:root{--bg:#f4f7fb;--paper:#fff;--ink:#102a43;--muted:#5d7186;--line:#dce6ef;--brand:#155eef;--brand-dark:#0b3fa6;--cyan:#dff8f4;--orange:#fff0d9;--danger:#d92d20;--shadow:0 18px 50px rgba(16,42,67,.12);--radius:22px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;line-height:1.65}button,input,select,textarea{font:inherit}button{cursor:pointer}a{color:var(--brand);text-decoration-thickness:1px;text-underline-offset:3px}.lr-shell{width:min(1180px,calc(100% - 32px));margin-inline:auto}.lr-skip{position:fixed;left:16px;top:-80px;z-index:9999;background:#fff;padding:10px 14px;border-radius:10px;box-shadow:var(--shadow)}.lr-skip:focus{top:16px}
.lr-topbar{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:blur(16px);border-bottom:1px solid var(--line)}.lr-topbar__inner{min-height:70px;display:flex;align-items:center;justify-content:space-between;gap:24px}.lr-logo{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-weight:850}.lr-logo__symbol{display:grid;place-items:center;width:40px;height:40px;border-radius:13px;background:linear-gradient(145deg,var(--brand),#4d8dff);color:#fff;font-size:1.1rem}.lr-logo__text{letter-spacing:-.02em}.lr-navigation{display:flex;align-items:center;gap:20px}.lr-navigation a{color:var(--ink);text-decoration:none;font-weight:650}.lr-navigation a:hover{color:var(--brand)}.lr-nav-toggle{display:none;border:0;background:#eef4ff;border-radius:12px;padding:10px}
.lr-intro{padding:72px 0 44px;background:radial-gradient(circle at 75% 20%,rgba(21,94,239,.10),transparent 28%),linear-gradient(180deg,#fff,#f4f7fb)}.lr-intro__copy{max-width:820px}.lr-overline,.lr-label{margin:0 0 10px;color:var(--brand);font-size:.78rem;font-weight:850;letter-spacing:.14em;text-transform:uppercase}.lr-intro h1{margin:0;font-size:clamp(2.4rem,6vw,5.2rem);line-height:1.02;letter-spacing:-.055em}.lr-intro__lead{max-width:720px;margin:22px 0 0;color:var(--muted);font-size:clamp(1.05rem,2vw,1.28rem)}
.lr-calculator-zone{padding:26px 0 84px}.lr-v3-wrap{background:var(--paper);border:1px solid var(--line);border-radius:28px;box-shadow:var(--shadow);overflow:hidden}.lr-v3-heading{display:flex;align-items:end;justify-content:space-between;gap:28px;padding:30px 34px;border-bottom:1px solid var(--line)}.lr-v3-heading h2{margin:0 0 6px;font-size:clamp(1.55rem,3vw,2.25rem);letter-spacing:-.035em}.lr-v3-heading p{margin:0;color:var(--muted)}.lr-mode-tabs{display:inline-flex;padding:5px;background:#edf3f8;border-radius:15px;white-space:nowrap}.lr-mode-tab{border:0;background:transparent;color:#53677a;padding:11px 16px;border-radius:11px;font-weight:800}.lr-mode-tab.is-active{background:#fff;color:var(--brand-dark);box-shadow:0 4px 14px rgba(16,42,67,.10)}
.lr-tool-stage{display:grid;grid-template-columns:minmax(0,1fr) 390px;gap:28px;padding:34px;background:linear-gradient(135deg,#eefbff 0%,#f7fbff 55%,#fff8ee 100%)}.lr-workbench-main{min-width:0}.calculator-view[hidden]{display:none}.calculator-view.is-active{display:block}.lr-v3-calculator{width:min(100%,520px);margin:auto;background:#f8fbff;border:1px solid #cdddea;border-radius:24px;padding:20px;box-shadow:0 18px 42px rgba(28,68,101,.12)}.lr-v3-calculator--science{width:min(100%,590px)}.lr-v3-brandrow,.lr-v3-subrow,.lr-v3-science-meta{display:flex;align-items:center;justify-content:space-between;gap:14px}.lr-v3-brandrow{margin-bottom:14px;font-size:.78rem;letter-spacing:.12em}.lr-size-switch{display:flex;gap:6px}.lr-size-switch button{width:26px;height:26px;padding:0;border:1px solid #bdd0df;background:#fff;border-radius:8px;color:var(--brand-dark)}.lr-size-switch