.learn-shell{--ink:#080d15;--paper:#edf0e9;--acid:#d4ff53;--violet:#b8a2ff;--dust:#8d98aa;--rule:#ffffff20;--display:Unbounded,sans-serif;--body:Onest,Arial,sans-serif;--mono:'JetBrains Mono',monospace;position:fixed;inset:0;margin:0;width:100%;height:100%;max-width:none;max-height:none;padding:0;border:0;background:radial-gradient(ellipse at 90% 0%,#25213d 0%,transparent 45%),var(--ink);color:var(--paper);font:15px var(--body);overflow:hidden}.learn-shell::backdrop{background:#080d15}.learn-shell *{box-sizing:border-box}.learn-shell button,.learn-shell input{font:inherit}.learn-shell button{cursor:pointer}.learn-shell button:focus-visible,.learn-shell a:focus-visible{outline:2px solid var(--acid);outline-offset:5px}.learn-shell button:disabled{cursor:default}.learn-shell a{color:inherit}.learn-shell h1,.learn-shell h2,.learn-shell h3,.learn-shell p{margin:0}.learn-shell button{border:0;background:none;color:inherit}.learn-shell em{font-style:normal;color:var(--acid)}.learn-header{height:100px;display:flex;align-items:center;gap:30px;padding:0 4.5%;border-bottom:1px solid var(--rule);background:#080d15b3;backdrop-filter:blur(20px)}.learn-wordmark{font:800 26px var(--display)!important;text-align:left;letter-spacing:-1px;line-height:1!important}.learn-wordmark span{display:block;font:8px var(--mono);letter-spacing:2.5px;color:var(--dust);margin-top:9px}.learn-header nav{display:flex;gap:28px;justify-content:center;flex:1}.learn-header nav button{font:12px var(--body);padding:14px 0;position:relative;color:#a3adbc}.learn-header nav button.is-active{color:var(--acid)}.learn-header nav button.is-active:after{content:'';position:absolute;bottom:5px;left:0;right:0;height:2px;background:var(--acid)}.learn-progress{display:flex;align-items:center;gap:10px}.learn-progress-num{font:26px var(--display);color:var(--acid)}.learn-progress>span:last-child{font:7px/1.8 var(--mono);letter-spacing:1px;color:var(--dust)}.learn-close{width:45px;height:45px;border:1px solid #ffffff40!important;border-radius:50%;font-size:25px!important;transition:background .2s,transform .3s}.learn-close:hover{background:var(--acid);color:var(--ink);transform:rotate(90deg)}.learn-scroll{height:calc(100% - 100px);overflow-y:auto;overscroll-behavior:contain;scroll-behavior:smooth}.learn-content{max-width:1500px;margin:auto;padding:0 7%}.learn-kicker{font:9px/1.7 var(--mono);letter-spacing:2px;color:var(--dust)}.learn-kicker i{display:inline-block;width:6px;height:6px;background:var(--acid);border-radius:50%;box-shadow:0 0 12px #d4ff5380;margin-right:10px}.learn-hero{padding:70px 0 50px;position:relative;overflow:hidden;isolation:isolate}.learn-hero h1{font:500 clamp(40px,6.5vw,96px)/1.2 var(--display);letter-spacing:-4px;margin:32px 0}.learn-hero-bottom{display:flex;justify-content:space-between;align-items:flex-end;gap:25px;max-width:950px}.learn-hero-bottom p{font-size:16px;line-height:1.7;color:#a4afbf}.learn-mono{font:8px/1.8 var(--mono);letter-spacing:1px;color:var(--dust)}.learn-orbit{position:absolute;width:350px;height:350px;right:-40px;top:35px;z-index:-1;perspective:500px;opacity:.45}.learn-orbit span{position:absolute;inset:20px;border:1px solid #b8a2ff70;border-radius:50%;transform:rotateY(60deg) rotateX(25deg)}.learn-orbit span:nth-child(2){transform:rotateY(-40deg) rotateX(60deg)}.learn-orbit span:nth-child(3){transform:rotateY(15deg) rotateX(-30deg)}.learn-orbit b{position:absolute;inset:140px 0 auto;text-align:center;font:15px var(--mono);color:var(--violet)}.learn-course-toolbar{display:flex;align-items:center;justify-content:space-between;padding:30px 0 18px;border-bottom:1px solid var(--rule);gap:20px}.learn-search{display:flex;align-items:center;gap:10px;border-bottom:1px solid #ffffff40;padding:6px 0}.learn-search>span{font-size:25px;color:var(--acid)}.learn-search input{background:none;border:0;outline:0;color:var(--paper);font-size:12px;width:210px;padding:6px}.learn-search input:focus{box-shadow:0 1px var(--acid)}.learn-search input::placeholder{color:var(--dust)}.learn-chapter{display:grid;grid-template-columns:95px 1fr 70px 50px;width:100%;text-align:left;border-bottom:1px solid var(--rule)!important;padding:28px 0;align-items:center;gap:15px;transition:padding .3s,background .3s}.learn-chapter:hover{padding-left:20px;padding-right:20px;background:linear-gradient(90deg,#d4ff530b,transparent)}.learn-chapter-no{font:30px var(--display);color:#566072;transition:color .3s}.learn-chapter:hover .learn-chapter-no{color:var(--acid)}.learn-chapter-main h2{font:400 clamp(16px,1.6vw,23px)/1.45 var(--display);letter-spacing:-.5px;margin:8px 0}.learn-chapter-main