*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:16px;-webkit-text-size-adjust:100%}
body{
  font-family:var(--font);
  background:var(--c-bg);
  color:var(--c-text);
  line-height:1.7;
  font-size:1rem;
}
a{color:var(--c-primary);text-decoration:none}
a:hover{text-decoration:underline}
img,svg,canvas{max-width:100%;display:block}
button{font-family:inherit;cursor:pointer}
input,select{font-family:inherit;font-size:1rem}
code,kbd{font-family:var(--mono);background:#eaeef2;padding:1px 5px;border-radius:4px;font-size:.9em}

h1,h2,h3,h4{line-height:1.3;font-weight:600}
h1{font-size:1.6rem}
h2{font-size:1.25rem;margin:1.4rem 0 .6rem}
h3{font-size:1.08rem;margin:1.1rem 0 .5rem}
p{margin:.5rem 0}

.katex{font-size:1.05em}
.formula-block{
  background:var(--c-surface);border:1px solid var(--c-border);
  border-radius:var(--radius-sm);padding:14px 18px;margin:10px 0;
  overflow-x:auto;text-align:center;
}