/* ============================================================
   배움과 나눔 연구소 — 공유 스타일
   강정석 산업현장교수 홈페이지
============================================================ */

/* ----- Reset ----- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
:root{
  --bg:       #0A0F1E;
  --bg2:      #0F1629;
  --card:     #111827;
  --card2:    #1a2235;
  --border:   rgba(255,255,255,0.08);
  --blue:     #3B82F6;
  --blue-d:   #2563EB;
  --red:      #EF4444;
  --gold:     #F59E0B;
  --gold-d:   #D97706;
  --green:    #10B981;
  --white:    #F9FAFB;
  --gray:     #9CA3AF;
  --gray2:    #6B7280;
  --kakao:    #FEE500;
  --r:        14px;
  --r2:       20px;
  --t:        0.3s ease;
}
html{scroll-behavior:smooth;}
body{
  font-family:'Noto Sans KR',sans-serif;
  background:var(--bg);
  color:var(--white);
  line-height:1.7;
  overflow-x:hidden;
}
a{text-decoration:none;color:inherit;}
ul{list-style:none;}
img{max-width:100%;display:block;}

/* ----- Layout ----- */
.container{max-width:1100px;margin:0 auto;padding:0 24px;}
.section{padding:100px 0;}

/* ----- Tags & Dividers ----- */
.tag{
  display:inline-block;
  font-size:11px;font-weight:700;letter-spacing:.12em;
  text-transform:uppercase;
  padding:5px 14px;border-radius:100px;
  background:rgba(59,130,246,.15);
  color:var(--blue);
  border:1px solid rgba(59,130,246,.3);
  margin-bottom:18px;
}
.tag.gold{background:rgba(245,158,11,.12);color:var(--gold);border-color:rgba(245,158,11,.3);}
.tag.red{background:rgba(239,68,68,.12);color:var(--red);border-color:rgba(239,68,68,.3);}
.tag.green{background:rgba(16,185,129,.12);color:var(--green);border-color:rgba(16,185,129,.3);}
.divider{
  width:48px;height:3px;
  background:linear-gradient(90deg,var(--blue),var(--gold));
  border-radius:2px;margin-bottom:32px;
}

/* ----- Typography ----- */
.sec-title{font-size:clamp(28px,4vw,44px);font-weight:900;line-height:1.2;margin-bottom:16px;}
.sec-sub{font-size:16px;color:var(--gray);line-height:1.85;max-width:560px;}
.page-title{
  font-size:clamp(32px,5vw,56px);font-weight:900;line-height:1.15;
  margin-bottom:20px;
}
.page-title em{font-style:normal;color:var(--blue);}
.page-desc{font-size:17px;color:var(--gray);line-height:1.9;max-width:560px;}

/* ----- Buttons ----- */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:14px 28px;border-radius:10px;
  font-size:15px;font-weight:700;
  cursor:pointer;border:none;transition:all var(--t);
  font-family:'Noto Sans KR',sans-serif;
}
.btn-blue{background:var(--blue);color:#fff;}
.btn-blue:hover{background:var(--blue-d);transform:translateY(-2px);box-shadow:0 8px 24px rgba(59,130,246,.35);}
.btn-outline{background:transparent;color:var(--white);border:1.5px solid rgba(255,255,255,.25);}
.btn-outline:hover{border-color:var(--blue);color:var(--blue);}
.btn-kakao{background:var(--kakao);color:#191919;}
.btn-kakao:hover{background:#f0d800;transform:translateY(-2px);box-shadow:0 8px 24px rgba(254,229,0,.4);}
.btn-sm{padding:10px 20px;font-size:13px;}

/* ----- Cards ----- */
.card{
  background:var(--card);border:1px solid var(--border);
  border-radius:var(--r2);
  transition:transform var(--t),border-color var(--t),box-shadow var(--t);
}
.card:hover{
  border-color:rgba(59,130,246,.3);
  box-shadow:0 12px 40px rgba(0,0,0,.5);
}

/* ----- Fade animations ----- */
.fade{opacity:0;transform:translateY(32px);transition:opacity .65s ease,transform .65s ease;}
.fade.in{opacity:1;transform:none;}
.fade-d1{transition-delay:.1s;}
.fade-d2{transition-delay:.2s;}
.fade-d3{transition-delay:.3s;}
.fade-d4{transition-delay:.4s;}