p{font-size:13px;color:var(--dust);line-height:1.6}.learn-chapter .learn-kicker{font-size:8px}.learn-chapter-time{font:9px var(--mono);color:var(--dust)}.learn-chapter-arrow{display:grid;place-items:center;width:42px;height:42px;border:1px solid #ffffff30;border-radius:50%;font-size:20px;transition:transform .3s,background .3s}.learn-chapter:hover .learn-chapter-arrow{transform:rotate(45deg);background:var(--acid);color:var(--ink);border-color:var(--acid)}.learn-chapter-arrow.is-complete{color:var(--acid);border-color:#d4ff5360}.learn-empty{padding:40px 0;color:var(--dust)}.learn-course-note{display:flex;align-items:center;gap:25px;padding:45px 0}.learn-course-note>span{font-size:45px;color:var(--violet)}.learn-course-note p{max-width:550px;font-size:14px;color:var(--dust);line-height:1.8}.learn-link{font:11px var(--body)!important;padding:10px 0!important;text-decoration:none;color:var(--acid)!important;white-space:nowrap}.learn-link:hover{text-decoration:underline}.learn-course-note .learn-link{margin-left:auto}.learn-footer{max-width:1500px;margin:35px auto 0;border-top:1px solid var(--rule);padding:25px 7%;display:flex;justify-content:space-between;align-items:center;gap:20px}.learn-footer>span{font:8px var(--mono);letter-spacing:1.6px;color:var(--dust)}.learn-footer button{font:11px var(--body);color:var(--acid)}.learn-footer button span{margin-left:18px}.learn-reader-top{display:flex;justify-content:space-between;align-items:center;padding:32px 0;border-bottom:1px solid var(--rule);gap:20px}.learn-reader{display:grid;grid-template-columns:220px minmax(0,1fr);gap:65px;padding-top:40px}.learn-reader-aside{align-self:start;position:sticky;top:25px}.learn-giant-number{font:90px/1 var(--display);letter-spacing:-8px;color:#ffffff15}.learn-reader-aside>.learn-kicker{margin-top:15px;color:var(--violet)}.learn-toc{margin:35px 0}.learn-toc a{display:flex;gap:10px;font:9px/1.7 var(--mono);padding:12px 0;border-bottom:1px solid var(--rule);color:#68788c;text-decoration:none}.learn-toc a span{font:11px/1.7 var(--body);color:#a7b2c0}.learn-toc a:hover span{color:var(--acid)}.learn-practice-btn{font-size:10px!important;width:100%;display:flex;justify-content:space-between;padding:15px!important;border:1px solid #d4ff5350!important;border-radius:3px;color:var(--acid)!important}.learn-reader-body{max-width:780px;min-width:0;padding-bottom:20px}.learn-reader-body h1{font:400 clamp(27px,3vw,45px)/1.35 var(--display);letter-spacing:-1.5px}.learn-lead{font-size:17px!important;line-height:1.8!important;color:var(--dust);margin-top:20px!important}.learn-reader-body blockquote{border-left:2px solid var(--violet);margin:35px 0;padding:18px 24px;background:linear-gradient(90deg,#b8a2ff10,transparent);font-size:16px;line-height:1.85;color:#d4cfec}.learn-reader-body blockquote span{display:block;font:8px var(--mono);letter-spacing:2px;color:var(--violet);margin-bottom:10px}.learn-prose{margin:40px 0;scroll-margin-top:25px}.learn-prose h2{font:400 20px/1.5 var(--display);letter-spacing:-.5px;margin:12px 0 15px}.learn-prose p{font:16px/1.95 var(--body);color:#b9c2cf}.learn-source{display:flex;gap:20px;align-items:center;flex-wrap:wrap;border-top:1px solid var(--rule);border-bottom:1px solid var(--rule);padding:20px 0;margin:35px 0}.learn-source a{font:11px var(--mono);color:var(--violet);text-underline-offset:4px}.learn-check{padding:28px;border:1px solid #d4ff5340;background:linear-gradient(135deg,#d4ff5306,#080d1500);border-radius:5px}.learn-check h2{font:400 19px/1.6 var(--display);margin:15px 0 25px;letter-spacing:-.5px}.learn-options{display:grid;gap:10px}.learn-option{width:100%;display:flex;align-items:center;gap:18px;text-align:left;padding:18px!important;border:1px solid #ffffff30!important;border-radius:3px;transition:border-color .25s,background .25s,transform .25s}.learn-option>span{font:11px var(--mono);color:var(--dust);border:1px solid #ffffff25;display:grid;place-items:center;width:30px;height:30px;flex-shrink:0}.learn-option b{font:400 14px/1.7 var(--body);flex:1}.learn-option i{font-style:normal;font-size:18px;color:var(--dust)}.learn-option:not(:disabled):hover{border-color:var(--acid)!important;background:#d4ff5307;transform:translateX(3px)}.learn-option.is-correct{border-color:var(--acid)!important;background:#d4ff5310}.learn-option.is-correct>span{color:var(--acid);border-color:#d4ff5370}.learn-option.is-wrong{border-color:#ff8d9b!important;background:#ff8d9b10}.learn-feedback{font-size:12px;line-height:1.9;color:var(--dust);margin-top:20px!important}.learn-reader-next{display:flex;justify-content:space-between;align-items:center;gap:18px;margin-top:30px}.learn-solid{display:inline-flex;align-items:center;justify-content:space-between;gap:25px;background:var(--acid)!important;color:var(--ink)!important;font:600 