:root{
  --bg:#f5f7fb;
  --surface:#fff;
  --surface-2:#f8fafc;
  --text:#142033;
  --muted:#667085;
  --border:#e4e8ef;
  --accent:#111827;
  --accent-2:#1d2939;
  --danger:#b42318;
  --danger-soft:#fef3f2;
  --danger-border:#fecdca;
  --shadow:0 12px 38px rgba(15,23,42,.08);
}

html[data-theme="dark"]{
  --bg:#0b1220;
  --surface:#111827;
  --surface-2:#182230;
  --text:#f8fafc;
  --muted:#aab4c3;
  --border:#344054;
  --accent:#f8fafc;
  --accent-2:#d0d5dd;
  --shadow:0 12px 38px rgba(0,0,0,.24);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--bg)}
body{margin:0;font-family:Tahoma,Arial,sans-serif;background:var(--bg);color:var(--text)}
button,textarea,a,select,input{font:inherit}
button{color:inherit}
html[data-text-size="large"] body{font-size:18px}

.app-shell{min-height:100dvh;display:grid;grid-template-columns:280px minmax(0,1fr)}
.sidebar{background:#101828;color:#fff;padding:18px 14px;display:flex;flex-direction:column;min-height:100dvh;position:sticky;top:0;height:100dvh}
.brand-row{display:flex;align-items:center;justify-content:space-between;padding:4px 6px 14px}
.brand{color:#fff;text-decoration:none;font-size:21px;font-weight:800}
.new-chat{border:1px solid #344054;background:#1d2939;color:#fff;border-radius:12px;padding:12px 14px;cursor:pointer;text-align:right}
.new-chat:disabled{opacity:.48;cursor:not-allowed}
.conversation-list{margin-top:14px;overflow:auto;display:flex;flex-direction:column;gap:6px;min-height:0}
.conversation-entry{display:grid;grid-template-columns:minmax(0,1fr) 34px;align-items:center;border-radius:10px}
.conversation-entry:hover,.conversation-entry.active{background:#1d2939}
.conversation-item{width:100%;border:0;background:transparent;color:#d0d5dd;text-align:right;padding:10px 11px;border-radius:10px;cursor:pointer;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.conversation-entry.active .conversation-item{color:#fff}
.conversation-delete{width:30px;height:30px;border:0;background:transparent;color:#98a2b3;border-radius:8px;cursor:pointer;font-size:20px;line-height:1}
.conversation-delete:hover{background:#344054;color:#fff}
.sidebar-foot{margin-top:auto;padding:14px 4px 2px;display:grid;grid-template-columns:1fr 1fr;gap:8px}
.sidebar-foot-action{min-height:40px;border:1px solid #344054;background:#1d2939;color:#d0d5dd;border-radius:10px;padding:9px 10px;text-decoration:none;font-size:13px;display:flex;align-items:center;justify-content:center;cursor:pointer;text-align:center}
.sidebar-foot-action:hover{background:#344054;color:#fff}

.workspace{min-width:0;display:grid;grid-template-rows:auto auto minmax(0,1fr) auto;height:100dvh;min-height:0}
.topbar{height:76px;background:color-mix(in srgb,var(--surface) 94%,transparent);backdrop-filter:blur(12px);border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:0 24px;position:sticky;top:0;z-index:5}
.topbar-start{display:flex;align-items:center;gap:10px;min-width:0}
.topbar h1{font-size:19px;margin:0}
.topbar p{margin:4px 0 0;color:var(--muted);font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:min(58vw,520px)}
.upgrade-link{border:0;background:#101828;color:#fff;padding:9px 14px;border-radius:10px;font-size:14px;cursor:pointer}
html[data-theme="dark"] .upgrade-link{background:#f8fafc;color:#101828}

.feature-strip{display:flex;gap:8px;overflow:auto;padding:12px 20px;background:var(--surface);border-bottom:1px solid var(--border);scrollbar-width:none}
.feature-pill{white-space:nowrap;border:1px solid var(--border);background:var(--surface);color:var(--text);padding:8px 12px;border-radius:999px;cursor:pointer}
.feature-pill.active{background:#111827;color:#fff;border-color:#111827}
html[data-theme="dark"] .feature-pill.active{background:#f8fafc;color:#101828;border-color:#f8fafc}
.feature-pill.locked{opacity:.48;cursor:not-allowed}
.feature-pill.locked::after{content:' 🔒';font-size:11px}

