:root{--paper:#f6f4ee;--paper-2:#efebe1;--card:#fffdf8;--ink:#17251f;--muted:#5d6b64;--line:#ddd8cc;--green:#0c6b58;--green-dark:#084c40;--green-soft:#dcefe8;--orange:#e9832d;--orange-soft:#fbe9d7;--code:#0d1b1a;--code-ink:#dce9e4;--shadow:0 18px 50px rgba(35,51,43,0.09);--radius:18px;--sans:"Avenir Next","Segoe UI","Helvetica Neue",Arial,"PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;--mono:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace}*{box-sizing:border-box}[hidden]{display:none!important}html{scroll-behavior:smooth}body{margin:0;background:radial-gradient(circle at 10% -10%,rgba(12,107,88,0.10),transparent 32rem),radial-gradient(circle at 95% 4%,rgba(233,131,45,0.10),transparent 26rem),var(--paper);color:var(--ink);font-family:var(--sans);font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased}a{color:var(--green);text-underline-offset:3px}a:hover{color:var(--green-dark)}img{max-width:100%}button,input,select,textarea{font:inherit}button{cursor:pointer}:focus-visible{outline:3px solid rgba(233,131,45,0.65);outline-offset:3px}.skip-link{position:absolute;left:12px;top:-80px;z-index:100;background:var(--ink);color:white;padding:10px 14px;border-radius:8px}.skip-link:focus{top:12px}.wrap{width:min(1120px,calc(100% - 40px));margin:0 auto}.narrow{width:min(760px,calc(100% - 40px));margin:0 auto}.site-header{position:sticky;top:0;z-index:40;background:rgba(246,244,238,0.92);border-bottom:1px solid rgba(221,216,204,0.85);backdrop-filter:blur(14px)}.header-inner{display:flex;align-items:center;gap:24px;min-height:70px}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-weight:800;letter-spacing:-0.02em;font-size:1.08rem}.brand-mark{display:grid;place-items:center;width:34px;height:34px;border-radius:10px;background:var(--ink);color:#e8ff78;font-family:var(--mono);font-size:0.78rem;font-weight:700}.brand span{color:var(--green)}.site-nav{margin-left:auto;display:flex;align-items:center;gap:4px}.site-nav a{padding:9px 11px;border-radius:9px;color:var(--muted);text-decoration:none;font-size:0.92rem;font-weight:650}.site-nav a:hover,.site-nav a[aria-current="page"]{color:var(--ink);background:rgba(255,255,255,0.7)}.nav-toggle{display:none;border:1px solid var(--line);background:var(--card);border-radius:9px;padding:7px 10px}.lang-switch{margin-left:6px;padding:7px 9px!important;border:1px solid var(--line);border-radius:8px;font-size:0.78rem!important;letter-spacing:0.01em}.lang-switch:hover{background:var(--card)!important;border-color:#bfb7a5}html[lang^="zh"] body{font-family:"PingFang SC","Microsoft YaHei","Noto Sans SC","Source Han Sans SC",var(--sans)}html[lang^="zh"] h1,html[lang^="zh"] h2,html[lang^="zh"] h3{letter-spacing:-0.02em}html[lang^="zh"] .hero h1{line-height:1.15}html[lang^="zh"] .page-hero h1{max-width:26ch;word-break:keep-all;overflow-wrap:anywhere;text-wrap:balance}html[lang^="zh"] .hero-lede,html[lang^="zh"] .lesson-body p,html[lang^="zh"] .guide-page p{line-height:1.85}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:0 20px;border-radius:11px;border:1px solid transparent;text-decoration:none;font-weight:750;font-size:0.95rem;letter-spacing:-0.01em;transition:transform 0.15s ease,background 0.15s ease,border-color 0.15s ease}.btn:hover{transform:translateY(-1px)}.btn-primary{background:var(--ink);color:#fff}.btn-primary:hover{background:#293a33;color:#fff}.btn-secondary{background:transparent;color:var(--ink);border-color:var(--line)}.btn-secondary:hover{background:var(--card)}.btn-green{background:var(--green);color:#fff}.btn-green:hover{background:var(--green-dark);color:#fff}.btn-sm{min-height:38px;padding:0 