@layer theme{:root,:host{--font-sans:ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";--font-mono:ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;--spacing:.25rem;--default-font-family:var(--font-sans);--default-mono-font-family:var(--font-mono)}}@layer base{*,:after,:before,::backdrop{box-sizing:border-box;border:0 solid;margin:0;padding:0}::file-selector-button{box-sizing:border-box;border:0 solid;margin:0;padding:0}html,:host{-webkit-text-size-adjust:100%;tab-size:4;line-height:1.5;font-family:var(--default-font-family,ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji");font-feature-settings:var(--default-font-feature-settings,normal);font-variation-settings:var(--default-font-variation-settings,normal);-webkit-tap-highlight-color:transparent}hr{height:0;color:inherit;border-top-width:1px}abbr:where([title]){-webkit-text-decoration:underline dotted;text-decoration:underline dotted}h1,h2,h3,h4,h5,h6{font-size:inherit;font-weight:inherit}a{color:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;text-decoration:inherit}b,strong{font-weight:bolder}code,kbd,samp,pre{font-family:var(--default-mono-font-family,ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace);font-feature-settings:var(--default-mono-font-feature-settings,normal);font-variation-settings:var(--default-mono-font-variation-settings,normal);font-size:1em}small{font-size:80%}sub,sup{vertical-align:baseline;font-size:75%;line-height:0;position:relative}sub{bottom:-.25em}sup{top:-.5em}table{text-indent:0;border-color:inherit;border-collapse:collapse}:-moz-focusring{outline:auto}progress{vertical-align:baseline}summary{display:list-item}ol,ul,menu{list-style:none}img,svg,video,canvas,audio,iframe,embed,object{vertical-align:middle;display:block}img,video{max-width:100%;height:auto}button,input,select,optgroup,textarea{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}::file-selector-button{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}:where(select:is([multiple],[size])) optgroup{font-weight:bolder}:where(select:is([multiple],[size])) optgroup option{padding-inline-start:20px}::file-selector-button{margin-inline-end:4px}::placeholder{opacity:1}@supports (not ((-webkit-appearance:-apple-pay-button))) or (contain-intrinsic-size:1px){::placeholder{color:currentColor}@supports (color:color-mix(in lab, red, red)){::placeholder{color:color-mix(in oklab, currentcolor 50%, transparent)}}}textarea{resize:vertical}::-webkit-search-decoration{-webkit-appearance:none}::-webkit-date-and-time-value{min-height:1lh;text-align:inherit}::-webkit-datetime-edit{display:inline-flex}::-webkit-datetime-edit-fields-wrapper{padding:0}::-webkit-datetime-edit{padding-block:0}::-webkit-datetime-edit-year-field{padding-block:0}::-webkit-datetime-edit-month-field{padding-block:0}::-webkit-datetime-edit-day-field{padding-block:0}::-webkit-datetime-edit-hour-field{padding-block:0}::-webkit-datetime-edit-minute-field{padding-block:0}::-webkit-datetime-edit-second-field{padding-block:0}::-webkit-datetime-edit-millisecond-field{padding-block:0}::-webkit-datetime-edit-meridiem-field{padding-block:0}::-webkit-calendar-picker-indicator{line-height:1}:-moz-ui-invalid{box-shadow:none}button,input:where([type=button],[type=reset],[type=submit]){appearance:button}::file-selector-button{appearance:button}::-webkit-inner-spin-button{height:auto}::-webkit-outer-spin-button{height:auto}[hidden]:where(:not([hidden=until-found])){display:none!important}}@layer components;@layer utilities{.relative{position:relative}.static{position:static}.start{inset-inline-start:var(--spacing)}.block{display:block}.table{display:table}}:root{--ink:#17324d;--muted:#617284;--paper:#f6f1e8;--orange:#ff6b35;--orange-dark:#d84b20;--line:#d7d1c6;--green:#17745a}*{box-sizing:border-box}html{scroll-behavior:smooth}body{background:var(--paper);color:var(--ink);margin:0;font-family:Arial,PingFang SC,Microsoft YaHei,sans-serif}button,textarea{font:inherit}button{cursor:pointer}button:focus-visible,textarea:focus-visible,a:focus-visible{outline-offset:3px;outline:3px