.chat-layout{display:grid;grid-template-columns:240px minmax(0,1fr);gap:24px;align-items:start}
.chat-layout>.chat-view-container{min-width:0}
.chat-history-panel{min-width:0;height:calc(100vh - 200px);min-height:560px;max-height:1000px;border:1px solid var(--border-hairline);border-radius:20px;background:var(--bg-subtle);overflow:auto;padding:12px}
.chat-history-panel:not([open]){height:auto;min-height:0}
.chat-history-panel>summary{min-height:44px;cursor:pointer;padding:8px 6px;font-weight:600}
.history-count{font-size:13px;font-weight:400;color:var(--color-text-muted);margin-left:8px}
.history-tools{margin:10px 0 14px}
.history-tools .form-input{font-size:14px;padding:10px;min-width:0}
.history-list{display:flex;flex-direction:column;gap:6px;min-width:0}
.history-item{display:flex;flex-direction:column;gap:5px;width:100%;min-width:0;min-height:64px;padding:12px;text-align:left;font:inherit;line-height:1.5;color:var(--color-text);background:transparent;border:1px solid transparent;border-radius:12px;cursor:pointer}
.history-item:hover{background:var(--bg-hover)}
.history-item.active{background:#fff;border-color:var(--border-strong)}
.history-item-title{font-size:15px;overflow-wrap:anywhere;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.history-item-meta{font-size:12px;color:var(--color-text-muted);overflow-wrap:anywhere}
.history-empty,.history-error{padding:16px 8px;font-size:14px;line-height:1.7;color:var(--color-text-secondary)}
.history-error{color:var(--color-error)}
.chat-session-bar{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px;min-width:0}
.chat-session-bar h3{font-size:19px;font-weight:600;overflow-wrap:anywhere;min-width:0;flex:1 1 140px}
.chat-session-actions{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.chat-session-actions .btn{padding:7px 12px}
.chat-session-status{font-size:13px;color:var(--color-text-secondary);margin-top:10px;line-height:1.6}
.chat-session-status:empty{display:none}
#chat-load-older{margin-top:12px}
#chat-history-more{margin:12px 0;width:100%}
.chat-turn-pending{padding:12px 18px;background:var(--bg-subtle);border-radius:12px;color:var(--color-text-secondary);font-size:14px;align-self:flex-start}
.chat-turn-error{padding:14px 18px;border:1px solid var(--color-error-border);background:var(--color-error-bg);border-radius:12px;font-size:14px;line-height:1.7}
.chat-turn-error .btn{margin-top:10px}
.chat-manage-dialog{margin:auto;width:calc(100vw - 32px);max-width:480px;max-height:90dvh;overflow:auto;border:1px solid var(--border-hairline);border-radius:20px;padding:24px;background:#fff;color:var(--color-text);font-family:var(--font-sans)}
.chat-manage-dialog::backdrop{background:rgba(41,41,41,.35)}
.chat-manage-form h2{font-size:22px;margin:0 0 20px}
.chat-manage-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:24px}
#chat-manage-error:empty{display:none}
#chat-delete-message{font-size:16px;line-height:1.8}
@media(max-width:1100px){.chat-layout{grid-template-columns:205px minmax(0,1fr);gap:16px}}
@media(max-width:900px){
 .chat-layout{grid-template-columns:minmax(0,1fr);gap:16px}
 .chat-history-panel{height:auto;min-height:0;max-height:none;border-radius:16px}
 .history-list{max-height:240px;overflow:auto}
 .history-tools .form-input{font-size:16px}
 .chat-layout>.chat-view-container{height:calc(100dvh - 270px);min-height:540px}
 .chat-session-bar{align-items:flex-start}
 .chat-session-bar h3{flex-basis:100%}
 .chat-session-actions{width:100%;gap:6px}
 .chat-session-actions .btn{font-size:13px;padding:6px 10px}
 .chat-manage-dialog{padding:20px}
 .chat-layout .assistant-bubble{padding:16px}
}
@media(prefers-reduced-motion:reduce){.history-item{transition:none}}