*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;color:#182b36;background:#fafcfd;font-family:Arial,"Noto Sans KR",sans-serif;font-size:16px;line-height:1.75}a{color:inherit;text-decoration:none}a:focus-visible,summary:focus-visible{outline:3px solid #18a99b;outline-offset:5px}header{background:#fff;border-bottom:1px solid #e1e7eb}.nav{max-width:1200px;margin:auto;display:flex;align-items:center;justify-content:space-between;padding:23px 26px;gap:24px}.brand{font-weight:850;font-size:24px;letter-spacing:-1px;display:flex;gap:10px;align-items:center}.mark{display:grid;place-items:center;width:35px;height:35px;background:#087d76;color:#fff;border-radius:50%;font-size:24px}nav{display:flex;gap:30px;font-size:15px;font-weight:700}main{max-width:1200px;margin:auto;padding:36px 26px 70px}.eyebrow{font-size:13px;letter-spacing:2px;font-weight:800;color:#077d74}.hero{display:grid;grid-template-columns:1.5fr 1fr;gap:50px;background:#0e303b;color:#fff;padding:44px 48px;border-radius:6px;margin:16px 0 42px;align-items:center}.hero .eyebrow{color:#79d8c9}h1{font-size:43px;line-height:1.4;letter-spacing:-2px;margin:14px 0 18px}p{margin:12px 0}.hero p{color:#c7d9df;max-width:510px}.button{display:inline-block;background:#bef2bc;color:#153932;padding:12px 22px;border-radius:4px;font-weight:700;margin-top:16px}.lesson-preview{border-top:1px solid #46616b;padding-top:20px}.lesson-preview span{color:#87b3bc;font-size:14px}.lesson-preview a{display:flex;padding:16px 0;border-bottom:1px solid #365660;gap:20px;font-weight:600}.lesson-preview b{color:#98d8ca;font-weight:400}h2{font-size:26px;letter-spacing:-1px;line-height:1.4;margin:0}h3{font-size:20px;line-height:1.55;letter-spacing:-.5px;margin:14px 0 10px}.heading{display:flex;justify-content:space-between;align-items:end;margin:30px 0 22px;gap:20px}.muted{color:#617581;font-size:14px}.layout{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:35px}.cards{display:grid;grid-template-columns:1fr 1fr;gap:18px}.card{background:white;border:1px solid #dce5e9;border-radius:6px;padding:25px;display:block;transition:transform .15s,border-color .15s}.card:hover{transform:translateY(-3px);border-color:#087d76}.tag{display:inline-block;color:#08766d;background:#e8f5f1;border-radius:3px;padding:3px 9px;font-size:13px;font-weight:700}.card p{font-size:15px;color:#5f737d}.meta{display:flex;justify-content:space-between;font-size:13px;color:#697f89;margin-top:22px}.num{font-size:30px;color:#abc6c6;line-height:1;float:right;font-weight:700}.aside{padding:26px;background:#eef4f6;border-radius:6px;height:fit-content}.aside h3{margin-top:0}.aside a{display:block;border-bottom:1px solid #d5e1e5;padding:13px 0;font-size:15px}.aside small{display:block;color:#657e89}.note{border-left:3px solid #109184;padding:8px 18px;margin-top:26px;font-size:14px;color:#546f78}.ad{margin-top:24px;padding:23px;text-align:center;border:1px dashed #c8d5dc;color:#6d818b;font-size:14px}.ad span{font-size:11px;letter-spacing:2px;display:block;margin-bottom:5px}.glossary{margin-top:48px;border-top:2px solid #203e49;padding-top:25px}details{border-bottom:1px solid #d9e3e8;background:white}summary{padding:18px 20px;cursor:pointer;font-weight:700}details p{padding:0 20px 20px;color:#526b77;margin:0}footer{border-top:1px solid #dce5e9;background:#f0f5f7;padding:32px 