:root{color-scheme:light;font-family:Segoe UI,Helvetica Neue,sans-serif;background:radial-gradient(circle at top left,rgba(255,216,168,.8),transparent 28%),radial-gradient(circle at bottom right,rgba(107,188,255,.5),transparent 30%),#f7f3eb;color:#18222e}*{box-sizing:border-box}body{margin:0;min-height:100vh}button,input,textarea{font:inherit}.auth-shell,.chat-shell{min-height:100vh}.auth-shell{display:grid;place-items:center;padding:32px}.auth-card,.sidebar,.chat-panel{-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);background:#ffffffb3;border:1px solid rgba(24,34,46,.08);box-shadow:0 20px 60px #18222e1f}.auth-card{width:min(100%,540px);padding:32px;border-radius:28px}.eyebrow{margin:0 0 8px;text-transform:uppercase;letter-spacing:.16em;font-size:.78rem;color:#58687a}.supporting-text{color:#58687a;line-height:1.6}.mode-switch,.auth-form,.contact-list,.conversation-list,.message-list,.composer{display:grid;gap:12px}.mode-switch{grid-template-columns:repeat(2,1fr);margin:24px 0}.mode-switch button,.ghost-button,.contact-card,.conversation-card,.primary-button{border:0;border-radius:16px;cursor:pointer}.mode-switch button,.ghost-button{background:#18222e0f;padding:12px 16px}.mode-switch .active,.primary-button{background:linear-gradient(135deg,#0e8f78,#2768d8);color:#fff}.auth-form label{display:grid;gap:8px}.auth-form input,.search-input,.composer textarea{width:100%;border-radius:16px;border:1px solid rgba(24,34,46,.12);background:#ffffffe6;padding:14px 16px}.composer textarea{min-height:110px;resize:vertical}.primary-button{padding:14px 18px;font-weight:600}.error-box{color:#8c1f1f;background:#f05e5e1f;border-radius:16px;padding:12px 14px}.chat-shell{display:grid;grid-template-columns:340px 1fr;gap:20px;padding:20px}.sidebar,.chat-panel{border-radius:28px;padding:20px}.panel-header{display:flex;justify-content:space-between;align-items:start;gap:12px;margin-bottom:18px}.contact-card,.conversation-card{display:grid;text-align:left;gap:4px;padding:14px;background:#ffffffc7}.conversation-card.active{outline:2px solid rgba(39,104,216,.28)}.chat-panel{display:grid;grid-template-rows:auto 1fr auto}.message-list{align-content:start;overflow:auto;padding:12px 0}.message-bubble{max-width:72%;padding:14px;border-radius:20px}.message-bubble p{margin:0 0 8px}.message-bubble.incoming{background:#fffffff2}.message-bubble.outgoing{background:linear-gradient(135deg,#0e8f78,#2768d8);color:#fff;margin-left:auto}@media(max-width:900px){.chat-shell{grid-template-columns:1fr}}