/* =============================================
   KESC Common Styles
   - 폰트, 변수, 리셋, 헤더, 푸터, 네비게이션
============================================= */

/* FONT - Google Fonts CDN */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@300;400;500;600&display=swap');

/* CSS VARIABLES */
:root{
  --primary:#1a365d;
  --primary-light:#2c5282;
  --primary-dark:#0f2744;
  --blue:#007dff;
  --blue-hover:#2e52d5;
  --blue-light:#ebf4ff;
  --blue-pale:#f7fafc;
  --red:#c53030;
  --white:#fff;
  --bg:#f8f9fa;
  --bg2:#edf2f7;
  --gray-50:#f9fafb;
  --gray-100:#f3f4f6;
  --gray-200:#e5e7eb;
  --gray-300:#d1d5db;
  --gray-400:#9ca3af;
  --gray-500:#6b7280;
  --gray-600:#4b5563;
  --gray-700:#374151;
  --gray-800:#1f2937;
  --gray-900:#111827;
  --text:#111827;
  --text2:#1f2937;
  --text3:#4b5563;
  --text4:#6b7280;
  --border:#e5e7eb;
  --border2:#f3f4f6;
  --tr:0.3s cubic-bezier(0.4,0,0.2,1);
  --tr-fast:0.15s ease;
  --teal:#0d9488;
  --orange:#d97706;
  --shadow-sm:0 1px 2px 0 rgba(0,0,0,0.05);
  --shadow:0 4px 6px -1px rgba(0,0,0,0.1),0 2px 4px -1px rgba(0,0,0,0.06);
  --shadow-md:0 10px 15px -3px rgba(0,0,0,0.1),0 4px 6px -2px rgba(0,0,0,0.05);
  --shadow-lg:0 20px 25px -5px rgba(0,0,0,0.1),0 10px 10px -5px rgba(0,0,0,0.04);
  --shadow-xl:0 25px 50px -12px rgba(0,0,0,0.25);
}

/* RESET */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:'Noto Sans KR',-apple-system,BlinkMacSystemFont,system-ui,sans-serif;color:var(--text);background:var(--white);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;line-height:1.7;letter-spacing:-0.01em;overflow-x:hidden}
a{text-decoration:none;color:inherit;transition:var(--tr)}
ul,ol{list-style:none}
img{max-width:100%;height:auto}
.ct{max-width:1280px;margin:0 auto;padding:0 40px}

/* UTILITY BAR */
.utl{background:linear-gradient(90deg,var(--gray-900) 0%,var(--gray-800) 100%);font-size:12px;color:rgba(255,255,255,.5);letter-spacing:0}
.utl .ct{display:flex;justify-content:flex-end;align-items:center;height:36px;gap:20px}
.utl a{color:rgba(255,255,255,.5);font-weight:400;transition:var(--tr-fast)}.utl a:hover{color:var(--blue)}
.utl-div{width:1px;height:10px;background:rgba(255,255,255,.12)}

/* HEADER */
.hd{background:var(--white);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:1000}
.hd-in{display:flex;align-items:center;justify-content:space-between;height:80px}
.logo{display:flex;align-items:center;gap:14px}
.logo-mark{width:48px;height:48px;background:linear-gradient(135deg,var(--primary) 0%,var(--primary-light) 100%);display:none;align-items:center;justify-content:center;color:#fff;font-weight:800;font-size:17px;letter-spacing:-.03em;border-radius:4px;box-shadow:var(--shadow)}
.logo-img{height:44px;width:auto}
.logo-txt{display:flex;flex-direction:column;gap:2px}
.logo-kr{font-size:18px;font-weight:600;color:var(--text);letter-spacing:-.02em}
.logo-en{font-size:10px;color:var(--text4);letter-spacing:.06em;text-transform:uppercase;font-weight:500}