14px;font-size:0.85rem;border-radius:9px}.eyebrow{display:inline-flex;align-items:center;gap:8px;text-transform:uppercase;letter-spacing:0.12em;font-size:0.72rem;font-weight:800;color:var(--green)}.eyebrow::before{content:"";width:18px;height:2px;background:var(--orange)}.hero{padding:72px 0 58px}.hero-grid{display:grid;grid-template-columns:1.08fr 0.92fr;gap:52px;align-items:center}.hero h1{margin:14px 0 20px;font-size:clamp(2.55rem,6vw,4.35rem);line-height:1.02;letter-spacing:-0.055em;max-width:13ch}.hero h1 em{font-style:normal;color:var(--green);position:relative;white-space:nowrap}.hero h1 em::after{content:"";position:absolute;left:0;right:0;bottom:5px;height:9px;background:#e8ff78;z-index:-1;transform:rotate(-1.5deg)}.hero-lede{font-size:1.15rem;color:var(--muted);max-width:54ch;margin:0 0 26px}.hero-actions{display:flex;flex-wrap:wrap;gap:12px;align-items:center}.hero-note{color:var(--muted);font-size:0.83rem;margin-top:18px}.metrics{display:grid;grid-template-columns:repeat(3,1fr);gap:0;margin-top:38px;max-width:470px;border-top:1px solid var(--line);padding-top:22px}.metrics div{padding-right:18px;border-right:1px solid var(--line)}.metrics div:last-child{border-right:0;padding-left:18px}.metrics div:nth-child(2){padding-left:18px}.metrics strong{display:block;font-size:1.45rem;letter-spacing:-0.04em;line-height:1.1}.metrics span{color:var(--muted);font-size:0.78rem}.hero-card{position:relative;background:var(--card);border:1px solid var(--line);border-radius:24px;box-shadow:var(--shadow);padding:18px;transform:rotate(1.4deg)}.hero-card::before{content:"";position:absolute;inset:10px -10px -10px 10px;border:1px solid #cfc8b8;border-radius:24px;z-index:-1}.browser-bar{display:flex;align-items:center;gap:6px;padding:4px 2px 16px}.browser-bar i{width:8px;height:8px;border-radius:50%;background:#d5cec0;display:block}.browser-bar span{margin-left:auto;font-family:var(--mono);font-size:0.68rem;color:var(--muted)}.code-card{background:var(--code);border-radius:13px;padding:18px 18px 20px;overflow:hidden}.code-card .dots{display:flex;gap:5px;margin-bottom:14px}.code-card .dots i{width:7px;height:7px;border-radius:50%;background:#37504a}pre{margin:0;white-space:pre-wrap;word-break:break-word}.code-card pre{color:var(--code-ink);font-family:var(--mono);font-size:0.82rem;line-height:1.75}.code-card .c-key{color:#e8ff78}.code-card .c-str{color:#f5c38a}.code-card .c-fn{color:#8ddcc8}.code-card .c-com{color:#718b83}.run-line{display:flex;align-items:center;gap:8px;margin-top:18px;padding-top:14px;border-top:1px solid #263c37;color:#93aaa2;font-family:var(--mono);font-size:0.7rem}.run-line b{color:#e8ff78;font-weight:600}.hero-side-label{position:absolute;right:24px;bottom:-17px;background:var(--orange);color:#2c1a0c;border-radius:999px;padding:5px 12px;font-size:0.7rem;font-weight:800;letter-spacing:0.04em;transform:rotate(-1.4deg)}.section{padding:58px 0}.section-head{display:flex;justify-content:space-between;align-items:end;gap:24px;margin-bottom:28px}.section-head h2{margin:4px 0 0;font-size:clamp(1.75rem,3.6vw,2.55rem);line-height:1.08;letter-spacing:-0.04em;max-width:18ch}.section-head p{color:var(--muted);max-width:42ch;margin:0 0 