/* ===== 学习首页（交互版） ===== */
.hp{--hc-bg:#1f1e1c;--hc-panel:#262523;--hc-line:#393834;--hc-fg:#ece9e0;--hc-muted:#a5a298;--hc-blue:#e38c6b;--hc-ok:#94c79f;--hc-path:#e3bb6d;--hc-edge:#4a4842;--hc-soft:#2e2d2a;--hc-ink:#1f1e1c;--mono:ui-monospace,'SF Mono',Menlo,Consolas,monospace;padding-bottom:24px}

/* Hero */
.hp-hero{padding-top:56px}
.hp-hero-copy{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);gap:56px;align-items:end;margin-bottom:36px}
.hp-hero h1{font-size:clamp(2.1rem,4.4vw,3.5rem);line-height:1.22;letter-spacing:-.03em;font-weight:700}
.hp-hero-side p{color:var(--muted);line-height:1.9;max-width:34em}
.hp-hero-side .button-row{margin-top:20px}

/* Console */
.hp-console{background:var(--hc-bg);color:var(--hc-fg);border-radius:18px;border:1px solid var(--hc-line);box-shadow:0 30px 70px -30px #2a1f1640;overflow:hidden}
.hp-console-bar{display:flex;align-items:stretch;gap:16px;border-bottom:1px solid var(--hc-line);padding:0 14px 0 6px}
.hp-stage-tabs{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));flex:1;min-width:0}
.hp-stage-tab{position:relative;display:flex;align-items:center;gap:10px;padding:17px 14px 19px;background:none;border:0;color:var(--hc-muted);font-size:.875rem;text-align:left;min-width:0;transition:color .2s}
.hp-stage-tab:hover{color:var(--hc-fg)}
.hp-stage-tab[aria-selected=true]{color:var(--hc-fg)}
.hp-stage-tab:focus-visible{outline:2px solid var(--hc-blue);outline-offset:-4px;border-radius:10px}
.hp-stage-num{position:relative;flex:none;width:24px;height:24px;border-radius:50%;border:1px solid var(--hc-edge);display:grid;place-items:center;font-size:.75rem;transition:background .25s,border-color .25s}
.hp-stage-num b{font-weight:600}
.hp-stage-num svg{position:absolute;width:14px;height:14px;stroke-width:2.4;opacity:0;transition:opacity .2s}
.hp-stage-tab[aria-selected=true] .hp-stage-num{border-color:var(--hc-blue);color:var(--hc-blue)}
.hp-stage-tab.is-done .hp-stage-num{background:var(--hc-ok);border-color:var(--hc-ok);color:var(--hc-ink)}
.hp-stage-tab.is-done .hp-stage-num b{opacity:0}
.hp-stage-tab.is-done .hp-stage-num svg{opacity:1}
.hp-stage-name{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.hp-stage-progress{position:absolute;left:14px;right:14px;bottom:0;height:2px;background:var(--hc-soft);overflow:hidden}
.hp-stage-progress>i{position:absolute;inset:0;background:var(--hc-blue);transform:scaleX(0);transform-origin:left;transition:transform .35s ease}
.hp-stage-tab.is-done .hp-stage-progress>i{background:var(--hc-ok)}
.hp-console-controls{display:flex;align-items:center;gap:6px;flex:none}
.hp-ctl{display:inline-flex;align-items:center;gap:6px;padding:6px 11px;border-radius:8px;border:1px solid transparent;background:none;color:var(--hc-muted);font-size:.8125rem;transition:color .2s,background .2s,border-color .2s}
.hp-ctl svg{width:16px;height:16px;stroke-width:2}
.hp-ctl:hover:not(:disabled){color:#fff;background:#ffffff0d}
.hp-ctl:disabled{opacity:.35;cursor:default}
.hp-ctl:focus-visible{outline:2px solid var(--hc-blue);outline-offset:2px}
.hp-ctl .hp-ico-play{display:none}
.hp-ctl.is-paused .hp-ico-play{display:block}
.hp-ctl.is-paused .hp-ico-pause{display:none}
.hp-ctl.is-ready{color:#fff;border-color:var(--hc-blue);background:#3a2a22}