/* ============================================================
   HEADER
============================================================ */
#hd{
  position:fixed;top:0;left:0;right:0;z-index:999;
  background:rgba(10,15,30,.85);
  backdrop-filter:blur(16px);
  border-bottom:1px solid var(--border);
  transition:box-shadow var(--t);
}
#hd.scrolled{box-shadow:0 2px 24px rgba(0,0,0,.5);}
.nav{display:flex;align-items:center;justify-content:space-between;height:68px;}

.logo{display:flex;flex-direction:column;gap:2px;}
.logo-main{font-size:15px;font-weight:800;color:var(--white);line-height:1;}
.logo-sub{font-size:10px;color:var(--gray);letter-spacing:.06em;}

.nav-links{display:flex;gap:24px;}
.nav-links a{
  font-size:13px;font-weight:500;color:var(--gray);
  position:relative;padding-bottom:2px;transition:color var(--t);
}
.nav-links a::after{
  content:'';position:absolute;bottom:-2px;left:0;
  width:0;height:1.5px;background:var(--blue);
  border-radius:1px;transition:width var(--t);
}
.nav-links a:hover,.nav-links a.active{color:var(--white);}
.nav-links a:hover::after,.nav-links a.active::after{width:100%;}

.nav-cta .btn{padding:10px 18px;font-size:13px;}
.hamburger{display:none;flex-direction:column;gap:5px;cursor:pointer;padding:4px;}
.hamburger span{display:block;width:22px;height:2px;background:var(--white);border-radius:1px;transition:all var(--t);}
.mob-menu{
  display:none;flex-direction:column;
  padding:16px 24px 24px;gap:4px;
  background:var(--bg2);border-top:1px solid var(--border);
}
.mob-menu.open{display:flex;}
.mob-menu a{
  padding:12px 0;font-size:15px;font-weight:500;
  border-bottom:1px solid var(--border);color:var(--gray);transition:color var(--t);
}
.mob-menu a.active,.mob-menu a:hover{color:var(--white);}

/* ============================================================
   PAGE HERO (내부 페이지용)
============================================================ */
.page-hero{
  padding:140px 0 80px;
  background:radial-gradient(ellipse 70% 50% at 50% 30%,rgba(59,130,246,.07) 0%,transparent 70%),var(--bg2);
  border-bottom:1px solid var(--border);
  position:relative;overflow:hidden;
}
.page-hero::before{
  content:'';position:absolute;inset:0;
  background-image:radial-gradient(rgba(255,255,255,.03) 1px,transparent 1px);
  background-size:36px 36px;pointer-events:none;
}
.page-hero .container{position:relative;z-index:1;}
.breadcrumb{
  display:flex;align-items:center;gap:8px;
  font-size:12px;color:var(--gray2);margin-bottom:24px;
}
.breadcrumb a{color:var(--gray2);transition:color var(--t);}
.breadcrumb a:hover{color:var(--white);}
.breadcrumb span{color:var(--gray2);}

/* ============================================================
   IDENTITY STRIP
============================================================ */
.strip{
  background:linear-gradient(90deg,#0d1526,#111f3a,#0d1526);
  border-top:1px solid var(--border);border-bottom:1px solid var(--border);
  padding:32px 0;
}
.strip-inner{display:flex;justify-content:center;flex-wrap:wrap;}
.strip-item{
  display:flex;flex-direction:column;align-items:center;
  padding:12px 44px;border-right:1px solid rgba(255,255,255,.1);
}
.strip-item:last-child{border-right:none;}
.strip-num{
  font-size:38px;font-weight:900;line-height:1;
  background:linear-gradient(135deg,var(--gold),#fbbf24);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
}
.strip-lbl{font-size:13px;color:var(--gray);margin-top:4px;text-align:center;line-height:1.4;}

