:root{
  --ls-blue:#155eef;
  --ls-blue-dark:#0b46bd;
  --ls-ink:#0f172a;
  --ls-muted:#64748b;
  --ls-line:#e2e8f0;
  --ls-bg:#f8fafc;
  --ls-card:#ffffff;
  --ls-soft:#eff6ff;
  --ls-danger:#b42318;
  --ls-radius:18px;
  --ls-shadow:0 18px 48px rgba(15,23,42,.07);
  --ls-frame:min(1120px,calc(100% - 40px));
  --ls-reading:min(790px,calc(100% - 40px));
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--ls-bg);color:var(--ls-ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.6;-webkit-font-smoothing:antialiased}
button,input,textarea{font:inherit}
button{cursor:pointer}
a{color:inherit;text-decoration:none}
img{max-width:100%}
[hidden]{display:none!important}
.ls-frame{width:var(--ls-frame);margin-inline:auto}
.ls-reading{width:var(--ls-reading);margin-inline:auto}
.ls-skip{position:fixed;left:12px;top:12px;z-index:9999;transform:translateY(-140%);background:#fff;padding:10px 14px;border:1px solid var(--ls-line);border-radius:10px}.ls-skip:focus{transform:none}

.ls-header{background:rgba(248,250,252,.96);border-bottom:1px solid var(--ls-line)}
.ls-header__inner{height:74px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.ls-brand{display:flex;align-items:center;gap:11px;font-weight:800;letter-spacing:-.03em;font-size:1.06rem}
.ls-brand img{border-radius:10px}
.ls-brand__mark{width:38px;height:38px;border-radius:11px;background:var(--ls-blue);color:#fff;display:grid;grid-template-columns:1fr 1fr;place-items:center;font-weight:900;box-shadow:0 8px 20px rgba(21,94,239,.2)}
.ls-brand__mark span{font-size:14px}
.ls-nav{display:flex;align-items:center;gap:30px;font-size:.94rem;font-weight:650;color:#334155}
.ls-nav a:hover{color:var(--ls-blue)}
.ls-menu{display:none;width:42px;height:42px;border:0;background:transparent;padding:9px}
.ls-menu span{display:block;height:2px;background:var(--ls-ink);margin:5px 0;border-radius:2px}

.ls-hero{padding:68px 0 42px;background:linear-gradient(180deg,#f8fafc 0%,#eef4ff 100%)}
.ls-hero__inner{text-align:center;max-width:760px}
.ls-kicker,.ls-eyebrow{font-size:.75rem;letter-spacing:.16em;font-weight:800;color:var(--ls-blue)}
.ls-hero h1{font-size:clamp(2.8rem,7vw,5rem);line-height:.98;letter-spacing:-.06em;margin:12px 0 18px}
.ls-hero__lead{max-width:660px;margin:0 auto;color:#475569;font-size:clamp(1.02rem,2.1vw,1.18rem)}
.ls-hero__signals{display:flex;justify-content:center;flex-wrap:wrap;gap:10px;margin-top:22px}
.ls-hero__signals span{background:#fff;border:1px solid #dbe4f0;border-radius:999px;padding:7px 12px;font-size:.82rem;font-weight:700;color:#475569}

.ls-tool{padding:32px 0 70px;background:#eef4ff}
.ls-tool__heading{max-width:760px;margin:0 auto 16px;display:flex;justify-content:space-between;align-items:end;gap:20px}
.ls-tool__heading h2{font-size:1.45rem;margin:3px 0 0;letter-spacing:-.03em}
.ls-mode-switch{display:inline-flex;background:#dfe8f8;border:1px solid #ced9ec;border-radius:12px;padding:4px}
.ls-mode-switch button{border:0;background:transparent;color:#52637b;font-weight:750;padding:8px 13px;border-radius:9px}
.ls-mode-switch button.is-active{background:#fff;color:var(--ls-blue);box-shadow:0 2px 8px rgba(15,23,42,.08)}