button.is-active{background:var(--brand-dark);color:#fff}.lr-v3-screen{position:relative;min-height:112px;padding:18px;border:8px solid #c8dbe2;border-radius:18px;background:#f1f8df;box-shadow:inset 0 3px 10px rgba(16,42,67,.12);overflow:hidden}.lr-v3-expression,.lr-v3-expression-input{width:100%;min-height:28px;border:0;background:transparent;text-align:right;color:#52677b;outline:none}.lr-v3-result{display:block;width:100%;text-align:right;font-size:2.25rem;font-weight:850;line-height:1.25}.lr-v3-status{position:absolute;left:10px;bottom:7px;font-size:.7rem;font-weight:800}.lr-v3-subrow{margin:12px 0}.lr-v3-subrow button{border:0;background:transparent;color:var(--brand-dark);font-weight:750;padding:0}.lr-history-toggle:before{content:"";display:inline-block;width:8px;height:8px;margin-right:6px;border-radius:50%;background:#58d7c2;box-shadow:0 0 0 4px rgba(88,215,194,.15)}.lr-v3-rounding{display:flex;justify-content:space-between;align-items:center;margin:12px 0;font-size:.82rem;color:var(--muted)}.lr-v3-rounding select,.lr-v3-science-meta select{border:1px solid var(--line);background:#fff;border-radius:9px;padding:5px 9px}.lr-v3-keypad{display:grid;grid-template-columns:repeat(4,1fr);gap:9px}.lr-v3-key{min-height:58px;border:1px solid #c6d8e8;border-radius:14px;background:#fff;color:var(--ink);font-weight:850;font-size:1.05rem;box-shadow:0 4px 0 #b9cbd8;transition:.12s}.lr-v3-key:hover{transform:translateY(-1px);border-color:#89aee0}.lr-v3-key:active{transform:translateY(3px);box-shadow:0 1px 0 #b9cbd8}.lr-v3-key--operator{background:#edf4ff;color:var(--brand)}.lr-v3-key--clear{color:var(--danger);border-color:#f3b5b0}.lr-v3-key--zero-wide{grid-column:span 2}.lr-v3-key--equals{background:linear-gradient(145deg,var(--brand),#2f70ee);color:#fff;border-color:var(--brand-dark);box-shadow:0 4px 0 var(--brand-dark)}
.lr-v3-science-tools{display:grid;grid-template-columns:repeat(6,1fr);gap:8px;margin:12px 0}.lr-v3-science-tools button{min-height:39px;border:1px solid #f0c57f;border-radius:12px;background:var(--orange);color:#7a4200;font-weight:800}.lr-rate-panel{margin:10px 0;padding:12px;border:1px solid var(--line);border-radius:12px;background:#fff}.lr-rate-panel input{width:110px}.lr-angle-switch{display:flex;gap:5px}.lr-angle-switch button{border:0;border-radius:8px;padding:7px 10px;background:#edf3f8}.lr-angle-switch button.is-active{background:var(--brand);color:#fff}
.lr-history-pad{min-width:0}.lr-history-paper{height:100%;min-height:590px;background:#fff;border:1px solid #cedce8;border-radius:22px;padding:22px;box-shadow:0 14px 36px rgba(16,42,67,.08)}.lr-history-head{display:block;padding-bottom:15px;border-bottom:1px solid var(--line)}.lr-history-head__top{display:flex;align-items:flex-start;justify-content:space-between;gap:14px}.lr-history-head__copy{display:flex;flex-direction:column}.lr-history-head__copy span{color:var(--muted);font-size:.8rem}.lr-history-head time{flex:0 0 auto;font-size:.72rem;color:var(--brand);white-space:nowrap}.lr-history-toolbar{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:6px;width:100%;margin-top:12px}.lr-history-toolbar button,.lr-history-actions button{display:flex;align-items:center;justify-content:center;gap:5px;min-width:0;border:1px solid #cbdbe7;border-radius:9px;background:#f8fbff;padding:7px 6px;color:#34516a;white-space:nowrap}.lr-history-toolbar__label{min-width:0;font-size:.86rem}.lr-history-list{margin-top:16px}.lr-history-item{display:grid;grid-template-columns:62px 1fr;gap:9px;padding:12px 0;border-bottom:1px solid var(--line)}.lr-history-item__time{color:#5d8fbd;font-size:.72rem}.lr-history-item__result{grid-column:2;font-weight:850}.lr-history-empty{color:var(--muted)}.lr-history-editor{width:100%;min-height:380px;margin-top:16px;border:1px solid var(--line);border-radius:12px;padding:12px}.lr-history-actions--mobile{display:none}
