:root{--ink:#163153;--muted:#506986;--teal:#00a8a8;--teal-dark:#007a83;--blue:#2f80ed;--sky:#e6f4ff;--mint:#e8fff3;--cream:#fff5cf;--purple:#f1e9ff;--line:#cfe4ff;--paper:rgba(255,255,255,.96);--shadow:0 22px 55px rgba(70,91,143,.16)}
*{box-sizing:border-box}body{margin:0;min-height:100vh;font-family:"Trebuchet MS","Segoe UI Rounded","Segoe UI",system-ui,sans-serif;color:var(--ink);background:radial-gradient(circle at 8% 8%,rgba(255,209,102,.5),transparent 26%),radial-gradient(circle at 92% 10%,rgba(96,211,255,.45),transparent 30%),radial-gradient(circle at 18% 92%,rgba(255,141,177,.22),transparent 30%),linear-gradient(rgba(79,184,255,.09) 1px,transparent 1px),linear-gradient(90deg,rgba(79,184,255,.09) 1px,transparent 1px),#fffdf6;background-size:auto,auto,auto,34px 34px,34px 34px;line-height:1.55}input[name=page]{position:absolute;width:1px;height:1px;opacity:0;pointer-events:none}.wrap{width:min(1060px,100%);margin:0 auto;padding:16px}.topbar{position:sticky;top:0;z-index:10;display:flex;justify-content:space-between;gap:12px;align-items:center;padding:8px 0 14px;backdrop-filter:blur(10px)}.back,.pill{display:inline-flex;align-items:center;justify-content:center;min-height:44px;padding:9px 15px;border-radius:999px;border:2px solid rgba(47,128,237,.22);background:rgba(255,255,255,.94);color:#1455a3;font-weight:900;text-decoration:none;box-shadow:0 10px 22px rgba(70,91,143,.12)}.book{overflow:hidden;border:4px solid #fff;border-radius:34px;background:var(--paper);box-shadow:var(--shadow)}.hero{display:grid;grid-template-columns:180px 1fr;gap:22px;align-items:center;padding:30px;background:radial-gradient(circle at 92% 18%,rgba(255,255,255,.5),transparent 20%),linear-gradient(135deg,#50d5ff 0%,#8df0b1 50%,#ffe17a 100%);border-bottom:4px solid #fff}.badge{display:grid;place-items:center;min-height:132px;border-radius:30px;background:linear-gradient(145deg,#ff8fb3,#ffbd59 52%,#43d5c6);color:#fff;text-align:center;font-weight:950;border:4px solid rgba(255,255,255,.66);box-shadow:0 16px 28px rgba(70,91,143,.18),inset 0 -12px 26px rgba(0,0,0,.08)}.badge small{display:block;font-size:1.5rem;letter-spacing:1px}.badge strong{display:block;font-size:3rem;line-height:1}h1{margin:0;font-size:clamp(2rem,5vw,3.55rem);line-height:1.05;letter-spacing:0;color:#12264a;text-shadow:0 2px 0 rgba(255,255,255,.75)}.lead{margin:12px 0 0;max-width:760px;color:#24486d;font-size:1.1rem;font-weight:800}.pages{padding:26px;background:linear-gradient(135deg,rgba(255,245,207,.55),transparent 45%),#fff}.page{display:none;animation:show .25s ease}@keyframes show{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}#page1:checked~.book .page-1,#page2:checked~.book .page-2,#page3:checked~.book .page-3,#page4:checked~.book .page-4{display:block}#page1:checked~.book .dot-1,#page2:checked~.book .dot-2,#page3:checked~.book .dot-3,#page4:checked~.book .dot-4{background:var(--teal);border-color:var(--teal);color:#fff}.lesson{display:grid;grid-template-columns:minmax(300px,.95fr) minmax(320px,1.05fr);gap:24px;align-items:start}.visual-card,.note-card{border:2px solid #d4ebe7;border-radius:30px;background:#fff;box-shadow:0 12px 28px rgba(70,91,143,.11)}.visual-card{padding:20px;border:5px solid #fff0b8;background:linear-gradient(135deg,#fff5cf,#e6f4ff);align-self:start}.visual-card h3{margin:0 0 12px;color:#1b3766;font-size:clamp(1.35rem,3vw,2rem);line-height:1.12}.visual-card p{margin:0 0 14px;color:#506986;font-weight:800}.formula-grid{display:grid;gap:10px}.formula-grid div{padding:12px 14px;border-radius:18px;background:rgba(255,255,255,.88);border:2px solid rgba(47,128,237,.12);font-weight:900}.note-card{padding:24px;background:radial-gradient(circle at 100% 0,rgba(255,209,102,.38),transparent 34%),radial-gradient(circle at 0 100%,rgba(80,213,255,.16),transparent 30%),#fff}.label{display:inline-flex;align-items:center;min-height:36px;margin-bottom:14px;padding:6px 14px;border-radius:999px;background:linear-gradient(135deg,#ffec99,#d9fbf6);color:#0c5570;font-weight:950;border:2px solid rgba(255,255,255,.8);box-shadow:0 6px 12px rgba(70,91,143,.08)}h2{margin:0 0 14px;font-size:clamp(1.45rem,3.4vw,2.25rem);line-height:1.12;color:#1b3766}.note-card p{margin:0 0 16px;color:#4f6682;font-size:1.04rem;font-weight:760}.point-list,.step-list{display:grid;gap:12px;margin:18px 0 0;padding:0;list-style:none}.point-list li,.step-list li{display:grid;grid-template-columns:40px 1fr;gap:12px;align-items:start;padding:13px;border-radius:22px;background:var(--sky);border:2px solid #bfe5ff;font-weight:800;box-shadow:inset 0 -8px 0 rgba(255,255,255,.38)}.point-list li:nth-child(2),.step-list li:nth-child(2){background:var(--mint);border-color:#c8efe5}.point-list li:nth-child(3),.step-list li:nth-child(3){background:var(--cream);border-color:#f6e6b3}.point-list li:nth-child(4),.step-list li:nth-child(4){background:var(--purple);border-color:#dfd2ff}.num{display:grid;place-items:center;width:34px;height:34px;border-radius:50%;background:linear-gradient(135deg,#ff8fb3,#ffbd59);color:#fff;font-weight:950;box-shadow:0 7px 12px rgba(255,143,179,.25)}.mini-title{display:block;margin-bottom:4px;color:var(--ink);font-size:1.03rem;font-weight:950}.mini-desc{display:block;color:var(--muted);font-weight:720}.example-box{margin-top:18px;padding:16px;border-radius:24px;background:linear-gradient(135deg,#fff7d6,#e9fbff);border:2px solid #bfe9e4;box-shadow:0 12px 22px rgba(70,91,143,.08)}.example-box h3{margin:0 0 12px;color:#0c5570;font-size:1.12rem}.example-list{display:grid;gap:12px}.example{padding:13px;border-radius:18px;background:rgba(255,255,255,.92);border:2px solid rgba(47,128,237,.14)}.example strong{display:block;margin-bottom:6px;color:#15284a}.work{margin:0;white-space:pre-wrap;font-family:"Consolas","Courier New",monospace;font-weight:800;color:#17345d;line-height:1.35;overflow-x:auto}.table-wrap{overflow-x:auto;margin-top:18px;border-radius:18px;border:2px solid #cae5ff;background:#fff;box-shadow:0 8px 16px rgba(70,91,143,.07)}table{width:100%;min-width:520px;border-collapse:collapse;font-weight:750}th,td{padding:13px;border-bottom:2px solid #d9edf9;border-right:2px solid #d9edf9;text-align:left}th{color:#0f4c81;background:linear-gradient(135deg,#e8f5ff,#fff5cf)}tr:last-child td{border-bottom:0}th:last-child,td:last-child{border-right:0}.long-division{display:block;width:min(100%,360px);max-width:100%;margin:8px auto 