solid #ffd19b}main{overflow:hidden}.topbar{justify-content:space-between;align-items:center;width:min(1180px,100% - 40px);height:78px;margin:auto;display:flex}.brand{color:var(--ink);align-items:center;gap:11px;font-size:19px;font-weight:800;text-decoration:none;display:flex}.brand-mark{background:var(--ink);color:#fff;border:2px solid var(--ink);place-items:center;width:37px;height:37px;display:grid;transform:rotate(-3deg);box-shadow:4px 4px #f5a65b}.promise{letter-spacing:.06em;font-size:13px;font-weight:700}.promise i{background:var(--orange);border-radius:50%;width:8px;height:8px;margin-right:8px;display:inline-block}.hero{grid-template-columns:1.18fr .82fr;align-items:center;gap:60px;width:min(1180px,100% - 40px);min-height:610px;margin:8px auto 70px;display:grid;position:relative}.hero:before{content:"";opacity:.75;background:#ffd66c;border-radius:48% 52% 61% 39%/45% 41% 59% 55%;width:480px;height:480px;position:absolute;top:30px;right:-80px;transform:rotate(-7deg)}.hero:after{content:"";border-top:3px solid var(--orange);border-radius:50%;width:85px;height:9px;position:absolute;top:154px;left:312px;transform:rotate(-4deg)}.hero-copy{z-index:2;position:relative}.eyebrow{color:var(--orange-dark);letter-spacing:.18em;text-transform:uppercase;margin:0 0 16px;font-size:13px;font-weight:900}h1{letter-spacing:-.045em;max-width:680px;margin:0;font-family:Georgia,Songti SC,serif;font-size:clamp(48px,6vw,76px);line-height:1.08}h1 em{color:var(--orange);font-style:normal;position:relative}.lede{max-width:610px;color:var(--muted);margin:22px 0 28px;font-size:17px;line-height:1.8}.ask-box{border:2px solid var(--ink);box-shadow:8px 8px 0 var(--ink);background:#fff;padding:18px}.ask-box label{margin-bottom:10px;font-size:13px;font-weight:800;display:block}.ask-row{grid-template-columns:1fr auto;gap:10px;display:grid}.ask-row textarea{resize:none;width:100%;color:var(--ink);background:#fbfcfd;border:1px solid #b7c0c8;padding:13px 15px;line-height:1.5}.ask-row button{color:#fff;background:var(--orange);border:0;min-width:154px;padding:0 18px;font-weight:800;box-shadow:inset 0 -3px #00000024}.ask-row button:hover{background:var(--orange-dark);transform:translateY(-1px)}.ask-row button:disabled{opacity:.45;cursor:not-allowed}.ask-row button span{margin-left:6px;font-size:20px}.examples{flex-wrap:wrap;align-items:center;gap:7px;padding-top:12px;display:flex}.examples>span{color:var(--muted);font-size:12px}.examples button{color:#456075;background:#edf2f4;border:0;padding:6px 9px;font-size:12px}.examples button:hover{color:var(--orange-dark);background:#fff0e9}.trust-row{color:#536878;flex-wrap:wrap;gap:20px;margin-top:22px;font-size:13px;font-weight:700;display:flex}.trust-row span:before{color:var(--green)}.hero-visual{z-index:1;height:500px;position:relative}.beaker{border:10px solid var(--ink);background:#ffffff61;border-top:0;border-radius:8px 8px 44px 44px;width:245px;height:285px;position:absolute;top:96px;right:78px;overflow:hidden;transform:rotate(3deg);box-shadow:14px 16px #17324d24}.beaker:before{content:"";border:10px solid var(--ink);border-bottom:0;width:140px;height:70px;position:absolute;top:-42px;left:43px}.beaker:after{content:"100 ml\\A—\\A 50 ml\\A—";white-space:pre;color:var(--ink);opacity:.55;font:700 12px/2.7 monospace;position:absolute;top:55px;right:15px}.liquid{background:#a33984;border-top:7px solid #692856;position:absolute;inset:116px 0 0}.liquid:before{content:"";background:#be4ca0;border-radius:50%;width:110%;height:25px;position:absolute;top:-14px;left:-5%}.liquid i{border:2px solid #fffc;border-radius:50%;width:11px;height:11px;animation:3s ease-in infinite bubble;position:absolute}.liquid i:first-child{bottom:18px;left:35px}.liquid i:nth-child(2){width:7px;height:7px;animation-delay:1s;bottom:45px;left:90px}.liquid i:nth-child(3){animation-delay:1.7s;bottom:12px;left:155px}@keyframes bubble{0%{opacity:0;transform:translateY(0)}25%{opacity:1}to{opacity:0;transform:translateY(-90px)}}.color-strip{border:2px solid