:root{font-family:Microsoft YaHei,PingFang SC,sans-serif;font-synthesis:none;color:#20334a;background:#f5f7fa;--primary: #245bc2;--muted: #596b80;--line: #dce3ec;--surface: #fff}*{box-sizing:border-box}body{margin:0}a{color:inherit;text-decoration:none}button{font:inherit;color:inherit;cursor:pointer}a,button{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible{outline:3px solid var(--primary);outline-offset:4px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}.skip-link{position:fixed;top:12px;left:16px;z-index:40;padding:12px 18px;background:#fff;border-radius:8px;transform:translateY(-180%)}.skip-link:focus{transform:translateY(0)}.app-shell{display:flex;min-height:100dvh;font-size:15px}.sidebar{width:256px;position:fixed;inset:0 auto 0 0;padding:28px 20px;background:var(--surface);border-right:1px solid var(--line);z-index:20;overflow-y:auto}.brand-row{display:flex;align-items:center;margin-bottom:36px;gap:8px}.brand{display:flex;align-items:center;gap:12px;white-space:nowrap}.brand-mark{display:grid;place-items:center;width:40px;height:44px;border-radius:12px;background:var(--primary);color:#fff;font-size:26px;font-weight:600}.brand strong{font-size:18px;letter-spacing:-.4px}.sidebar nav{display:grid;gap:8px}.sidebar nav a{display:flex;align-items:center;gap:12px;min-height:48px;padding:12px;border-radius:8px;color:var(--muted);font-size:16px;transition:background-color .15s,color .15s}.sidebar nav a:hover{background:#f1f4f8;color:#20334a}.sidebar nav a.active{background:#eaf0fb;color:var(--primary);font-weight:600}.sidebar nav a:focus-visible{outline-offset:-3px}.sidebar nav svg{flex-shrink:0}.sidebar nav small{margin-left:auto;font-size:11px;border:1px solid var(--line);padding:2px 5px;border-radius:4px}.main-shell{margin-left:256px;flex:1;min-width:0}.topbar{height:72px;padding:0 40px;display:flex;align-items:center;background:var(--surface);border-bottom:1px solid var(--line)}.breadcrumb{display:flex;align-items:center;gap:14px;font-size:13px;color:var(--muted)}.breadcrumb strong{color:#20334a;font-weight:500}.slash{color:#8c9aab}main{max-width:1440px;margin:auto;padding:40px}main:focus{outline:none}.page-title{margin-bottom:26px}h1{margin:0;font-size:28px;font-weight:650;letter-spacing:-.6px;line-height:1.4}.app-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.app-card{--app-accent: #245bc2;--app-tint: #eaf0fb;display:flex;flex-direction:column;min-width:0;padding:28px;border:1px solid var(--line);border-radius:14px;background:var(--surface);box-shadow:0 2px 4px #20334a03;transition:border-color .16s,box-shadow .16s}.app-card--tiku{--app-accent: #167360;--app-tint: #e8f4ef}.app-card--jiaowu{--app-accent: #97611c;--app-tint: #fcf1df}.app-card:hover{border-color:var(--app-accent);box-shadow:0 8px 24px #20334a0b}.module-icon{display:grid;place-items:center;width:58px;height:58px;border-radius:14px;color:var(--app-accent);background:var(--app-tint);margin-bottom:24px}.app-card h2{margin:0 0 30px;font-size:22px;font-weight:600;line-height:1.5}.app-card-bottom{display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--line);padding-top:20px;margin-top:auto;font-size:15px;font-weight:500;color:var(--app-accent)}.icon-button{display:inline-flex;align-items:center;justify-content:center;width:44px;height:44px;padding:10px;border:0;border-radius:8px;background:transparent;flex-shrink:0}.icon-button:hover{background:#eaf0fb}.mobile-menu,.nav-close,.scrim{display:none}@media(max-width:1150px){.app-grid{gap:16px}main{padding:32px 28px}.topbar{padding:0 28px}.app-card{padding:24px 20px}}@media(max-width:850px){.sidebar{width:min(304px,calc(100vw - 32px));transform:translate(-100%);visibility:hidden}.sidebar.open{transform:translate(0);visibility:visible}.main-shell{margin-left:0}.topbar{height:64px;padding:0 18px}.brand-row{justify-content:space-between;gap:4px}.brand{gap:8px}.brand strong{font-size:17px}.mobile-menu,.nav-close{display:inline-flex}.scrim{display:block;position:fixed;top:0;right:0;bottom:0;left:0;border:0;background:#172b4d66;z-index:19}}@media(max-width:600px){main{padding:28px 20px}.page-title{margin-bottom:22px}.app-grid{grid-template-columns:1fr;gap:16px}.app-card{display:grid;grid-template-columns:52px 1fr;column-gap:18px;padding:22px;align-items:center}.module-icon{width:52px;height:52px;margin:0;border-radius:12px}.app-card h2{margin:0}.app-card-bottom{grid-column:1 / -1;margin-top:20px;padding-top:16px}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{transition:none!important;animation:none!important}}