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*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:28px}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.65 var(--sans);-webkit-font-smoothing:antialiased}
body.dialog-open{overflow:hidden}
a{color:inherit;text-decoration:none}
button,input{font:inherit}
button{cursor:pointer;color:inherit}
button:disabled{cursor:default}
button,a,input{touch-action:manipulation}
:focus-visible{outline:3px solid #af762e;outline-offset:4px}
img{display:block;max-width:100%}
svg{display:block}
h1,h2,h3,p,ol{margin:0}
button{border:0}
[hidden]{display:none !important}
.wrap{width:min(1180px,88%);margin-inline:auto}
.symbol-library{width:0;height:0;overflow:hidden;position:absolute}
.sr-only,.skip:not(:focus){position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
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.masthead-inner{min-height:72px;justify-content:space-between;gap:25px}
.brand{gap:11px;flex-shrink:0;line-height:1}
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.main-nav a:hover,.text-link:hover,.footer a:hover{color:#86591d}
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.hero h1 em{font-style:normal;color:#f9f1da}
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.section{padding-block:53px 58px}
.section-head{justify-content:space-between;gap:24px;margin-bottom:23px}
.section-title{gap:13px}
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h2{font:700 clamp(27px,2.45vw,38px)/1.3 var(--serif);letter-spacing:.025em}
.filters{display:flex;align-items:center;border:1px solid #dcdfd5;background:#eeeee7;padding:3px;border-radius:25px}
.filters button{background:transparent;border-radius:20px;font-size:13px;color:#526155;padding:5px 15px;min-height:32px;transition:background .16s,color .16s}
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.filters button[aria-pressed=true]{background:#264a3d;color:white}
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.lesson{min-width:0}
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.lesson-art img{width:100%;height:100%;object-fit:cover;transition:transform .35s}
.lesson-action:hover .lesson-art img{transform:scale(1.025)}
.art-icon{position:absolute;bottom:13px;right:13px;width:33px;height:33px;display:grid;place-items:center;background:rgba(255,255,250,.92);color:#274437;border:1px solid rgba(32,57,43,.1);box-shadow:0 1px 3px #213c2810;border-radius:50%}
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.lesson-body{width:100%;padding:16px 0 0}
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.subject{border-radius:3px;padding:3px 8px;font-weight:600;letter-spacing:.05em}
.tag-physics{background:#e2eae0;color:#315542}.tag-chemistry{background:#f4e5d6;color:#85532e}.tag-math{background:#e3ebef;color:#3d6476}
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.lesson-title{font:700 clamp(18px,1.55vw,24px)/1.48 var(--serif);margin-top:9px;color:#203b2d}
.lesson-action:hover .lesson-title{color:#86591d}
.lesson-description{font-size:14px;color:var(--muted);margin-top:4px;line-height:1.75}
.experience-section{background:#ecf0e7;border-block:1px solid #dce3d7}
.experience-layout{display:grid;grid-template-columns:minmax(0,.86fr) minmax(0,1.4fr);gap:8%;padding-block:54px}
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.text-link{display:inline-flex;gap:8px;font-size:14px;font-weight:600;color:#2d503f}
.experience-list{list-style:none;padding:0}
.experience-list li{display:grid;grid-template-columns:76px 1fr;gap:18px;border-top:1px solid #c9d3c5;padding:14px 0 16px}
.experience-list li:last-child{padding-bottom:0}
.experience-list time{font:italic 23px/1.34 Georgia,serif;color:#47604c}
.experience-list h3{font-size:16px;line-height:1.7}
.experience-list p{font-size:14px;color:var(--muted);margin-top:2px}
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.about-photo{margin:0;padding:6px;background:#fff;border:1px solid var(--line);border-radius:5px;transform:rotate(-2deg);box-shadow:3px 5px 0 #e9e8dd}
.about-photo img{width:100%;height:auto;border-radius:2px}
.feedback-section{border-bottom:1px solid var(--line)}
.feedback-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px;margin-top:22px}
.classroom-note{display:flex;flex-direction:column;border:1px solid #d7ded2;border-radius:9px;background:#fffef9;overflow:hidden}
.classroom-figure{position:relative;aspect-ratio:1.96;margin:0;background:#e3e8df;overflow:hidden}
