border-radius:1px;
  background:var(--gold); opacity:.8; transform:rotate(45deg);
}

/* ============================================================
   USE CASES
   ============================================================ */
.cases{ background:var(--ink-2); border-block:1px solid var(--line); }
.case-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:18px; margin-bottom:26px; }
.case-card{
  background:var(--card); border:1px solid var(--line); border-radius:var(--r); padding:34px 30px;
  transition:transform .3s var(--ease), border-color .3s var(--ease);
}
.case-card:hover{ transform:translateY(-4px); border-color:rgba(57,207,224,.32); }
.case-num{ font-family:var(--f-mono); font-size:1.6rem; color:transparent; background:var(--grad); -webkit-background-clip:text; background-clip:text; display:block; margin-bottom:16px; }
.case-card h3{ font-family:var(--f-display); font-weight:600; font-size:1.22rem; margin-bottom:12px; }
.case-card p{ color:var(--text-2); font-size:.96rem; }
.case-note{ color:var(--text-3); font-size:.85rem; }

/* ============================================================
   TEAM
   ============================================================ */
.team{ background:var(--ink); }
.team-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:18px; margin-bottom:26px; }
.member{
  background:var(--card); border:1px solid var(--line); border-radius:var(--r);
  padding:32px 28px; transition:transform .3s var(--ease), border-color .3s var(--ease);
}
.member:hover{ transform:translateY(-4px); border-color:var(--line-2); }
.member-photo{
  width:64px; height:64px; border-radius:16px; margin-bottom:22px;
  display:flex; align-items:center; justify-content:center;
  background:linear-gradient(160deg, rgba(212,164,55,.18), rgba(57,207,224,.18));
  border:1px solid var(--line-2);
}
.member-photo span{ font-family:var(--f-mono); font-size:1.4rem; color:var(--cyan-lt); }
.member-body h3{ font-family:var(--f-display); font-weight:600; font-size:1.4rem; margin-bottom:6px; }
.member-role{ color:var(--gold-lt); font-size:.92rem; font-weight:500; margin-bottom:4px; }
.member-career{ font-family:var(--f-mono); font-size:.72rem; color:var(--text-3); letter-spacing:.04em; margin-bottom:16px; }
.member-desc{ color:var(--text-2); font-size:.94rem; }
.team-note{ color:var(--text-3); font-size:.85rem; }

/* ============================================================
   CONTACT
   ============================================================ */
.contact{ background:var(--ink-2); padding:120px 0; }
.contact-card{
  position:relative; overflow:hidden;
  background:
    radial-gradient(70% 120% at 50% -10%, rgba(57,207,224,.12), transparent 60%),
    var(--card);
  border:1px solid var(--line-2); border-radius:28px;
  padding:70px 40px; text-align:center;
}
.contact-symbol{ width:60px; height:60px; margin:0 auto 24px; opacity:.95; }
.contact .eyebrow{ margin-bottom:14px; }
.contact-title{
  font-family:var(--f-display); font-weight:600;
  font-size:clamp(1.7rem, 4.2vw, 2.7rem); line-height:1.25; letter-spacing:-.02em;
  margin-bottom:16px;
}
.contact-sub{ color:var(--text-2); font-size:1.05rem; margin-bottom:40px; }
.contact-lines{ display:flex; justify-content:center; gap:14px; flex-wrap:wrap; margin-bottom:38px; }
.contact-line{
  display:flex; flex-direction:column; gap:6px; align-items:center;
  padding:18px 30px; border:1px solid var(--line); border-radius:14px; min-width:240px;
  background:rgba(255,255,255,.02);
  transition:border-color .25s var(--ease), transform .25s var(--ease);
}
.contact-line:hover{ border-color:var(--cyan); transform:translateY(-2px); }
.cl-label{ font-family:var(--f-mono); font-size:.66rem; letter-spacing:.2em; color:var(--text-3); }
.cl-value{ font-size:1.05rem; font-weight:500; color:var(--text); }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer{ background:var(--ink); border-top:1px solid var(--line); padding:54px 0; }
.footer-inner{ display:flex; flex-direction:column; align-items:center; gap:12px; text-align:center; }
.footer-logo{ height:26px; width:auto; opacity:.9; }
.footer-tag{ font-family:var(--f-mono); font-size:.7rem; letter-spacing:.18em; color:var(--text-3); text-transform:uppercase; }
.footer-copy{ color:var(--text-3); font-size:.84rem; }

/* ============================================================
   REVEAL ANIMATION
   ============================================================ */
.reveal{ opacity:0; transform:translateY(24px); transition:opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in{ opacity:1; transform:none; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width:980px){
  .svc-grid{ grid-template-columns:repeat(2,1fr); }
  .case-grid{ grid-template-columns:1fr; }
  .team-grid{ grid-template-columns:1fr; }
  .equation{ grid-template-columns:1fr; }
  .eq-op{ transform:rotate(90deg); font-size:1.3rem; padding:4px 0; }
  .why-note{ white-space:normal; font-size:1.12rem; }
}
@media (max-width:760px){
  .section{ padding:88px 0; }
  .section-head{ margin-bottom:44px; }
  .nav{
    position:fixed; inset:0 0 0 auto; width:min(78vw,320px);
    flex-direction:column; align-items:flex-start; justify-content:center; gap:26px;
    background:rgba(12,14,18,.97); backdrop-filter:blur(18px);
    padding:0 40px; transform:translateX(100%); transition:transform .35s var(--ease);
    border-left:1px solid var(--line);
  }
  .nav.open{ transform:translateX(0); }
  .nav a{ font-size:1.2rem; }
  .nav-toggle{ display:flex; z-index:101; }
  .compare{ grid-template-columns:1fr; }
  .contact{ padding:88px 0; }
  .contact-card{ padding:54px 24px; }
  .contact-line{ min-width:100%; }
}
@media (max-width:480px){
  .svc-grid{ grid-template-columns:1fr; }
  .hero-keywords li{ font-size:.78rem; padding:7px 13px; }
}

