/* Layout: a school exercise book. Ruled-paper hero, ink-blue type, crayon colors as the only accents; content in a centred 1120px column. */
:root{
  --paper:#FBFCFF; --ruled:#DCE6F5; --margin:#F2A6A6;
  --ink:#1F2F5C; --ink-soft:#4C5B82; --line:#E2E8F3; --card:#FFFFFF;
  --crayon-red:#E0473A; --crayon-yellow:#F6C343; --crayon-green:#3E9B5A; --crayon-blue:#2F78C4; --crayon-purple:#8A5BB8;
  --accent:#E0473A; --accent-ink:#FFFFFF; --tip:#FFF6D6; --tip-ink:#5A4A12; --ad:#F1F4FA;
  --f-display:"Baloo 2", "Trebuchet MS", system-ui, sans-serif;
  --f-body:"Lexend", "Segoe UI", system-ui, sans-serif;
  --f-hand:"Patrick Hand", "Comic Sans MS", cursive;
  --r:14px;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --paper:#141A2B; --ruled:#222C45; --margin:#5A2E35; --ink:#EEF2FB; --ink-soft:#AEB9D3; --line:#2A3452; --card:#1B2338;
  --accent:#FF6A5C; --accent-ink:#1A0F0E; --tip:#3A3320; --tip-ink:#F5E7B5; --ad:#1F283F; color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#141A2B; --ruled:#222C45; --margin:#5A2E35; --ink:#EEF2FB; --ink-soft:#AEB9D3; --line:#2A3452; --card:#1B2338;
  --accent:#FF6A5C; --accent-ink:#1A0F0E; --tip:#3A3320; --tip-ink:#F5E7B5; --ad:#1F283F; color-scheme:dark}
*{box-sizing:border-box}
body{background:var(--paper);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.6;margin:0}
body::before{content:"";position:fixed;inset:0 0 auto;height:env(safe-area-inset-top,0px);z-index:10;background:var(--card)}
a{color:inherit}
.wrap{max-width:1120px;margin:0 auto;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
h1,h2,h3{font-family:var(--f-display);line-height:1.15;text-wrap:balance;margin:0}
h1{font-size:clamp(2.1rem,5vw,3.4rem);font-weight:800}
h2{font-size:clamp(1.5rem,3vw,2rem);font-weight:700}
h3{font-size:1.2rem;font-weight:700}
p{margin:0}
:focus-visible{outline:3px solid var(--crayon-blue);outline-offset:2px;border-radius:6px}

/* header */
header.top{position:sticky;top:env(safe-area-inset-top,0px);z-index:5;background:var(--card);border-bottom:1px solid var(--line)}
header.top .wrap{display:flex;align-items:center;gap:20px;padding-block:12px;flex-wrap:wrap}
.logo{display:flex;align-items:center;gap:10px;text-decoration:none;font-family:var(--f-display);font-weight:800;font-size:1.45rem;color:var(--ink)}
.logo span b{color:var(--accent)}
nav.main{display:flex;gap:4px;margin-left:auto;flex-wrap:wrap}
nav.main a{text-decoration:none;font-weight:500;padding:6px 12px;border-radius:999px;font-size:.95rem}
nav.main a:hover,nav.main a[aria-current="page"]{background:var(--ad)}