.ls-calculator{max-width:760px;margin:0 auto;background:var(--ls-card);border:1px solid #dbe3ee;border-radius:22px;padding:20px;box-shadow:var(--ls-shadow)}
.ls-screen{position:relative;min-height:132px;background:#f5f8fd;border:1px solid #dce4ef;border-radius:16px;padding:18px 20px;display:flex;flex-direction:column;align-items:flex-end;justify-content:flex-end;overflow:hidden}
.ls-screen__expression{min-height:24px;color:#7b8798;font-size:.98rem;max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ls-screen__value{display:block;width:100%;text-align:right;font-size:clamp(2.7rem,8vw,4.1rem);line-height:1.05;font-weight:700;letter-spacing:-.055em;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ls-screen__input{width:100%;border:0;outline:0;background:transparent;color:#52637b;text-align:right;font-size:1.05rem;margin-bottom:6px}
.ls-memory-badge,.ls-angle-state{position:absolute;left:17px;top:16px;border-radius:8px;background:#dbeafe;color:#1d4ed8;font-size:.72rem;font-weight:800;padding:5px 7px}
.ls-memory-row{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;margin:14px 0 10px}
.ls-memory-row button,.ls-science-toolbar button,.ls-angle-switch button,.ls-science-functions button{border:1px solid var(--ls-line);background:#fff;color:#475569;border-radius:10px;min-height:38px;font-weight:700;font-size:.86rem}
.ls-memory-row button:hover,.ls-science-functions button:hover{background:#f8fafc;border-color:#cbd5e1}
.ls-keypad{display:grid;gap:10px}
.ls-keypad--basic{grid-template-columns:repeat(4,1fr)}
.ls-keypad--science{grid-template-columns:repeat(4,1fr);margin-top:10px}
.ls-key{min-height:58px;border:1px solid #dfe5ee;background:#fff;border-radius:13px;color:var(--ls-ink);font-weight:760;font-size:1.08rem;transition:background .15s,border-color .15s,transform .15s}
.ls-key:hover{background:#f8fafc;border-color:#cbd5e1}
.ls-key:active{transform:translateY(1px)}
.ls-key--utility{background:#f8fafc;color:#556277}
.ls-key--operator{background:#eef4ff;color:var(--ls-blue);border-color:#d5e2fb}
.ls-key--equals{background:var(--ls-blue);color:#fff;border-color:var(--ls-blue);font-size:1.25rem}
.ls-key--equals:hover{background:var(--ls-blue-dark);border-color:var(--ls-blue-dark)}
.ls-key--zero{grid-column:span 2;padding-left:24px}
.ls-science-toolbar{display:flex;justify-content:space-between;gap:10px;margin:14px 0 10px}
.ls-angle-switch{display:flex;gap:5px}.ls-angle-switch button{padding:0 12px}.ls-angle-switch button.is-active{background:var(--ls-blue);border-color:var(--ls-blue);color:#fff}
.ls-science-functions{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}.ls-science-functions button{min-height:44px}

.ls-history{max-width:760px;margin:18px auto 0;background:#fff;border:1px solid var(--ls-line);border-radius:18px;padding:18px 20px}
.ls-history__head{display:flex;justify-content:space-between;align-items:center;gap:18px;margin-bottom:12px}
.ls-history__head h3{margin:3px 0 0;font-size:1.08rem;letter-spacing:-.02em}
.ls-history__actions{display:flex;gap:8px}.ls-history__actions button{border:1px solid var(--ls-line);background:#fff;border-radius:9px;padding:7px 10px;color:#52637b;font-size:.82rem;font-weight:700}
.ls-history__list{display:grid;gap:7px;max-height:220px;overflow:auto}
.ls-history-item{display:grid;grid-template-columns:1fr auto;gap:12px;text-align:left;border:0;border-top:1px solid #eef2f7;background:transparent;padding:11px 2px;color:#52637b}.ls-history-item strong{color:var(--ls-ink)}
.ls-history__empty{color:#94a3b8;margin:0;padding:7px 0}
.ls-shortcuts{max-width:760px;margin:12px auto 0;display:flex;flex-wrap:wrap;justify-content:center;gap:8px 18px;color:#64748b;font-size:.82rem}
kbd{background:#fff;border:1px solid #cbd5e1;border-bottom-width:2px;border-radius:6px;padding:2px 6px;font:700 .75rem ui-monospace,SFMono-Regular,Menlo,monospace;color:#334155}

