:root{--bg:#EEF0F8;--deep:#E0E4F2;--surface:#F7F8FD;--soft:#EBEEF8;--title:#1A1840;--text:#2C2A48;--muted:#5A5680;--assist:#7A76A0;--purple:#5B4BDB;--blue:#3A6BD4;--dark:#1C1A3A;--mist:#8AA4E0;--lilac:#8A6AD4;--border:rgba(58,107,212,.18);--strong:rgba(91,75,219,.42);--shadow:0 12px 28px rgba(28,26,58,.08);--max:1000px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font-family:"Microsoft YaHei","PingFang SC",Arial,sans-serif;font-size:15px;line-height:1.7;overflow-x:hidden}body.is-locked{overflow:hidden}a{color:inherit;text-decoration:none}button{font:inherit;cursor:pointer}img{display:block;max-width:100%}.shell{width:min(calc(100% - 32px),var(--max));margin:auto}.skip-link{position:fixed;left:16px;top:-80px;z-index:1600;background:var(--surface);padding:10px 14px;border-radius:10px}.skip-link:focus{top:8px}.address-bar{position:fixed;inset:0 0 auto;height:22px;z-index:1000;background:var(--dark);color:#F7F8FD;font-size:12px}.address-inner{height:100%;display:flex;align-items:center;justify-content:space-between;gap:10px}.text-action{border:0;background:transparent;color:#F7F8FD;padding:0 6px;min-height:22px}.window-head{position:fixed;top:22px;left:0;right:0;height:54px;z-index:990;background:#EBE8FA;border-bottom:1px solid var(--strong)}.window-head-inner{height:100%;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:10px}.brand-link{justify-self:start;display:flex;align-items:center;min-height:44px}.brand-logo{height:24px;width:auto;max-width:160px;object-fit:contain;object-position:center}.brand-text{font-size:16px;font-weight:800;color:var(--title)}.app-entry{min-height:44px;display:flex;align-items:center;padding:0 14px;font-weight:800;border-radius:10px}.drawer-button{justify-self:end;min-height:44px;padding:0 14px;border:1px solid var(--strong);background:var(--surface);color:var(--dark);border-radius:10px;font-weight:800}.section-tabs{position:fixed;top:76px;left:0;right:0;z-index:980;min-height:42px;background:var(--surface);border-bottom:1px solid var(--border)}.section-tabs-inner{min-height:42px;display:flex;justify-content:center;align-items:center;gap:8px;flex-wrap:wrap;padding:5px 0}.tab{min-height:32px;padding:0 15px;border-radius:999px;display:flex;align-items:center;justify-content:center;font-size:13px;color:var(--muted);border:1px solid transparent}.tab:hover,.tab:focus-visible{border-color:var(--strong);outline:0}.tab.is-active{background:var(--purple);color:#F7F8FD}.site-main{padding-top:146px;min-height:60vh}.page-intro{padding:34px 0 22px}.eyebrow{font-size:13px;font-weight:800;color:var(--purple);letter-spacing:.04em;margin:0 0 8px}h1,h2,h3{color:var(--title);margin-top:0}h1{font-size:24px;line-height:1.3;margin-bottom:12px}h2{font-size:20px;line-height:1.45;margin-bottom:10px}h3{font-size:16px;line-height:1.5;margin-bottom:8px}p{margin:0 0 14px}.lead{font-size:16px;color:var(--muted);max-width:780px}.section{padding:26px 0}.section+.section{border-top:1px solid var(--border)}.section-head{display:flex;justify-content:space-between;align-items:end;gap:18px;margin-bottom:18px}.section-head p{max-width:620px;color:var(--muted);margin:0}.btn{min-height:42px;padding:0 17px;border-radius:10px;display:inline-flex;align-items:center;justify-content:center;font-size:14px;font-weight:800;border:1px solid transparent;white-space:nowrap}.btn-primary{background:linear-gradient(135deg,#8AA4E0 0%,#5B4BDB 55%,#3A6BD4 100%);color:#F7F8FD}.btn-secondary{background:var(--surface);color:var(--dark);border-color:var(--strong)}.button-row,.inline-links{display:flex;gap:10px;flex-wrap:wrap;margin-top:18px}.centered{justify-content:center}.inline-links a{min-height:42px;display:inline-flex;align-items:center;padding:0 14px;border:1px solid var(--strong);border-radius:10px;background:var(--surface);font-weight:800}.btn:hover{filter:brightness(.98);transform:translateY(-1px)}a:focus-visible,button:focus-visible{outline:3px