:root{--paper: #eef2f6;--ink: #122033;--muted: #5a6a7d;--line: #d5dee8;--card: #ffffff;--field: #1e4d6b;--field-ink: #14344a;--warm: #9a4a32;--radius: .95rem;--shadow: 0 10px 28px color-mix(in srgb, #122033 8%, transparent);--font: "Apple SD Gothic Neo", "Noto Sans KR", "Pretendard", sans-serif}*,*:before,*:after{box-sizing:border-box}html,body{margin:0;min-height:100%;background:radial-gradient(1200px 480px at 8% -10%,color-mix(in srgb,var(--field) 14%,transparent),transparent 55%),radial-gradient(900px 420px at 100% 0%,color-mix(in srgb,var(--warm) 10%,transparent),transparent 50%),var(--paper);color:var(--ink);font-family:var(--font);font-size:17px;line-height:1.65}a{color:var(--field);text-decoration-thickness:1px;text-underline-offset:3px}.wrap{width:min(1100px,calc(100% - 2rem));margin-inline:auto}.site-header{position:sticky;top:0;z-index:30;border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--card) 86%,transparent);backdrop-filter:blur(14px)}.bar{display:flex;flex-wrap:wrap;gap:.75rem 1.25rem;align-items:center;justify-content:space-between;padding:.7rem 0 .45rem}.brand{color:var(--ink);font-weight:750;text-decoration:none;font-size:1.18rem;letter-spacing:-.02em}.brand span{display:block;font-size:.72rem;font-weight:500;color:var(--muted)}.nav-study,.nav-exams{display:flex;flex-wrap:wrap;gap:.35rem .75rem;font-size:.9rem}.nav-study a,.nav-exams a{text-decoration:none;color:var(--muted);padding:.2rem .15rem}.nav-study a:hover,.nav-exams a:hover{color:var(--field)}.nav-exams-wrap{padding:0 0 .65rem}.nav-exams a{font-size:.82rem;padding:.22rem .55rem;border-radius:999px;border:1px solid transparent;background:color-mix(in srgb,var(--field) 7%,var(--card));color:var(--field-ink)}.nav-exams a:hover{border-color:color-mix(in srgb,var(--field) 28%,var(--line))}.site-footer{border-top:1px solid var(--line);margin-top:3rem;padding:1.5rem 0 2.5rem;color:var(--muted);font-size:.92rem}main{padding:1.75rem 0 2rem}.hero h1,h1{font-size:clamp(1.75rem,3vw,2.35rem);margin:0 0 .55rem;letter-spacing:-.03em}.lede{max-width:44rem;color:var(--muted)}.kicker{font-size:.8rem;letter-spacing:.04em;color:var(--muted)}.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:1rem;margin-top:1.5rem}.card{display:block;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:1.1rem 1.15rem 1.2rem;color:inherit;text-decoration:none;box-shadow:var(--shadow);transition:transform .15s ease,border-color .15s ease}.card:hover{transform:translateY(-2px);border-color:color-mix(in srgb,var(--field) 40%,var(--line))}.card h2{margin:0 0 .35rem;font-size:1.12rem}.card p{margin:0;color:var(--muted);font-size:.95rem}.meta{margin-top:.65rem;font-size:.82rem;color:var(--field)}.hero-actions,.toolbar{display:flex;flex-wrap:wrap;gap:.45rem;margin:1rem 0 .55rem}.btn{font:inherit;padding:.42rem .78rem;border-radius:999px;border:1px solid var(--line);background:var(--card);color:var(--ink);cursor:pointer;font-size:.9rem;text-decoration:none;display:inline-block}.btn.primary{background:var(--field);color:#fff;border-color:transparent}.notice{margin:1rem 0;padding:.7rem .9rem;background:color-mix(in srgb,var(--warm) 10%,var(--card));border-radius:.6rem;font-size:.92rem}.drill{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:1.15rem 1.2rem 1.25rem;box-shadow:var(--shadow);border-left:4px solid var(--field)}#list{display:flex;flex-direction:column;gap:1rem}.drill h2{margin:0 0 .45rem;font-size:1.08rem}.drill .kicker{margin:0 0 .35rem}.choice{display:block;margin:.35rem 0;padding:.42rem .6rem;border-radius:.55rem;border:1px solid transparent;cursor:pointer}.choice:hover{background:color-mix(in srgb,var(--field) 8%,var(--card));border-color:var(--line)}.exam{margin:.7rem 0 0;padding:.55rem .75rem;background:color-mix(in srgb,var(--field) 10%,var(--card));border-radius:.55rem;font-size:.92rem}.filter{display:block;margin:.4rem 0 .8rem;width:min(28rem,100%);font:inherit;padding:.55rem .75rem;border:1px solid var(--line);border-radius:.6rem;background:var(--card)}.timer-bar{position:sticky;top:4.6rem;z-index:20;display:flex;flex-wrap:wrap;gap:.75rem;align-items:center;justify-content:space-between;margin-bottom:1rem;padding:.55rem .85rem;background:var(--card);border:1px solid var(--line);border-radius:.7rem;box-shadow:var(--shadow)}.timer-bar.warn{border-color:var(--warm);color:var(--warm)}.skip{position:absolute;left:-9999px}.skip:focus{left:.75rem;top:.75rem;z-index:40;background:var(--card);padding:.4rem .7rem;border:1px solid var(--line)}.crumbs{font-size:.9rem;color:var(--muted);margin-bottom:1rem}.explain .why{margin:0}.explain strong{display:inline-block;margin-right:.35rem}.formula{margin:.55rem 0 0;padding:.45rem .55rem;background:color-mix(in srgb,var(--ink) 5%,var(--card));border-radius:.4rem;font-size:.9rem}.formula span{display:block;margin-bottom:.15rem;color:var(--muted);font-size:.72rem;font-weight:650;letter-spacing:.02em}.formula-sheet ul{list-style:none;padding:0;margin:0 0 1.5rem;display:grid;gap:.65rem}.formula-sheet li{padding:.7rem .85rem;background:var(--card);border:1px solid var(--line);border-radius:.7rem}.formula-sheet li strong{display:block;margin-bottom:.2rem}.formula-sheet li span{color:var(--muted);font-size:.95rem}.formula-sheet.terms ul{grid-template-columns:repeat(auto-fit,minmax(16rem,1fr))}#cardFilter{width:min(100%,24rem);padding:.55rem .75rem;border:1px solid var(--line);border-radius:.55rem;background:var(--card);color:var(--ink);font:inherit}