/* NAVIGATION - MEGA MENU */
.nm{display:flex;align-items:center;height:80px}
.nm-bar{display:flex;align-items:center;height:100%;gap:0}
.nm-bar>.ni{display:flex;align-items:center;height:100%;padding:0 20px;font-size:15px;font-weight:600;color:var(--text3);position:relative;letter-spacing:-.01em;transition:var(--tr)}
.nm-bar>.ni:hover{color:var(--blue)}
.nm-bar>.ni.active{color:var(--blue)}
.nm-body{display:none}
.mega{position:absolute;top:80px;left:0;width:100%;background:#fff;opacity:0;visibility:hidden;transition:all 0.3s ease;z-index:998;overflow:hidden;border-top:1px solid var(--border)}
.mega-lines{position:absolute;inset:0;pointer-events:none;overflow:hidden}
.mega-lines::before{content:'';position:absolute;top:0;left:0;width:600px;height:600px;background:linear-gradient(135deg,rgba(0,125,255,.15) 0px,rgba(0,125,255,.15) 35px,transparent 35px,transparent 55px,rgba(59,130,246,.11) 55px,rgba(59,130,246,.11) 85px,transparent 85px,transparent 105px,rgba(0,180,255,.08) 105px,rgba(0,180,255,.08) 130px,transparent 130px)}
.mega-lines::after{content:'';position:absolute;bottom:0;right:0;width:600px;height:600px;background:linear-gradient(-45deg,rgba(0,125,255,.15) 0px,rgba(0,125,255,.15) 35px,transparent 35px,transparent 55px,rgba(59,130,246,.11) 55px,rgba(59,130,246,.11) 85px,transparent 85px,transparent 105px,rgba(0,180,255,.08) 105px,rgba(0,180,255,.08) 130px,transparent 130px)}
.nm-bar:hover~.mega,.mega:hover{opacity:1;visibility:visible}
.mega-in{display:flex;padding:44px 0;gap:32px;position:relative;z-index:1}
.mega-col{flex:1;min-width:0}
.mega-title{font-size:15px;font-weight:600;color:var(--primary);margin-bottom:20px;padding-bottom:12px;border-bottom:1px solid rgba(0,125,255,.15)}
.mega-col a{display:block;font-size:14px;color:var(--text3);padding:10px 12px;margin:0 -12px;border-radius:8px;transition:all 0.2s ease;white-space:nowrap}
.mega-col a:hover{color:var(--blue);background:rgba(0,125,255,.06)}
.mega-col a.active{color:var(--blue);background:rgba(0,125,255,.08)}
.mt{display:none;background:none;border:none;cursor:pointer;padding:8px}
.mt span{display:block;width:22px;height:2px;background:var(--text);margin:5px 0;transition:var(--tr)}
.sub-arrow{display:none}
.nd{display:none}

/* SUB NAVIGATION */
.sub-nav{background:#fff;border-bottom:1px solid var(--border);position:sticky;top:80px;z-index:100}
.sub-nav-inner{display:flex;align-items:center;gap:0;height:56px}
.sub-nav-primary{position:relative;padding-right:32px;border-right:1px solid var(--border);margin-right:32px}
.sub-nav-current{display:flex;align-items:center;gap:8px;font-size:15px;font-weight:600;color:var(--primary);cursor:pointer;padding:8px 0;transition:var(--tr)}
.sub-nav-current:hover{color:var(--blue)}
.sub-nav-current svg{width:16px;height:16px;stroke:currentColor;fill:none;stroke-width:2;transition:transform 0.2s}
.sub-nav-primary:hover .sub-nav-current svg{transform:rotate(180deg)}
.sub-nav-dropdown{position:absolute;top:100%;left:-16px;background:#fff;border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow-lg);padding:8px;min-width:180px;opacity:0;visibility:hidden;transform:translateY(-8px);transition:all 0.2s ease}
.sub-nav-primary:hover .sub-nav-dropdown{opacity:1;visibility:visible;transform:translateY(0)}
.sub-nav-dropdown a{display:block;padding:10px 16px;font-size:14px;color:var(--text3);border-radius:8px;transition:var(--tr-fast)}
.sub-nav-dropdown a:hover{background:var(--blue-pale);color:var(--blue)}
.sub-nav-dropdown a.active{background:var(--blue-pale);color:var(--blue);font-weight:600}
.sub-nav-links{display:flex;gap:4px;overflow-x:auto;scrollbar-width:none;-ms-overflow-style:none;flex:1;min-width:0}
.sub-nav-links::-webkit-scrollbar{display:none}
.sub-nav-links a{font-size:14px;font-weight:500;color:var(--text4);padding:8px 16px;border-radius:6px;transition:var(--tr);white-space:nowrap;flex-shrink:0}
.sub-nav-links a:hover{color:var(--blue);background:var(--blue-pale)}
.sub-nav-links a.active{color:var(--blue);background:var(--blue-pale);font-weight:600}
.scroll-arrow{display:none}

