/* Desktop layout based on the supplied laptop references. */
@media(min-width:901px){
 :root{--sidebar-w:266px}
 .sidebar{background:var(--bg-deep);border-right:1px solid var(--line-soft)}
 .sidebar .sb-head{padding:20px 16px 14px;gap:8px}
 .sidebar .brand-name{font-size:26px;letter-spacing:-.04em}
 .sidebar .brand>.ic{width:22px;height:22px}
 .desktop-new{padding:0 10px 7px;display:block}
 .desktop-new .sb-link,.desktop-nav-extra .sb-link{width:100%;background:transparent;border:0;text-align:left;font:inherit;cursor:pointer}
 .desktop-new .sb-link{padding:10px 12px;font-size:14px}
 .sb-search{margin:0 12px 8px}
 .sb-search .input{min-height:34px;font-size:12px;background:transparent}
 .sb-nav{padding:0 10px 14px;border:0;gap:2px}
 .sb-nav .sb-link{padding:9px 12px;font-size:14px;border-radius:8px}
 .desktop-nav-extra{display:flex;flex-direction:column;gap:2px}
 .sb-list{padding:0 9px 12px}
 .desktop-recent{padding:10px 12px 6px;color:var(--ink-3);font-size:12px}
 .sb-section{font-size:10px;padding:8px 12px 4px;opacity:.7}
 .conv-item>a{padding:8px 11px;font-size:13px;line-height:1.45;border-radius:8px}
 .conv-item[aria-current="page"]{background:var(--surface-3);border-radius:8px}
 .sb-foot{padding:10px;border-top:1px solid var(--line-soft);background:var(--bg-deep)}
 .sb-foot .sb-settings-link,.sb-foot .sb-new-bottom{display:none}
 .user-chip{width:100%;padding:7px;background:transparent;border-radius:10px}
 .user-chip .avatar{width:28px;height:28px;font-size:12px}
 .user-chip .credit-line{font-size:11px}
 .chat>.topbar{min-height:52px;padding:7px 24px;border-bottom:1px solid var(--line-soft)}
 .chat .topbar-title{text-align:left;font-size:14px}
 .chat .topbar-title button{text-align:left;max-width:min(460px,100%)}
 .chat-mode-bar{padding:7px 20px;min-height:42px;background:var(--bg);border-bottom:1px solid var(--line-soft)}
 .chat-mode-bar .btn{min-height:28px;padding:4px 10px;font-size:12px}
 .thread-inner{width:100%;max-width:880px;padding:28px 36px 48px;gap:24px}
 .msg.user .bubble{max-width:85%;padding:12px 18px;font-size:15px}
 .prose{font-size:15px;line-height:1.8}
 .composer-wrap{padding:8px 28px 16px}
 .composer,.composer-hint{max-width:840px}
 .composer{border-radius:18px;border:1px solid var(--line);background:var(--surface);box-shadow:0 4px 16px #00000005}
 .composer textarea{padding:14px 18px 6px;min-height:52px;font-size:15px}
 .composer-bar{padding:6px 12px 10px;gap:6px}
 .pill-btn{height:30px;font-size:12px;background:transparent;border-color:transparent;padding:0 9px}
 .send-btn{width:32px;height:32px}
 .composer-hint{font-size:11px;color:var(--ink-3)}
 .activity-trace{border:1px solid var(--line-soft);border-radius:14px;overflow:hidden;background:transparent}
 .activity-trace summary{padding:12px 16px;font-size:13px}
 .activity-trace li{margin:0;padding:10px 16px;border:0;border-top:1px solid var(--line-soft);font-size:13px}
 .menu{min-width:260px;border-radius:16px;padding:8px;box-shadow:0 12px 36px #00000020,0 0 0 1px var(--line);background:var(--surface)}
 .menu>button{padding:10px 12px;font-size:14px;gap:12px;border-radius:8px}
 .menu-note{overflow-wrap:anywhere;padding:10px 12px;font-size:12px}
 .welcome h1{font-size:38px}
}
@media(min-width:901px) and (max-width:1150px){:root{--sidebar-w:238px}.thread-inner{padding-left:24px;padding-right:24px}.composer-wrap{padding-left:18px;padding-right:18px}}