12px var(--body)!important;padding:17px 23px!important;border-radius:3px;transition:background .2s,transform .2s}.learn-solid:hover{background:#e4ff94!important;transform:translateY(-2px)}.learn-solid[hidden]{display:none!important}.learn-quiz-intro{padding-bottom:80px}.learn-quiz-intro h1{font-size:clamp(45px,7vw,105px)}.learn-quiz-stat{display:flex;align-items:center;gap:20px;margin:35px 0}.learn-quiz-stat>span{font:45px var(--display);color:var(--acid);letter-spacing:-3px}.learn-quiz-stat small{font:20px var(--display);color:#596173;margin-left:9px;letter-spacing:-1px}.learn-quiz-stat p{font:8px/1.9 var(--mono);letter-spacing:1px;color:var(--dust)}.learn-quiz-scene{max-width:960px;padding:60px 0 65px;position:relative;isolation:isolate}.learn-quiz-scene>.learn-kicker{display:flex;gap:15px;flex-wrap:wrap}.learn-quiz-scene>.learn-kicker span{color:#5c6c81}.learn-quiz-line{display:flex;gap:7px;margin:25px 0 45px}.learn-quiz-line i{height:3px;flex:1;background:#ffffff20}.learn-quiz-line i.is-done{background:var(--acid)}.learn-quiz-line i.is-now{background:var(--violet);box-shadow:0 0 15px #b8a2ff60}.learn-question-number{position:absolute;right:-25px;top:65px;font:240px var(--display);color:#ffffff04;letter-spacing:-20px;pointer-events:none;z-index:-1}.learn-quiz-scene h1{font:400 clamp(24px,3vw,40px)/1.55 var(--display);letter-spacing:-1px;margin-bottom:35px}.learn-quiz-scene .learn-option{padding:22px!important}.learn-answer-result{min-height:50px;margin:22px 0}.learn-answer-result strong{color:var(--acid);font-size:15px}.learn-answer-result p{color:#a7b4c6;font-size:14px;line-height:1.8;margin-top:9px}.learn-quiz-finish{padding:60px 0 80px;max-width:900px}.learn-score{font:clamp(100px,15vw,210px)/1.1 var(--display);letter-spacing:-12px;color:var(--acid);margin:35px 0 20px}.learn-score span{font:30px var(--display);color:#566174;letter-spacing:-1px;margin-left:20px}.learn-quiz-finish h1{font:400 clamp(30px,4vw,55px)/1.3 var(--display);letter-spacing:-2px;margin-bottom:25px}.learn-quiz-finish>p{font:16px/1.9 var(--body);color:var(--dust);max-width:620px}.learn-finish-actions{display:flex;gap:25px;align-items:center;flex-wrap:wrap;margin-top:35px}.learn-tools-hero{padding:60px 0 35px}.learn-tools-hero h1{font:400 clamp(35px,4.8vw,70px)/1.3 var(--display);letter-spacing:-3px;margin:25px 0}.learn-tools-hero>p{font-size:15px;line-height:1.8;color:var(--dust)}.learn-tool-tabs{display:flex;border-bottom:1px solid var(--rule);gap:35px;padding:15px 0}.learn-tool-tabs button{font:10px var(--mono);color:var(--dust);padding:12px 0}.learn-tool-tabs button.is-active{color:var(--acid)}.learn-tool-stage{padding:45px 0;display:grid;grid-template-columns:1fr 1.2fr;gap:70px;min-height:550px}.learn-tool-explain h2{font:400 clamp(25px,3vw,39px)/1.45 var(--display);letter-spacing:-1.5px;margin:20px 0}.learn-tool-explain>p{font:14px/1.9 var(--body);color:var(--dust);max-width:400px}.learn-tool-footnote{font-size:10px!important;border-top:1px solid var(--rule);margin-top:30px!important;padding-top:20px}.learn-cidr-form{margin:0 0 25px}.learn-cidr-form label{display:block;font:8px var(--mono);letter-spacing:1.5px;color:var(--dust);margin-bottom:12px}.learn-cidr-form>div{display:flex;border-bottom:1px solid var(--acid);padding-bottom:12px;gap:10px}.learn-cidr-form input{flex:1;min-width:0;border:0;background:none;color:var(--paper);font:clamp(16px,2vw,26px) var(--mono)!important;outline:none}.learn-cidr-form input:focus{color:var(--acid)}.learn-cidr-form button{font-size:28px!important;color:var(--acid)!important;padding:0 8px!important}.learn-bits{display:grid;grid-template-columns:repeat(16,1fr);gap:4px;margin:25px 0}.learn-bits span{display:grid;place-items:center;aspect-ratio:.8;font:10px var(--mono);border-radius:2px}.learn-bits .network-bit{background:#d4ff5320;color:var(--acid)}.learn-bits .host-bit{background:#b8a2ff20;color:var(--violet)}.learn-address-count{display:flex;align-items:baseline;flex-wrap:wrap;gap:14px;margin:25px 0}.learn-address-count strong{font:clamp(25px,3.5vw,46px) var(--display);letter-spacing:-2px;color:var(--acid)}.learn-address-count>span{font:8px var(--mono);color:var(--dust);letter-spacing:1px}.learn-subnet-output dl{margin:0}.learn-subnet-output dl>div{display:flex;justify-content:space-between;border-top:1px solid var(--rule);gap:25px;padding:15px 0}.learn-subnet-output dt{font:11px/1.8 var(--body);color:var(--dust)}.learn-subnet-output