/* ============================================================
   CONTACT MODAL
   ============================================================ */
.modal-overlay{
  position:fixed; inset:0; z-index:200;
  display:flex; align-items:center; justify-content:center;
  padding:24px;
  background:rgba(5,6,8,.72);
  backdrop-filter:blur(8px); -webkit-backdrop-filter:blur(8px);
  opacity:0; transition:opacity .28s var(--ease);
}
.modal-overlay.open{ opacity:1; }
.modal-overlay[hidden]{ display:none; }

.modal{
  position:relative;
  display:grid; grid-template-columns:.82fr 1.18fr;
  width:100%; max-width:920px; max-height:90vh; overflow:hidden;
  background:var(--card); border:1px solid var(--line-2); border-radius:24px;
  transform:translateY(12px) scale(.97); opacity:.6;
  transition:transform .3s var(--ease), opacity .3s var(--ease);
}
.modal-overlay.open .modal{ transform:none; opacity:1; }

.modal-close{
  position:absolute; top:16px; right:16px; z-index:3;
  width:38px; height:38px; border-radius:50%;
  display:flex; align-items:center; justify-content:center;
  background:rgba(255,255,255,.05); border:1px solid var(--line); color:var(--text-2);
  cursor:pointer; transition:background .2s var(--ease), color .2s var(--ease), border-color .2s var(--ease);
}
.modal-close:hover{ background:rgba(255,255,255,.1); color:var(--text); border-color:var(--line-2); }

/* left info panel */
.modal-info{
  padding:42px 34px;
  background:
    radial-gradient(80% 60% at 20% 10%, rgba(212,164,55,.12), transparent 70%),
    radial-gradient(80% 60% at 90% 100%, rgba(57,207,224,.14), transparent 72%),
    var(--card-2);
  border-right:1px solid var(--line);
  display:flex; flex-direction:column;
}
.modal-symbol{ width:46px; height:46px; margin-bottom:24px; }
.modal-info .eyebrow{ margin-bottom:12px; }
.modal-title{
  font-family:var(--f-display); font-weight:600; font-size:1.8rem; line-height:1.2;
  letter-spacing:-.02em; margin-bottom:16px;
}
.modal-info-sub{ color:var(--text-2); font-size:.95rem; margin-bottom:auto; }
.modal-info-list{ display:flex; flex-direction:column; gap:18px; margin-top:34px; }
.modal-info-list li{ display:flex; flex-direction:column; gap:5px; }
.mi-label{ font-family:var(--f-mono); font-size:.62rem; letter-spacing:.18em; color:var(--text-3); }
.mi-value{ font-size:1rem; font-weight:500; color:var(--text); transition:color .2s var(--ease); }
.mi-value:hover{ color:var(--cyan); }

/* right form panel */
.modal-form-wrap{ padding:42px 38px; overflow-y:auto; }
.modal-form{ display:flex; flex-direction:column; gap:18px; }
.field{ display:flex; flex-direction:column; gap:7px; }
.field label{ font-size:.84rem; color:var(--text-2); font-weight:500; }
.field label span{ color:var(--cyan); }
.field input, .field textarea{
  font-family:var(--f-body); font-size:.97rem; color:var(--text);
  background:rgba(255,255,255,.03); border:1px solid var(--line); border-radius:10px;
  padding:13px 15px; width:100%; transition:border-color .2s var(--ease), background .2s var(--ease);
}
.field textarea{ resize:vertical; min-height:104px; line-height:1.55; }
.field input::placeholder, .field textarea::placeholder{ color:var(--text-3); }
.field input:focus, .field textarea:focus{
  outline:none; border-color:var(--cyan); background:rgba(57,207,224,.04);
}
.field.invalid input, .field.invalid textarea{ border-color:#E5616B; }

.field-check{ display:flex; align-items:flex-start; gap:10px; cursor:pointer; }
.field-check input{ width:17px; height:17px; margin-top:2px; accent-color:var(--cyan); flex-shrink:0; cursor:pointer; }
.field-check span{ font-size:.82rem; color:var(--text-3); line-height:1.5; }
.field-check.invalid span{ color:#E5868D; }

.form-status{ font-size:.85rem; min-height:1.2em; margin:-4px 0 0; }
.form-status.error{ color:#E5868D; }
.form-status.ok{ color:var(--cyan-lt); }

.modal-submit{ margin-top:4px; width:100%; }

@media (max-width:760px){
  .modal{ grid-template-columns:1fr; max-height:92vh; overflow-y:auto; }
  .modal-info{ border-right:0; border-bottom:1px solid var(--line); padding:38px 28px 30px; }
  .modal-title{ font-size:1.55rem; }
  .modal-info-list{ margin-top:26px; flex-direction:row; flex-wrap:wrap; gap:22px; }
  .modal-form-wrap{ padding:30px 28px 34px; }
}

/* ============================================================
   ACCESSIBILITY
   ============================================================ */
:focus-visible{ outline:2px solid var(--cyan); outline-offset:3px; border-radius:4px; }
@media (prefers-reduced-motion:reduce){
  *{ animation:none!important; transition:none!important; scroll-behavior:auto!important; }
  .reveal{ opacity:1; transform:none; }
}