.lr-fraction-workspace{display:grid;grid-template-columns:1fr auto 1fr auto 1.05fr;align-items:center;gap:14px;margin-top:18px}.lr-fraction-card{min-width:0;border:1px solid #d4e1ec;border-radius:18px;padding:14px}.lr-fraction-card legend{font-weight:850}.lr-fraction-card label{display:block;color:var(--muted);font-size:.75rem}.lr-fraction-card input{width:100%;margin-top:4px;padding:10px;border:1px solid #c9d9e5;border-radius:10px;text-align:center}.lr-fraction-stack{margin-top:10px}.lr-fraction-line{display:block;height:2px;background:#526b80;margin:7px 0}.lr-fraction-mini-actions{display:flex;justify-content:space-around;margin-top:12px}.lr-fraction-mini-actions button{border:0;background:transparent;font-weight:800}.lr-fraction-operators{display:grid;gap:8px}.lr-fraction-operators button{width:44px;height:44px;border:0;border-radius:11px;background:#dce7f2;font-weight:900}.lr-fraction-operators button.is-active{background:var(--brand);color:#fff}.lr-fraction-equals{font-size:1.5rem;font-weight:900}.lr-fraction-result-card{background:linear-gradient(155deg,var(--brand),#234fc7);color:#fff;border-radius:20px;padding:18px}.lr-fraction-result-label{font-size:.76rem;font-weight:850;text-transform:uppercase}.lr-fraction-result-main{display:grid;place-items:center;margin:10px 0;font-size:1.45rem;font-weight:900}.lr-fraction-result-line{display:block;width:70px;height:2px;background:#fff}.lr-fraction-result-card dl{margin:0}.lr-fraction-result-card dl div{display:flex;justify-content:space-between}.lr-fraction-result-card button{width:100%;margin-top:12px;border:0;border-radius:10px;padding:10px;background:#fff;color:var(--brand-dark);font-weight:850}.lr-fraction-footer-actions{display:grid;grid-template-columns:1fr 2fr;gap:12px;margin-top:16px}.lr-fraction-footer-actions button{border:0;border-radius:12px;padding:13px;font-weight:850}.lr-fraction-clear{background:#dfe8f1}.lr-fraction-calculate{background:var(--brand);color:#fff}.lr-fraction-error{margin-top:12px;padding:10px;border-radius:10px;background:#fff0ef;color:var(--danger)}
.lr-content-zone,.lr-faq-zone,.lr-document-zone{padding:76px 0}.lr-content-layout{max-width:860px}.lr-prose{font-size:1.05rem}.lr-prose h2{margin:2.1em 0 .55em;font-size:clamp(1.45rem,3vw,2rem);letter-spacing:-.025em}.lr-prose h3{margin:1.6em 0 .4em}.lr-prose p,.lr-prose li{color:#385168}.lr-prose section:first-child h2{margin-top:0}.lr-faq-zone{background:#fff}.lr-section-heading{text-align:center;max-width:720px;margin:0 auto 30px}.lr-section-heading h2{font-size:clamp(1.8rem,4vw,2.7rem);letter-spacing:-.04em}.lr-faq-list{max-width:850px;margin:auto}.lr-faq-list details{border-bottom:1px solid var(--line);padding:18px 0}.lr-faq-list summary{display:flex;justify-content:space-between;gap:20px;cursor:pointer;font-weight:850;list-style:none}.lr-faq-list details p{color:var(--muted)}
.lr-page-head{padding:60px 0 28px;background:#fff}.lr-page-head h1{font-size:clamp(2.2rem,5vw,4rem);letter-spacing:-.05em;margin:10px 0}.lr-page-intro{max-width:760px;color:var(--muted);font-size:1.14rem}.lr-breadcrumbs{font-size:.82rem;color:var(--muted)}.lr-document-grid{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:42px}.lr-side-faq{position:sticky;top:96px;align-self:start}.lr-contact-form{display:grid;gap:14px}.lr-form-row{display:grid;grid-template-columns:1fr 1fr;gap:14px}.lr-contact-form input,.lr-contact-form textarea{width:100%;padding:12px;border:1px solid var(--line);border-radius:11px}.lr-submit{border:0;border-radius:12px;background:var(--brand);color:#fff;padding:12px 18px;font-weight:850}.lr-alert{padding:12px;border-radius:10px;background:#e9fff9}
