/*
Theme Name: Regra de 3 Caderno
Theme URI: https://regrade3online.com
Author: Regra de 3 Online
Description: Tema calculator-first para regrade3online.com. Estética de caderno escolar: papel quadriculado, azul caneta, marcações do professor. Zero requisições externas.
Version: 1.0.0
License: Proprietary
Text Domain: regra3-caderno
*/

:root{
	--ink:#1E4FA3;
	--ink-soft:#4A6FB8;
	--paper:#FDFDF8;
	--page:#F2F5FA;
	--grid:#E3E8F0;
	--red:#C93A2C;
	--ok:#1C7C43;
	--txt:#22303F;
	--mut:#6B7686;
	--maxw:760px;
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--page);color:var(--txt);
	font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Ubuntu,sans-serif;
	font-size:17px;line-height:1.65}

/* ---------- Header ---------- */
.site-header{background:var(--paper);border-bottom:2px solid var(--ink);position:sticky;top:0;z-index:50}
.site-header .wrap{max-width:var(--maxw);margin:0 auto;padding:12px 16px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--txt);font-weight:700;font-size:1.1rem}
.brand .mark{width:34px;height:34px;border-radius:50%;background:var(--red);color:#fff;display:flex;align-items:center;justify-content:center;font-size:1.15rem;font-weight:800;flex:none}
.brand small{display:block;font-weight:500;color:var(--mut);font-size:.7rem;letter-spacing:.04em}
.site-nav{display:flex;gap:4px;flex-wrap:wrap}
.site-nav a{color:var(--ink);text-decoration:none;font-size:.9rem;font-weight:600;padding:6px 10px;border-radius:8px}
.site-nav a:hover,.site-nav a[aria-current="page"]{background:#EEF2F9}

/* ---------- Layout ---------- */
.content{max-width:var(--maxw);margin:0 auto;padding:28px 16px 64px}
.front-hero{margin:6px 0 8px}
.front-hero h1{font-size:clamp(1.5rem,4.5vw,2.1rem);line-height:1.25;color:var(--ink);margin:0 0 6px;font-weight:800}
.front-hero .sub{color:var(--mut);margin:0 0 22px;font-size:1rem}
.front-hero .sub b{color:var(--red);font-weight:700}

/* ---------- Typography (entry content) ---------- */
.entry h1{font-size:clamp(1.5rem,4.5vw,2rem);color:var(--ink);line-height:1.25}
.entry h2{font-size:1.35rem;color:var(--ink);margin:2.2em 0 .6em;padding-bottom:6px;border-bottom:2px solid var(--grid);font-weight:700}
.entry h3{font-size:1.1rem;color:var(--txt);margin:1.6em 0 .5em}
.entry p{margin:0 0 1.1em}
.entry a{color:var(--ink);text-decoration:underline;text-decoration-color:var(--ink-soft);text-underline-offset:2px}
.entry a:hover{text-decoration-color:var(--ink)}
.entry ul,.entry ol{padding-left:1.4em;margin:0 0 1.2em}
.entry li{margin-bottom:.4em}
.entry table{border-collapse:collapse;width:100%;margin:0 0 1.4em;font-size:.95rem}
.entry th,.entry td{border:1px solid var(--grid);padding:9px 12px;text-align:left}
.entry th{background:#EEF2F9;color:var(--ink)}
.entry blockquote{margin:0 0 1.2em;padding:12px 16px;border-left:3px solid var(--red);background:var(--paper);border-radius:0 8px 8px 0;color:var(--mut)}

/* Exemplo box — mini "caderno" callout reused across content */
.entry .exemplo{background:var(--paper);border:1px solid var(--grid);border-radius:10px;padding:14px 16px 14px 30px;position:relative;margin:0 0 1.2em;
	background-image:linear-gradient(var(--grid) 1px,transparent 1px);background-size:100% 26px}
.entry .exemplo::before{content:"";position:absolute;top:0;bottom:0;left:18px;width:1px;background:#F0B9B2}
.entry .exemplo b:first-child{color:var(--ink)}

/* ---------- Cards / archive ---------- */
.post-card{background:var(--paper);border:1px solid var(--grid);border-radius:12px;padding:18px 20px;margin-bottom:14px}
.post-card h2{margin:0 0 6px;font-size:1.15rem}
.post-card h2 a{color:var(--ink);text-decoration:none}
.post-card p{margin:0;color:var(--mut);font-size:.93rem}

/* ---------- Footer ---------- */
.site-footer{border-top:1px solid var(--grid);background:var(--paper)}
.site-footer .wrap{max-width:var(--maxw);margin:0 auto;padding:24px 16px;font-size:.85rem;color:var(--mut);display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
.site-footer a{color:var(--ink);text-decoration:none}
.site-footer a:hover{text-decoration:underline}

/* ---------- Utilities ---------- */
.screen-reader-text{clip:rect(1px,1px,1px,1px);position:absolute!important;height:1px;width:1px;overflow:hidden}
:focus-visible{outline:2px solid var(--ink);outline-offset:2px}
img{max-width:100%;height:auto}

@media (max-width:560px){
	.site-header .wrap{flex-direction:column;align-items:flex-start;gap:8px}
	.site-nav{margin-left:-10px}
}