3px;font-size:0.96rem}.lesson-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}.lesson-card{display:flex;gap:18px;align-items:flex-start;padding:22px;background:rgba(255,253,248,0.72);border:1px solid var(--line);border-radius:15px;text-decoration:none;color:var(--ink);transition:background 0.15s ease,transform 0.15s ease,border-color 0.15s ease}.lesson-card:hover{background:var(--card);border-color:#bfb7a5;transform:translateY(-2px);color:var(--ink)}.lesson-num{flex:0 0 38px;height:38px;display:grid;place-items:center;border-radius:10px;background:var(--green-soft);color:var(--green-dark);font-family:var(--mono);font-size:0.76rem;font-weight:700}.lesson-card:nth-child(3n) .lesson-num{background:var(--orange-soft);color:#7a400f}.lesson-card h3{margin:0 0 5px;font-size:1.02rem;letter-spacing:-0.02em}.lesson-card p{margin:0;color:var(--muted);font-size:0.87rem;line-height:1.5}.lesson-meta{display:flex;gap:10px;margin-top:10px;color:var(--muted);font-size:0.72rem;font-weight:650}.lesson-card:hover .lesson-arrow{transform:translateX(3px)}.lesson-arrow{margin-left:auto;color:var(--green);align-self:center;transition:transform 0.15s ease}.how{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.how-card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:24px}.how-card .step{font-family:var(--mono);font-size:0.72rem;color:var(--orange);font-weight:700}.how-card h3{margin:12px 0 7px;font-size:1.03rem;letter-spacing:-0.02em}.how-card p{margin:0;color:var(--muted);font-size:0.9rem}.quote-band{margin:18px 0;background:var(--ink);color:#f2f5ed;border-radius:20px;padding:36px 40px;display:grid;grid-template-columns:1fr auto;gap:28px;align-items:center}.quote-band blockquote{margin:0;font-size:clamp(1.2rem,2.5vw,1.65rem);line-height:1.35;letter-spacing:-0.025em;max-width:34ch}.quote-band p{margin:0;color:#a9bdb5;font-size:0.82rem}.guide-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}.guide-card{display:block;text-decoration:none;color:var(--ink);background:var(--card);border:1px solid var(--line);border-radius:15px;padding:22px}.guide-card:first-child{grid-column:span 2;background:var(--green-soft);border-color:#c0dcd2}.guide-card:hover{border-color:#aeb8ac;color:var(--ink)}.guide-card .tag{font-size:0.7rem;text-transform:uppercase;letter-spacing:0.1em;color:var(--green);font-weight:800}.guide-card h3{margin:9px 0 7px;font-size:1.22rem;letter-spacing:-0.025em}.guide-card p{margin:0;color:var(--muted);font-size:0.9rem}.faq{display:grid;gap:0;border-top:1px solid var(--line)}.faq details{border-bottom:1px solid var(--line);padding:18px 0}.faq summary{cursor:pointer;font-weight:750;list-style:none;display:flex;justify-content:space-between;gap:18px}.faq summary::-webkit-details-marker{display:none}.faq summary::after{content:"+";color:var(--orange);font-size:1.2rem;line-height:1}.faq details[open] summary::after{content:"−"}.faq p{color:var(--muted);margin:12px 0 0;max-width:68ch}.cta-band{margin:26px 0 10px;display:flex;align-items:center;justify-content:space-between;gap:28px;padding:30px 34px;border:1px solid #c8d9d0;background:linear-gradient(120deg,#e8f3ed,#f7f4e9);border-radius:18px}.cta-band h2{margin:0 0 6px;font-size:1.45rem;letter-spacing:-0.03em}.cta-band p{margin:0;color:var(--muted);font-size:0.9rem}.ad-slot{margin:26px auto;min-height:92px;border:1px dashed #cfc8b8;border-radius:12px;background:rgba(255,253,248,0.55);display:flex;flex-direction:column;justify-content:center;align-items:center;gap:5px;color:var(--muted);text-align:center;padding:14px}.ad-slot[hidden]{display:none!important}.ad-slot .ad-label{font-size:0.61rem;text-transform:uppercase;letter-spacing:0.14em;font-weight:800;color:var(--muted)}.ad-slot .ad-copy{font-size:0.78rem}.site-footer{margin-top:54px;border-top:1px solid var(--line);padding:38px 0 30px}.