/* PAGE HERO (서브페이지용) */
.page-hero{position:relative;padding:100px 0 60px;overflow:hidden}
.page-hero-bg{position:absolute;inset:0;background-size:cover;background-position:center;background-repeat:no-repeat}
.page-hero-bg::after{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(26,54,93,.82) 0%,rgba(15,39,68,.78) 100%)}
.page-hero .ct{position:relative;z-index:1}
.page-breadcrumb{display:flex;align-items:center;gap:8px;font-size:13px;color:rgba(255,255,255,.5);margin-bottom:16px}
.page-breadcrumb a{color:rgba(255,255,255,.6);transition:var(--tr-fast)}
.page-breadcrumb a:hover{color:#fff}
.page-title{font-size:42px;font-weight:800;color:#fff;letter-spacing:-.03em}
.page-subtitle{font-size:16px;color:rgba(255,255,255,.7);margin-top:12px}

/* FOOTER */
.ft{background:linear-gradient(180deg,var(--gray-900) 0%,#050607 100%);color:rgba(255,255,255,.45);padding:70px 0 0}
.ft-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr 1fr;gap:40px;padding-bottom:50px;border-bottom:1px solid rgba(255,255,255,.06)}
.ft-brand-t{font-size:18px;font-weight:600;color:#fff;margin-bottom:16px;letter-spacing:-.02em}
.ft-brand p{font-size:13px;line-height:2;color:rgba(255,255,255,.35)}
.ft-col h4{font-size:11px;font-weight:600;color:var(--blue);letter-spacing:.12em;text-transform:uppercase;margin-bottom:20px}
.ft-col a{display:block;font-size:13px;color:rgba(255,255,255,.4);padding:6px 0;transition:var(--tr-fast)}
.ft-col a:hover{color:#fff;padding-left:4px}
.ft-bot{display:flex;justify-content:space-between;align-items:center;padding:24px 0;font-size:12px;color:rgba(255,255,255,.2)}
.ft-bot a{color:rgba(255,255,255,.25);transition:var(--tr-fast)}.ft-bot a:hover{color:var(--blue)}

/* BACK TO TOP */
.btt{position:fixed;bottom:32px;right:32px;width:50px;height:50px;background:linear-gradient(135deg,var(--blue) 0%,var(--blue-hover) 100%);border:none;display:flex;align-items:center;justify-content:center;cursor:pointer;opacity:0;visibility:hidden;transition:var(--tr);z-index:999;border-radius:50%;box-shadow:0 4px 20px rgba(43,108,176,.4)}
.btt.v{opacity:1;visibility:visible}
.btt:hover{transform:translateY(-4px);box-shadow:0 8px 30px rgba(43,108,176,.5)}
.btt svg{width:16px;height:16px;stroke:#fff;fill:none;stroke-width:2.5}

/* MOBILE MENU OVERLAY */
.menu-overlay{position:fixed;inset:0;background:rgba(0,0,0,.5);opacity:0;visibility:hidden;transition:var(--tr);z-index:998}
.menu-overlay.open{opacity:1;visibility:visible}