.hp-console-body{display:grid;grid-template-columns:300px minmax(0,1fr);min-height:372px}
.hp-stage-info{padding:28px 26px;border-right:1px solid var(--hc-line);display:flex;flex-direction:column}
.hp-stage-step{font-size:.8125rem;color:var(--hc-muted)}
.hp-stage-info h2{font-size:1.1875rem;line-height:1.5;margin:6px 0 22px;font-weight:600;color:var(--hc-fg)}
.hp-checks{list-style:none;margin:0;padding:0;display:grid;gap:13px}
.hp-checks li{display:flex;gap:11px;align-items:flex-start;font-size:.875rem;line-height:1.6;color:var(--hc-muted);transition:color .3s}
.hp-checks li span{flex:none;width:17px;height:17px;margin-top:3px;border-radius:5px;border:1.5px solid var(--hc-edge);position:relative;transition:background .25s,border-color .25s}
.hp-checks li span::after{content:'';position:absolute;left:5px;top:1.5px;width:4px;height:8px;border:solid var(--hc-ink);border-width:0 2px 2px 0;transform:rotate(45deg) scale(0);transition:transform .25s cubic-bezier(.3,1.6,.5,1)}
.hp-checks li.is-done{color:var(--hc-fg)}
.hp-checks li.is-done span{background:var(--hc-ok);border-color:var(--hc-ok)}
.hp-checks li.is-done span::after{transform:rotate(45deg) scale(1)}
.hp-stage-actions{margin-top:auto;padding-top:24px;display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.hp-stage-actions .text-link{margin:0;color:var(--hc-blue)}
.hp-copy-stage{background:none;border:1px solid var(--hc-edge);color:var(--hc-fg);border-radius:7px;padding:4px 11px;font-size:.8125rem}
.hp-copy-stage:hover{border-color:var(--hc-blue)}

.hp-term{display:flex;flex-direction:column;min-width:0;background:var(--hc-panel)}
.hp-term-head{display:flex;align-items:center;gap:12px;padding:11px 18px;border-bottom:1px solid var(--hc-line);font-size:.75rem;color:var(--hc-muted)}
.hp-dots{display:flex;gap:5px}.hp-dots i{width:7px;height:7px;border-radius:50%;background:var(--hc-edge)}
.hp-term-note{margin-left:auto;padding:1px 8px;border:1px solid var(--hc-edge);border-radius:20px}
.hp-term-body{flex:none;height:318px;overflow:hidden;padding:18px 22px;font:13.5px/1.95 var(--mono)}
.hp-line{white-space:pre-wrap;word-break:break-all;color:var(--hc-fg)}
.hp-prompt{color:var(--hc-blue);margin-right:10px;user-select:none}
.hp-line:last-child .hp-cmd::after{content:'';display:inline-block;width:7px;height:1.05em;margin-left:2px;vertical-align:-2px;background:var(--hc-blue);animation:hp-caret 1s steps(1) infinite}
.hp-out{white-space:pre-wrap;word-break:break-all;color:var(--hc-muted);padding-left:20px}
.hp-out.ok{color:var(--hc-ok)}
.hp-out.path{color:var(--hc-path)}
.hp-plot{margin:6px 0 0 20px;max-width:380px}
.hp-plot svg{width:100%;height:auto;display:block;overflow:visible;stroke:none;fill:none}
.hp-bars rect{fill:var(--hc-blue);transform:scaleY(0);transform-box:fill-box;transform-origin:bottom;transition:transform .45s cubic-bezier(.2,.8,.3,1)}
.hp-bars.is-grown rect{transform:scaleY(1)}
.hp-bars.no-anim rect{transition:none}
.hp-axis,.hp-ticks line{stroke:var(--hc-edge);stroke-width:1}
.hp-ticks text,.hp-xlabel,.hp-plot-tag{fill:var(--hc-muted);font:9px var(--mono);text-anchor:middle}
.hp-xlabel,.hp-plot-tag{text-anchor:end}
.hp-plot-tag{fill:var(--hc-muted)}
.hp-console-foot{margin-top:12px;font-size:.8125rem;color:var(--muted)}
@keyframes hp-caret{50%{opacity:0}}