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:28px}.footer-brand p{color:var(--muted);font-size:0.84rem;max-width:34ch;margin:12px 0 0}.footer-col h3{font-size:0.72rem;text-transform:uppercase;letter-spacing:0.12em;color:var(--muted);margin:4px 0 10px}.footer-col a{display:block;color:var(--muted);text-decoration:none;font-size:0.84rem;padding:3px 0}.footer-col a:hover{color:var(--ink)}.footer-bottom{margin-top:30px;padding-top:18px;border-top:1px solid var(--line);display:flex;justify-content:space-between;gap:20px;color:var(--muted);font-size:0.75rem}.disclosure{color:var(--muted);font-size:0.74rem;max-width:70ch;margin-top:8px}.page-hero{padding:50px 0 34px;border-bottom:1px solid var(--line)}.page-hero h1{margin:8px 0 14px;font-size:clamp(2rem,4.8vw,3.5rem);line-height:1.05;letter-spacing:-0.05em;max-width:18ch}.page-hero p{margin:0;max-width:63ch;color:var(--muted);font-size:1.06rem}.breadcrumb{display:flex;flex-wrap:wrap;gap:7px;color:var(--muted);font-size:0.78rem;margin-bottom:14px}.breadcrumb a{color:var(--muted);text-decoration:none}.breadcrumb span{color:#b0b3a9}.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:52px;padding:44px 0 20px;align-items:start}.lesson-body{min-width:0}.lesson-body h2{margin:38px 0 10px;font-size:1.55rem;letter-spacing:-0.035em;line-height:1.2}.lesson-body h2:first-child{margin-top:0}.lesson-body p{margin:0 0 14px;color:#384740}.lesson-body .code-block{margin:18px 0 24px}.lesson-body .code-caption{color:var(--muted);font-size:0.74rem;margin:6px 0 0}.story{margin:0 0 26px;padding:20px 24px;border:1px solid #d5e2d9;border-left:4px solid var(--green);border-radius:4px 14px 14px 4px;background:linear-gradient(180deg,#f1f7ef,#fbfaf4)}.story-tag{display:block;font-family:var(--mono);font-size:0.68rem;letter-spacing:0.12em;text-transform:uppercase;color:var(--green-dark);margin-bottom:7px}.story p{margin:0;color:#2c3f36;font-size:1.02rem;line-height:1.65}.lesson-aside{position:sticky;top:92px;display:grid;gap:14px}.aside-card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:18px}.aside-card h2{margin:0 0 9px;font-size:0.78rem;text-transform:uppercase;letter-spacing:0.1em;color:var(--green)}.aside-card ul{margin:0;padding-left:18px;color:var(--muted);font-size:0.84rem}.aside-card li + li{margin-top:6px}.aside-card a{color:var(--ink);font-weight:700;text-decoration:none}.aside-card a:hover{color:var(--green)}.challenge{margin:26px 0;padding:20px 22px;border-left:4px solid var(--orange);background:var(--orange-soft);border-radius:0 12px 12px 0}.challenge strong{display:block;font-size:0.72rem;text-transform:uppercase;letter-spacing:0.11em;color:#81450f;margin-bottom:5px}.challenge p{margin:0;color:#4e3a29}.key-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:28px 0}.key-box{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:18px}.key-box h2{margin:0 0 8px;font-size:0.78rem;text-transform:uppercase;letter-spacing:0.1em;color:var(--green)}.key-box ul{margin:0;padding-left:18px;color:var(--muted);font-size:0.85rem}.key-box li + li{margin-top:6px}.code-block{background:var(--code);border-radius:13px;padding:18px 18px 