.messages{min-height:0;padding:28px max(20px,calc((100% - 860px)/2));overflow:auto;overscroll-behavior:contain}
.welcome-card{text-align:center;max-width:760px;margin:clamp(28px,8vh,86px) auto 0}
.orb{width:64px;height:64px;border-radius:20px;margin:0 auto 18px;background:linear-gradient(145deg,#101828,#475467);display:grid;place-items:center;color:#fff;font-weight:800;box-shadow:var(--shadow)}
.welcome-card h2{font-size:29px;margin:0 0 10px}
.welcome-card>p{color:var(--muted);line-height:1.8;margin:0 auto 22px;max-width:650px}
.prompt-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.prompt-card{background:var(--surface);border:1px solid var(--border);padding:14px;border-radius:14px;text-align:right;cursor:pointer;color:var(--text)}
.hide-prompts .prompt-grid{display:none}

.message-row{display:flex;margin:0 0 18px}
.message-row.user{justify-content:flex-start}
.message-row.assistant{justify-content:flex-end}
.message-bubble{max-width:min(780px,88%);border-radius:17px;padding:13px 15px;line-height:1.8;white-space:pre-wrap;overflow-wrap:anywhere}
.user .message-bubble{background:#111827;color:#fff;border-bottom-right-radius:6px}
html[data-theme="dark"] .user .message-bubble{background:#344054}
.assistant .message-bubble{background:var(--surface);border:1px solid var(--border);box-shadow:0 5px 18px rgba(15,23,42,.04);border-bottom-left-radius:6px}
.message-row.failed .message-bubble{opacity:.58;outline:1px solid #f97066}
.typing{opacity:.7}

.composer-wrap{padding:12px max(18px,calc((100% - 860px)/2)) max(14px,env(safe-area-inset-bottom));background:linear-gradient(to top,var(--bg) 72%,color-mix(in srgb,var(--bg) 20%,transparent))}
.composer{display:flex;align-items:flex-end;gap:10px;background:var(--surface);border:1px solid #cfd5df;border-radius:18px;padding:10px 12px;box-shadow:var(--shadow)}
html[data-theme="dark"] .composer{border-color:var(--border)}
.composer textarea{border:0;outline:0;resize:none;flex:1;min-height:28px;max-height:180px;line-height:1.7;background:transparent;color:var(--text)}
.composer textarea::placeholder{color:#98a2b3}
.send-btn{width:42px;height:42px;border-radius:12px;border:0;background:#111827;color:#fff;cursor:pointer;flex:0 0 auto}
html[data-theme="dark"] .send-btn{background:#f8fafc;color:#101828}
.send-btn:disabled{opacity:.5}
.composer-note{font-size:11px;color:#98a2b3;text-align:center;margin:7px 0 0;line-height:1.7}

.icon-btn{border:0;background:transparent;color:inherit;font-size:24px;cursor:pointer}
.mobile-only{display:none}

.error-banner{max-width:780px;margin:0 auto 16px;background:var(--danger-soft);color:var(--danger);border:1px solid var(--danger-border);border-radius:12px;padding:11px 13px}
.error-banner.auth-required{max-width:720px;display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:12px;padding:12px 14px}
.error-banner .error-message{line-height:1.7;min-width:0}
.error-action{display:inline-flex;align-items:center;justify-content:center;min-height:40px;padding:8px 14px;border-radius:10px;background:#b42318;color:#fff;text-decoration:none;font-weight:700;white-space:nowrap;box-shadow:0 4px 12px rgba(180,35,24,.14)}
.error-action:hover{background:#912018}
.error-action:focus-visible{outline:3px solid rgba(180,35,24,.22);outline-offset:2px}

.upgrade-dialog,.settings-dialog{border:0;padding:0;background:transparent;max-width:none;max-height:none}
.upgrade-dialog::backdrop,.settings-dialog::backdrop{background:rgba(15,23,42,.55)}
.upgrade-dialog{width:min(440px,calc(100% - 34px))}
.dialog-body{padding:26px;position:relative;background:var(--surface);color:var(--text);border-radius:18px;box-shadow:0 30px 80px rgba(0,0,0,.22)}
.dialog-close{position:absolute;left:12px;top:10px;border:0;background:transparent;color:var(--text);font-size:25px;cursor:pointer}
.dialog-body p{color:var(--muted);line-height:1.7}
.dialog-action{display:inline-block;border:0;background:#111827;color:#fff;border-radius:10px;padding:10px 14px;margin-top:8px;cursor:pointer}