/* Sections */
.hp-section{padding-top:96px}
.hp-section-head{display:flex;justify-content:space-between;align-items:end;gap:32px;margin-bottom:28px}
.hp-section-head h2{font-size:clamp(1.5rem,2.4vw,2rem);letter-spacing:-.02em;line-height:1.3}
.hp-section-head p{color:var(--muted);max-width:30em}
.hp-section-head .text-link{margin:0}

/* Path picker */
.hp-path{border:1px solid var(--line);border-radius:16px;background:var(--panel);overflow:hidden}
.hp-path-tabs{display:flex;gap:6px;padding:10px;border-bottom:1px solid var(--line);background:var(--surface);overflow-x:auto;scrollbar-width:none}
.hp-path-tabs::-webkit-scrollbar{display:none}
.hp-path-tabs button{flex:none;border:1px solid transparent;background:none;border-radius:9px;padding:8px 16px;font-size:.9375rem;color:var(--muted);transition:background .2s,color .2s,border-color .2s}
.hp-path-tabs button:hover{color:var(--fg)}
.hp-path-tabs button[aria-selected=true]{background:var(--panel);color:var(--blue-text);border-color:var(--line);font-weight:600;box-shadow:0 2px 8px #2a1f1612}
.hp-path-panel{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:40px;padding:32px;animation:hp-swap .3s ease}
.hp-path-panel[hidden]{display:none}
.hp-path-main h3{font-size:1.25rem;line-height:1.5;margin-bottom:16px}
.hp-path-links{display:grid;gap:10px}
.hp-path-links a{display:block;padding:14px 16px;border-radius:10px;border:1px solid var(--line);transition:border-color .2s,background .2s}
.hp-path-links a:hover{border-color:var(--blue);background:var(--blue-soft)}
.hp-path-links strong{display:block;font-weight:600}
.hp-path-links span{display:block;font-size:.8125rem;color:var(--muted);line-height:1.6;margin-top:2px}
.hp-path-side .code-block{margin:0}
.hp-path-check{display:flex;gap:10px;margin-top:16px;font-size:.9375rem;line-height:1.7}
.hp-path-check span{flex:none;width:24px;height:24px;border-radius:50%;background:var(--blue-soft);color:var(--blue-text);display:grid;place-items:center;margin-top:1px}
.hp-path-check svg{width:14px;height:14px;stroke-width:2.4}
@keyframes hp-swap{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:none}}

/* Task index */
.hp-tasks{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));border-top:1px solid var(--line)}
.hp-task-group{padding:22px 24px 26px 0;border-bottom:1px solid var(--line)}
.hp-task-group:not(:nth-child(3n+1)){padding-left:24px;border-left:1px solid var(--line)}
.hp-task-group h3{font-size:1rem;margin-bottom:10px}
.hp-task-group ul{list-style:none;margin:0;padding:0}
.hp-task-group a{display:block;padding:5px 0;color:var(--muted);font-size:.9375rem}
.hp-task-group a:hover{color:var(--blue-text);text-decoration:underline;text-underline-offset:4px}

/* About */
.hp-about{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,1fr);gap:48px;align-items:center}
.hp-detector{margin:0}
.hp-detector img{width:100%;height:auto;display:block;border-radius:16px;background:#102236}
.hp-detector figcaption{font-size:.75rem;color:var(--muted);margin-top:8px}
.hp-detector figcaption a{text-decoration:underline;text-underline-offset:3px}
.hp-about-copy h2{font-size:clamp(1.5rem,2.4vw,2rem);letter-spacing:-.02em;margin-bottom:12px}
.hp-about-copy>p{color:var(--muted);line-height:1.9}
.hp-manual{display:grid;grid-template-columns:auto 1fr;gap:4px 14px;margin-top:26px;padding:18px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.hp-manual-icon{width:38px;height:38px;border-radius:9px;background:var(--blue-soft);color:var(--blue-text);display:grid;place-items:center}
.hp-manual p{font-size:.8125rem;color:var(--muted)}
.hp-manual .text-link{grid-column:2;margin:4px 0 0}