16px;overflow:auto}.code-block pre{color:var(--code-ink);font-family:var(--mono);font-size:0.8rem;line-height:1.7}.code-block .dots{display:flex;gap:5px;margin-bottom:12px}.code-block .dots i{width:7px;height:7px;border-radius:50%;background:#37504a}.runner{margin:32px 0;border:1px solid #b9c9c1;border-radius:16px;overflow:hidden;background:var(--card);box-shadow:0 10px 28px rgba(25,48,38,0.06)}.runner-head{display:flex;align-items:center;gap:10px;flex-wrap:wrap;padding:13px 16px;background:#e5f0e9;border-bottom:1px solid #c7d9cf}.runner-head strong{font-size:0.84rem}.runner-head .runner-status{color:var(--muted);font-size:0.72rem;margin-right:auto}.runner textarea{display:block;width:100%;min-height:150px;resize:vertical;border:0;border-radius:0;padding:16px;background:var(--code);color:var(--code-ink);font-family:var(--mono);font-size:0.82rem;line-height:1.65;tab-size:4}.runner textarea:focus{outline:2px solid var(--orange);outline-offset:-2px}.runner-output{margin:0;padding:14px 16px;border-top:1px solid #263c37;background:#081310;color:#bfe9d8;font-family:var(--mono);font-size:0.78rem;min-height:44px;max-height:280px;overflow:auto}.runner-output.is-error{color:#ffc4ae}.runner-foot{display:flex;flex-wrap:wrap;gap:8px;align-items:center;padding:12px 16px}.runner-foot .note{color:var(--muted);font-size:0.7rem;margin-left:auto}.solution-source,.runner textarea.solution-source{display:none!important}.practice-shell{padding:34px 0 40px;display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:30px;align-items:start}.practice-shell>*{min-width:0}.bank-switch{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:10px}.bank-tab{flex:1 1 190px;min-width:0;display:flex;flex-direction:column;align-items:flex-start;gap:1px;min-height:58px;padding:9px 15px;border:1px solid var(--line);border-radius:12px;background:var(--card);color:var(--ink);text-align:left;font-weight:800;font-size:0.9rem;letter-spacing:-0.01em}.bank-tab span{color:var(--muted);font-size:0.72rem;font-weight:650;letter-spacing:0}.bank-tab:hover{border-color:#b9b19f}.bank-tab.is-active{background:var(--ink);border-color:var(--ink);color:#fff}.bank-tab.is-active span{color:#cfe0d9}.bank-note{margin:0 0 14px;color:var(--muted);font-size:0.82rem;line-height:1.55}.practice-toolbar{display:flex;flex-wrap:wrap;gap:10px;align-items:end;padding:16px;border:1px solid var(--line);background:var(--card);border-radius:14px;margin-bottom:14px}.field{display:grid;gap:4px;min-width:0}.practice-toolbar .field{flex:1 1 180px}.field label{font-size:0.68rem;text-transform:uppercase;letter-spacing:0.1em;color:var(--muted);font-weight:800}.field select,.field input{width:100%;max-width:100%;min-height:40px;border:1px solid var(--line);border-radius:8px;padding:0 10px;background:#fff;color:var(--ink);font-size:0.86rem}.practice-stats{margin-left:auto;text-align:right;color:var(--muted);font-size:0.78rem;line-height:1.35}.practice-stats strong{color:var(--ink);font-size:1.15rem;letter-spacing:-0.03em}.question-card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:25px;box-shadow:var(--shadow)}.question-meta{display:flex;flex-wrap:wrap;gap:8px;align-items:center;color:var(--muted);font-size:0.73rem;margin-bottom:13px}.question-meta .source-note{font-size:0.68rem;color:#6d766e}.pill{display:inline-flex;align-items:center;border-radius:999px;padding:3px 