var(--ink);background:#fff;padding:8px;display:flex;position:absolute;bottom:52px;right:18px;transform:rotate(-5deg)}.color-strip i{width:38px;height:19px;display:block}.color-strip i:first-child{background:#d74c61}.color-strip i:nth-child(2){background:#bb4f9a}.color-strip i:nth-child(3){background:#713c8f}.color-strip i:nth-child(4){background:#346bae}.color-strip i:nth-child(5){background:#159582}.note{z-index:3;border:2px solid var(--ink);background:#fffdf4;padding:12px 16px;position:absolute;transform:rotate(-4deg);box-shadow:5px 5px #17324d2e}.note b,.note span{display:block}.note b{margin-bottom:5px;font-family:Georgia,Songti SC,serif}.note span{color:var(--muted);font-size:11px}.note-a{top:42px;left:10px}.note-b{background:#fff0e8;top:332px;right:0;transform:rotate(4deg)}.note-b b{color:var(--orange-dark)}.scribble{font:italic 700 14px Georgia,serif;position:absolute;bottom:70px;left:8px;transform:rotate(-8deg)}.plan-wrap{border-top:1px solid var(--line);background:#eef0eb;padding:76px max(20px,50vw - 590px) 90px;scroll-margin-top:20px}.plan-heading{border-bottom:2px solid var(--ink);justify-content:space-between;align-items:flex-end;gap:30px;padding-bottom:28px;display:flex}.plan-heading h2{letter-spacing:-.03em;margin:0 0 16px;font:700 clamp(34px,5vw,54px)/1.15 Georgia,Songti SC,serif}.meta{flex-wrap:wrap;gap:8px;display:flex}.meta span{color:#546a72;background:#fff;border:1px solid #bdc5c3;padding:6px 10px;font-size:12px}.actions{gap:8px;display:flex}.actions button{color:var(--ink);border:1px solid var(--ink);background:0 0;padding:10px 13px;font-size:12px;font-weight:700}.actions button:hover{background:var(--ink);color:#fff}.plan-grid{grid-template-columns:minmax(0,1.6fr) minmax(285px,.74fr);align-items:start;gap:24px;margin-top:24px;display:grid}.main-column{gap:18px;display:grid}.card,.side-card{background:#fff;border:1px solid #d0d5d2;padding:27px;position:relative}.card-title{align-items:center;gap:13px;margin-bottom:24px;display:flex}.card-title .num{border:2px solid var(--ink);place-items:center;width:36px;height:36px;font:700 12px Georgia,serif;display:grid}.card-title small,.pitfall-title small{color:var(--orange-dark);letter-spacing:.18em;font:800 9px/1 monospace}.card-title h3,.pitfall-title h3{margin:3px 0 0;font:700 22px Georgia,Songti SC,serif}.feasibility{min-height:180px;padding-right:180px}.feasibility .score{align-items:center;display:flex;position:absolute;top:28px;right:28px}.score strong{color:var(--green);font:700 47px/1 Georgia,serif}.score span{color:var(--muted);margin-left:5px;font-size:9px;line-height:1.5}.feasibility>p{color:#49606d;line-height:1.75}.verdict{color:var(--green);background:#e5f3ed;padding:7px 10px;font-size:12px;font-weight:800;display:inline-block}.equipment-list{grid-template-columns:1fr 1fr;gap:0 24px;display:grid}.equipment-item{border-bottom:1px dashed #cfd3d0;grid-template-columns:20px 1fr auto;align-items:center;gap:6px;min-height:48px;font-size:13px;display:grid}.equipment-item .check{color:var(--green)}.equipment-item>span:not(.check){color:var(--muted)}.equipment-item small{color:#8a7164;grid-column:2/-1;margin-top:-9px;padding-bottom:6px}.steps{margin:0;padding:0;list-style:none}.steps li{grid-template-columns:50px 1fr;gap:12px;padding:0 0 25px;display:grid;position:relative}.steps li:last-child{padding-bottom:0}.steps li>span{background:var(--ink);color:#fff;z-index:1;border-radius:50%;place-items:center;width:36px;height:36px;font:700 12px monospace;display:grid}.steps li:not(:last-child):before{content:"";border-left:1px dashed #98a7ad;height:calc(100% - 24px);position:absolute;top:34px;left:18px}.steps h4{margin:2px 0 6px;font-size:15px}.steps p{color:#566a76;margin:0;font-size:14px;line-height:1.7}.steps aside{border-left:3px solid var(--orange);color:#8d4c2f;background:#fff3e8;margin-top:10px;padding:8px 10px;font-size:12px}.observation{grid-template-columns:260px 1fr;align-items:center;gap:28px;display:grid}.sample-cups{background:#f6f3ee;border:1px dashed #aaa59a;justify-content:space-between;align-items:end;padding:25px 18px 