:root{
  --ink:#14213d;--muted:#5f6b7a;--bg:#f6f8fb;--surface:#fff;--line:#e5e9f0;--accent:#3f5efb;--accent-2:#16a78a;--accent-soft:#eef1ff;--success:#16794f;--danger:#bb3344;--warning:#9b6500;--shadow:0 18px 55px rgba(20,33,61,.10);--radius:20px;--radius-sm:14px;--container:1180px;
  --font:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.6}a{color:inherit;text-decoration:none}button,input,select{font:inherit}.container{width:min(var(--container),calc(100% - 32px));margin-inline:auto}.skip-link{position:fixed;left:16px;top:10px;background:var(--ink);color:#fff;padding:8px 12px;border-radius:10px;transform:translateY(-160%);z-index:100}.skip-link:focus{transform:none}
.site-header{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--surface) 92%,transparent);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}.nav-wrap{height:72px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:flex;align-items:center;gap:10px;min-width:0}.brand-mark{width:40px;height:40px;border-radius:12px;background:var(--ink);color:#fff;display:grid;place-items:center;position:relative;font-weight:800;box-shadow:0 8px 24px rgba(20,33,61,.16)}.brand-mark span{position:relative;z-index:2;font-size:19px}.brand-mark i{position:absolute;width:12px;height:12px;right:5px;top:5px;border-radius:50%;background:#6df2c8;box-shadow:0 0 0 4px rgba(109,242,200,.12)}.brand-copy{display:flex;flex-direction:column;line-height:1.05;white-space:nowrap}.brand-copy strong{font-size:15px;letter-spacing:-.02em}.brand-copy em{font-size:10px;color:var(--muted);font-style:normal;margin-top:4px}.desktop-nav{display:flex;gap:6px;align-items:center}.desktop-nav a{padding:10px 12px;border-radius:10px;color:#344054;font-size:14px;font-weight:650}.desktop-nav a:hover{background:var(--accent-soft);color:var(--accent)}.nav-actions{display:flex;align-items:center;gap:8px}.icon-btn,.menu-btn{width:40px;height:40px;border:1px solid var(--line);background:var(--surface);border-radius:11px;display:grid;place-items:center;color:var(--ink);cursor:pointer}.menu-btn{display:none;padding:8px}.menu-btn span{display:block;width:18px;height:2px;background:currentColor;border-radius:99px}.mobile-menu{border-top:1px solid var(--line);background:var(--surface)}.mobile-menu-inner{padding:12px 0 18px;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px}.mobile-menu a{padding:11px 13px;border:1px solid var(--line);border-radius:12px;font-weight:650}
main{padding-bottom:80px}.hero{padding:72px 0 28px;background:radial-gradient(circle at 75% 20%,rgba(63,94,251,.12),transparent 28%),linear-gradient(180deg,var(--surface),var(--bg))}.eyebrow{display:inline-flex;align-items:center;gap:8px;padding:7px 11px;background:var(--accent-soft);color:var(--accent);border-radius:999px;font-size:12px;font-weight:800;letter-spacing:.02em;text-transform:uppercase}.eyebrow::before{content:"";width:7px;height:7px;background:currentColor;border-radius:50%}.hero h1{font-size:clamp(38px,6vw,64px);line-height:1.03;letter-spacing:-.05em;max-width:900px;margin:18px 0 16px}.hero p{font-size:18px;color:var(--muted);max-width:760px;margin:0}.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:28px;align-items:end}.hero-card{margin-top:36px;background:var(--ink);color:#fff;border-radius:28px;padding:26px;box-shadow:var(--shadow);position:relative;overflow:hidden}.hero-card::after{content:"";position:absolute;width:260px;height:260px;background:radial-gradient(circle,rgba(109,242,200,.22),transparent 68%);right:-100px;top:-120px}.hero-stat-row{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.hero-stat{padding:14px;border:1px solid rgba(255,255,255,.12);border-radius:15px;background:rgba(255,255,255,.05)}.hero-stat strong{display:block;font-size:22px}.hero-stat span{display:block;color:rgba(255,255,255,.64);font-size:12px;margin-top:2px}
.section{padding:36px 0}.section-head{display:flex;justify-content:space-between;align-items:end;gap:18px;margin-bottom:18px}.section-head h2{margin:0;font-size:27px;letter-spacing:-.035em}.section-head p{margin:0;color:var(--muted);max-width:650px}.tool-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.tool-card{background:var(--surface);border:1px solid var(--line);border-radius:18px;padding:18px;transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease}.tool-card:hover{transform:translateY(-2px);box-shadow:0 16px 36px rgba(20,33,61,.08);border-color:#cbd3e2}.tool-icon{width:40px;height:40px;border-radius:12px;background:var(--accent-soft);color:var(--accent);display:grid;place-items:center;font-weight:800;margin-bottom:12px}.tool-card h3{font-size:16px;margin:0 0 4px}.tool-card p{font-size:13px;color:var(--muted);margin:0}
