:root{
	--bg:#eef1f6;--panel:#ffffff;--panel2:#fafbfd;--text:#1c2530;--muted:#5b6b82;
	--blue:#2454d1;--blue-strong:#173a99;--blue-soft:#eef3fd;
	--border:#dde3ec;--red:#c53030;
	--shadow:0 10px 28px #1c25301a;
}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--text);font-family:"IBM Plex Sans",Segoe UI,sans-serif}
button{font:inherit;cursor:pointer}
input{font:inherit}
img{max-width:100%}
[hidden]{display:none!important}

/* ---------- Auth screen ---------- */
.auth-screen{min-height:100dvh;display:grid;place-items:center;padding:20px;background:radial-gradient(circle at 20% 0,#dbe6fb 0,var(--bg) 45%)}
.auth-card{width:min(420px,100%);background:var(--panel);border:1px solid var(--border);border-radius:20px;padding:28px;box-shadow:var(--shadow)}
.brand{display:flex;align-items:center;gap:10px;margin-bottom:18px}
.brand-logo{width:40px;height:40px;border-radius:10px}
.brand strong{font-size:1.15rem;letter-spacing:-.01em}
.auth-tabs{display:flex;gap:6px;background:var(--panel2);border:1px solid var(--border);border-radius:12px;padding:4px;margin-bottom:18px}
.auth-tab{flex:1;padding:9px;border:0;border-radius:9px;background:transparent;color:var(--muted);font-weight:700}
.auth-tab.active{background:var(--blue);color:#fff}
form{display:grid;gap:12px}
label{display:grid;gap:6px;font-size:.85rem;font-weight:700;color:var(--text)}
input{padding:11px 12px;border:1px solid var(--border);border-radius:10px;background:var(--panel2);color:var(--text)}
input:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px #2454d11f}
.primary{background:linear-gradient(135deg,#5b8def,var(--blue-strong));color:#fff;border:0;border-radius:10px;padding:11px 16px;font-weight:700;box-shadow:0 8px 20px #2454d13a}
.primary:hover{filter:brightness(1.06)}
.secondary{background:var(--panel);border:1px solid var(--border);border-radius:10px;padding:9px 14px;font-weight:700;color:var(--text)}
.secondary:hover{border-color:var(--blue);color:var(--blue)}
.error{color:var(--red);font-size:.82rem;min-height:1em;margin:0}

/* ---------- App shell ---------- */
.app-shell{display:grid;grid-template-columns:320px 1fr;height:100dvh}
.icon-button{width:38px;height:38px;border-radius:10px;border:1px solid var(--border);background:var(--panel);display:grid;place-items:center;font-size:1rem}
.icon-button:hover{border-color:var(--blue);color:var(--blue)}

.conversations-panel{border-right:1px solid var(--border);background:var(--panel);display:flex;flex-direction:column;min-height:0}
.conversations-head{display:flex;align-items:center;justify-content:space-between;padding:16px;border-bottom:1px solid var(--border)}
.new-chat-row{display:flex;gap:8px;padding:12px 16px}
.new-chat-row .secondary{flex:1;font-size:.82rem}
.conversation-list{flex:1;overflow-y:auto;padding:6px 8px}
.empty-hint{color:var(--muted);font-size:.85rem;padding:16px;text-align:center}
.conversation-item{display:flex;align-items:center;gap:10px;width:100%;padding:10px;border:0;border-radius:12px;background:transparent;text-align:left}
.conversation-item:hover{background:var(--panel2)}
.conversation-item.active{background:var(--blue-soft)}
.conversation-avatar{width:40px;height:40px;border-radius:50%;background:linear-gradient(135deg,#5b8def,var(--blue-strong));color:#fff;display:grid;place-items:center;font-weight:800;flex:none}
.conversation-info{display:grid;gap:2px;min-width:0}
.conversation-info strong{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.conversation-info small{color:var(--muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.chat-panel{display:flex;flex-direction:column;min-height:0;min-width:0}
.chat-empty{flex:1;display:grid;place-items:center;gap:14px;color:var(--muted);text-align:center;padding:20px}
.chat-empty-logo{width:64px;height:64px;border-radius:16px;opacity:.5}
.chat-active{display:flex;flex-direction:column;min-height:0;height:100%}
.chat-head{display:flex;align-items:center;gap:10px;padding:14px 18px;border-bottom:1px solid var(--border);background:var(--panel)}
.back-button{display:none}
.messages{flex:1;overflow-y:auto;padding:18px;display:flex;flex-direction:column;gap:10px;background:var(--bg)}
.message-bubble{max-width:min(72%,480px);background:var(--panel);border:1px solid var(--border);border-radius:14px 14px 14px 4px;padding:9px 12px;align-self:flex-start}
.message-bubble.mine{align-self:flex-end;background:linear-gradient(135deg,#5b8def,var(--blue-strong));color:#fff;border-color:transparent;border-radius:14px 14px 4px 14px}
.message-bubble p{margin:2px 0 4px;white-space:pre-wrap;word-break:break-word}
.message-sender{display:block;font-weight:800;color:var(--blue);margin-bottom:2px}
.message-time{display:block;font-size:.68rem;opacity:.7;text-align:right}
.message-image{border-radius:10px;margin-bottom:6px;display:block;max-width:min(100%,320px);max-height:320px;width:auto;height:auto;object-fit:cover;cursor:zoom-in}
.message-form{display:flex;align-items:center;gap:8px;padding:12px 14px;border-top:1px solid var(--border);background:var(--panel)}
.message-form input[type=text]{flex:1;border-radius:999px}
.attach-button{display:grid;place-items:center;width:38px;height:38px;border-radius:50%;background:var(--panel2);border:1px solid var(--border);cursor:pointer;font-size:1.1rem}
.message-form .primary{border-radius:999px}

/* ---------- Dialogs ---------- */
.dialog{border:0;border-radius:16px;padding:0;box-shadow:var(--shadow);width:min(420px,calc(100% - 32px))}
.dialog::backdrop{background:#0f172acc}
.dialog form{padding:22px}
.dialog h3{margin:0 0 14px}
.dialog-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:6px}

/* ---------- Mobile ---------- */
@media(max-width:780px){
	.app-shell{grid-template-columns:1fr;position:relative;overflow:hidden}
	.conversations-panel{position:absolute;inset:0;z-index:1}
	.chat-panel{position:absolute;inset:0;z-index:0;transform:translateX(100%);transition:transform .2s ease}
	body.chat-open .chat-panel{transform:translateX(0);z-index:2}
	body.chat-open .conversations-panel{visibility:hidden}
	.back-button{display:grid}
	.message-bubble{max-width:84%}
}
.send-error{padding:0 12px}
.unread-badge{margin-left:auto;min-width:22px;height:22px;padding:0 6px;border-radius:11px;background:var(--blue-strong);color:#fff;font-size:.75rem;font-weight:700;display:inline-flex;align-items:center;justify-content:center;flex:none}