:root{
  --premium-purple:#6138c7;--premium-purple-dark:#47249d;--premium-orange:#ed7d22;--premium-green:#16744a;--premium-red:#b42318;--premium-ink:#111827;--premium-muted:#5d6472;--premium-line:#deddea;--premium-surface:#ffffff;--premium-soft:#f7f7fb;font-family:"Times New Roman",Times,serif;
}
body{background:var(--premium-soft);color:var(--premium-ink);overflow-x:hidden}.premium-shell{min-height:100vh}.premium-topbar{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.96);border-bottom:1px solid var(--premium-line);backdrop-filter:blur(14px);box-shadow:0 5px 24px rgba(24,18,53,.04)}.premium-flow{max-width:1320px;margin:0 auto;padding:28px clamp(16px,4vw,52px) 70px}.premium-hero{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(320px,.8fr);gap:28px;padding:20px 0 10px}.premium-hero-copy,.premium-capability,.premium-demo,.premium-panel,.premium-human-support{background:var(--premium-surface);border:1px solid var(--premium-line);border-radius:22px;box-shadow:0 12px 38px rgba(24,18,53,.055)}.premium-hero-copy{padding:clamp(28px,5vw,64px)}.premium-hero-copy h1{font-size:clamp(2.1rem,5vw,3.6rem);line-height:1.04;margin:14px 0 20px;font-weight:600;letter-spacing:-.025em}.premium-hero-copy p,.premium-capability p,.premium-capability li{line-height:1.65}.premium-capability{padding:30px}.premium-capability h2,.premium-section-head h2{margin:6px 0 14px;font-weight:600}.premium-capability ul{padding-inline-start:24px;line-height:1.65}.premium-tier-strip{display:grid;gap:10px;margin-top:20px;padding-top:18px;border-top:1px solid var(--premium-line)}.premium-tier-strip>div{display:grid;grid-template-columns:58px 1fr;gap:10px;align-items:start}.premium-tier-strip span{color:var(--premium-muted)}.premium-pro-upgrade{display:grid;gap:10px;margin-top:16px;padding:14px;border:1px solid #d9cff8;border-radius:14px;background:#f8f5ff}.premium-pro-upgrade>span{color:var(--premium-muted);line-height:1.45}.premium-pro-upgrade .premium-anchor{justify-self:start;min-height:44px}.premium-actions,.premium-launch-row{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin-top:24px}.premium-demo-button{background:var(--premium-orange)!important;border-color:var(--premium-orange)!important}.premium-demo-button:hover{filter:brightness(.94)}.premium-anchor{display:inline-flex;align-items:center;justify-content:center;text-decoration:none}.premium-demo{margin-top:24px;padding:clamp(20px,4vw,36px)}.premium-demo[hidden],.premium-human-support[hidden]{display:none!important}.premium-section-head{display:flex;justify-content:space-between;gap:18px;align-items:flex-start}.premium-close{font-size:1.5rem;line-height:1;min-width:48px}.premium-demo-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;margin-top:16px}.premium-demo-card{border:1px solid var(--premium-line);border-radius:18px;padding:18px;background:#fcfcff}.premium-demo-card h3{font-weight:600;margin:0 0 8px}.premium-mini-graph{position:relative;display:flex;gap:8px;align-items:end;justify-content:center;min-height:210px;padding:10px 10px 14px;background:linear-gradient(#fff,#faf9ff);border:1px solid #e7e4f2;border-radius:14px}.premium-axis{display:none}.premium-mini-graph button,.premium-choice-row button{z-index:1;background:#fff;border:1px solid var(--premium-purple);border-radius:12px;padding:8px 12px}.premium-control-row,.premium-choice-row{display:flex;flex-wrap:wrap;gap:10px;align-items:end}.premium-control-row label{display:grid;gap:5px}.premium-control-row input{width:82px;border:1px solid var(--premium-line);border-radius:10px;padding:8px}.premium-demo-feedback{min-height:42px;margin-top:12px;color:#333}.premium-panel{margin-top:24px}.premium-catalog-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.premium-policy-row{display:grid;gap:10px;margin-top:14px}.premium-policy-badge,.premium-policy-note{padding:12px 