dd{font:12px/1.8 var(--mono);text-align:right;margin:0}.learn-bit-legend{display:flex;gap:20px;font:8px var(--mono);margin-top:20px;flex-wrap:wrap}.learn-bit-legend>span:first-child{color:var(--acid)}.learn-bit-legend>span:last-child{color:var(--violet)}.learn-error{font:13px/1.8 var(--body);color:#ff9cab}.learn-osi-stack{perspective:900px;padding:15px 15px 25px 30px}.learn-osi-stack button{display:flex;align-items:center;gap:20px;width:100%;padding:20px 25px;margin:6px 0;border:1px solid #b8a2ff35!important;background:linear-gradient(120deg,#b8a2ff0c,#b8a2ff18);transform:rotateX(10deg) rotateY(-12deg);transform-origin:100% 50%;box-shadow:7px 10px 0 #02050a50;transition:transform .35s,background .35s,border-color .35s;text-align:left}.learn-osi-stack button>span{font:15px var(--mono);color:var(--violet)}.learn-osi-stack button>b{font:400 13px var(--display);flex:1}.learn-osi-stack button>i{font-style:normal;color:var(--violet)}.learn-osi-stack button:hover,.learn-osi-stack button.is-active{transform:translateX(-20px) rotateX(10deg) rotateY(-12deg);background:var(--acid);color:var(--ink);border-color:var(--acid)!important}.learn-osi-stack button.is-active>span,.learn-osi-stack button.is-active>i{color:#3d5214}.learn-osi-description{margin-top:28px;border-left:2px solid var(--acid);padding:4px 0 4px 18px}.learn-osi-description h3{font:500 19px var(--body);margin:10px 0}.learn-osi-description p{font:13px/1.8 var(--body);color:#bac5d1}.learn-dns-copy{margin:25px 0}.learn-dns-copy>.learn-kicker{color:var(--violet)}.learn-dns-copy h3{font:500 19px/1.5 var(--body);margin:10px 0}.learn-dns-copy p{font:14px/1.9 var(--body);color:var(--dust)}.learn-dns-actions{display:flex;gap:28px;align-items:center}.learn-dns-actions .learn-link:disabled{opacity:.3}.learn-dns-network{position:relative;padding-left:30px}.learn-dns-network:before{content:'';position:absolute;top:30px;bottom:30px;left:58px;width:1px;background:#b8a2ff50}.learn-dns-node{position:relative;display:flex;align-items:center;gap:25px;width:100%;text-align:left;min-height:76px}.learn-dns-node>span{font:10px var(--mono);background:var(--ink);border:1px solid #b8a2ff40;border-radius:50%;width:56px;height:56px;display:grid;place-items:center;flex-shrink:0;z-index:1;color:var(--dust);transition:.3s}.learn-dns-node>b{font:400 15px var(--display);flex:1;color:#78879d;transition:color .3s}.learn-dns-node>i{font-style:normal;color:#3d4858}.learn-dns-node.is-active>span{border-color:var(--acid);background:#d4ff5315;color:var(--acid);box-shadow:0 0 35px #d4ff5310;transform:scale(1.1)}.learn-dns-node.is-active>b{color:var(--paper)}.learn-dns-node.is-active>i{color:var(--acid)}.learn-dns-node.is-done>span{border-color:#d4ff5350;color:var(--acid)}.learn-dns-node.is-done>i{color:var(--acid)}.learn-handshake{position:relative;border:1px solid var(--rule);padding:25px 30px;background:linear-gradient(135deg,#b8a2ff09,transparent)}.learn-handshake-ends{display:flex;justify-content:space-between;font:9px var(--mono);letter-spacing:1.5px;color:var(--dust);border-bottom:1px solid var(--rule);padding-bottom:20px;margin-bottom:25px}.learn-tcp-arrow{height:78px;display:flex;align-items:center;border-bottom:1px dashed #ffffff15;opacity:.2;transition:opacity .5s,transform .5s;transform:translateX(-8px)}.learn-tcp-arrow:nth-of-type(3){justify-content:flex-end;transform:translateX(8px)}.learn-tcp-arrow span{font:15px var(--mono);color:var(--violet);background:#151c29;padding:12px 17px;border:1px solid #b8a2ff50;min-width:70%}.learn-tcp-arrow.is-sent{opacity:1;transform:translateX(0)}.learn-tcp-arrow.is-sent span{color:var(--acid);border-color:#d4ff5360}.learn-handshake>.learn-mono{margin-top:30px;color:var(--acid);font-size:8px}.learn-shell [hidden]{display:none!important}
@media(min-width:1700px){.learn-content{padding:0 100px}.learn-hero h1{font-size:100px}.learn-reader{gap:100px}}@media(max-width:1050px){.learn-header{gap:20px;padding:0 4%}.learn-header nav{gap:20px}.learn-content{padding:0 5%}.learn-reader{grid-template-columns:170px minmax(0,1fr);gap:35px}.learn-tool-stage{gap:35px}.learn-hero h1{letter-spacing:-3px}.learn-course-note{gap:18px}.learn-course-note p{max-width:460px}.learn-orbit{right:-120px}.learn-tool-tabs{gap:25px}.learn-osi-stack{padding-left:15px}.learn-osi-stack button{padding:19px 17px;gap:15px}.learn-osi-stack button>b{font-size:11px}}@media(max-width:750px){.learn-header{height:116px;padding:17px 5% 48px;position:relative;gap:15px}.learn-wordmark{font-size:20px!important}.learn-wordmark span{font-size:6px;margin-top:7px}.learn-header