#study-dialog{position:fixed;inset:0;width:100%;height:100svh;max-width:none;max-height:none;margin:0;padding:0;border:0;border-radius:0;background:#f9faf5;color:#202b35;overflow:auto;overscroll-behavior:contain;scrollbar-width:thin;scroll-padding-top:76px}
#study-dialog:not([open]){display:none}
#study-dialog[open]{display:block}
#study-dialog::backdrop{background:#f9faf5}
.study-topbar{position:sticky;top:0;z-index:2;display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:62px;padding:8px max(18px,calc((100vw - 1280px)/2));background:#f9faf5f2;border-bottom:1px solid #d7dfe4;backdrop-filter:blur(10px);font-family:"Microsoft YaHei","PingFang SC",sans-serif}
.study-topbar h2{margin:0;font-size:20px;font-weight:600;color:#202b35}
#study-close{min-height:44px;min-width:116px;padding:9px 16px;border:1px solid #a6b7c7;border-radius:6px;background:#fff;color:#255a97;font-size:16px;box-shadow:none;cursor:pointer}
#study-close:focus-visible{outline:3px solid #5585c8;outline-offset:2px}
#study-host{min-width:0;display:block}
body.study-is-open{overflow:hidden}
.about-learning{flex:none;margin:0;padding:16px 24px 18px;border-top:1px solid var(--line);background:var(--panel)}
.about-learning h3{margin:0 0 5px;font-size:18px;color:var(--text)}
.about-learning p{margin:0 0 11px;font-size:14px;line-height:1.6;color:var(--muted)}
#about-dialog{display:flex;flex-direction:column;max-height:calc(100svh - 32px)}
#about-dialog:not([open]){display:none}
#about-dialog .about-head{flex:none}
#about-dialog .about-body{flex:1;min-height:0;max-height:none}
#learn-open{display:flex;align-items:center;justify-content:center;gap:12px;width:100%;min-height:48px;border:1px solid var(--cyan);border-radius:6px;background:color-mix(in srgb,var(--cyan) 8%,var(--panel));color:var(--cyan);font-size:16px;text-decoration:none;touch-action:manipulation}
#learn-open:hover{background:color-mix(in srgb,var(--cyan) 15%,var(--panel))}
@media(max-width:760px){.study-topbar{min-height:58px;padding:7px 14px}.study-topbar h2{font-size:18px}#study-close{min-width:108px;font-size:15px}.about-learning{padding:12px 17px 15px}.about-learning p{font-size:13px;margin-bottom:9px}#about-dialog{max-height:calc(100svh - 24px)}}