9px;background:var(--green-soft);color:var(--green-dark);font-size:0.68rem;font-weight:800;letter-spacing:0.04em;text-transform:uppercase}.pill.orange{background:var(--orange-soft);color:#7a400f}.pill.gray{background:#ece9df;color:#616a63}.question-card h2{margin:0 0 15px;font-size:1.28rem;line-height:1.35;letter-spacing:-0.025em}.question-code{margin:0 0 18px;background:var(--code);border-radius:11px;padding:15px;color:var(--code-ink);font-family:var(--mono);font-size:0.8rem;line-height:1.65;overflow:auto}.question-code.is-clipped{max-height:11.5rem;overflow:hidden;-webkit-mask-image:linear-gradient(180deg,#000 62%,rgba(0,0,0,0));mask-image:linear-gradient(180deg,#000 62%,rgba(0,0,0,0))}.code-toggle{display:block;width:100%;min-height:42px;margin:-10px 0 18px;padding:0 12px;border:1px solid var(--line);border-radius:9px;background:transparent;color:var(--ink);font:inherit;font-size:0.82rem;font-weight:650;cursor:pointer}.code-toggle:hover{background:var(--card)}.code-toggle:focus-visible{outline:2px solid var(--green);outline-offset:2px}@media (max-width:520px){.question-actions .btn{flex:1 1 100%}.question-foot{flex-direction:column;align-items:flex-start;gap:6px}.bank-switch .bank-tab{flex:1 1 100%}.practice-toolbar .field{flex:1 1 100%}.hero-card{transform:none}.hero-card::before{inset:8px -6px -8px 8px}}@media (max-width:620px){.question-code{font-size:0.74rem;line-height:1.6;padding:12px}.question-code.is-clipped{max-height:10rem}.code-toggle{min-height:44px;font-size:0.84rem}}.choice-list{display:grid;gap:9px;margin:0;padding:0;border:0}.choice-option{display:flex;gap:10px;align-items:flex-start;border:1px solid var(--line);background:#fff;border-radius:10px;padding:12px 13px;cursor:pointer;font-size:0.88rem}.choice-option:hover{border-color:#a9bdb2;background:#f8fbf8}.choice-option input{margin-top:3px;accent-color:var(--green)}.choice-option.is-correct{border-color:#76b8a0;background:#e9f5ee}.choice-option.is-wrong{border-color:#e5a58e;background:#fff0ea}.answer-row{display:flex;gap:9px;flex-wrap:wrap;align-items:flex-start}.answer-row input,.answer-row textarea{flex:1 1 250px;min-height:46px;border:1px solid var(--line);border-radius:9px;padding:10px 13px;background:#fff;color:var(--ink);font-family:var(--mono);font-size:0.88rem;line-height:1.55}.answer-row textarea{resize:vertical}.question-actions{display:flex;flex-wrap:wrap;gap:9px;margin-top:18px;align-items:center}.feedback{margin-top:17px;padding:14px 15px;border-radius:10px;font-size:0.86rem;display:none}.feedback.show{display:block}.feedback.good{background:#e9f5ee;border:1px solid #b9dcc9;color:#1c523c}.feedback.bad{background:#fff1ea;border:1px solid #f0c6b4;color:#7d3d24}.feedback .explain{color:inherit;margin-top:6px;font-size:0.82rem}.question-foot{display:flex;justify-content:space-between;gap:14px;align-items:center;margin-top:18px;padding-top:14px;border-top:1px solid var(--line);color:var(--muted);font-size:0.72rem}.kbd{border:1px solid #cfc8b8;border-bottom-width:2px;border-radius:5px;padding:1px 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0;color:var(--green);font-weight:800;font-size:0.88rem}.support-pact{display:flex;flex-direction:column;justify-content:center;background:var(--ink);color:#fff;border-radius:20px;padding:32px 30px}.support-pact-label{color:#e8ff78;font-size:0.68rem;font-weight:800;letter-spacing:0.12em;text-transform:uppercase}.support-pact strong{margin:10px 0 12px;font-size:clamp(1.45rem,2.7vw,1.95rem);line-height:1.2;letter-spacing:-0.04em}.support-pact