14px;border-radius:13px;border:1px solid var(--premium-line);background:#f4f2fb}.premium-policy-badge[data-state="no"]{background:#fff0ef;color:var(--premium-red);border-color:#f2bbb6}.premium-policy-badge[data-state="yes"]{background:#eaf7f0;color:var(--premium-green);border-color:#b9dfca}.premium-policy-note{background:#fff7e8;border-color:#efd19b}.premium-lesson-preview{margin-top:18px}.premium-workspace{margin-top:24px}.premium-answer-area{margin-top:18px}.premium-keyboard{margin-top:12px;border:1px solid var(--premium-line);border-radius:14px;overflow:hidden;background:#fff}.premium-keyboard-tabs{display:flex;overflow:auto;background:#f7f6fb;border-bottom:1px solid var(--premium-line)}.premium-keyboard-tabs button{border:0;border-inline-end:1px solid var(--premium-line);background:transparent;padding:8px 14px;min-height:44px;min-width:max-content}.premium-keyboard-tabs button.is-active{background:#fff;color:var(--premium-purple)}.premium-keyboard-keys{display:flex;flex-wrap:wrap;gap:8px;padding:10px}.premium-keyboard-keys button{min-width:48px;min-height:44px;border:1px solid var(--premium-line);background:#fff;border-radius:10px;padding:6px 10px}.premium-human-support{margin-top:18px;padding:22px;display:grid;grid-template-columns:52px 1fr;gap:16px;background:linear-gradient(135deg,#fbf9ff,#fff)}.premium-support-icon{width:52px;height:52px;border-radius:14px;display:grid;place-items:center;background:var(--premium-purple);color:#fff;font-size:1.4rem;font-weight:600}.premium-human-support h3{font-size:1.35rem;font-weight:600;margin:7px 0}.premium-footer{text-align:center;padding:26px;color:#686d79;font-size:.9rem}.premium-panel .primary-action,.premium-hero .primary-action{border-radius:14px}.premium-panel .secondary-action,.premium-hero .secondary-action{border-radius:14px}.access-card[data-tier="pro"]{border-color:#cdbdf8;background:#f7f3ff}.access-card[data-tier="free"]{border-color:#d7d9e2}.graph-display svg{max-width:100%;height:auto}.math-display,.inline-math-fragment,[dir="rtl"] .math-display{direction:ltr;unicode-bidi:isolate}.premium-demo-card :where(p,h3),.premium-human-support :where(p,h3){overflow-wrap:anywhere}

body{background:radial-gradient(circle at 10% 5%,#eef7ff 0,transparent 28%),radial-gradient(circle at 92% 12%,#f4edff 0,transparent 30%),linear-gradient(180deg,#f8fbff 0,#fbfbff 48%,#f7fbf8 100%)}
.premium-topbar{border-bottom:1px solid #d9e4f5;box-shadow:0 8px 26px rgba(51,65,110,.08)}.brand-mark{box-shadow:0 8px 22px rgba(97,56,199,.24)}.premium-hero-copy{background:linear-gradient(135deg,#fff 0,#f5f9ff 52%,#faf5ff 100%);border-color:#d9e4f6}.premium-capability{background:linear-gradient(145deg,#fff 0,#f9f6ff 100%);border-color:#e2d9f8}.premium-demo{background:linear-gradient(150deg,#fff 0,#f7f9ff 100%);border-color:#dbe4fa}.premium-demo-card{position:relative;overflow:hidden;border:1px solid #dfe6f6;box-shadow:0 9px 24px rgba(55,70,120,.07)}.premium-demo-card:nth-child(1)::before,.premium-demo-card:nth-child(2)::before,.premium-demo-card:nth-child(3)::before{content:"";position:absolute;inset:0 0 auto;height:5px}.premium-demo-card:nth-child(1)::before{background:#6138c7}.premium-demo-card:nth-child(2)::before{background:#1976d2}.premium-demo-card:nth-child(3)::before{background:#ed7d22}
