:root{
  --bg:#f6f7fb;
  --card:#ffffff;
  --text:#1c2230;
  --sub:#5b6472;
  --line:#e4e7ee;
  --brand:#2453ff;
  --brand-dark:#1636b0;
  --accent:#ff6b3d;
  --easy:#1f9d55;
  --normal:#c98a00;
  --hard:#d6432f;
  --unknown:#8b93a1;
  --radius:14px;
  --maxw:1080px;
}
@media (prefers-color-scheme: dark){
  :root{
    --bg:#12141c;
    --card:#1b1e29;
    --text:#eceef3;
    --sub:#a4abba;
    --line:#2b2f3d;
    --brand:#5b7dff;
    --brand-dark:#8ba0ff;
    --accent:#ff8a63;
    --easy:#3fc17a;
    --normal:#e3ac2e;
    --hard:#f0665a;
    --unknown:#7c8494;
  }
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  background:var(--bg);
  color:var(--text);
  font-family:"Pretendard","Apple SD Gothic Neo","Malgun Gothic","Noto Sans KR",sans-serif;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
img,svg{max-width:100%}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px}

header.site-header{
  background:linear-gradient(135deg,var(--brand),var(--brand-dark));
  color:#fff;
  padding:18px 0;
  position:sticky;top:0;z-index:50;
  box-shadow:0 2px 12px rgba(0,0,0,.12);
}
header.site-header .wrap{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:10px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.15rem;color:#fff}
.brand .dot{width:10px;height:10px;border-radius:50%;background:var(--accent);display:inline-block}
nav.main-nav{display:flex;gap:6px;flex-wrap:wrap}
nav.main-nav a{
  color:#fff;opacity:.88;padding:8px 14px;border-radius:999px;font-weight:600;font-size:.92rem;
}
nav.main-nav a:hover{background:rgba(255,255,255,.16);opacity:1;text-decoration:none}
nav.main-nav a.active{background:rgba(255,255,255,.22);opacity:1}

.hero{padding:56px 0 40px}
.hero h1{font-size:2.1rem;margin:0 0 12px;letter-spacing:-.02em}
.hero p.lead{color:var(--sub);font-size:1.05rem;max-width:640px;margin:0 0 22px}
.badge-row{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:22px}
.badge{
  display:inline-flex;align-items:center;gap:6px;
  background:var(--card);border:1px solid var(--line);
  padding:6px 12px;border-radius:999px;font-size:.82rem;color:var(--sub);font-weight:600;
}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  background:var(--brand);color:#fff;font-weight:700;
  padding:12px 20px;border-radius:10px;font-size:.95rem;border:none;cursor:pointer;
}
.btn:hover{background:var(--brand-dark);text-decoration:none}
.btn.outline{background:transparent;color:var(--brand);border:1.5px solid var(--brand)}
.btn.small{padding:7px 13px;font-size:.82rem;border-radius:8px}

section{padding:36px 0}
section h2{font-size:1.5rem;margin:0 0 6px;letter-spacing:-.01em}
section .section-sub{color:var(--sub);margin:0 0 22px;font-size:.95rem}

.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
@media (max-width:820px){.grid3{grid-template-columns:1fr}}

.card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:20px;
}
.card h3{margin:0 0 8px;font-size:1.05rem}
.card p{color:var(--sub);font-size:.9rem;margin:0}

.notice{
  background:var(--card);border:1px solid var(--line);border-left:4px solid var(--accent);
  border-radius:10px;padding:16px 18px;font-size:.9rem;color:var(--sub);margin:20px 0;
}
.notice b{color:var(--text)}

footer{
  border-top:1px solid var(--line);padding:28px 0;color:var(--sub);font-size:.82rem;
}

/* Year tabs */
.year-tabs{display:flex;gap:8px;margin-bottom:22px;flex-wrap:wrap}
.year-tab{
  padding:9px 18px;border-radius:999px;border:1px solid var(--line);background:var(--card);
  font-weight:700;cursor:pointer;color:var(--sub);font-size:.92rem;
}
.year-tab.active{background:var(--brand);border-color:var(--brand);color:#fff}

.exam-list{display:flex;flex-direction:column;gap:12px}
.exam-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
}
.exam-head{
  display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding:16px 20px;cursor:pointer;flex-wrap:wrap;
}
.exam-head:hover{background:rgba(36,83,255,.05)}
.exam-title{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.exam-title .ym{font-weight:800;font-size:1.05rem;min-width:110px}
.exam-title .host{color:var(--sub);font-size:.86rem}
.status{font-size:.78rem;font-weight:700;padding:4px 10px;border-radius:999px}
.status.done{background:rgba(31,157,85,.13);color:var(--easy)}
.status.upcoming{background:rgba(139,147,161,.15);color:var(--unknown)}
.diff-tags{display:flex;gap:6px;flex-wrap:wrap}
.tag{font-size:.76rem;font-weight:700;padding:3px 9px;border-radius:7px;background:var(--bg);border:1px solid var(--line)}
.tag.easy{color:var(--easy);border-color:var(--easy)}
.tag.normal{color:var(--normal);border-color:var(--normal)}
.tag.hard{color:var(--hard);border-color:var(--hard)}
.tag.unknown{color:var(--unknown)}
.chevron{transition:transform .2s;color:var(--sub);font-size:.9rem}
.exam-card.open .chevron{transform:rotate(180deg)}
.exam-body{
  max-height:0;overflow:hidden;transition:max-height .25s ease;
  border-top:1px solid transparent;
}
.exam-card.open .exam-body{border-top:1px solid var(--line)}
.exam-body-inner{padding:18px 20px 22px}
.exam-body h4{margin:0 0 8px;font-size:.9rem;color:var(--sub);font-weight:700}
.exam-body ul{margin:0 0 14px;padding-left:18px;font-size:.9rem}
.exam-body ul li{margin-bottom:4px}
.confidence{font-size:.76rem;color:var(--unknown);font-style:italic;margin-top:6px}
.dl-row{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px}
.gradecut-table{width:100%;border-collapse:collapse;font-size:.85rem;margin-bottom:10px}
.gradecut-table th,.gradecut-table td{border:1px solid var(--line);padding:6px 10px;text-align:center}
.gradecut-table th{background:var(--bg)}

/* Study page */
.subject-nav{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:24px}
.subject-nav a{
  padding:8px 16px;border-radius:999px;background:var(--card);border:1px solid var(--line);
  font-weight:700;font-size:.88rem;color:var(--text);
}
.subject-nav a:hover{border-color:var(--brand);color:var(--brand);text-decoration:none}
.subject-block{margin-bottom:36px;scroll-margin-top:90px}
.subject-block h3{
  font-size:1.25rem;display:flex;align-items:center;gap:10px;margin-bottom:14px;
  padding-bottom:10px;border-bottom:2px solid var(--line);
}
.subject-block h3 .icon{
  width:34px;height:34px;border-radius:9px;display:flex;align-items:center;justify-content:center;
  background:var(--brand);color:#fff;font-size:1rem;font-weight:800;flex-shrink:0;
}
.subject-block p{color:var(--sub);margin:0 0 8px}
.subject-block ul{margin:0;padding-left:18px;font-size:.9rem;color:var(--sub)}
.subject-block ul li{margin-bottom:4px}

.link-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:10px}
.link-list li{
  background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 16px;
  display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;
}
.link-list .meta b{display:block;font-size:.95rem;margin-bottom:2px}
.link-list .meta span{font-size:.82rem;color:var(--sub)}