p{margin:0;color:#c5d2ca;font-size:0.92rem;line-height:1.75}html[lang^="zh"] .support-quote{max-width:26ch;line-height:1.75}html[lang^="zh"] .support-pact p,html[lang^="zh"] .support-card p,html[lang^="zh"] .support-faq details p{line-height:1.85}.support-section{padding:28px 0}.support-section-head{display:grid;grid-template-columns:minmax(0,1fr) minmax(280px,0.8fr);gap:28px;align-items:end;margin-bottom:20px}.support-section-head h2{margin:8px 0 0;font-size:clamp(1.65rem,3vw,2.2rem);line-height:1.12;letter-spacing:-0.04em}.support-section-head 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li{position:relative;padding-left:21px;color:#33433b;font-size:0.88rem}.support-gift-facts li::before{content:"✓";position:absolute;left:0;top:0;color:var(--green);font-weight:900}.support-gift-actions{display:flex;flex-wrap:wrap;gap:9px}.support-gift-actions .btn{min-height:43px;font-size:0.84rem}.support-gift-hash{overflow-wrap:anywhere;word-break:break-word}.support-gift-aside{display:flex;flex-direction:column;justify-content:center;padding:26px;border-radius:17px;background:var(--ink);color:#f2f5ed}.support-gift-aside .support-card-num{color:#e8ff78}.support-gift-aside strong{margin:12px 0 12px;font-size:clamp(1.65rem,3vw,2.05rem);line-height:1.08;letter-spacing:-0.04em}.support-gift-aside p{margin:0 0 15px;color:#c5d2ca;font-size:0.85rem}.support-gift-aside ul{display:grid;gap:5px;margin:0;padding-left:18px;color:#c5d2ca;font-size:0.8rem}.support-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.support-link-card{display:flex;align-items:center;gap:14px;padding:16px;border:1px solid var(--line);border-radius:14px;background:#faf8f1;color:var(--ink);text-decoration:none;transition:transform 0.15s ease,border-color 0.15s ease}.support-link-card:hover{border-color:#aeb8ac;color:var(--ink);transform:translateY(-1px)}.support-link-mark{display:grid;place-items:center;width:44px;height:44px;flex:0 0 44px;border-radius:12px;background:var(--green);color:#fff;font-size:1.1rem;font-weight:850}.support-link-card:nth-child(2n) .support-link-mark{background:var(--orange-soft);color:#7a400f}.support-link-copy{display:flex;flex-direction:column;gap:2px;min-width:0}.support-link-copy strong{font-size:0.95rem}.support-link-copy 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#c8d9d0;border-radius:12px;background:#eef6f1;color:#33433b;font-size:0.88rem}.project-checks li::before{content:"✓";position:absolute;left:15px;top:13px;color:var(--green);font-weight:900}.project-extend-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.project-extend-card{padding:20px;border:1px solid var(--line);border-radius:14px;background:var(--card)}.project-extend-card h3{margin:0 0 6px;font-size:0.98rem}.project-extend-card p{margin:0;color:var(--muted);font-size:0.86rem}.project-next{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;padding:26px 0 50px;border-top:1px solid var(--line)}@media (max-width:820px){.project-callout{grid-template-columns:1fr;gap:18px}.project-brief,.project-steps,.project-checks,.project-extend-grid{grid-template-columns:1fr}.project-section-head{grid-template-columns:1fr;gap:10px}.project-runner textarea{min-height:360px}}.guide-page{padding:44px 0 20px}.guide-page .guide-intro{font-size:1.15rem;color:#3b4a43;max-width:65ch}.guide-page h2{margin:34px 0 9px;font-size:1.5rem;letter-spacing:-0.035em}.guide-page h3{margin:24px 0 8px;font-size:1.1rem}.guide-page