nav{position:absolute;bottom:0;left:5%;right:5%;justify-content:flex-start;gap:24px;overflow:auto;height:39px}.learn-header nav button{padding:7px 0;white-space:nowrap;font-size:10px}.learn-progress{margin-left:auto;gap:7px}.learn-progress-num{font-size:21px}.learn-progress>span:last-child{font-size:6px}.learn-close{width:34px;height:34px;font-size:23px!important}.learn-scroll{height:calc(100% - 116px)}.learn-content{padding:0 6%}.learn-hero{padding:40px 0 30px}.learn-hero h1{font-size:clamp(33px,7vw,55px);letter-spacing:-1.8px;margin:23px 0}.learn-kicker{font-size:7px;letter-spacing:1.4px}.learn-hero-bottom{display:block}.learn-hero-bottom p{font-size:13px}.learn-hero-bottom .learn-mono{display:block;margin-top:22px}.learn-orbit{width:230px;height:230px;top:15px;right:-100px;opacity:.2}.learn-orbit b{top:100px;font-size:10px}.learn-course-toolbar{padding:20px 0 15px;align-items:flex-start;flex-direction:column;gap:12px}.learn-search{width:100%}.learn-search input{width:100%;font-size:12px}.learn-chapter{grid-template-columns:38px minmax(0,1fr) 32px;gap:12px;padding:23px 0}.learn-chapter-no{font-size:19px;align-self:start;margin-top:16px}.learn-chapter-main h2{font-size:14px;letter-spacing:-.4px;line-height:1.55}.learn-chapter-main p{font-size:11px}.learn-chapter .learn-kicker{font-size:6px;letter-spacing:1.2px}.learn-chapter-time{display:none}.learn-chapter-arrow{width:30px;height:30px;font-size:16px}.learn-chapter:hover{padding-left:5px;padding-right:5px}.learn-course-note{display:grid;grid-template-columns:30px 1fr;gap:12px;padding:25px 0}.learn-course-note>span{font-size:30px}.learn-course-note p{font-size:12px}.learn-course-note .learn-link{grid-column:2;margin-left:0;justify-self:start}.learn-footer{padding:22px 6%;margin-top:20px;display:block}.learn-footer>span{font-size:6px;display:block;margin-bottom:15px}.learn-footer button{font-size:10px}.learn-reader-top{padding:20px 0;gap:10px;align-items:flex-start}.learn-reader-top>.learn-kicker{font-size:6px;text-align:right;padding-top:10px}.learn-reader{display:block;padding-top:25px}.learn-reader-aside{position:static;display:flex;align-items:center;gap:20px;margin-bottom:20px}.learn-giant-number{font-size:45px;letter-spacing:-3px}.learn-reader-aside>.learn-kicker{margin:0;font-size:6px;flex:1}.learn-toc{display:none}.learn-practice-btn{width:auto;font-size:8px!important;padding:12px!important;gap:15px}.learn-reader-body h1{font-size:26px;letter-spacing:-1px}.learn-lead{font-size:14px!important;margin-top:16px!important}.learn-reader-body blockquote{margin:25px 0;padding:15px 18px;font-size:13px}.learn-reader-body blockquote span{font-size:7px}.learn-prose{margin:30px 0}.learn-prose h2{font-size:16px;margin:10px 0 13px}.learn-prose p{font-size:14px;line-height:1.9}.learn-source{gap:10px;margin:28px 0;display:block}.learn-source a{font-size:9px;display:block;margin-top:12px;overflow-wrap:anywhere}.learn-check{padding:20px 15px}.learn-check h2{font-size:14px;line-height:1.7;margin:14px 0 20px}.learn-option{gap:12px;padding:14px 11px!important}.learn-option>span{width:25px;height:25px;font-size:9px}.learn-option b{font-size:12px;line-height:1.7}.learn-option i{font-size:14px}.learn-feedback{font-size:11px}.learn-reader-next{display:block}.learn-reader-next>.learn-link{display:block;text-align:left;margin-bottom:12px}.learn-solid{padding:15px 18px!important;font-size:11px!important}.learn-quiz-intro{padding-bottom:40px}.learn-quiz-intro .learn-lead{font-size:13px!important}.learn-quiz-stat>span{font-size:35px}.learn-quiz-stat small{font-size:17px}.learn-quiz-stat p{font-size:7px}.learn-quiz-scene{padding:35px 0}.learn-quiz-scene h1{font-size:22px;line-height:1.6;letter-spacing:-.8px;margin-bottom:25px}.learn-quiz-line{gap:5px;margin:20px 0 30px}.learn-quiz-scene .learn-option{padding:17px 12px!important}.learn-question-number{font-size:140px;right:0;top:50px;letter-spacing:-10px}.learn-answer-result p{font-size:12px}.learn-answer-result strong{font-size:13px}.learn-quiz-finish{padding:35px 0}.learn-score{font-size:105px;letter-spacing:-8px;margin:28px 0}.learn-score span{font-size:20px;margin-left:14px}.learn-quiz-finish h1{font-size:29px;letter-spacing:-1px}.learn-quiz-finish>p{font-size:13px}.learn-finish-actions{gap:15px;align-items:flex-start;flex-direction:column;margin-top:25px}.learn-tools-hero{padding:35px 0 20px}.learn-tools-hero h1{font-size:30px;letter-spacing:-1.5px;margin:20px 0}.learn-tools-hero>p{font-size:12px}.learn-tool-tabs{gap:20px;overflow:auto;padding:8px 0}.learn-tool-tabs button{font-size:8px;white-space:nowrap}.learn-tool-stage{grid-template-columns:1fr;gap:30px;padding:30px 