.ls-feature-strip{padding:62px 0;background:#fff;border-top:1px solid var(--ls-line);border-bottom:1px solid var(--ls-line)}
.ls-feature-strip__grid{display:grid;grid-template-columns:repeat(4,1fr);gap:28px}.ls-feature-strip article{min-width:0}.ls-feature-strip article>span{display:inline-grid;place-items:center;width:34px;height:34px;border-radius:9px;background:#eef4ff;color:var(--ls-blue);font-weight:850;font-size:.75rem}.ls-feature-strip h3{margin:14px 0 6px;font-size:1.05rem}.ls-feature-strip p{margin:0;color:#64748b;font-size:.92rem}

.ls-content{padding:76px 0;background:#fff}.ls-prose{font-size:1.03rem;color:#334155}.ls-prose h2{color:var(--ls-ink);font-size:clamp(1.65rem,4vw,2.25rem);line-height:1.2;letter-spacing:-.04em;margin:2.2em 0 .65em}.ls-prose h3{color:var(--ls-ink);font-size:1.25rem;margin:1.8em 0 .55em}.ls-prose p{margin:0 0 1.15em}.ls-prose ul,.ls-prose ol{padding-left:1.35em;margin:0 0 1.3em}.ls-prose li{margin:.4em 0}.ls-prose a{color:var(--ls-blue);text-decoration:underline;text-underline-offset:3px}.ls-prose table{width:100%;border-collapse:collapse;margin:1.5em 0;font-size:.95rem}.ls-prose th,.ls-prose td{padding:11px 12px;border:1px solid var(--ls-line);text-align:left}.ls-prose th{background:#f8fafc;color:var(--ls-ink)}

.ls-faq{padding:72px 0 86px;background:#f8fafc;border-top:1px solid var(--ls-line)}
.ls-section-title{margin-bottom:24px}.ls-section-title h2{font-size:clamp(1.7rem,4vw,2.3rem);line-height:1.18;letter-spacing:-.04em;margin:7px 0 0}
.ls-faq__list details,.ls-page-faq details{border-top:1px solid var(--ls-line)}.ls-faq__list details:last-child,.ls-page-faq details:last-child{border-bottom:1px solid var(--ls-line)}
.ls-faq__list summary,.ls-page-faq summary{list-style:none;display:flex;align-items:center;justify-content:space-between;gap:20px;padding:18px 0;font-weight:760;cursor:pointer}.ls-faq__list summary::-webkit-details-marker,.ls-page-faq summary::-webkit-details-marker{display:none}.ls-faq__list summary span,.ls-page-faq summary span{font-size:1.3rem;color:var(--ls-blue)}.ls-faq__list p,.ls-page-faq p{margin:-2px 0 18px;color:#64748b}

.ls-page-hero{padding:56px 0 38px;background:#eef4ff;border-bottom:1px solid var(--ls-line)}
.ls-breadcrumb{display:flex;gap:8px;align-items:center;color:#718096;font-size:.86rem;margin-bottom:24px}.ls-breadcrumb a:hover{color:var(--ls-blue)}
.ls-page-hero h1{font-size:clamp(2.2rem,6vw,4rem);line-height:1.03;letter-spacing:-.055em;margin:0 0 16px}.ls-page-intro{font-size:1.08rem;color:#52637b;max-width:680px}
.ls-document{padding:64px 0 82px;background:#fff}.ls-prose--document h2:first-child{margin-top:0}.ls-page-faq{margin-top:52px}.ls-page-faq h2{font-size:1.45rem;margin-bottom:12px}
.ls-alert{border-radius:12px;padding:12px 14px;margin:20px 0}.ls-alert.is-success{background:#ecfdf3;color:#027a48}.ls-alert.is-error{background:#fef3f2;color:#b42318}
.ls-contact{margin-top:28px;display:grid;gap:16px}.ls-contact__row{display:grid;grid-template-columns:1fr 1fr;gap:16px}.ls-contact label{display:grid;gap:7px;font-weight:700;color:#334155}.ls-contact input,.ls-contact textarea{width:100%;border:1px solid #cbd5e1;border-radius:11px;background:#fff;padding:12px 13px;outline:0}.ls-contact input:focus,.ls-contact textarea:focus{border-color:#8eb2fb;box-shadow:0 0 0 3px rgba(21,94,239,.1)}.ls-submit{justify-self:start;border:0;border-radius:11px;background:var(--ls-blue);color:#fff;font-weight:800;padding:12px 18px}.ls-hp{position:absolute!important;left:-10000px!important;width:1px!important;height:1px!important;overflow:hidden!important}