10px;padding:12px;border-radius:18px;background:linear-gradient(135deg,#f8fdff,#fffaf0);border:2px solid #bfe9e4;overflow:hidden}.ld-table{width:auto!important;min-width:0!important;margin:0 auto;border-collapse:separate;border-spacing:0;table-layout:auto;font-family:"Consolas","Courier New",monospace;font-weight:900;color:#17345d}.ld-table td{box-sizing:border-box;width:clamp(24px,7vw,34px);min-width:0!important;height:clamp(25px,7vw,30px);padding:0!important;text-align:center;vertical-align:middle;border:1px solid #d8efff;background:#fff;font-size:clamp(.82rem,3vw,1rem);line-height:1}.ld-table .blank{border-color:transparent;background:transparent}.ld-table .op{width:clamp(14px,4vw,18px);border-color:transparent;background:transparent;color:#d03333}.ld-table .divisor{width:clamp(30px,9vw,42px);text-align:right;padding-right:5px!important;border-color:transparent;background:transparent}.ld-table .bracket{width:clamp(14px,4vw,18px);border-color:transparent;background:transparent;font-size:clamp(1.05rem,4vw,1.35rem);line-height:1}.ld-table .dividend{border-top:3px solid #17345d;background:#fbfeff}.ld-table .first{border-left:3px solid #17345d}.ld-table .minus{color:#d03333;background:#fff8f8}.ld-table .dash{background:#eef8ff;color:#5d7596}.ld-note{margin:8px 0 0;color:#4f6682;font-weight:850;font-size:.92rem}.pager{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:22px}.dots{display:flex;gap:8px;align-items:center;justify-content:center}.dot{display:grid;place-items:center;width:34px;height:34px;border-radius:50%;border:2px solid #b9d8d4;background:#fff;color:#1455a3;font-weight:950;cursor:pointer}.btn{display:inline-flex;align-items:center;justify-content:center;min-height:48px;padding:11px 18px;border-radius:18px;background:linear-gradient(135deg,#2f80ed,#00b8a9);color:#fff;font-weight:950;text-decoration:none;cursor:pointer;box-shadow:0 13px 26px rgba(47,128,237,.22)}.btn.secondary{background:#fff;color:var(--teal-dark);border:2px solid #bfe9e4;box-shadow:none}@media(max-width:760px){.wrap{padding:10px}.hero,.lesson{grid-template-columns:1fr}.hero,.pages,.note-card{padding:16px}.badge{min-height:96px}.badge small{font-size:1.2rem}.badge strong{font-size:2.25rem}.example-box{padding:12px}.work{font-size:.88rem}.table-wrap{overflow-x:visible}table{min-width:0;table-layout:fixed;font-size:.86rem}th,td{padding:9px 7px;word-break:break-word}.long-division{width:100%;padding:8px}.ld-table td{width:clamp(22px,10vw,30px);height:clamp(24px,10vw,28px)}.ld-table .divisor{width:clamp(28px,12vw,36px)}.pager{flex-direction:column;align-items:stretch}.pager .btn,.pager a{width:100%}.dots{order:-1}}
/* Responsive note visuals - 20260722 */
.visual-card{max-width:100%;overflow:hidden;display:block}
.note-visual-img{display:block;width:100%;max-width:100%;height:auto;aspect-ratio:4/3;object-fit:cover;border-radius:24px;border:3px solid rgba(255,255,255,.88);box-shadow:0 16px 34px rgba(70,91,143,.16)}
@media(max-width:760px){.visual-card{padding:12px!important;border-width:3px!important}.note-visual-img{width:100%!important;max-width:100%!important;border-radius:18px}.lesson{grid-template-columns:minmax(0,1fr)!important}.page,.book,.pages,.visual-card,.note-card{max-width:100%;overflow-wrap:break-word}}