15px;display:flex}.sample-cups div{text-align:center;color:var(--muted);font-size:10px}.sample-cups i{border:3px solid var(--ink);border-top:0;border-radius:2px 2px 12px 12px;width:52px;height:64px;margin-bottom:8px;display:block;position:relative;overflow:hidden}.sample-cups i:after{content:"";position:absolute;inset:24px 0 0}.sample-cups .acid:after{background:#dc5574}.sample-cups .neutral:after{background:#714194}.sample-cups .alkaline:after{background:#2f8f8b}.observation ul{color:#485e6b;padding-left:18px;font-size:14px;line-height:2}.observation li::marker{color:var(--orange)}.image-note{color:#8a766c;margin:18px 0 0;font-size:11px}.side-column{gap:18px;display:grid;position:sticky;top:16px}.pitfall-card{background:var(--ink);color:#fff;box-shadow:7px 7px 0 var(--orange);padding:25px}.pitfall-title{align-items:center;gap:12px;display:flex}.pitfall-title>span{background:var(--orange);place-items:center;width:35px;height:35px;font:800 23px Georgia,serif;display:grid;transform:rotate(-4deg)}.pitfall-title small{color:#ffb696}.pitfall-title h3{font-size:20px}.pitfall-card>p{color:#aebbc4;margin:14px 0 20px;font-size:12px}.risk{border-top:1px solid #ffffff2b;padding:15px 0 5px}.risk>div{justify-content:space-between;align-items:center;display:flex}.risk b{font-size:14px}.risk span{color:#ffbc9f;background:#ff6b3529;padding:4px 7px;font-size:10px}.risk p{color:#d5dde1;margin:7px 0;font-size:12px;line-height:1.6}.side-title{align-items:center;gap:10px;margin-bottom:14px;display:flex}.side-title span{color:var(--orange-dark);font:800 11px monospace}.side-title h3{margin:0;font:700 20px Georgia,Songti SC,serif}details{border-top:1px solid #d7dbd8}details:last-child{border-bottom:1px solid #d7dbd8}summary{cursor:pointer;justify-content:space-between;padding:14px 0;font-size:13px;font-weight:800;list-style:none;display:flex}summary::-webkit-details-marker{display:none}details[open] summary span{transform:rotate(45deg)}details p{color:#687b85;margin:-3px 0 10px;font-size:12px;line-height:1.6}details p.fix{color:#93603e;background:#fff4e9;padding:8px}.alternative{border-top:1px solid #d7dbd8;padding:13px 0}.alternative b{font-size:13px}.alternative p{color:#667984;margin:6px 0 0;font-size:12px;line-height:1.65}.teacher-note{background:#f5d96e;border:1px solid #c6aa3f;padding:20px;transform:rotate(1.2deg)}.teacher-note span{letter-spacing:.12em;font-size:10px;font-weight:900}.teacher-note p{margin:8px 0 0;font:italic 700 17px/1.6 Georgia,Songti SC,serif}footer{background:var(--ink);color:#fff;justify-content:space-between;align-items:center;gap:30px;min-height:110px;padding:30px max(20px,50vw - 590px);display:flex}footer span{font-weight:900}footer p{color:#9dafbb;max-width:650px;margin:0;font-size:11px;line-height:1.6}@media (max-width:900px){.hero{grid-template-columns:1fr;padding-top:50px}.hero-visual{width:100%;max-width:480px;height:440px;margin:-30px auto 0}.hero:before{top:520px;right:-140px}.plan-grid{grid-template-columns:1fr}.side-column{grid-template-columns:1fr 1fr;position:static}.pitfall-card,.teacher-note{grid-column:1/-1}}@media (max-width:620px){.topbar{width:calc(100% - 28px);height:66px}.promise{display:none}.hero{width:calc(100% - 28px);min-height:auto;margin-bottom:45px;padding-top:24px}h1{font-size:44px}.lede{font-size:15px}.ask-row{grid-template-columns:1fr}.ask-row button{min-height:48px}.hero-visual{transform-origin:top;margin-bottom:-80px;transform:scale(.82)}.plan-wrap{padding-top:50px}.plan-heading{flex-direction:column;align-items:flex-start}.actions{width:100%}.actions button{flex:1}.card,.side-card{padding:20px}.feasibility{padding-top:88px;padding-right:20px}.feasibility .score{top:20px;right:20px}.equipment-list,.observation,.side-column{grid-template-columns:1fr}.pitfall-card,.teacher-note{grid-column:auto}footer{flex-direction:column;align-items:flex-start}}@media print{.topbar,.hero,.actions,footer{display:none}.plan-wrap{padding:20px}.plan-grid{grid-template-columns:1fr}.side-column{position:static}.card,.side-card,.pitfall-card{break-inside:avoid;box-shadow:none}}