.ls-footer{background:#0f172a;color:#cbd5e1;padding:54px 0}.ls-footer__grid{display:grid;grid-template-columns:1.2fr .9fr 1fr;gap:40px}.ls-footer__brand{color:#fff;font-size:1.1rem;font-weight:850}.ls-footer p{max-width:370px;color:#94a3b8;font-size:.9rem}.ls-footer__links{display:grid;gap:9px;align-content:start}.ls-footer__links a:hover{color:#fff}.ls-footer__meta{display:grid;gap:8px;align-content:start;color:#94a3b8;font-size:.84rem}

@media(max-width:820px){
  :root{--ls-frame:min(100% - 28px,1120px);--ls-reading:min(100% - 28px,790px)}
  .ls-menu{display:block}.ls-nav{display:none;position:absolute;left:14px;right:14px;top:68px;z-index:50;flex-direction:column;align-items:stretch;gap:0;background:#fff;border:1px solid var(--ls-line);border-radius:14px;box-shadow:var(--ls-shadow);padding:8px}.ls-nav.is-open{display:flex}.ls-nav a{padding:12px 10px;border-radius:9px}.ls-nav a:hover{background:#f8fafc}
  .ls-hero{padding:48px 0 34px}.ls-tool{padding-top:22px}
  .ls-tool__heading{align-items:center}.ls-mode-switch button{padding:7px 10px}
  .ls-feature-strip__grid{grid-template-columns:1fr 1fr;gap:28px 20px}
  .ls-footer__grid{grid-template-columns:1fr 1fr}.ls-footer__meta{grid-column:1/-1}
}
@media(max-width:560px){
  .ls-header__inner{height:66px}.ls-brand{font-size:.98rem}.ls-brand__mark{width:35px;height:35px}
  .ls-hero h1{font-size:3.15rem}.ls-hero__signals{gap:7px}.ls-hero__signals span{font-size:.76rem;padding:6px 10px}
  .ls-tool__heading{display:grid;gap:12px}.ls-mode-switch{justify-self:start}
  .ls-calculator{padding:13px;border-radius:18px}.ls-screen{min-height:116px;padding:15px 16px}.ls-screen__value{font-size:3rem}
  .ls-memory-row{gap:6px}.ls-memory-row button{min-height:36px;font-size:.78rem}
  .ls-keypad{gap:7px}.ls-key{min-height:54px;border-radius:11px}
  .ls-science-functions{grid-template-columns:repeat(5,1fr);gap:6px}.ls-science-functions button{font-size:.76rem;padding:0;min-height:40px}
  .ls-history{padding:15px}.ls-history__head{align-items:flex-start}.ls-history__actions{display:grid;gap:5px}.ls-history__actions button{padding:6px 8px}
  .ls-history-item{grid-template-columns:1fr}.ls-history-item strong{justify-self:start}
  .ls-shortcuts{justify-content:flex-start}
  .ls-feature-strip{padding:48px 0}.ls-feature-strip__grid{grid-template-columns:1fr}
  .ls-content{padding:58px 0}.ls-faq{padding:56px 0 66px}
  .ls-contact__row{grid-template-columns:1fr}.ls-footer__grid{grid-template-columns:1fr;gap:24px}.ls-footer__meta{grid-column:auto}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.ls-key{transition:none}}