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.about-copy p{font-size:15px;line-height:1.9;color:var(--muted);margin-top:12px}
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.footer{border-top:1px solid var(--line);color:#52645a}
.footer-inner{justify-content:space-between;min-height:70px;gap:15px;font-size:13px}
.footer-inner strong{color:var(--ink);font:700 18px var(--serif)}
.footer-sep{color:#aab6aa;margin:0 8px}
.footer-inner a{gap:6px}
.lesson-dialog{width:min(760px,calc(100% - 28px));max-height:calc(100dvh - 40px);padding:0;border:1px solid #d7dfd2;border-radius:14px;background:var(--paper);color:var(--ink);box-shadow:0 20px 100px #0d211c55;overflow:auto;overscroll-behavior:contain}
.lesson-dialog::backdrop{background:rgba(9,27,22,.73)}
.dialog-shell{position:relative}
.dialog-close{position:absolute;top:13px;right:13px;z-index:1;border-radius:50%;width:36px;height:36px;display:grid;place-content:center;background:#e8ede3;color:#385548}
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.video-layout{display:grid;grid-template-columns:minmax(195px,.91fr) minmax(0,1fr);align-items:stretch}
.video-stage{display:flex;justify-content:center;align-items:center;background:#0e221c;min-width:0}
.video-stage video{display:block;width:100%;max-height:min(74dvh,620px);aspect-ratio:9/16;object-fit:contain}
.video-notes{padding:45px 28px 26px}
.lesson-dialog h2{font-size:25px;line-height:1.45;margin-top:14px}
.video-notes>p,.dialog-intro,.lab-bottom p{font-size:14px;color:var(--muted);line-height:1.85}
.video-notes>p{margin-top:12px}
.video-notes h3{font-size:15px;margin-top:22px}
.chapters{display:grid;margin-top:9px}
.chapters button{display:flex;align-items:center;gap:12px;padding:8px 0;border-top:1px solid var(--line);background:transparent;text-align:left;font-size:14px}
.chapters button:hover{color:#86591d;background:#edf0e8}
.chapters time{font:14px/1.5 Consolas,monospace;color:#5c715d}
.direct-video{display:inline-block;font-size:12px;color:var(--muted);text-decoration:underline;text-underline-offset:3px;margin-top:12px}
.lab-dialog{width:min(610px,calc(100% - 28px))}
.lab-shell{padding:29px 34px 25px}
.lab-shell>.lesson-meta{padding-right:28px}
.dialog-intro{margin-top:9px}
.equation{display:flex;align-items:center;justify-content:space-evenly;gap:7px;background:#f4e9dc;border-radius:8px;padding:18px 12px;margin-block:17px}
.molecule{display:grid;justify-items:center;gap:8px}
.molecule>strong{font:600 32px/1.2 Georgia,serif;color:#664229}
.molecule sub{font-size:.55em;line-height:0}
.formula-coefficient{color:#a45e32}
.equation-sign{font-size:22px;color:#97775a}
.stepper{display:inline-flex;align-items:center;background:#fffdf7;border:1px solid #d4bfa7;border-radius:5px}
.stepper button{display:grid;place-items:center;background:transparent;width:29px;height:29px;font:18px/1 Arial,sans-serif}
.stepper button:disabled{color:#b6b2a9}
.stepper output{min-width:16px;text-align:center;font:15px/1.1 Consolas,monospace}
.atom-table{border-collapse:collapse;width:100%;text-align:center;font-size:14px}
.atom-table th,.atom-table td{padding:5px;border-bottom:1px solid var(--line)}
.atom-table thead th{font-weight:500;color:var(--muted)}
.atom-table th:first-child{text-align:left}
.lab-feedback{padding:10px 13px;background:#e8eee3;color:#344d3c;border-left:3px solid #779377;font-size:14px;margin-top:14px;border-radius:2px}
.lab-bottom{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-top:13px}
.lab-bottom p{font-size:12px}
.lab-bottom button{flex:none;background:transparent;border:1px solid #c7cdbf;border-radius:4px;padding:4px 11px;font-size:13px}
.lab-bottom button:hover{background:#e8ede2}
.graph{width:100%;height:auto;background:#eaf0f0;border:1px solid #d4e0de;border-radius:8px;margin-top:15px}
.slider-row{display:flex;align-items:center;gap:16px;margin-top:13px;font-size:14px}
.slider-row input{accent-color:#3d6a77;flex:1;min-width:0}
.slider-row output{min-width:28px;text-align:center;font:17px/1.4 Georgia,serif}
@media(min-width:1600px){.hero-photo{right:3%;mask-image:linear-gradient(90deg,transparent 0%,#000 23%,#000 97%,transparent)}}
@media(max-width:1000px){.wrap{width:90%}.main-nav{gap:21px}.hero-copy{max-width:44%}.hero-intro{font-size:14px}.lesson-grid{gap:16px}.lesson-title{font-size:18px}.lesson-description{font-size:13px}.section{padding-block:41px 45px}.experience-layout{gap:6%}.photo-caption{right:5%}}
