:root{--bg: #ecf0f6;--panel: #f8fafc;--panel-strong: #ffffff;--border: #d3dae6;--text: #142033;--muted: #596779;--accent: #1a8f6d;--accent-soft: #d6f5ea;--mine: #d9e8ff;--radius: 14px;font-family:Segoe UI,SF Pro Text,-apple-system,sans-serif}*{box-sizing:border-box}body{margin:0;color:var(--text);background:radial-gradient(circle at 15% -10%,#f5dccf 0%,transparent 35%),radial-gradient(circle at 90% 0%,#d7ecfa 0%,transparent 30%),var(--bg)}.auth-shell{min-height:100vh;display:grid;place-items:center;padding:1rem}.auth-card{width:min(420px,100%);background:color-mix(in srgb,var(--panel-strong) 92%,white);border:1px solid var(--border);border-radius:var(--radius);padding:1.2rem}.auth-card h1{margin:0 0 .5rem}.auth-card p{margin:0 0 1rem;color:var(--muted)}.auth-form{display:grid;gap:.8rem}.auth-form label{display:grid;gap:.35rem;font-size:.9rem}.auth-form input{border:1px solid var(--border);border-radius:10px;padding:.7rem}.auth-form button{border:0;border-radius:10px;padding:.75rem 1rem;background:var(--accent);color:#fff;font-weight:600}.auth-error{margin:0;color:#b63b38;font-size:.9rem}.layout{min-height:100vh;display:grid;grid-template-columns:minmax(260px,320px) 1fr;gap:0}.sidebar{display:grid;grid-template-rows:auto 1fr;border-right:1px solid var(--border);background:color-mix(in srgb,var(--panel) 85%,white)}.sidebar-header{display:flex;align-items:center;justify-content:space-between;padding:1rem;border-bottom:1px solid var(--border)}.sidebar-header h1{margin:0;font-size:1.2rem}.welcome{margin:.2rem 0 0;font-size:.8rem;color:var(--muted)}.muted{opacity:.8}.header-actions{display:flex;gap:.4rem}.ghost{border:1px solid var(--border);border-radius:10px;background:var(--panel-strong);padding:.45rem .7rem;color:var(--muted)}.sidebar-section{padding:1rem;overflow:auto}.label{margin:0 0 .75rem;font-size:.75rem;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}.thread-list{list-style:none;margin:0;padding:0;display:grid;gap:.5rem}.thread{display:flex;justify-content:space-between;align-items:center;padding:.75rem;border-radius:10px;border:1px solid transparent;background:var(--panel-strong);cursor:pointer}.thread.active{border-color:var(--accent);background:var(--accent-soft)}.badge{min-width:1.4rem;text-align:center;border-radius:999px;background:var(--accent);color:#fff;font-size:.75rem;padding:.1rem .35rem}.chat-panel{display:grid;grid-template-rows:auto 1fr auto;min-width:0}.chat-header{padding:1rem 1.2rem;border-bottom:1px solid var(--border);background:color-mix(in srgb,var(--panel-strong) 90%,white)}.chat-header h2{margin:0;font-size:1.1rem}.chat-header p{margin:.3rem 0 0;color:var(--muted);font-size:.9rem}.message-feed{overflow:auto;padding:1rem 1rem 0;display:grid;align-content:start;gap:.75rem}.load-older{justify-self:center;border:1px solid var(--border);border-radius:10px;background:var(--panel-strong);color:var(--muted);padding:.45rem .75rem}.message{width:min(72ch,88%);background:var(--panel-strong);border:1px solid var(--border);border-radius:var(--radius);padding:.75rem .9rem}.message.mine{margin-left:auto;background:var(--mine)}.author{margin:0;font-size:.8rem;color:var(--muted)}.message-top{display:flex;align-items:center;justify-content:space-between;gap:.75rem}.message-delete{border:0;background:transparent;color:#b63b38;font-size:.8rem;cursor:pointer}.body{margin:.35rem 0 0}.meta{display:block;margin-top:.4rem;font-size:.75rem;color:var(--muted)}.composer{display:grid;grid-template-columns:1fr auto;gap:.75rem;padding:1rem;border-top:1px solid var(--border);background:color-mix(in srgb,var(--panel-strong) 90%,white)}.composer input{width:100%;border:1px solid var(--border);border-radius:10px;padding:.75rem;background:#fff}.composer button{border:0;border-radius:10px;padding:.75rem 1rem;background:var(--accent);color:#fff;font-weight:600}.placeholder{margin:.25rem 0 .6rem;color:var(--muted)}.global-error{margin:0;padding:.65rem 1rem .9rem;color:#b63b38;font-size:.9rem}.pref-overlay{position:fixed;inset:0;background:#0b0f186b;display:grid;place-items:center;padding:1rem}.pref-card{width:min(460px,100%);background:var(--panel-strong);border:1px solid var(--border);border-radius:var(--radius);padding:1rem;display:grid;gap:.7rem}.pref-card h3{margin:0 0 .2rem}.pref-card label{display:grid;gap:.35rem;font-size:.9rem}.pref-card input,.pref-card select{border:1px solid var(--border);border-radius:10px;padding:.6rem}.pref-hint{color:var(--muted);font-size:.8rem}.pref-actions{display:flex;justify-content:flex-end;gap:.5rem}@media(max-width:900px){.layout{grid-template-columns:1fr;grid-template-rows:auto 1fr}.sidebar{border-right:0;border-bottom:1px solid var(--border);max-height:40vh}.message{width:100%}}