.settings-dialog{width:min(760px,calc(100% - 28px));height:min(86dvh,820px)}
.settings-shell{height:100%;overflow:auto;background:var(--surface);color:var(--text);border-radius:20px;box-shadow:0 30px 90px rgba(0,0,0,.28)}
.settings-head{position:sticky;top:0;z-index:2;background:color-mix(in srgb,var(--surface) 96%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:18px 20px}
.settings-head h2{margin:0;font-size:22px}
.settings-close{width:38px;height:38px;border:1px solid var(--border);border-radius:10px;background:var(--surface-2);color:var(--text);font-size:22px;cursor:pointer}
.settings-content{padding:18px}
.settings-section{border:1px solid var(--border);background:var(--surface);border-radius:16px;padding:16px;margin-bottom:14px;scroll-margin-top:86px}
.settings-section h3{margin:0 0 12px;font-size:17px}
.settings-muted{margin:0;color:var(--muted);line-height:1.7;font-size:14px}
.settings-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.setting-field{display:grid;gap:6px}
.setting-field label,.setting-toggle span{font-size:14px;color:var(--text)}
.setting-field select{width:100%;min-height:44px;border:1px solid var(--border);border-radius:10px;background:var(--surface-2);color:var(--text);padding:9px 11px}
.setting-toggle{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:46px;border:1px solid var(--border);border-radius:10px;padding:9px 11px;background:var(--surface-2)}
.setting-toggle input{width:20px;height:20px;accent-color:#111827}
.settings-plans-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.settings-plan{border:1px solid var(--border);border-radius:14px;padding:14px;background:var(--surface-2);min-width:0}
.settings-plan.current{border-color:#667085;box-shadow:0 0 0 2px color-mix(in srgb,#667085 18%,transparent)}
.settings-plan-head{display:flex;align-items:center;justify-content:space-between;gap:8px}
.settings-plan h4{margin:0;font-size:17px}
.settings-plan-badge{font-size:11px;color:var(--muted);border:1px solid var(--border);border-radius:999px;padding:4px 7px;white-space:nowrap}
.settings-plan-price{display:block;margin:12px 0 8px;font-size:15px}
.settings-plan p{margin:6px 0;color:var(--muted);font-size:13px;line-height:1.6}
.settings-plan-features{border-top:1px solid var(--border);padding-top:8px}
.settings-actions{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.danger-button{border:1px solid var(--danger-border);background:var(--danger-soft);color:var(--danger);border-radius:10px;padding:10px 14px;cursor:pointer}
#settingsChatStatus{font-size:13px;color:var(--muted)}

@media(max-width:820px){
  .app-shell{display:block;min-height:100dvh}
  .workspace{height:100dvh;min-height:100dvh}
  .sidebar{position:fixed;right:0;top:0;width:min(84vw,320px);z-index:30;transform:translateX(105%);transition:.2s ease;box-shadow:-10px 0 40px rgba(0,0,0,.2)}
  .sidebar.open{transform:translateX(0)}
  .mobile-only{display:inline-grid;place-items:center}
  .topbar{padding:0 14px;height:72px}
  .topbar p{max-width:52vw}
  .messages{padding:20px 14px}
  .composer-wrap{padding:10px 12px max(12px,env(safe-area-inset-bottom))}
  .prompt-grid{grid-template-columns:1fr}
  .welcome-card{margin-top:24px}
  .feature-strip{padding-inline:12px}
  .settings-plans-grid{grid-template-columns:1fr}
  .settings-grid{grid-template-columns:1fr}
}

@media(max-width:520px){
  .error-banner.auth-required{grid-template-columns:1fr;gap:8px}
  .error-action{justify-self:start;width:auto;max-width:100%}
  .settings-dialog{width:calc(100% - 16px);height:min(92dvh,860px)}
  .settings-content{padding:12px}
  .settings-head{padding:14px 16px}
  .sidebar-foot{grid-template-columns:1fr 1fr}
}