0;min-height:0}.learn-tool-explain h2{font-size:27px;line-height:1.4;letter-spacing:-1px;margin:15px 0}.learn-tool-explain>p{font-size:12px;max-width:none}.learn-tool-footnote{font-size:9px!important;margin-top:20px!important;padding-top:15px}.learn-cidr-form input{font-size:19px!important}.learn-cidr-form label{font-size:7px}.learn-bits{gap:3px}.learn-bits span{font-size:8px}.learn-address-count strong{font-size:28px;letter-spacing:-1px}.learn-address-count>span{font-size:7px}.learn-subnet-output dt{font-size:10px}.learn-subnet-output dd{font-size:10px}.learn-subnet-output dl>div{padding:13px 0;gap:12px}.learn-bit-legend{font-size:7px;gap:12px}.learn-osi-stack{max-width:380px;margin:0 auto;width:100%;padding:0 5px 20px 20px}.learn-osi-stack button{padding:17px 19px;gap:18px}.learn-osi-stack button>b{font-size:11px}.learn-osi-description{margin-top:20px}.learn-osi-description h3{font-size:17px}.learn-osi-description p{font-size:12px}.learn-dns-copy h3{font-size:17px}.learn-dns-copy p{font-size:12px}.learn-dns-network{padding-left:0}.learn-dns-network:before{left:25px}.learn-dns-node{min-height:67px;gap:20px}.learn-dns-node>span{width:50px;height:50px;font-size:9px}.learn-dns-node>b{font-size:12px}.learn-handshake{padding:20px}.learn-handshake-ends{font-size:8px}.learn-tcp-arrow{height:68px}.learn-tcp-arrow span{font-size:12px;padding:11px 15px}.learn-handshake>.learn-mono{font-size:7px}}@media(prefers-reduced-motion:reduce){.learn-shell *{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
/* Motion edition: expressive type, living diagrams, calm reading. */
.learn-shell .learn-hero,.learn-shell .learn-tools-hero{isolation:isolate;position:relative;overflow:hidden}
.learn-shell .learn-hero{padding-top:65px;padding-bottom:52px;min-height:450px}
.learn-shell .learn-hero h1{font-weight:600;font-size:clamp(42px,6.1vw,90px);line-height:1.17;letter-spacing:-.065em;position:relative;z-index:2;font-variation-settings:'wght' 600;text-shadow:0 5px 35px #080d15}
.learn-shell .learn-hero h1 em,.learn-shell .learn-tools-hero h1 em{background:linear-gradient(110deg,#f2ffc2 0%,#d4ff53 42%,#b7e943 80%);-webkit-background-clip:text;background-clip:text;color:transparent}
.learn-shell .learn-hero>.learn-kicker,.learn-shell .learn-hero-bottom,.learn-shell .learn-hero>.learn-lead,.learn-shell .learn-hero>.learn-quiz-stat,.learn-shell .learn-hero>.learn-solid{position:relative;z-index:2}
.learn-shell .learn-tools-hero h1{font-weight:550;letter-spacing:-.065em;position:relative;z-index:2}
.learn-shell .learn-tools-hero>p,.learn-shell .learn-tools-hero>.learn-kicker{position:relative;z-index:2}
.learn-shell .learn-reader-body h1{font-weight:500;letter-spacing:-.055em}
.learn-shell .learn-quiz-scene h1{font-weight:500;letter-spacing:-.055em}
.learn-shell .learn-split-word{display:inline-block;white-space:nowrap;perspective:600px}
.learn-shell .learn-split-char{display:inline-block;transform-origin:50% 80%;backface-visibility:hidden}
.learn-shell .learn-hero h1 em .learn-split-char,.learn-shell .learn-tools-hero h1 em .learn-split-char{color:var(--acid)}
.learn-shell .learn-hero-bottom p{max-width:430px}
.learn-shell .learn-orbit{position:absolute;z-index:0;top:10px;right:-60px;width:440px;height:440px;perspective:900px;opacity:.83;pointer-events:none;contain:layout style;filter:drop-shadow(0 0 25px #b8a2ff0c)}
.learn-orbit-halo{position:absolute;inset:2%;border-radius:50%;background:radial-gradient(ellipse,#d4ff5311 0%,#b8a2ff0b 40%,transparent 70%)}
.learn-orbit-grid{position:absolute;inset:8%;border:1px solid #b8a2ff19;border-radius:50%;background:repeating-radial-gradient(circle at center,transparent 0 35px,#b8a2ff0f 36px,transparent 37px);transform:rotateX(22deg) rotateY(-18deg)}
.learn-orbit-grid:before,.learn-orbit-grid:after{content:'';position:absolute;left:50%;top:-10%;height:120%;width:1px;background:linear-gradient(transparent,#b8a2ff35,transparent);transform:rotate(37deg)}
.learn-orbit-grid:after{transform:rotate(-53deg)}
.learn-orbit-links{position:absolute;inset:0;width:100%;height:100%;overflow:visible}
.learn-orbit-links path{fill:none;stroke:#b8a2ff24;stroke-width:.65}
.learn-orbit-links .learn-electric-flow{stroke:#d4ff53;stroke-width:1.2;stroke-dasharray:4 170;stroke-dashoffset:0;opacity:.7}
.learn-orbit-links circle{fill:#d4ff53;stroke:#080d15;stroke-width:3;filter:drop-shadow(0 0 5px #d4ff5370)}
.learn-orbit-links circle:nth-child(even){fill:#b8a2ff}
.learn-orbit-plane{position:absolute;inset:12%;transform-style:preserve-3d}
.learn-orbit-plane.plane-one{transform:rotateX(58deg) rotateY(-18deg) rotateZ(-32deg)}