/* ============================================================
   CREDENTIAL CARD (cred-card)
============================================================ */
.cred-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;}
.cred-card{
  padding:20px;border-radius:var(--r);
  background:var(--card);border:1px solid var(--border);
  display:flex;align-items:flex-start;gap:14px;
  transition:all var(--t);
}
.cred-card:hover{border-color:rgba(59,130,246,.35);transform:translateY(-2px);}
.cred-icon{
  width:42px;height:42px;border-radius:10px;
  display:flex;align-items:center;justify-content:center;
  font-size:20px;flex-shrink:0;
}
.ci-blue{background:rgba(59,130,246,.12);}
.ci-red{background:rgba(239,68,68,.12);}
.ci-gold{background:rgba(245,158,11,.12);}
.ci-green{background:rgba(16,185,129,.12);}
.ci-purple{background:rgba(139,92,246,.12);}
.cred-title{font-size:13px;font-weight:700;color:var(--white);line-height:1.4;}
.cred-sub{font-size:12px;color:var(--gray2);margin-top:2px;}

/* ============================================================
   PROOF LAYERS
============================================================ */
.layers{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;}
.layer-card{border-radius:var(--r2);overflow:hidden;background:var(--card);border:1px solid var(--border);}
.layer-head{padding:20px 24px;display:flex;align-items:center;gap:14px;}
.layer-head.gold{background:linear-gradient(135deg,rgba(245,158,11,.18),rgba(217,119,6,.08));}
.layer-head.blue{background:linear-gradient(135deg,rgba(59,130,246,.18),rgba(37,99,235,.08));}
.layer-head.green{background:linear-gradient(135deg,rgba(16,185,129,.18),rgba(5,150,105,.08));}
.layer-num{width:36px;height:36px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:16px;font-weight:900;flex-shrink:0;}
.ln-gold{background:rgba(245,158,11,.2);color:var(--gold);}
.ln-blue{background:rgba(59,130,246,.2);color:var(--blue);}
.ln-green{background:rgba(16,185,129,.2);color:var(--green);}
.layer-title{font-size:16px;font-weight:800;}
.layer-sub{font-size:12px;color:var(--gray);margin-top:2px;}
.layer-body{padding:20px 24px;}
.layer-item{
  display:flex;align-items:flex-start;gap:10px;
  font-size:14px;color:var(--gray);
  padding:8px 0;border-bottom:1px solid var(--border);line-height:1.5;
}
.layer-item:last-child{border-bottom:none;}
.layer-dot{width:6px;height:6px;border-radius:50%;flex-shrink:0;margin-top:7px;}
.ld-gold{background:var(--gold);}
.ld-blue{background:var(--blue);}
.ld-green{background:var(--green);}

/* ============================================================
   SNS CARDS
============================================================ */
.sns-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;}
.sns-card{border-radius:var(--r2);overflow:hidden;background:var(--card);border:1px solid var(--border);display:flex;flex-direction:column;}
.sns-card-banner{height:8px;}
.scb-blue{background:linear-gradient(90deg,var(--blue),var(--blue-d));}
.scb-red{background:linear-gradient(90deg,var(--red),#b91c1c);}
.scb-gold{background:linear-gradient(90deg,var(--gold),var(--gold-d));}
.sns-card-body{padding:28px;flex:1;}
.sns-card-tag{font-size:10px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;margin-bottom:16px;}
.sct-blue{color:var(--blue);}
.sct-red{color:var(--red);}
.sct-gold{color:var(--gold);}
.sns-card-title{font-size:17px;font-weight:800;line-height:1.4;margin-bottom:16px;}
.sns-card-content{font-size:13px;color:var(--gray);line-height:1.9;white-space:pre-wrap;}
.sns-card-content strong{color:var(--white);}
.sns-card-footer{padding:14px 28px;border-top:1px solid var(--border);display:flex;justify-content:space-between;align-items:center;}
.sns-card-brand{font-size:11px;color:var(--gray2);}
.sns-copy-btn{
  display:flex;align-items:center;gap:6px;
  padding:6px 14px;border-radius:8px;
  font-size:12px;font-weight:700;
  background:var(--card2);border:1px solid var(--border);
  color:var(--gray);cursor:pointer;transition:all var(--t);
  font-family:'Noto Sans KR',sans-serif;
}
.sns-copy-btn:hover{border-color:var(--blue);color:var(--blue);}