/* FAQ */
.hp-faq{border-top:1px solid var(--line)}
.hp-faq details{border-bottom:1px solid var(--line)}
.hp-faq summary{list-style:none;display:flex;justify-content:space-between;align-items:center;gap:20px;padding:20px 4px;cursor:pointer;font-size:1.0625rem;font-weight:500}
.hp-faq summary::-webkit-details-marker{display:none}
.hp-faq summary b{flex:none;position:relative;width:14px;height:14px}
.hp-faq summary b::before,.hp-faq summary b::after{content:'';position:absolute;left:0;right:0;top:6px;height:2px;background:var(--muted);border-radius:2px;transition:transform .25s}
.hp-faq summary b::after{transform:rotate(90deg)}
.hp-faq details[open] summary b::after{transform:rotate(0)}
.hp-faq summary:hover{color:var(--blue-text)}
.hp-faq details>div{padding:0 4px 22px;max-width:46em;color:var(--muted);line-height:1.85}

/* Ask */
.hp-ask{padding-top:110px;padding-bottom:40px;text-align:center}
.hp-ask h2{font-size:clamp(1.6rem,3vw,2.4rem);letter-spacing:-.02em}
.hp-ask-form{display:flex;align-items:center;gap:10px;max-width:640px;margin:26px auto 0;padding:7px 7px 7px 18px;border:1px solid var(--line);border-radius:14px;background:var(--panel);box-shadow:0 18px 40px -24px #2a1f1630;transition:border-color .2s,box-shadow .2s}
.hp-ask-form:focus-within{border-color:var(--blue);box-shadow:0 0 0 4px var(--blue-soft)}
.hp-ask-form svg{flex:none;color:var(--muted)}
.hp-ask-form input{flex:1;min-width:0;border:0;background:none;outline:none;color:var(--fg);font-size:1rem;padding:8px 0}
.hp-ask-form .button{flex:none;border-radius:9px}
.hp-ask>p{margin-top:14px;font-size:.8125rem;color:var(--muted)}
.hp-ask kbd{margin-left:2px}

/* Dark theme tweaks */
:root[data-theme=dark] .hp-console{border-color:var(--hc-line)}
:root[data-theme=dark] .hp-path-tabs button[aria-selected=true]{box-shadow:none}

/* Responsive */
@media(max-width:1000px){
  .hp-hero-copy{grid-template-columns:1fr;gap:18px}
  .hp-console-body{grid-template-columns:1fr}
  .hp-stage-info{border-right:0;border-bottom:1px solid var(--hc-line);padding:22px}
  .hp-stage-info h2{margin-bottom:16px}
  .hp-stage-actions{padding-top:18px}
  .hp-about{grid-template-columns:1fr;gap:28px}
  .hp-tasks{grid-template-columns:repeat(2,minmax(0,1fr))}
  .hp-task-group:not(:nth-child(3n+1)){padding-left:0;border-left:0}
  .hp-task-group:nth-child(2n){padding-left:24px;border-left:1px solid var(--line)}
}
@media(max-width:760px){
  .hp-hero{padding-top:34px}
  .hp-hero-copy{margin-bottom:24px}
  .hp-console{border-radius:14px;margin:0 -8px}
  .hp-console-bar{flex-direction:column;gap:0;padding:0}
  .hp-stage-tab{flex-direction:column;align-items:center;gap:6px;padding:13px 4px 15px;font-size:.75rem;text-align:center}
  .hp-stage-progress{left:8px;right:8px}
  .hp-console-controls{justify-content:flex-end;padding:6px 10px;border-top:1px solid var(--hc-line)}
  .hp-term{order:-1}
  .hp-stage-info{border-bottom:0;border-top:1px solid var(--hc-line)}
  .hp-term-body{height:280px;padding:14px;font-size:12px}
  .hp-out,.hp-plot{padding-left:0;margin-left:0}
  .hp-section{padding-top:72px}
  .hp-section-head{flex-direction:column;align-items:start;gap:8px}
  .hp-path-panel{grid-template-columns:1fr;gap:24px;padding:20px}
  .hp-tasks{grid-template-columns:1fr}
  .hp-task-group,.hp-task-group:nth-child(2n){padding:18px 0;border-left:0}
  .hp-ask{padding-top:80px}
  .hp-ask-form{padding-left:14px}
}
@media(prefers-reduced-motion:reduce){
  .hp *,.hp *::before,.hp *::after{animation:none!important;transition:none!important}
}