:root{ --bg:#f7f8fb; --card:#fff; --text:#111; --muted:#6b7280; --pri:#2563eb; --pri2:#1e40af; --line:#e5e7eb; }
*{box-sizing:border-box} html,body{margin:0;padding:0;font-family:system-ui,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--text)}
a{color:var(--pri);text-decoration:none}
.container{max-width:980px;margin:20px auto;padding:0 14px}
.site-header{display:flex;align-items:center;gap:12px;justify-content:space-between;padding:12px 14px;background:#fff;border-bottom:1px solid var(--line)}
.brand{font-weight:800;font-size:20px;color:#111} .brand span{color:#ef4444}
nav a{margin-left:12px}
.btn,.btn-out{background:var(--pri);color:#fff;padding:8px 12px;border-radius:10px}
.btn:hover{background:var(--pri2)} .btn-out{background:#ef4444}
.badge{background:#ef4444;color:#fff;border-radius:999px;padding:2px 6px;font-size:12px;margin-left:6px}
.search input{border:1px solid var(--line);padding:6px 10px;border-radius:10px}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:16px;margin:12px 0;box-shadow:0 2px 6px rgba(0,0,0,.04)}
.alert{background:#fff3cd;border:1px solid #ffe49e;padding:8px;border-radius:10px;margin:8px 0}
.grid{display:grid;grid-template-columns:1fr 2fr;gap:12px}
@media(max-width:800px){.grid{grid-template-columns:1fr}}
label{display:block;margin:10px 0} input[type=text],input[type=password],input[type=email]{width:100%;padding:10px;border:1px solid var(--line);border-radius:10px}
.list{list-style:none;padding:0;margin:0} .list li{padding:8px 0;border-bottom:1px solid var(--line)}
.room{display:block;padding:8px;border-radius:10px}
.room:hover{background:#f1f5f9}
.hero{text-align:center;padding:40px 0}
.muted{color:var(--muted);font-size:13px}
.pf{display:flex;gap:16px;align-items:center}
.avatar{width:64px;height:64px;border-radius:50%;object-fit:cover;border:2px solid var(--line)}
.chatbox{height:380px;overflow:auto;border:1px solid var(--line);border-radius:14px;padding:10px;background:#fff}
.chat-input{display:flex;gap:8px;margin-top:8px;align-items:center}
.chat-input input[type=file]{border:none}
.msg{padding:8px 6px;border-bottom:1px dashed var(--line)}
.msg .time{color:var(--muted);font-size:12px;margin-left:6px}
.emoji{font-size:20px;margin-right:6px}
.img-msg{max-width:220px;border-radius:8px;border:1px solid var(--line)}