/* hero */
.hero{background:repeating-linear-gradient(var(--paper) 0 33px,var(--ruled) 33px 34px);border-bottom:1px solid var(--line);position:relative}
.hero::before{content:"";position:absolute;top:0;bottom:0;left:max(48px,8%);width:2px;background:var(--margin)}
.hero .wrap{display:grid;grid-template-columns:1.1fr 1fr;gap:32px;align-items:center;padding-block:48px 56px;position:relative}
.hero p.lead{font-size:1.15rem;color:var(--ink-soft);margin-top:14px;max-width:34ch}
.hero .note{font-family:var(--f-hand);font-size:1.35rem;color:var(--crayon-red);transform:rotate(-2deg);display:inline-block;margin-bottom:8px}
.search{display:flex;gap:8px;margin-top:22px;max-width:460px}
.search input{flex:1;min-width:0;font:inherit;padding:12px 16px;border-radius:999px;border:2px solid var(--line);background:var(--card);color:var(--ink)}
.btn{font:inherit;font-weight:600;border:0;border-radius:999px;padding:12px 20px;background:var(--accent);color:var(--accent-ink);cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;gap:8px}
.btn.ghost{background:transparent;color:var(--ink);border:2px solid var(--line)}
.stack{position:relative;height:340px;max-width:100%}
.stack img{position:absolute;width:52%;max-width:220px;border-radius:8px;box-shadow:0 10px 30px rgba(31,47,92,.18);border:1px solid var(--line)}
.stack img:nth-child(1){left:2%;top:30px;transform:rotate(-7deg)}
.stack img:nth-child(2){left:24%;top:0;transform:rotate(2deg);z-index:2}
.stack img:nth-child(3){left:46%;top:36px;transform:rotate(8deg)}
.trust{display:flex;gap:18px;flex-wrap:wrap;margin-top:20px;font-size:.9rem;color:var(--ink-soft)}
.trust span::before{content:"✓ ";color:var(--crayon-green);font-weight:700}

section.band{padding-block:44px}
.sec-head{display:flex;align-items:baseline;justify-content:space-between;gap:12px;margin-bottom:18px;flex-wrap:wrap}
.sec-head a{font-weight:600;color:var(--crayon-blue);text-decoration:none}

/* grades */
.grades{display:grid;grid-template-columns:repeat(8,1fr);gap:10px}
.grade{background:var(--card);border:2px solid var(--line);border-radius:var(--r);padding:14px 10px;text-align:center;text-decoration:none;display:flex;flex-direction:column;gap:2px}
.grade b{font-family:var(--f-display);font-size:1.3rem;color:var(--gc)}
.grade small{color:var(--ink-soft);font-size:.8rem}
.grade:hover{border-color:var(--gc)}
.grade.soon{opacity:.6}

/* subjects */
.subjects{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.subject{border-radius:var(--r);padding:20px;text-decoration:none;color:#1F2F5C;display:flex;flex-direction:column;gap:6px;min-height:130px}
.subject .ic{font-family:var(--f-display);font-weight:800;font-size:2rem;line-height:1}
.subject small{font-size:.85rem;opacity:.8}

/* worksheet cards */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(190px,1fr));gap:18px}
.ws{background:var(--card);border:1px solid var(--line);border-radius:var(--r);overflow:hidden;text-decoration:none;display:flex;flex-direction:column}
.ws .thumb{background:var(--tint);padding:16px 16px 0;display:flex;justify-content:center;align-items:flex-start;overflow:hidden;aspect-ratio:1/1;max-width:100%}
.ws .thumb img{display:block;width:86%;height:auto;max-width:100%;border-radius:4px 4px 0 0;box-shadow:0 4px 14px rgba(31,47,92,.2);transition:transform .2s ease}
.ws:hover .thumb img{transform:translateY(-4px)}
img{height:auto}
.t-red{--tint:#FFE3DD}.t-blue{--tint:#DDEBFA}.t-yellow{--tint:#FFF1C7}.t-green{--tint:#DFF2E3}.t-purple{--tint:#EDE3F7}
.ws .meta{padding:12px 14px 14px;display:flex;flex-direction:column;gap:4px}
.ws .meta b{font-family:var(--f-display);font-size:1.08rem;line-height:1.2}
.chips{display:flex;gap:6px;flex-wrap:wrap}
.chip{font-size:.72rem;font-weight:600;letter-spacing:.03em;text-transform:uppercase;padding:2px 8px;border-radius:999px;background:var(--ad);color:var(--ink-soft)}