/* BUTTONS (공용) */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:14px 28px;font-size:14px;font-weight:600;border:none;cursor:pointer;transition:var(--tr);font-family:inherit;letter-spacing:-.01em;border-radius:6px}
.btn-blue{background:linear-gradient(135deg,var(--blue) 0%,var(--blue-hover) 100%);color:#fff;box-shadow:0 4px 14px rgba(43,108,176,.4)}.btn-blue:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(43,108,176,.5)}
.btn-wh{background:var(--white);color:var(--text);border:1px solid var(--border)}.btn-wh:hover{border-color:var(--primary);color:var(--primary);transform:translateY(-2px);box-shadow:var(--shadow)}
.btn-out{background:transparent;color:var(--primary);border:2px solid var(--primary)}.btn-out:hover{background:var(--primary);color:#fff}
.btn-out-wh{background:rgba(255,255,255,.08);color:#fff;border:1px solid rgba(255,255,255,.25);backdrop-filter:blur(4px)}.btn-out-wh:hover{background:rgba(255,255,255,1);color:var(--text)}
.btn-arr{gap:6px}.btn-arr svg{width:16px;height:16px;stroke:currentColor;stroke-width:2;fill:none;transition:var(--tr-fast)}.btn-arr:hover svg{transform:translateX(3px)}

/* ANIMATIONS */
.fu{opacity:0;transform:translateY(30px);transition:opacity .7s cubic-bezier(0.4,0,0.2,1),transform .7s cubic-bezier(0.4,0,0.2,1)}
.fu.v{opacity:1;transform:translateY(0)}

/* =============================================
   RESPONSIVE - WIDE TABLET (1200px)
============================================= */
@media(max-width:1200px){
  .nm-bar>.ni{padding:0 12px;font-size:14px}
}

/* =============================================
   RESPONSIVE - TABLET (1024px)
============================================= */
@media(max-width:1024px){
  .ct{padding:0 24px}
  .nm-bar>.ni{padding:0 8px;font-size:13px}
  .ft-grid{grid-template-columns:1fr 1fr 1fr;gap:28px}
}

/* MOBILE QUICK NAV */
.mob-wrap{display:none}
.mob-nav{display:none}

/* =============================================
   RESPONSIVE - MOBILE (768px)
============================================= */
@media(max-width:768px){
  /* Header */
  .utl{display:none}

  /* Mobile Quick Nav */
  .mob-wrap{display:block;position:sticky;top:56px;z-index:99;background:#fff;border-bottom:1px solid var(--border)}
  .mob-nav{display:flex;overflow-x:auto;scrollbar-width:none;-webkit-overflow-scrolling:touch;padding:0}
  .mob-nav::-webkit-scrollbar{display:none}
  .mob-nav a{flex-shrink:0;padding:9px 14px;font-size:12px;font-weight:600;color:var(--text3);text-decoration:none;white-space:nowrap;border-bottom:2px solid transparent;transition:all .15s}
  .mob-nav a.on{color:var(--blue);border-bottom-color:var(--blue)}
  .mob-arr{position:absolute;top:0;bottom:0;width:28px;display:flex;align-items:center;justify-content:center;font-size:16px;color:var(--blue);z-index:2;cursor:pointer;transition:opacity .2s}
  .mob-arr-l{left:0;background:linear-gradient(90deg,#fff 60%,transparent)}
  .mob-arr-r{right:0;background:linear-gradient(90deg,transparent,#fff 40%)}
  .mob-arr.hide{opacity:0;pointer-events:none}
  .hd{border-bottom-width:1px}
  .hd-in{height:56px}
  .logo-mark{width:36px;height:36px;font-size:14px}
  .logo-img{height:36px}
  .logo-kr{font-size:14px}
  .logo-en{display:none}

