.flat-library{width:min(1160px,100%);margin:0 auto;padding:8px 0 40px;color:#242424}.flat-library-tabs{display:flex;gap:10px;margin:0 0 22px;padding:0;width:fit-content;border:0;border-radius:0;background:transparent}.flat-library-tabs button{border:0;border-radius:999px;padding:8px 18px;background:transparent;color:#777;font-family:inherit;font-size:13px;font-weight:400;line-height:20px;cursor:pointer}.flat-library-tabs button[aria-pressed=true]{background:#242424;color:#fff}.flat-atlas-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.flat-atlas-card{grid-column:auto;display:flex;flex-direction:column;align-items:stretch;min-width:0;min-height:250px;padding:24px;text-align:left;color:inherit;background:linear-gradient(145deg,#ffffff91,#ffffff26);border:1px solid #ffffffc9;border-radius:26px;box-shadow:0 12px 36px #22222206;backdrop-filter:blur(18px);cursor:pointer;transition:background .18s,transform .18s}.flat-atlas-card:hover{background:#ffffffae;transform:translateY(-3px)}.flat-atlas-card svg{display:block;width:100%;height:165px;margin:0 auto 20px;overflow:visible}.flat-atlas-card svg polyline{fill:none;stroke:#626262;stroke-width:.65;opacity:.6}.flat-atlas-card svg circle{fill:#414141}.flat-atlas-card svg .atlas-orbit{fill:none;stroke:#77777730;stroke-width:.65;stroke-dasharray:2 6}.flat-atlas-caption{display:flex;align-items:center;justify-content:space-between;gap:12px}.flat-atlas-caption strong{font:400 24px/1.4 'Songti SC',SimSun,serif}.flat-atlas-caption>span{font-size:12px;white-space:nowrap;color:#747474}.flat-atlas-dialog{position:fixed;inset:0;margin:auto;width:min(1440px,calc(100vw - 48px));height:calc(100dvh - 64px);max-width:none;max-height:none;padding:0;border:1px solid #ffffffbd;border-radius:26px;background:#ffffffb8;backdrop-filter:blur(24px);overflow:hidden;color:#222}.flat-atlas-dialog::backdrop{background:#00000030;backdrop-filter:blur(8px)}.flat-atlas-dialog header{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:18px 24px;height:78px;box-sizing:border-box;border-bottom:1px solid #ffffff88}.flat-atlas-dialog h2{margin:0;font:400 25px/1.3 'Songti SC',SimSun,serif}.flat-atlas-dialog header>div{display:flex;gap:8px}.flat-atlas-dialog button{min-height:42px;padding:9px 17px;border:1px solid #00000010;border-radius:999px;background:#ffffff55;color:#222;cursor:pointer;font:inherit}.flat-atlas-dialog [data-close]{font-size:24px;padding:3px 13px}.flat-atlas-dialog iframe{display:block;width:100%;height:calc(100% - 78px);border:0;background:transparent}.flat-atlas-dialog .atlas-exit{display:none}.flat-atlas-dialog.atlas-fullscreen{width:100vw;height:100dvh;border:0;border-radius:0}.flat-atlas-dialog.atlas-fullscreen header{display:none}.flat-atlas-dialog.atlas-fullscreen iframe{height:100%}.flat-atlas-dialog.atlas-fullscreen .atlas-exit{display:block;position:absolute;right:12px;top:12px;z-index:2;background:#ffffffb3}.flat-library button:focus-visible,.flat-atlas-dialog button:focus-visible{outline:2px solid #333;outline-offset:3px}
@media(max-width:760px){.flat-library{padding:0 0 24px}.flat-library-tabs{margin-bottom:20px}.flat-library-tabs button{padding:8px 16px}.flat-atlas-grid{gap:12px;grid-template-columns:1fr}.flat-atlas-card,.flat-atlas-card:nth-child(-n+2){grid-column:auto;flex-direction:row;align-items:center;gap:12px;min-height:128px;padding:16px;border-radius:22px}.flat-atlas-card svg{width:102px;height:90px;flex:0 0 102px;margin:0}.flat-atlas-caption{align-items:flex-start;flex-direction:column;gap:8px}.flat-atlas-caption strong{font-size:22px}.flat-atlas-dialog{width:calc(100vw - 24px);height:calc(100dvh - 32px);border-radius:20px}.flat-atlas-dialog header{height:72px;padding:12px;gap:8px}.flat-atlas-dialog h2{font-size:18px}.flat-atlas-dialog header>div{gap:4px}.flat-atlas-dialog header button{padding:8px 12px}.flat-atlas-dialog iframe{height:calc(100% - 72px)}}
@media(prefers-reduced-motion:reduce){.flat-atlas-card{transition:none}}

.flat-course-stage{position:relative;min-height:70vh}.flat-course-loading{position:absolute;inset:0;display:grid;place-items:center;margin:0;color:#777;z-index:1;background:#f6f5f0;pointer-events:none}