:root{--navy:#102d57;--blue:#2563eb;--orange:#ea6a16;--purple:#7c3aed;--green:#059669;--red:#dc2626;--ink:#172033;--muted:#64748b;--line:#d9e2ef;--bg:#f3f6fb;--shadow:0 12px 30px #102d5714}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.45 Inter,system-ui,-apple-system,"Segoe UI",sans-serif}button,input,select{font:inherit}header{padding:28px max(20px,calc((100vw - 1280px)/2));background:linear-gradient(125deg,#102d57,#184d91 62%,#2563eb);color:#fff;position:relative;overflow:hidden}header:after{content:"";position:absolute;width:250px;height:250px;border:42px solid #ffffff12;border-radius:50%;right:-65px;top:-105px}.eyebrow{margin:0 0 5px;color:#bed6ff;text-transform:uppercase;letter-spacing:.13em;font-size:.76rem;font-weight:800}h1{margin:0 0 8px;font-size:clamp(1.65rem,3vw,2.45rem);line-height:1.1}.sub{margin:0;color:#dce9ff;max-width:900px}main{width:min(1280px,calc(100% - 32px));margin:24px auto 50px}.back{display:inline-block;margin-bottom:12px;color:var(--blue);text-decoration:none;font-weight:800;font-size:.8rem}.tabs{display:flex;gap:7px;overflow:auto;margin:0 0 20px;padding:5px;background:#e7edf6;border-radius:14px;position:sticky;top:5px;z-index:5}.tab{border:0;background:transparent;color:#53657d;border-radius:10px;padding:10px 14px;font-weight:800;white-space:nowrap;cursor:pointer}.tab.active{background:#fff;color:var(--blue);box-shadow:0 3px 10px #102d5718}.panel{display:none}.panel.active{display:block}.card,.concept,.exercise,.table-card{background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:clamp(17px,2.2vw,26px)}.dash{display:grid;grid-template-columns:minmax(330px,.92fr) minmax(440px,1.25fr);gap:20px}.head,.section-head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;margin-bottom:18px}.head h2,.section-head h2{font-size:1.12rem;margin:0}.head p,.section-head p{margin:3px 0 0;color:var(--muted);font-size:.82rem}.badge,.tag{display:inline-block;background:#edf3fb;color:var(--navy);padding:6px 10px;border-radius:99px;font-size:.7rem;font-weight:800;text-transform:uppercase;white-space:nowrap}.tag{color:var(--blue);background:#eaf1ff}.controls{display:grid;grid-template-columns:1fr 1fr;gap:0 16px}.control{--accent:var(--blue);margin-bottom:17px}.control.orange{--accent:var(--orange)}.control.purple{--accent:var(--purple)}.control.green{--accent:var(--green)}label{display:block;font-weight:750;font-size:.86rem;margin-bottom:7px}.symbol{color:var(--accent);font:italic 1rem Georgia,serif}.range-row{display:grid;grid-template-columns:1fr 88px;gap:10px;align-items:center}input[type=range]{width:100%;height:7px;appearance:none;border-radius:20px;background:linear-gradient(90deg,var(--accent) var(--fill),#dce4ef var(--fill));outline:0}input[type=range]::-webkit-slider-thumb{appearance:none;width:22px;height:22px;border-radius:50%;background:#fff;border:6px solid var(--accent);box-shadow:0 2px 7px #0f172a33}.num{display:flex;align-items:center;border:1px solid var(--line);border-radius:10px;overflow:hidden}.num input{width:57px;border:0;outline:0;text-align:right;padding:8px 3px 8px 5px;font-weight:800}.num span{font-size:.68rem;color:var(--muted)}.metrics{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:10px}.metric{border:1px solid var(--line);border-radius:13px;background:#fbfdff;padding:10px;min-width:0}.metric small{display:block;color:var(--muted);font-size:.68rem;font-weight:700}.metric strong{display:block;font-size:clamp(.84rem,1.5vw,1.05rem);white-space:nowrap;margin-top:3px}.blue strong{color:var(--blue)}.orange strong{color:var(--orange)}.green strong{color:var(--green)}.purple strong{color:var(--purple)}.formula{padding:13px 15px;border-radius:13px;background:#eaf1ff;border-left:4px solid var(--blue);font:1.05rem/1.65 Georgia,serif;margin-bottom:12px}.phase{margin-top:10px;padding:11px 13px;border-radius:13px;background:#edf3fb;color:var(--navy);font-size:.79rem;font-weight:800}.section{margin-top:20px}.canvas-wrap{height:390px;border:1px solid var(--line);border-radius:14px;overflow:hidden;background:#fbfdff}canvas{display:block;width:100%;height:100%}.concept-grid,.exercise-grid,.two-col{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}.concept h3,.exercise h3{margin:7px 0 8px;color:var(--navy)}.concept p,.exercise p{color:var(--muted);margin:6px 0}.equation-box{background:#f6f8fc;border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin-top:12px;font:1.05rem/1.75 Georgia,serif}.tip{display:flex;gap:10px;margin-top:13px;padding:12px 14px;border-radius:13px;background:#fff8e8;border:1px solid #fde6ac;color:#77520b}.module-title{margin:0 0 18px}.module-title h2{margin:0;color:var(--navy)}.module-title p{margin:5px 0 0;color:var(--muted)}.table-card{margin-top:20px}.table-wrap{overflow:auto;border:1px solid var(--line);border-radius:13px}table{border-collapse:collapse;width:100%}th,td{text-align:left;padding:10px 13px;border-bottom:1px solid #e9eef5}th{background:#edf3fa;color:#40516a;font-size:.7rem;text-transform:uppercase}tbody tr:nth-child(even){background:#f9fbfe}.solve{width:100%;margin-top:13px;padding:10px;border:1px solid #b8cdf0;border-radius:10px;background:#edf4ff;color:var(--blue);font-weight:850;cursor:pointer}.solution{display:none;margin-top:12px;padding:13px;border-radius:11px;background:#f0fdf7;border:1px solid #bbf0d5;color:#176846}.solution.open{display:block}.foot{text-align:center;color:#8190a5;font-size:.72rem;margin-top:20px}.rights{display:block;margin-top:4px}@media(max-width:960px){.dash,.concept-grid,.exercise-grid,.two-col{grid-template-columns:1fr}.canvas-wrap{height:340px}}@media(max-width:640px){main{width:calc(100% - 20px);margin-top:12px}.card,.concept,.exercise,.table-card{padding:15px}.controls{grid-template-columns:1fr}.metrics{grid-template-columns:repeat(2,1fr)}.canvas-wrap{height:300px}.tab{padding:9px 12px}}