.trust-row{display:flex;flex-wrap:wrap;gap:9px;margin-top:24px}.trust-pill{padding:7px 10px;border:1px solid var(--line);border-radius:999px;background:var(--surface);font-size:12px;font-weight:700;color:#475467}.calculator-layout{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(320px,.88fr);gap:20px;align-items:start}.calc-card,.result-card,.content-card,.faq-card{background:var(--surface);border:1px solid var(--line);border-radius:22px;box-shadow:0 10px 35px rgba(20,33,61,.05)}.calc-card{padding:22px}.result-card{padding:22px;position:sticky;top:92px}.card-top{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:18px}.card-top h2,.content-card h2,.faq-card h2{font-size:21px;margin:0;letter-spacing:-.03em}.mode-tabs{display:flex;gap:7px;overflow:auto;padding-bottom:2px;margin-bottom:20px}.mode-tabs button{border:1px solid var(--line);background:var(--surface);padding:9px 11px;border-radius:10px;color:#475467;cursor:pointer;white-space:nowrap;font-weight:700;font-size:12px}.mode-tabs button[aria-selected="true"]{background:var(--ink);border-color:var(--ink);color:#fff}.field-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.field label{display:block;font-size:12px;font-weight:800;margin-bottom:6px;color:#3d4756}.field input,.field select{width:100%;height:46px;border:1px solid var(--line);border-radius:12px;padding:0 12px;background:var(--surface);color:var(--ink);outline:none}.field input:focus,.field select:focus{border-color:var(--accent);box-shadow:0 0 0 4px rgba(63,94,251,.1)}.field small{display:block;color:#8a95a5;font-size:11px;margin-top:4px}.action-row{display:flex;gap:10px;align-items:center;margin-top:18px;flex-wrap:wrap}.btn{border:0;border-radius:12px;padding:12px 16px;font-weight:800;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:8px}.btn-primary{background:var(--accent);color:#fff;box-shadow:0 10px 20px rgba(63,94,251,.18)}.btn-secondary{background:var(--surface);color:var(--ink);border:1px solid var(--line)}.btn-quiet{background:transparent;color:var(--muted)}.notice{margin-top:15px;border:1px solid #f0e3ba;background:#fff9e8;color:#775100;border-radius:12px;padding:10px 12px;font-size:12px}.error{border-color:#f3c6cd;background:#fff2f4;color:#9b2e3f}.success{border-color:#bfe8d1;background:#f0fbf5;color:#186c49}.result-kicker{font-size:12px;color:var(--muted);font-weight:800;text-transform:uppercase;letter-spacing:.05em}.big-result{font-size:52px;line-height:1;margin:5px 0 4px;letter-spacing:-.06em}.grade-badge{display:inline-flex;padding:8px 10px;border-radius:999px;background:var(--accent-soft);color:var(--accent);font-weight:900}.result-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin-top:18px}.result-mini{padding:12px;border:1px solid var(--line);border-radius:14px}.result-mini span{display:block;color:var(--muted);font-size:11px}.result-mini strong{display:block;margin-top:2px;font-size:16px}.meter{height:9px;background:#edf1f6;border-radius:99px;overflow:hidden;margin-top:14px}.meter > span{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--accent),#6df2c8);border-radius:inherit;transition:width .3s ease}.formula{background:#f7f9fc;border:1px dashed #ccd4df;padding:12px;border-radius:13px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12px;overflow:auto}.helper{font-size:12px;color:var(--muted);margin-top:10px}.content-wrap{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:20px;margin-top:24px}.content-card{padding:24px}.content-card h3{font-size:18px;margin:26px 0 8px}.content-card h3:first-child{margin-top:0}.content-card p,.content-card li{color:#4f5b6b}.content-card ul{padding-left:20px}.callout{padding:15px;border-left:4px solid var(--accent);background:var(--accent-soft);border-radius:0 12px 12px 0;margin:18px 0}.side-card{background:var(--ink);color:#fff;border-radius:22px;padding:20px;height:max-content;position:sticky;top:92px}.side-card a{display:block;padding:9px 0;color:rgba(255,255,255,.82);border-bottom:1px solid rgba(255,255,255,.08);font-size:13px}.side-card a:last-child{border-bottom:0}.side-card h3{margin:0 0 12px;font-size:15px}.faq-card{margin-top:20px;padding:24px}.faq{border-top:1px solid var(--line);padding:16px 0}.faq:first-child{border-top:0}.faq summary{cursor:pointer;font-weight:800}.faq p{color:var(--muted);margin:10px 0 0;font-size:14px}.table-wrap{overflow:auto;border:1px solid var(--line);border-radius:14px}.grade-table{width:100%;border-collapse:collapse;min-width:460px}.grade-table