.ad{background:var(--ad);border:1px dashed var(--line);border-radius:10px;color:var(--ink-soft);font-size:.75rem;letter-spacing:.08em;text-transform:uppercase;display:grid;place-items:center;min-height:90px;margin-block:8px}

/* tips strip */
.tips{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.tipcard{background:var(--tip);color:var(--tip-ink);border-radius:4px;padding:20px 20px 22px;box-shadow:0 2px 0 rgba(0,0,0,.06);transform:rotate(var(--rot,0deg))}
.tipcard h3{font-family:var(--f-hand);font-weight:400;font-size:1.5rem;margin-bottom:6px}

/* detail */
.crumbs{font-size:.88rem;color:var(--ink-soft);padding-block:18px 0;display:flex;gap:6px;flex-wrap:wrap}
.crumbs a{color:var(--crayon-blue);text-decoration:none}
.detail{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.1fr);gap:40px;padding-block:20px 40px;align-items:start}
.detail .sheet{border-radius:10px;box-shadow:0 12px 40px rgba(31,47,92,.16);border:1px solid var(--line);width:100%;max-width:440px}
.detail .body{display:flex;flex-direction:column;gap:18px;min-width:0}
.facts{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.facts div{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:10px 12px}
.facts small{display:block;font-size:.72rem;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-soft)}
.facts b{font-family:var(--f-display);font-size:1.05rem}
.parent-tip{background:var(--tip);color:var(--tip-ink);border-radius:4px;padding:16px 18px}
.parent-tip b{font-family:var(--f-hand);font-weight:400;font-size:1.35rem;display:block}
.steps{margin:0;padding-left:1.3em;display:flex;flex-direction:column;gap:6px}
.dl-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.dl-note{font-size:.88rem;color:var(--ink-soft)}
.dl-note[hidden]{display:none}

/* article */
.article{max-width:68ch;padding-block:24px 48px;display:flex;flex-direction:column;gap:16px}
.article h1{font-size:clamp(1.9rem,4vw,2.6rem)}
.article .by{color:var(--ink-soft);font-size:.9rem}
.article h2{font-size:1.4rem;margin-top:10px}
.article ul{margin:0;padding-left:1.2em;display:flex;flex-direction:column;gap:6px}
.posts{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.post{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px;text-decoration:none;display:flex;flex-direction:column;gap:8px}
.post .kicker{font-size:.72rem;text-transform:uppercase;letter-spacing:.08em;font-weight:600;color:var(--pc)}
.post p{color:var(--ink-soft);font-size:.95rem}

footer{border-top:1px solid var(--line);background:var(--card);margin-top:20px}
footer .wrap{padding-block:28px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:.9rem;color:var(--ink-soft)}
footer nav{display:flex;gap:16px;flex-wrap:wrap}
footer a{text-decoration:none}

@media (max-width:900px){
  .hero .wrap,.detail{grid-template-columns:1fr}
  .stack{height:300px}
  .grades{grid-template-columns:repeat(4,1fr)}
  .subjects{grid-template-columns:repeat(2,1fr)}
  .tips,.posts{grid-template-columns:1fr}
  .tipcard{transform:none}
}
@media (max-width:480px){
  .grid{grid-template-columns:repeat(2,1fr);gap:12px}
  .facts{grid-template-columns:1fr 1fr}
  nav.main{margin-left:0;width:100%;flex-wrap:nowrap;overflow-x:auto;gap:2px}
  nav.main a{font-size:.88rem;padding:6px 10px;white-space:nowrap}
  header.top .wrap{gap:8px;padding-block:10px}
  .ws .meta{padding:10px 12px 12px}
  .ws .meta b{font-size:1rem}
  .hero::before{display:none}
}
@media (prefers-reduced-motion:reduce){.ws .thumb img{transition:none}}
.subject.soon{opacity:.65}
.subject .count{font-family:var(--f-display);font-weight:700;font-size:1rem;margin-top:auto}