  /* Mobile Menu - Full Overlay */
  .nm-bar{display:none}
  .mega{display:none !important}
  .mt{display:flex !important;flex-direction:column;align-items:center;justify-content:center;width:44px;height:44px;background:none;border:none;cursor:pointer;position:relative;z-index:1001;padding:0}
  .mt span{display:block;width:20px;height:2px;background:var(--text);transition:all 0.3s cubic-bezier(0.4,0,0.2,1);border-radius:2px;position:absolute;left:50%;transform:translateX(-50%)}
  .mt span:nth-child(1){top:12px}
  .mt span:nth-child(2){top:19px}
  .mt span:nth-child(3){top:26px}
  .mt.active span{background:#fff}
  .mt.active span:nth-child(1){top:19px;transform:translateX(-50%) rotate(45deg)}
  .mt.active span:nth-child(2){opacity:0}
  .mt.active span:nth-child(3){top:19px;transform:translateX(-50%) rotate(-45deg)}

  .nm{position:fixed !important;top:0 !important;left:0 !important;right:0 !important;bottom:0 !important;width:100vw !important;height:100vh !important;height:100dvh !important;background:#000;flex-direction:column;padding:0;opacity:0;visibility:hidden;transition:all 0.4s cubic-bezier(0.4,0,0.2,1);z-index:999;overflow:hidden;display:flex !important;transform:none}
  .nm::before{content:'';position:absolute;top:0;left:0;right:0;bottom:0;background:url('https://images.unsplash.com/photo-1587280501635-68a0e82cd5ff?w=800&q=80') center/cover no-repeat;opacity:0.25;z-index:1;pointer-events:none}
  .nm::after{content:'';position:absolute;top:0;left:0;right:0;bottom:0;background:linear-gradient(180deg,rgba(0,0,0,.8) 0%,rgba(0,0,0,.5) 50%,rgba(0,0,0,.85) 100%);z-index:2;pointer-events:none}
  .nm.open{opacity:1;visibility:visible}

  /* Menu Body */
  .nm-body{flex:1;overflow-y:auto;-webkit-overflow-scrolling:touch;padding:80px 32px 40px;position:relative;z-index:3;display:flex !important;flex-direction:column;align-items:stretch;max-width:400px;margin:0 auto;width:100%}
  .nm-body .ni{height:auto !important;border-bottom:none;width:100%;padding:0}
  .nm-body .ni>a{display:flex !important;justify-content:space-between;align-items:center;padding:16px 0 !important;font-size:18px !important;font-weight:600;color:rgba(255,255,255,.9) !important;height:auto !important;letter-spacing:-.01em;border-radius:0;margin:0;border-bottom:1px solid rgba(255,255,255,.1);transition:color 0.2s ease}
  .nm-body .ni>a:focus,.nm-body .ni>a:active,.nm-body .ni>a:visited{color:rgba(255,255,255,.9) !important;outline:none}
  .nm-body .ni:last-child>a{border-bottom:none}
  .nm-body .ni>a::after{display:none !important}
  .nm-body .ni>a>span:first-child{flex:1}
  .nd{display:block !important;position:static !important;opacity:1 !important;visibility:visible !important;transform:none !important;border:none !important;box-shadow:none !important;min-width:auto;padding:0;max-height:0;overflow:hidden;transition:max-height 0.4s cubic-bezier(0.4,0,0.2,1);width:100%;background:rgba(255,255,255,.05);border-radius:8px;margin:0 0 8px 0}
  .ni.sub-open .nd{max-height:500px;padding:8px 0}
  .ni.sub-open>a,.ni.sub-open>a:focus,.ni.sub-open>a:active{border-bottom:none;color:var(--blue) !important}
  .nd a{display:block;padding:12px 20px;font-size:14px;color:rgba(255,255,255,.6);border-bottom:none !important;background:transparent;margin:0;border-radius:0;transition:var(--tr-fast)}
  .nd a:last-child{margin-bottom:0}
  .nd a:active{color:var(--blue)}