.learn-orbit-plane.plane-two{inset:15%;transform:rotateX(-32deg) rotateY(58deg) rotateZ(20deg)}
.learn-orbit-plane.plane-three{inset:19%;transform:rotateX(15deg) rotateY(-35deg) rotateZ(-48deg)}
.learn-orbit-ring{position:absolute;inset:0;border-radius:50%;border:1px solid #b8a2ff80;box-shadow:inset 0 0 10px #b8a2ff05,0 0 10px #b8a2ff05;transform:rotate(0)}
.learn-orbit-ring:before{content:'';position:absolute;inset:-3px;border:2px solid transparent;border-top-color:#d4ff53;border-right-color:#d4ff5340;border-radius:50%;transform:rotate(22deg)}
.learn-orbit-ring:after{content:'';position:absolute;inset:12px;border:1px dashed #b8a2ff30;border-radius:50%}
.learn-orbit-ring i{position:absolute;left:50%;top:-5px;width:9px;height:9px;border-radius:50%;background:#e3ff8c;box-shadow:0 0 12px #d4ff5380,0 0 25px #d4ff5330;transform:translateX(-50%)}
.learn-orbit-ring i:nth-child(2){top:auto;bottom:-4px;width:7px;height:7px;background:#b8a2ff;box-shadow:0 0 14px #b8a2ff80}
.learn-orbit-plane.plane-two .learn-orbit-ring{border-color:#d4ff5360}
.learn-orbit-plane.plane-two .learn-orbit-ring:before{border-top-color:#b8a2ff;border-right-color:#b8a2ff50}
.learn-orbit-plane.plane-three .learn-orbit-ring{border-color:#e6eafe30}
.learn-orbit-sweep{position:absolute;inset:5%;border-radius:50%;background:conic-gradient(from 0deg,transparent 0deg,transparent 310deg,#d4ff5303 335deg,#d4ff5320 359deg,transparent 360deg);transform:rotate(-60deg);mix-blend-mode:screen}
.learn-orbit-core{position:absolute;inset:35%;display:flex;flex-direction:column;justify-content:center;align-items:center;border:1px solid #d4ff5335;border-radius:50%;background:radial-gradient(circle,#0d1722 0%,#080d15ee 70%);box-shadow:0 0 45px #d4ff5309,inset 0 0 25px #b8a2ff10}
.learn-shell .learn-orbit-core b{position:static;inset:auto;display:block;font:500 37px/1 var(--display);letter-spacing:-3px;color:#e9ffad;text-align:center}
.learn-orbit-core small{display:block;font:5px var(--mono);letter-spacing:1.3px;color:#9caaae;margin-top:10px}
.learn-orbit-core-dot{position:absolute;top:17%;width:3px;height:3px;border-radius:50%;background:#d4ff53;box-shadow:0 0 8px #d4ff53}
.learn-orbit-readout{position:absolute;font:6px/1.7 var(--mono);letter-spacing:1.3px;color:#7e8caa}
.learn-orbit-readout.readout-one{left:12%;top:18%;padding:5px 7px;border:1px solid #b8a2ff30;background:#080d1590}
.learn-orbit-readout.readout-one i{font-style:normal;color:var(--acid);margin-left:14px}
.learn-orbit-readout.readout-two{right:5%;bottom:17%;text-align:right}
.learn-shell .learn-orbit-readout b{position:static;inset:auto;display:block;font:8px var(--mono);letter-spacing:3px;color:#b8a2ff;margin-top:8px}
.learn-shell .learn-quiz-intro .learn-orbit{width:520px;height:520px;right:-20px;top:40px}
.learn-shell .learn-tools-hero .learn-orbit{width:345px;height:345px;right:0;top:10px;opacity:.58}
.learn-shell .learn-tools-hero .learn-orbit-core b{font-size:35px}
.learn-shell .learn-quiz-intro .learn-orbit-core b{font-size:55px}
.learn-shell .learn-chapter{position:relative;isolation:isolate;overflow:hidden;transition:padding .35s,background .35s}
.learn-shell .learn-chapter:before{content:'';position:absolute;left:0;top:0;bottom:0;width:3px;background:var(--acid);transform:scaleY(0);transform-origin:50% 100%;transition:transform .35s;z-index:-1}
.learn-shell .learn-chapter:after{content:'';position:absolute;inset:0;background:linear-gradient(105deg,transparent 10%,#d4ff5307 35%,#b8a2ff10 47%,transparent 70%);transform:translateX(-110%);transition:transform .75s ease;z-index:-1;pointer-events:none}
.learn-shell .learn-chapter:hover:before,.learn-shell .learn-chapter:focus-visible:before{transform:scaleY(1)}
.learn-shell .learn-chapter:hover:after,.learn-shell .learn-chapter:focus-visible:after{transform:translateX(100%)}
.learn-shell .learn-chapter-main h2{font-weight:450;transition:color .3s,letter-spacing .4s,font-variation-settings .4s;font-variation-settings:'wght' 450}
.learn-shell .learn-chapter:hover h2,.learn-shell .learn-chapter:focus-visible h2{color:#e6ffc0;font-variation-settings:'wght' 550;letter-spacing:-.02em}
.learn-shell .learn-chapter-no{transition:color .3s,transform .4s;font-variation-settings:'wght' 400}
.learn-shell .learn-chapter:hover .learn-chapter-no{transform:translateY(-3px);color:var(--acid)}
.learn-shell .learn-tool-tabs button{position:relative}
.learn-shell .learn-tool-tabs button:after{content:'';position:absolute;left:0;right:0;bottom:0;height:2px;background:var(--acid);transform:scaleX(0);transform-origin:0 50%;transition:transform .35s}
.learn-shell .learn-tool-tabs button.is-active:after{transform:scaleX(1)}