.lr-footer{background:#0c253d;color:#dce9f5;padding:48px 0 28px}.lr-footer__main{display:grid;grid-template-columns:1.2fr 1fr;gap:46px;width:min(1180px,calc(100% - 32px));max-width:1180px}.lr-footer a{color:#fff}.lr-footer__links{display:grid;grid-template-columns:repeat(2,1fr);gap:8px 24px}.lr-footer__note{grid-column:1/-1;width:100%;margin:22px 0 0;padding-top:20px;border-top:1px solid rgba(255,255,255,.15);color:#9fb3c5;font-size:.86rem;text-align:center}
@media(max-width:900px){.lr-tool-stage{grid-template-columns:1fr}.lr-history-paper{min-height:320px}.lr-document-grid{grid-template-columns:1fr}.lr-side-faq{position:static}.lr-fraction-workspace{grid-template-columns:1fr auto 1fr}.lr-fraction-equals{display:none}.lr-fraction-result-card{grid-column:1/-1}.lr-v3-heading{align-items:flex-start;flex-direction:column}}
@media(max-width:680px){.lr-shell{width:min(100% - 20px,1180px)}.lr-navigation{display:none;position:absolute;left:10px;right:10px;top:62px;padding:16px;background:#fff;border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);flex-direction:column;align-items:stretch}.lr-navigation.is-open{display:flex}.lr-nav-toggle{display:block}.lr-intro{padding:48px 0 30px}.lr-tool-stage{padding:12px}.lr-v3-heading{padding:22px 18px}.lr-mode-tabs{width:100%;overflow:auto}.lr-mode-tab{flex:1}.lr-v3-calculator{padding:13px;border-radius:18px}.lr-v3-key{min-height:52px}.lr-v3-science-tools{grid-template-columns:repeat(3,1fr)}.lr-history-toolbar{display:none}.lr-history-paper{padding:16px}.lr-history-actions--mobile{display:grid;grid-template-columns:repeat(2,1fr);gap:7px;margin-top:10px}.lr-fraction-workspace{grid-template-columns:1fr}.lr-fraction-operators{grid-template-columns:repeat(4,1fr)}.lr-fraction-operators button{width:100%}.lr-fraction-result-card{grid-column:auto}.lr-form-row,.lr-footer__main{grid-template-columns:1fr}.lr-footer__links{grid-template-columns:1fr 1fr}}
/* Structural hooks kept intentionally minimal for template semantics. */
.lr-intro__grid,.lr-page-head__inner,.lr-tool-frame__top,.lr-history-workbench,.lr-v3-zone{position:relative}.lr-footer__brand{max-width:440px}.lr-footer__brand p{color:#afc2d3}.lr-prose--document{max-width:780px}.lr-section-heading--center{text-align:center}.lr-history-rings{display:none}.lr-history-toolbar__icon{font-weight:900}.lr-v3-key--backspace{color:var(--brand)}.lr-v3-keypad--simple{width:100%}.lr-fraction-calculator{width:min(100%,760px)}

/* v3.0.2 — history toolbar desktop/mobile correction */
.lr-history-toolbar{grid-template-columns:repeat(4,minmax(0,1fr));gap:5px}
.lr-history-toolbar button{width:100%;padding:7px 4px;gap:4px;font-size:.78rem;line-height:1.1;overflow:hidden}
.lr-history-toolbar__icon{flex:0 0 auto;font-size:.9rem}
.lr-history-toolbar__label{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:.78rem}
@media(max-width:680px){
  .lr-history-paper{min-height:0;height:auto;padding:16px}
  .lr-history-list{min-height:170px}
  .lr-history-actions--mobile{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;margin-top:16px;padding-top:14px;border-top:1px solid var(--line)}
  .lr-history-actions--mobile button{min-height:58px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;padding:8px;border-radius:12px;font-size:.78rem;font-weight:800;line-height:1.1}
  .lr-history-actions--mobile button span:first-child{font-size:1rem}
}