26px;color:#617582;font-size:13px}.foot{max-width:1148px;margin:auto;display:flex;justify-content:space-between;gap:35px}.foot p{max-width:620px}.foot a{display:inline-block;margin-right:18px;text-decoration:underline}.article{max-width:780px;margin:25px auto}.article h1{font-size:38px}.article h2{font-size:23px;margin-top:36px}.article p,.article li{line-height:1.95}.article .intro{font-size:19px;color:#56717c;border-bottom:1px solid #d8e3e8;padding-bottom:25px;margin-bottom:28px}.example{background:#eaf4f1;padding:22px 26px;border-radius:5px;margin:25px 0}.source{font-size:14px;border-top:1px solid #d6e1e5;margin-top:35px;padding-top:20px}.source a{text-decoration:underline;color:#087d76}.crumb{color:#617b86;font-size:14px}.next{display:block;border:1px solid #c7d9de;padding:20px;margin-top:36px;font-weight:700}.about{padding:30px 0}.about p{color:#59717b;max-width:820px}@media(max-width:800px){.hero{padding:30px;gap:25px;grid-template-columns:1fr}.hero h1{font-size:34px}.layout{grid-template-columns:1fr}.aside{display:grid;grid-template-columns:1fr 1fr;gap:0 20px}.aside h3,.aside .note,.aside .ad{grid-column:1/-1}.foot{display:block}.nav{padding:18px 20px;flex-wrap:wrap;gap:14px}nav{gap:22px}.article h1{font-size:30px}}@media(max-width:480px){main{padding:24px 18px 45px}.brand{font-size:22px}.hero{padding:26px 24px}.hero h1{font-size:29px}.cards{grid-template-columns:1fr}.heading{display:block}.heading .muted{margin-top:8px}.aside{display:block}.article h1{font-size:28px}}
/* Shared ad placeholders for application and static reading pages. */
/* Empty AdSense spaces: cap widths to prevent mobile overflow. */
.site-ad-slot{box-sizing:border-box;display:block;width:calc(100% - 24px);max-width:728px;height:90px;margin:24px auto;padding:0;border:0;background:transparent}
main .site-ad-slot{margin:32px auto;max-width:100%}
#ads-top{width:calc(100% - 24px);max-width:728px;height:90px}
#ads-middle{width:300px;max-width:100%;height:250px}
#ads-bottom{width:336px;max-width:100%;height:280px}
@media print{.site-ad-slot{display:none!important}}

.site-header{position:relative;z-index:30}.site-header .nav{max-width:1440px;flex-wrap:wrap;gap:16px}.site-header .main-nav{display:flex;flex-wrap:wrap;align-items:center;gap:8px;overflow:visible}.main-nav>a,.nav-group>summary{padding:12px 16px;border-radius:10px;cursor:pointer;white-space:nowrap}.nav-group{position:relative;border:0;background:none;padding:0;margin:0}.nav-group>summary{list-style:none;font-weight:700}.nav-group>summary::after{content:' ▾';font-size:11px}.nav-group[open]>summary,.nav-group>summary.active,.main-nav>a[aria-current]{background:#e5ecde;color:#244f3d}.nav-submenu{position:absolute;top:100%;right:0;width:210px;padding:10px;border:1px solid #cdd7c6;border-radius:14px;background:#fafbf5;box-shadow:0 12px 30px #20352320;display:grid;gap:3px;z-index:50}.site-header .nav-submenu a{padding:11px 13px;border-radius:7px;display:block}.nav-submenu a:hover,.nav-submenu a[aria-current]{background:#e5ecde}.main-nav :focus-visible{outline:3px solid #527b5b;outline-offset:2px}
@media(max-width:700px){.site-header .nav{padding:18px}.site-header .main-nav{width:100%;gap:2px}.main-nav>a,.nav-group>summary{padding:10px;font-size:13px}.nav-group{position:static}.nav-submenu{left:18px;right:18px;width:auto;top:auto;grid-template-columns:1fr 1fr}}