p{color:#3b4a43}.checklist{display:grid;gap:8px;padding:0;margin:22px 0;list-style:none}.checklist li{position:relative;padding-left:27px;color:#3b4a43;font-size:0.92rem}.checklist li::before{content:"✓";position:absolute;left:0;top:-1px;color:var(--green);font-weight:900}.guide-cta{margin-top:40px}.consent-banner{position:fixed;left:18px;right:18px;bottom:18px;z-index:80;background:#12211d;color:#eef4ec;border:1px solid #344a41;border-radius:14px;box-shadow:0 18px 50px rgba(0,0,0,0.25);padding:16px 18px;display:none;gap:16px;align-items:center;justify-content:space-between;max-width:1000px;margin:0 auto}.consent-banner.show{display:flex}.consent-banner p{margin:0;font-size:0.8rem;color:#c5d2ca;max-width:640px}.consent-banner 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p{margin:0;color:#33433b}.answer-key-note{color:var(--muted);font-size:0.9rem;margin:0 0 28px}.answer-key-list{display:grid;gap:26px}.answer-item{padding-top:24px;border-top:1px solid var(--line)}.answer-item h2{margin:8px 0 12px;font-size:1.18rem;line-height:1.45;letter-spacing:-0.02em}.answer-item .code-block{margin:12px 0 14px}.answer-options{margin:10px 0 14px;padding-left:22px;color:#3b4a43}.answer-options li{margin:5px 0}.answer-options li.correct{color:var(--green-dark);font-weight:700}.correct-mark{display:inline-block;margin-left:8px;padding:2px 6px;border-radius:999px;background:var(--green-soft);color:var(--green-dark);font-size:0.62rem;font-weight:800;letter-spacing:0.04em;text-transform:uppercase}.answer-value{margin:12px 0 7px;color:#33433b}.answer-value code{padding:2px 6px;border-radius:5px;background:#edf0e7;color:#17251f}.answer-why{margin:0;color:var(--muted);font-size:0.92rem}.answer-key-pager{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-top:30px}.answer-key-cta{margin-top:34px}.answer-key-page .lesson-aside{top:22px}@media (max-width:920px){.hero-grid{grid-template-columns:1fr;gap:36px}.hero h1{max-width:16ch}.hero-card{max-width:570px}.lesson-layout,.practice-shell{grid-template-columns:1fr;gap:26px}.lesson-aside,.practice-aside{position:static;grid-row:auto}.lesson-aside{grid-template-columns:1fr 1fr}.lesson-aside .aside-card:first-child{grid-column:1 / -1}.practice-aside .aside-card{position:static}.footer-grid{grid-template-columns:1.5fr 1fr 1fr}.footer-col:last-child{grid-column:span 3}}@media (max-width:780px){body{font-size:16px}.wrap,.narrow{width:min(100% - 28px,1120px)}.header-inner{min-height:60px}.site-nav{display:none}.nav-toggle{display:inline-flex;margin-left:auto}.mobile-nav{display:none;position:absolute;top:60px;left:0;right:0;background:var(--paper);border-bottom:1px solid var(--line);padding:10px 14px 16px;box-shadow:var(--shadow)}.mobile-nav.show{display:grid;gap:3px}.mobile-nav a{text-decoration:none;color:var(--ink);padding:10px 11px;border-radius:8px;font-weight:700;font-size:0.9rem}.mobile-nav a:hover{background:var(--card)}.hero{padding:42px 0 36px}.hero h1{font-size:clamp(2.2rem,11vw,3.4rem);max-width:13ch}.hero-lede{font-size:1rem}.metrics{margin-top:27px}.metrics strong{font-size:1.2rem}.metrics span{font-size:0.7rem}.section{padding:40px 0}.section-head{display:block}.section-head p{margin-top:10px}.lesson-grid,.guide-grid,.how{grid-template-columns:1fr}.guide-card:first-child{grid-column:auto}.quote-band{grid-template-columns:1fr;padding:28px 24px;gap:15px}.cta-band{display:block;padding:24px}.cta-band 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