  /* Arrow for submenu */
  .sub-arrow{display:flex !important;align-items:center;justify-content:center;width:32px;height:32px;border:none;background:rgba(255,255,255,.1);border-radius:8px;transition:all 0.25s ease;flex-shrink:0;position:relative}
  .sub-arrow::before{content:'';width:6px;height:6px;border-right:2px solid rgba(255,255,255,.5);border-bottom:2px solid rgba(255,255,255,.5);transform:rotate(45deg);transition:transform 0.3s cubic-bezier(0.4,0,0.2,1)}
  .ni.sub-open .sub-arrow{background:var(--blue)}
  .ni.sub-open .sub-arrow::before{transform:rotate(-135deg);border-color:#fff}

  /* Sub Navigation - Underline Tabs */
  .sub-nav{top:90px;border-bottom:none}
  .sub-nav-inner{height:auto;padding:0;position:relative}
  .sub-nav-primary{display:none}
  .sub-nav-links{display:flex;gap:0;overflow-x:auto;-webkit-overflow-scrolling:touch;scrollbar-width:none;-ms-overflow-style:none;border-bottom:1px solid var(--border)}
  .sub-nav-links::-webkit-scrollbar{display:none}
  .sub-nav-links a{white-space:nowrap;font-size:14px;padding:14px 16px;color:var(--text4);font-weight:500;flex-shrink:0;text-align:center;border-bottom:2px solid transparent;margin-bottom:-1px;transition:all 0.2s;border-radius:0}
  .sub-nav-links.fit{flex:1;width:100%;justify-content:stretch}
  .sub-nav-links.fit a{flex:1 0 auto;padding:10px 0}
  .sub-nav-links a:hover{color:var(--text);background:none}
  .sub-nav-links a.active{color:var(--blue);border-bottom-color:var(--blue);background:none}

  /* Scroll Arrows */
  .scroll-arrow{position:absolute;top:0;bottom:1px;width:28px;display:flex;align-items:center;justify-content:center;font-size:18px;color:var(--blue);z-index:2;cursor:pointer;transition:opacity 0.2s}
  .scroll-arrow-left{left:0;background:linear-gradient(90deg,#fff 50%,transparent)}
  .scroll-arrow-right{right:0;background:linear-gradient(90deg,transparent,#fff 50%)}
  .scroll-arrow.hidden{opacity:0;pointer-events:none}

  /* Page Hero */
  .page-hero{padding:80px 0 50px}
  .page-title{font-size:28px}
  .page-subtitle{font-size:14px}

  /* Footer */
  .ft-grid{grid-template-columns:1fr;gap:28px}
  .ft-col{display:none}
  .ft-bot{flex-direction:column;gap:8px;font-size:10px}
}

/* =============================================
   RESPONSIVE - SMALL MOBILE (480px)
============================================= */
@media(max-width:480px){
  .ct{padding:0 16px}
  .page-title{font-size:24px}
  .page-subtitle{font-size:13px}
  .page-hero{padding:70px 0 40px}
  .page-breadcrumb{font-size:11px;gap:6px}
  .nm-body{padding:70px 20px 30px}

  /* Sub Navigation */
  .sub-nav-links a{font-size:13px;padding:12px 14px}

  .ft-bot{font-size:9px}
}

/* =============================================
   RESPONSIVE - EXTRA SMALL MOBILE (360px)
============================================= */
@media(max-width:360px){
  .ct{padding:0 12px}
  .hd-in{height:50px}
  .logo-mark{width:32px;height:32px;font-size:12px}
  .logo-kr{font-size:13px}

  .page-hero{padding:60px 0 32px}
  .page-title{font-size:20px}
  .page-subtitle{font-size:12px}
  .page-breadcrumb{font-size:10px;gap:4px;margin-bottom:12px}

  /* Sub Navigation */
  .sub-nav{top:50px}
  .sub-nav-links a{font-size:12px;padding:10px 12px}

  .nm-body{padding:60px 16px 24px}
  .nm-body .ni>a{font-size:16px !important;padding:14px 0 !important}
  .nd a{padding:10px 16px;font-size:13px}

  .ft-bot{font-size:8px;padding:16px 0}
}