.learn-shell .learn-quiz-scene .learn-question-number{font-weight:600;color:#b8a2ff08;text-shadow:0 0 60px #b8a2ff08}
.learn-shell .learn-option{position:relative;overflow:hidden}
.learn-shell .learn-option:before{content:'';position:absolute;inset:0;background:linear-gradient(115deg,transparent 10%,#d4ff5312 48%,transparent 75%);transform:translateX(-110%);transition:transform .7s;pointer-events:none}
.learn-shell .learn-option:not(:disabled):hover:before{transform:translateX(110%)}
.learn-shell .learn-option.is-correct{box-shadow:inset 3px 0 var(--acid),0 0 25px #d4ff5305}
.learn-shell .learn-progress-num{font-variation-settings:'wght' 650}
.learn-shell .learn-check h2,.learn-shell .learn-prose h2{font-weight:450}
.learn-motion-live .learn-orbit-ring{animation:learn-orbit-spin 23s linear infinite}
.learn-motion-live .plane-two .learn-orbit-ring{animation-duration:31s;animation-direction:reverse}
.learn-motion-live .plane-three .learn-orbit-ring{animation-duration:39s}
.learn-motion-live .learn-orbit-sweep{animation:learn-orbit-spin 16s linear infinite}
.learn-motion-live .learn-electric-flow{animation:learn-electric-flow 7s linear infinite}
.learn-motion-live .learn-orbit-core-dot{animation:learn-beacon 3.2s ease-in-out infinite}
.learn-motion-live .learn-orbit-halo{animation:learn-core-breathe 7s ease-in-out infinite}
.learn-motion-live .learn-kicker>i{animation:learn-beacon 3.2s ease-in-out infinite}
.learn-motion-live .learn-quiz-line .is-now{animation:learn-beacon 2.6s ease-in-out infinite}
@keyframes learn-orbit-spin{to{transform:rotate(360deg)}}
@keyframes learn-electric-flow{to{stroke-dashoffset:-1044}}
@keyframes learn-core-breathe{0%,100%{opacity:.55;transform:scale(.94)}50%{opacity:1;transform:scale(1.04)}}
@keyframes learn-beacon{0%,100%{opacity:.45}50%{opacity:1}}
@media(min-width:1700px){.learn-shell .learn-hero h1{font-size:96px}.learn-shell .learn-orbit{right:-30px;top:5px;width:470px;height:470px}}
@media(max-width:1050px){.learn-shell .learn-orbit{right:-110px;width:400px;height:400px;opacity:.65}.learn-shell .learn-hero h1{font-size:clamp(42px,6.4vw,76px)}.learn-shell .learn-hero-bottom{align-items:flex-start;flex-direction:column;gap:18px}.learn-shell .learn-hero-bottom .learn-mono{font-size:7px}.learn-shell .learn-tools-hero .learn-orbit{right:-60px;opacity:.4}.learn-shell .learn-quiz-intro .learn-orbit{right:-120px}}
@media(max-width:750px){.learn-shell .learn-hero{padding-top:35px;padding-bottom:35px;min-height:0}.learn-shell .learn-hero h1{font-size:clamp(34px,7.7vw,55px);line-height:1.25;letter-spacing:-.065em;margin:24px 0}.learn-shell .learn-orbit{right:-100px;top:3px;width:280px;height:280px;opacity:.34}.learn-shell .learn-hero-bottom{gap:0}.learn-shell .learn-hero-bottom p{font-size:12px;max-width:85%}.learn-shell .learn-hero-bottom .learn-mono{font-size:6px;line-height:1.8;margin-top:18px}.learn-shell .learn-orbit-core b{font-size:26px;letter-spacing:-2px}.learn-orbit-core small{font-size:3.5px;letter-spacing:.8px;margin-top:7px}.learn-orbit-readout{font-size:4px;letter-spacing:.5px}.learn-shell .learn-orbit-readout b{font-size:6px;margin-top:5px}.learn-orbit-readout.readout-one{padding:4px}.learn-orbit-ring i{width:7px;height:7px;top:-4px}.learn-orbit-ring i:nth-child(2){width:5px;height:5px;bottom:-3px}.learn-shell .learn-tools-hero .learn-orbit{width:250px;height:250px;right:-100px;opacity:.27}.learn-shell .learn-quiz-intro .learn-orbit{width:320px;height:320px;right:-130px;top:25px;opacity:.3}.learn-shell .learn-quiz-intro .learn-orbit-core b{font-size:35px}.learn-shell .learn-tools-hero .learn-orbit-core b{font-size:24px}.learn-shell .learn-chapter:hover{padding-left:8px;padding-right:0}.learn-shell .learn-chapter:hover h2{letter-spacing:-.4px}.learn-shell .learn-prose h2{font-size:16px}}
html[data-motion='reduced'] .learn-shell *,html[data-motion='reduced'] .learn-shell *:before,html[data-motion='reduced'] .learn-shell *:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}
@media(prefers-reduced-motion:reduce){.learn-shell *,.learn-shell *:before,.learn-shell *:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
/* Keep chapter row metrics fixed while the hover light moves across them. */
.learn-shell .learn-chapter-main h2{transition:color .3s,transform .35s}
.learn-shell .learn-chapter:hover h2,.learn-shell .learn-chapter:focus-visible h2{font-variation-settings:'wght' 450;letter-spacing:-.5px;transform:translateX(3px)}
@media(max-width:750px){.learn-shell .learn-chapter:hover h2,.learn-shell .learn-chapter:focus-visible h2{letter-spacing:-.4px;transform:translateX(2px)}}