th,.grade-table td{text-align:left;padding:11px 12px;border-bottom:1px solid var(--line);font-size:13px}.grade-table th{background:#f8fafc;font-weight:800}.grade-table tr:last-child td{border-bottom:0}.teacher-toolbar{display:flex;gap:10px;flex-wrap:wrap;align-items:end}.teacher-big{display:grid;grid-template-columns:1fr 1fr;gap:14px}.stepper{display:flex;align-items:center;gap:8px}.stepper button{width:46px;height:46px;border:1px solid var(--line);background:var(--surface);border-radius:12px;font-weight:900;cursor:pointer}.stepper input{flex:1}.chart-scroll{max-height:480px;overflow:auto;border:1px solid var(--line);border-radius:14px}.chart-row{display:grid;grid-template-columns:72px 1fr 1fr 72px;gap:8px;padding:9px 12px;border-bottom:1px solid var(--line);font-size:12px}.chart-row.head{position:sticky;top:0;background:var(--surface);font-weight:800}.guide-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.guide-card{background:var(--surface);border:1px solid var(--line);border-radius:18px;padding:20px}.guide-card .tag{font-size:11px;font-weight:800;color:var(--accent);text-transform:uppercase}.guide-card h3{margin:7px 0 6px;font-size:18px}.guide-card p{margin:0;color:var(--muted);font-size:13px}.site-footer{background:#0f1930;color:#fff;padding:54px 0 18px}.footer-grid{display:grid;grid-template-columns:1.5fr repeat(3,1fr);gap:34px}.footer-brand p{color:rgba(255,255,255,.62);max-width:330px;font-size:13px}.footer-brand-link .brand-copy strong{color:#fff}.footer-brand-link .brand-copy em{color:rgba(255,255,255,.58)}.site-footer h3{font-size:13px;margin:0 0 10px;color:#fff}.site-footer a:not(.footer-brand-link){display:block;color:rgba(255,255,255,.62);font-size:12px;padding:3px 0}.site-footer a:not(.footer-brand-link):hover{color:#fff}.footer-bottom{border-top:1px solid rgba(255,255,255,.08);margin-top:32px;padding-top:16px;display:flex;justify-content:space-between;gap:12px;color:rgba(255,255,255,.45);font-size:11px}
.page-head{padding:52px 0 20px}.page-head h1{font-size:clamp(34px,5vw,52px);line-height:1.06;letter-spacing:-.045em;margin:12px 0}.page-head p{max-width:760px;color:var(--muted);font-size:17px}.divider{height:1px;background:var(--line);margin:26px 0}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media (max-width:1000px){.desktop-nav{display:none}.menu-btn{display:grid}.hero-grid,.calculator-layout,.content-wrap{grid-template-columns:1fr}.result-card,.side-card{position:static}.tool-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.footer-grid{grid-template-columns:1.2fr repeat(2,1fr)}}
@media (max-width:680px){.container{width:min(var(--container),calc(100% - 20px))}.nav-wrap{height:64px}.brand-copy strong{font-size:14px}.brand-copy em{font-size:9px}.hero{padding:44px 0 16px}.hero h1{font-size:42px}.hero p{font-size:16px}.hero-stat-row{grid-template-columns:1fr}.tool-grid,.guide-grid,.field-grid,.teacher-big{grid-template-columns:1fr}.section{padding:24px 0}.calc-card,.result-card,.content-card,.faq-card{padding:17px;border-radius:18px}.big-result{font-size:46px}.footer-grid{grid-template-columns:1fr 1fr}.footer-brand{grid-column:1/-1}.footer-bottom{flex-direction:column}.page-head{padding:38px 0 14px}.page-head h1{font-size:37px}.mobile-menu-inner{grid-template-columns:1fr}}
.dark body{--ink:#f4f7fb;--muted:#aeb8c7;--bg:#0b1222;--surface:#121c2f;--line:#233047;--accent-soft:#18264b;--shadow:0 18px 55px rgba(0,0,0,.28)}.dark .hero{background:radial-gradient(circle at 75% 20%,rgba(63,94,251,.17),transparent 28%),linear-gradient(180deg,#0f182a,#0b1222)}.dark .desktop-nav a{color:#cbd5e1}.dark .tool-card,.dark .calc-card,.dark .result-card,.dark .content-card,.dark .faq-card,.dark .guide-card,.dark .icon-btn,.dark .menu-btn,.dark .btn-secondary,.dark .field input,.dark .field select,.dark .mobile-menu{background:var(--surface);color:var(--ink)}.dark .tool-card p,.dark .content-card p,.dark .content-card li,.dark .helper,.dark .page-head p{color:var(--muted)}.dark .grade-table th,.dark .formula,.dark .notice{background:#101a2c}.dark .grade-table th{color:#e8edf5}.dark .meter{background:#243147}

@media print{.site-header,.site-footer,.nav-actions,.side-card,.action-row,.trust-row,.eyebrow{display:none!important}.hero{display:none}.section{padding:8px 0}.calc-card,.result-card,.content-card{box-shadow:none;border-color:#bbb}.page-head{padding:12px 0}.chart-scroll{max-height:none;overflow:visible}.chart-row{break-inside:avoid}.container{width:100%}body{background:#fff;color:#111}.result-card{position:static!important}}