.primary-action{background:linear-gradient(135deg,#5b35c5,#3f66d9)!important;border-color:transparent!important;box-shadow:0 7px 18px rgba(73,74,190,.20)}.premium-demo-button{background:linear-gradient(135deg,#ef8b2c,#df6d19)!important}.secondary-action,.quiet-action{transition:transform .16s ease,box-shadow .16s ease,border-color .16s ease}.secondary-action:hover,.quiet-action:hover{transform:translateY(-1px)}.premium-panel{border-color:#dfe6f2;box-shadow:0 12px 34px rgba(50,65,105,.065)}.catalog-grid select,.catalog-grid input{border-color:#ccd9ed!important;background:#fff!important}.catalog-grid select:focus,.catalog-grid input:focus,#student-answer:focus{outline:3px solid rgba(76,112,220,.16)!important;border-color:#667fdd!important}.question-panel{border:2px solid #cfdcf4!important;border-radius:22px!important;box-shadow:0 15px 38px rgba(52,72,125,.09)!important}.question-text{line-height:1.5}.answer-row{gap:10px}.access-card{border:1px solid #d9e4f5!important;border-radius:16px!important;background:linear-gradient(135deg,#f7fbff,#f8f5ff)!important;box-shadow:0 7px 18px rgba(69,76,126,.07)}.access-card[data-tier="pro"]{background:linear-gradient(135deg,#f5efff,#fff8ec)!important;border-color:#d8c6fb!important}.access-card #access-sessions{display:inline-block;margin-top:4px;padding:6px 10px;border-radius:999px;background:#fff;border:1px solid #dfe6f4}.premium-keyboard{border-color:#d4dff0;box-shadow:0 8px 20px rgba(58,75,120,.05)}.premium-keyboard-tabs{background:#eef3fb}.premium-keyboard-tabs button.is-active{background:#fff;color:#4e2aaa;box-shadow:inset 0 -3px #6138c7}.premium-keyboard-keys button{border-color:#d4deee;box-shadow:0 2px 6px rgba(45,58,95,.05)}.premium-keyboard-keys button:hover{border-color:#866fe0;background:#f8f5ff}.premium-human-support{border:2px solid #dccffa;background:linear-gradient(135deg,#fbf8ff,#f5fbff)}.batch1-support-contact{padding:12px 14px;border:1px solid #d9e3f4;border-radius:13px;background:#fff;line-height:1.55}.batch1-support-contact a{font-weight:600;color:#4f2ead}.batch1-demo-svg{position:absolute;inset:10px 10px 52px;width:calc(100% - 20px);height:145px;pointer-events:none}.batch1-transform-svg{display:block;width:100%;height:auto;max-height:190px;margin:14px 0;border:1px solid #dfe5f2;border-radius:13px;background:#fff}.b1-axis{stroke:#7d879a;stroke-width:1.4}.b1-curve{fill:none;stroke:#5d42c7;stroke-width:3;stroke-linecap:round;stroke-linejoin:round}.b1-point{fill:#ed7d22}.b1-label{font:14px "Times New Roman",Times,serif;fill:#30394a}.batch1-synthetic-layout{display:grid;grid-template-columns:42px repeat(4,1fr);gap:7px;align-items:center;margin:14px 0;padding:12px;border:1px solid #e4ddf4;border-radius:13px;background:#fff;text-align:center;font-size:1.05rem}.batch1-synthetic-layout .b1-divisor{grid-row:1/span 3}.batch1-synthetic-layout .b1-divider{grid-column:2/6;border-top:1.5px solid #6e7481}.batch1-synthetic-layout .b1-missing{border:2px dashed #ed7d22;border-radius:8px;padding:3px;background:#fff8ee}[dir="rtl"] .premium-keyboard,[dir="rtl"] #student-answer,[dir="rtl"] .batch1-transform-svg,[dir="rtl"] .batch1-demo-svg{direction:ltr;unicode-bidi:isolate}#server-authority-note[hidden]{display:none!important}
@media(max-width:900px){.premium-hero{grid-template-columns:1fr}.premium-demo-grid,.premium-catalog-grid{grid-template-columns:1fr 1fr}.premium-topbar{position:relative}}
@media(max-width:600px){.premium-flow{padding:16px 12px 56px}.premium-hero{padding-top:4px;gap:14px}.premium-hero-copy,.premium-capability,.premium-demo,.premium-panel,.premium-human-support{border-radius:17px}.premium-hero-copy{padding:24px 20px}.premium-hero-copy h1{font-size:2rem}.premium-capability{padding:21px}.premium-demo-grid,.premium-catalog-grid{grid-template-columns:1fr}.premium-section-head{align-items:flex-start}.premium-actions,.premium-launch-row{display:grid;grid-template-columns:1fr}.premium-actions>*:not(.launch-status),.premium-launch-row>*:not(.launch-status){width:100%;text-align:center}.premium-human-support{grid-template-columns:1fr}.premium-keyboard-tabs{font-size:.86rem}.premium-tier-strip>div{grid-template-columns:1fr}.premium-pro-upgrade .premium-anchor{justify-self:stretch;text-align:center}.premium-mini-graph{min-height:205px}.batch1-demo-svg{height:140px}}