@media(max-width:720px){html{scroll-padding-top:15px}.masthead-inner{min-height:60px}.brand strong{font-size:23px}.brand-caption{font-size:12px}.main-nav{display:none;position:absolute;left:0;right:0;top:100%;padding:9px 5% 16px;background:var(--paper);box-shadow:0 12px 16px #162b2214;border-top:1px solid var(--line)}.main-nav.is-open{display:grid;gap:0}.main-nav a{padding:11px 0}.main-nav .nav-resume{border:0;padding:11px 0;border-radius:0}.menu-toggle{display:grid;place-items:center;background:transparent;width:42px;height:42px}.menu-toggle svg{width:22px;height:22px}.hero-inner{min-height:430px;padding-block:42px 53px}.hero-copy{max-width:61%}.hero h1{font-size:clamp(51px,8vw,60px)}.hero-kicker{font-size:11px}.hero-intro{font-size:13px;max-width:245px;line-height:1.8}.hero-actions{gap:15px;flex-wrap:wrap}.hero-link{font-size:12px}.hero-photo{object-position:64% 52%}.hero-shade{background:linear-gradient(90deg,rgba(9,34,26,.95) 0%,rgba(8,30,25,.74) 33%,rgba(8,30,24,.05) 85%)}.photo-caption{bottom:14px}.lesson-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:26px 16px}.section-head{gap:13px}.experience-layout{grid-template-columns:1fr;gap:23px;padding-block:34px}.experience-intro>p{max-width:none;margin:10px 0}.about-section{grid-template-columns:105px 1fr;gap:24px}.about-photo{align-self:start;margin-top:5px}.about-copy p{font-size:14px}.section-line{width:18px}.section-title{gap:10px}.filters button{padding:4px 10px}.hero-actions .button{font-size:13px;padding:9px 13px}}
@media(max-width:520px){.hero-inner{min-height:492px;padding-block:27px 36px;align-items:flex-start}.hero-copy{max-width:100%}.hero-kicker{font-size:11px}.hero h1{font-size:53px;margin-top:10px}.hero-intro{max-width:235px;margin-top:12px}.hero-actions{margin-top:16px}.hero-photo{width:112%;height:58%;top:auto;bottom:0;left:-12%;object-position:79% 60%}.hero-shade{background:linear-gradient(180deg,#102e26 0%,#102e26 39%,rgba(16,46,38,.87) 46%,rgba(16,46,38,.06) 65%,transparent 78%)}.photo-caption{font-size:10px}.photo-caption i{font-size:11px}.section{padding-block:32px 39px}.section-head{margin-bottom:15px;align-items:flex-start;flex-direction:column}.filters{padding:2px}.filters button{min-height:31px;padding-inline:14px}.lesson-grid{grid-template-columns:1fr;gap:26px}.lesson-body{padding-top:12px}.lesson-title{font-size:21px;margin-top:7px}.lesson-description{font-size:14px}.experience-list li{grid-template-columns:57px 1fr;gap:12px}.experience-list time{font-size:20px}.about-section{grid-template-columns:1fr;gap:16px}.about-photo{width:90px;grid-column:1;grid-row:1;justify-self:end;margin:0 4px 0 0}.about-copy{grid-column:1;grid-row:1}.about-copy .section-title{margin:0 0 9px;min-height:34px}.about-copy p:first-of-type{min-height:85px;padding-right:105px}.footer-inner{min-height:60px}.video-layout{grid-template-columns:1fr}.video-stage{padding:8px 0}.video-stage video{width:auto;max-width:100%;height:52dvh;max-height:470px}.video-notes{padding:18px 20px 22px}.video-notes h3{margin-top:13px}.video-notes .lesson-meta{padding-right:24px}.video-dialog .dialog-close{position:sticky;float:right;margin:8px 8px -44px 0;top:8px;right:8px}.lesson-dialog{max-height:calc(100dvh - 20px)}.lab-shell{padding:21px 17px 19px}.lesson-dialog h2{font-size:22px}.equation{padding:12px 5px;gap:2px}.molecule>strong{font-size:26px}.stepper button{width:25px;height:33px}.equation-sign{font-size:18px}.lab-bottom{gap:9px}}
@media(max-width:355px){.brand-caption{font-size:11px;padding-left:8px}.equation-sign{font-size:14px}.stepper button{width:22px}.stepper output{min-width:13px}.hero-actions{gap:11px}.about-photo{width:80px}.about-copy p:first-of-type{padding-right:92px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition-duration:0s!important;animation-duration:0s!important}}
@media(max-width:520px){
  .hero{display:flex;flex-direction:column}
  .hero-inner{order:1;min-height:0;padding-block:26px 11px}
  .hero-intro{max-width:100%}
  .hero-photo{order:2;position:relative;inset:auto;width:100%;height:auto;max-height:235px;object-fit:cover;object-position:70% 58%;mask-image:linear-gradient(to bottom,transparent,#000 16%)}
  .hero-shade{display:none}
  .photo-caption{z-index:1}
}
@media(min-width:721px) and (max-width:900px){
  .brand-caption{display:none}
  .hero h1{font-size:clamp(46px,6.6vw,62px)}
}
@media(max-width:720px){
  .brand-portrait{width:34px;height:34px}
  .feedback-grid{gap:16px}
  .classroom-text{padding:14px}
  .feedback-example{font-size:15px}
}
@media(max-width:600px){
  .feedback-grid{grid-template-columns:1fr;gap:20px}
  .classroom-figure{aspect-ratio:1.85}
}