solid rgba(91,75,219,.24);outline-offset:2px}.media-slot{width:100%;background:linear-gradient(145deg,#F7F8FD,#E8ECF8);border:1px solid var(--border);border-radius:12px;display:flex;align-items:center;justify-content:center;overflow:hidden}.media-slot img{width:100%;height:100%;object-fit:contain;object-position:center}.slot-banner{height:168px}.slot-wide{height:176px}.slot-medium{height:188px}.slot-app{height:300px;max-width:420px;margin:auto}.slot-brand{height:220px}.frame-card,.longform,.policy-block,.note-item,.tool-item,.faq-item,.contact-card,.compare-card,.center-card,.product-card,.reading-paper,.path-step,.stair-card,.bookmark-board,.about-statement{background:var(--surface);border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow)}.frame-card,.longform,.policy-block,.note-item,.faq-item,.contact-card,.compare-card,.center-card,.path-step,.stair-card,.bookmark-board,.about-statement{padding:18px}.frame-topline{display:flex;gap:7px;margin-bottom:12px}.frame-dot{width:8px;height:8px;border-radius:50%;background:var(--mist)}.frame-dot:nth-child(2){background:var(--lilac)}.frame-dot:nth-child(3){background:var(--blue)}.home-hero{padding-top:18px}.home-hero-copy{padding:22px 4px 0;max-width:780px}.longform .media-slot,.compare-card .media-slot,.stair-card .media-slot{margin-bottom:14px}.stair-stack{display:grid;gap:12px;max-width:860px}.stair-card:nth-child(2){margin-left:24px}.stair-card:nth-child(3){margin-left:48px}.tag-wrap{display:flex;gap:10px;flex-wrap:wrap;margin:14px 0 18px}.tag-pill{background:#E5E8F6;color:var(--dark);border:1px solid var(--border);border-radius:999px;padding:8px 13px;font-weight:800}.bookmark-board{display:grid;gap:16px}.compare-grid,.center-cards,.contact-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.center-cards{max-width:820px;margin:auto}.center-card{text-align:center}.path-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.path-step strong{display:block;color:var(--purple);margin-bottom:6px}.product-card{max-width:760px;margin:auto;padding:24px;text-align:center}.product-card p{text-align:left}.product-icon{width:72px;height:72px;margin:0 auto 14px;background:var(--soft);border:1px solid var(--border);border-radius:18px;display:flex;align-items:center;justify-content:center}.product-icon img{width:48px;height:48px;object-fit:contain}.product-card .slot-app{margin-bottom:18px}.notice{background:#E6E9F8;border-left:4px solid var(--purple);border-radius:10px;padding:14px 16px;color:var(--dark)}.note-list,.tool-list,.policy-stack,.faq-list{display:grid;gap:12px}.tool-item{display:grid;grid-template-columns:110px 1fr;gap:16px;padding:16px}.tool-item>strong{color:var(--purple)}.reading-paper{max-width:820px;margin:auto;padding:26px}.reading-settings{display:flex;gap:10px;flex-wrap:wrap;margin:16px 0}.reading-settings span{padding:7px 12px;border-radius:999px;background:#E4E7F5;color:var(--dark);font-weight:700}.split-demo{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);gap:10px;background:#DDE3F5;border:1px solid var(--strong);padding:10px;border-radius:14px}.split-pane{background:var(--surface);border-radius:10px;padding:18px;min-height:190px}.split-pane.secondary{background:#E9ECF7}.site-footer{background:var(--dark);color:#EEF0F8;border-top:1px solid var(--mist);margin-top:42px;padding:34px 0 72px;font-size:13px}.footer-grid{display:grid;grid-template-columns:1.3fr repeat(4,1fr);gap:22px}.footer-brand{display:flex;flex-direction:column;align-items:flex-start;gap:6px}.footer-logo{height:24px;width:auto;max-width:150px;object-fit:contain}.footer-brand strong{font-size:16px}.footer-brand span,.footer-note{color:#C7CDE8}.footer-grid h2{font-size:13px;color:#F7F8FD;margin-bottom:8px}.footer-grid a{display:block;color:#D8DDF0;padding:3px 0}.footer-note{border-top:1px solid