/* ============================================================
   FORM
============================================================ */
.form-card{background:var(--card);border-radius:var(--r2);padding:36px;border:1px solid var(--border);}
.form-title{font-size:20px;font-weight:800;margin-bottom:6px;}
.form-sub{font-size:14px;color:var(--gray);margin-bottom:28px;}
.frow{margin-bottom:16px;}
.frow-2{display:grid;grid-template-columns:1fr 1fr;gap:12px;}
.frow-3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:12px;}
label{display:block;font-size:13px;font-weight:600;color:var(--white);margin-bottom:6px;}
label .req{color:var(--red);margin-left:2px;}
input,select,textarea{
  width:100%;padding:12px 14px;
  background:var(--bg2);border:1.5px solid var(--border);
  border-radius:8px;font-size:14px;font-family:'Noto Sans KR',sans-serif;
  color:var(--white);outline:none;transition:border-color var(--t),box-shadow var(--t);
}
input::placeholder,textarea::placeholder{color:var(--gray2);}
input:focus,select:focus,textarea:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(59,130,246,.15);}
input.err,textarea.err{border-color:var(--red);box-shadow:0 0 0 3px rgba(239,68,68,.12);}
select option{background:var(--bg2);color:var(--white);}
textarea{resize:vertical;min-height:96px;}
.err-msg{font-size:12px;color:var(--red);margin-top:4px;display:none;}
.radio-row{display:flex;gap:8px;flex-wrap:wrap;}
.rlabel{
  display:flex;align-items:center;gap:6px;cursor:pointer;
  font-size:13px;font-weight:500;color:var(--gray);
  padding:8px 14px;border-radius:8px;border:1.5px solid var(--border);
  transition:all var(--t);
}
.rlabel:hover{border-color:var(--blue);color:var(--white);}
.rlabel input[type="radio"]{width:auto;background:none;border:none;box-shadow:none;padding:0;}
.rlabel:has(input:checked){border-color:var(--blue);background:rgba(59,130,246,.1);color:var(--blue);font-weight:700;}
.submit-area{margin-top:24px;}
.btn-submit{
  width:100%;padding:17px;
  background:var(--kakao);color:#191919;
  border:none;border-radius:10px;
  font-size:16px;font-weight:900;
  cursor:pointer;font-family:'Noto Sans KR',sans-serif;
  display:flex;align-items:center;justify-content:center;gap:10px;
  transition:all var(--t);
}
.btn-submit:hover{background:#f0d800;transform:translateY(-2px);box-shadow:0 8px 28px rgba(254,229,0,.4);}
.submit-note{text-align:center;font-size:12px;color:var(--gray2);margin-top:12px;}

/* ============================================================
   FOOTER
============================================================ */
footer{
  background:#080C18;
  border-top:1px solid var(--border);
  padding:56px 0 32px;
}
.footer-inner{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:40px;margin-bottom:48px;}
.ft-brand-name{font-size:17px;font-weight:800;margin-bottom:4px;}
.ft-brand-sub{font-size:11px;color:var(--gray2);margin-bottom:16px;}
.ft-desc{font-size:13px;color:var(--gray2);line-height:1.75;}
.ft-col-title{font-size:12px;font-weight:800;color:var(--white);letter-spacing:.06em;text-transform:uppercase;margin-bottom:14px;}
.ft-links{display:flex;flex-direction:column;gap:10px;}
.ft-links a{font-size:13px;color:var(--gray2);transition:color var(--t);}
.ft-links a:hover{color:var(--white);}
.ft-bottom{
  padding-top:24px;border-top:1px solid var(--border);
  display:flex;justify-content:space-between;align-items:center;
  font-size:12px;color:var(--gray2);
}

/* ============================================================
   FLOATING KAKAO
============================================================ */
.float-wrap{
  position:fixed;bottom:28px;right:28px;z-index:998;
  display:flex;flex-direction:column;align-items:center;gap:6px;
  transition:opacity var(--t);
}
.float-lbl{background:rgba(0,0,0,.8);color:#fff;font-size:11px;font-weight:700;padding:3px 10px;border-radius:100px;}
.float-btn{
  width:58px;height:58px;border-radius:50%;background:var(--kakao);
  display:flex;align-items:center;justify-content:center;
  box-shadow:0 4px 20px rgba(0,0,0,.4);cursor:pointer;
  transition:transform var(--t),box-shadow var(--t);border:none;text-decoration:none;
}
.float-btn:hover{transform:scale(1.1);box-shadow:0 8px 32px rgba(254,229,0,.4);}

