:root{--green:#00a884;--dark:#111b21;--panel:#f0f2f5}*{box-sizing:border-box}body{margin:0;font-family:Inter,Arial,sans-serif;background:#dfe3e5}.app-shell{height:100vh;max-width:1500px;margin:auto;display:flex;background:#fff;box-shadow:0 0 30px #0002}.sidebar{width:360px;display:flex;flex-direction:column;border-right:1px solid #ddd;background:#fff}.brand{padding:18px;background:var(--dark);color:#fff;font-size:20px;font-weight:700;display:flex;gap:12px;align-items:center}.brand i{font-size:28px;color:#25d366}.sidebar-actions{padding:10px;background:var(--panel)}.contact-list{overflow:auto;flex:1}.contact-item{width:100%;border:0;background:#fff;display:flex;gap:12px;align-items:center;padding:12px;text-align:left;border-bottom:1px solid #eee}.contact-item:hover{background:#f5f6f6}.avatar{width:46px;height:46px;border-radius:50%;background:#cfd8dc;display:grid;place-items:center;font-weight:700}.contact-meta{display:flex;flex-direction:column;flex:1;min-width:0}.contact-meta small{color:#667781}.sidebar-footer{padding:12px;display:flex;justify-content:space-around;border-top:1px solid #ddd}.sidebar-footer a{text-decoration:none;color:#334}.chat-panel{flex:1;min-width:0;background:#efeae2}.empty-state{height:100%;display:grid;place-content:center;text-align:center;color:#667781}.empty-state i{font-size:80px;color:#b6c2c7}.chat-view{height:100%;display:flex;flex-direction:column}.chat-header{height:66px;background:var(--panel);padding:10px 18px;display:flex;justify-content:space-between;align-items:center}.chat-header div{display:flex;flex-direction:column}.messages{flex:1;overflow:auto;padding:24px;background-color:#efeae2;background-image:radial-gradient(#0000000b 1px,transparent 1px);background-size:18px 18px}.bubble-row{display:flex;margin:6px 0}.bubble-row.outbound{justify-content:flex-end}.bubble{max-width:72%;padding:9px 11px;border-radius:8px;background:#fff;box-shadow:0 1px 1px #0002;white-space:pre-wrap}.outbound .bubble{background:#d9fdd3}.bubble small{display:block;text-align:right;color:#667781;font-size:10px;margin-top:5px}.composer{padding:10px;background:var(--panel);display:flex;gap:10px}.composer textarea{flex:1;border:0;border-radius:10px;padding:12px;resize:none;outline:none}.send-btn{border:0;background:var(--green);color:#fff;width:46px;border-radius:50%}.login-page{min-height:100vh;display:grid;place-items:center;background:linear-gradient(135deg,#075e54,#25d366)}.login-card{width:min(420px,92vw);background:#fff;padding:30px;border-radius:16px;box-shadow:0 20px 60px #0004}@media(max-width:750px){.sidebar{width:42%}.brand span{display:none}.contact-meta small{display:none}.bubble{max-width:88%}}