rgba(138,164,224,.22);margin-top:24px;padding-top:16px}.page-overlay{position:fixed;inset:0;background:rgba(28,26,58,.42);z-index:1100;opacity:0;visibility:hidden;pointer-events:none;transition:.2s}.page-overlay.is-open{opacity:1;visibility:visible;pointer-events:auto}.tool-drawer{position:fixed;right:20px;bottom:20px;z-index:1200;width:min(360px,calc(100% - 32px));max-height:70vh;overflow:auto;background:var(--surface);border:1px solid var(--strong);border-radius:14px;box-shadow:0 24px 60px rgba(28,26,58,.22);padding:16px;opacity:0;visibility:hidden;pointer-events:none;transform:translateY(22px) scale(.98);transition:.2s}.tool-drawer.is-open{opacity:1;visibility:visible;pointer-events:auto;transform:none}.drawer-head{display:flex;justify-content:space-between;align-items:center;gap:12px;padding-bottom:12px;border-bottom:1px solid var(--border)}.drawer-brand{display:flex;align-items:center;gap:10px}.close-button{min-height:40px;padding:0 12px;border:1px solid var(--strong);background:var(--surface);color:var(--dark);border-radius:10px;font-weight:800}.drawer-group{padding-top:14px}.drawer-group h2{font-size:13px;color:var(--muted);margin-bottom:8px}.drawer-group a{display:block;padding:10px;border-radius:10px}.drawer-group a:hover{background:var(--soft)}.drawer-group span{display:block;font-weight:800;color:var(--title)}.drawer-group small{display:block;color:var(--muted);font-size:12px;line-height:1.5;margin-top:2px}.search-panel{position:fixed;top:76px;left:0;right:0;z-index:1190;opacity:0;visibility:hidden;pointer-events:none;transform:translateY(-10px);transition:.2s}.search-panel.is-open{opacity:1;visibility:visible;pointer-events:auto;transform:none}.search-card{background:#EBE8FA;border:1px solid var(--strong);border-radius:0 0 14px 14px;padding:18px;box-shadow:var(--shadow)}.search-card-head{display:flex;justify-content:space-between;align-items:center;gap:18px}.search-card-head p{margin:2px 0 0;color:var(--muted)}.search-presets{display:flex;gap:10px;flex-wrap:wrap;margin-top:14px}.search-presets a{min-height:42px;display:flex;align-items:center;padding:0 14px;border-radius:999px;background:var(--surface);border:1px solid var(--border)}.mobile-bottom{display:none}@media(max-width:760px){.section-tabs{display:none}.window-head-inner{grid-template-columns:1fr auto auto;gap:6px}.brand-logo{max-width:128px}.brand-text{font-size:15px}.app-entry,.drawer-button{padding:0 9px;font-size:13px}.site-main{padding-top:96px;padding-bottom:62px}.page-intro{padding-top:26px}.compare-grid,.center-cards,.contact-grid,.path-strip,.split-demo{grid-template-columns:1fr}.stair-card:nth-child(2),.stair-card:nth-child(3){margin-left:0}.tool-item{grid-template-columns:1fr;gap:6px}.footer-grid{grid-template-columns:1fr 1fr}.footer-brand{grid-column:1/-1}.site-footer{padding-bottom:92px}.tool-drawer{width:92%;right:4%;bottom:60px;max-height:74vh}.search-panel{top:0;bottom:0;background:var(--dark);padding:70px 0;overflow:auto}.search-card{width:calc(100% - 32px);border-radius:14px;background:var(--dark);color:#F7F8FD;border-color:rgba(247,248,253,.18)}.search-card-head p{color:#D9DDF0}.search-card .close-button,.search-presets a{background:#F7F8FD;color:var(--dark)}.mobile-bottom{position:fixed;display:grid;grid-template-columns:repeat(4,1fr);left:0;right:0;bottom:0;z-index:1050;min-height:48px;padding-bottom:env(safe-area-inset-bottom);background:var(--surface);border-top:1px solid var(--strong);box-shadow:0 -8px 20px rgba(28,26,58,.06)}.mobile-bottom a{min-height:48px;display:flex;align-items:center;justify-content:center;font-size:13px;color:var(--dark)}.mobile-bottom a.is-active{background:var(--purple);color:#F7F8FD}.slot-app{height:280px}}@media(max-width:460px){.footer-grid{grid-template-columns:1fr}.brand-link{min-width:0}.brand-text{white-space:nowrap}.app-entry{padding:0 6px}.drawer-button{padding:0 8px}}