/* ============================================================
   QR POPUP
============================================================ */
.qr-popup{
  position:fixed;bottom:100px;right:28px;z-index:999;
  background:#fff;border-radius:20px;
  padding:20px 20px 16px;
  box-shadow:0 12px 48px rgba(0,0,0,.45);
  text-align:center;
  opacity:0;pointer-events:none;
  transform:translateY(12px) scale(.95);
  transition:all .25s ease;
  width:220px;
}
.qr-popup.show{opacity:1;pointer-events:auto;transform:translateY(0) scale(1);}
.qr-popup img{width:180px;height:180px;border-radius:10px;display:block;margin:0 auto 10px;}
.qr-popup-lbl{
  font-size:12px;font-weight:700;color:#191919;
  margin-bottom:10px;line-height:1.5;
}
.qr-popup-link{
  display:block;width:100%;padding:10px;
  background:#FEE500;border-radius:10px;
  font-size:13px;font-weight:800;color:#191919;
  text-decoration:none;transition:opacity .2s;
}
.qr-popup-link:hover{opacity:.85;}
.qr-popup-close{
  position:absolute;top:10px;right:12px;
  background:none;border:none;font-size:16px;
  color:#9CA3AF;cursor:pointer;line-height:1;padding:2px;
}
.qr-popup-close:hover{color:#191919;}
@media(max-width:768px){
  .qr-popup{right:16px;bottom:90px;width:200px;}
  .qr-popup img{width:164px;height:164px;}
}

/* ============================================================
   TOAST
============================================================ */
.toast{
  position:fixed;bottom:28px;left:50%;transform:translateX(-50%) translateY(20px);
  background:var(--card2);color:var(--white);
  padding:13px 22px;border-radius:10px;
  font-size:14px;font-weight:600;
  box-shadow:0 8px 32px rgba(0,0,0,.5);
  border:1px solid var(--border);
  opacity:0;transition:all .3s ease;z-index:9999;white-space:nowrap;
}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0);}

/* ============================================================
   CHIP LIST
============================================================ */
.chip-list{display:flex;flex-wrap:wrap;gap:8px;}
.chip{
  padding:6px 14px;border-radius:100px;
  font-size:12px;font-weight:600;
  background:var(--card2);border:1px solid var(--border);
  color:var(--gray);transition:all var(--t);
}
.chip:hover{border-color:var(--blue);color:var(--blue);}

/* ============================================================
   SECTION HEADER (centered)
============================================================ */
.sec-header{text-align:center;margin-bottom:56px;}
.sec-header .sec-sub{margin:0 auto;}
.sec-header .divider{margin:0 auto 32px;}

/* ============================================================
   RESPONSIVE
============================================================ */
@media(max-width:1024px){
  .layers{grid-template-columns:1fr;}
  .footer-inner{grid-template-columns:1fr 1fr;}
  .cred-grid{grid-template-columns:1fr;}
}
@media(max-width:768px){
  .section{padding:72px 0;}
  .nav-links,.nav-cta{display:none;}
  .hamburger{display:flex;}
  .strip-inner{flex-direction:column;align-items:center;}
  .strip-item{border-right:none;border-bottom:1px solid rgba(255,255,255,.08);width:100%;padding:16px 0;}
  .strip-item:last-child{border-bottom:none;}
  .sns-grid{grid-template-columns:1fr;}
  .frow-2,.frow-3{grid-template-columns:1fr;}
  .footer-inner{grid-template-columns:1fr;}
  .ft-bottom{flex-direction:column;gap:8px;text-align:center;}
  .float-wrap{bottom:16px;right:16px;}
  .toast{width:calc(100% - 48px);white-space:normal;text-align:center;}
  .page-hero{padding:110px 0 60px;}
}