:root {
  --bg: #0a0c11;
  --panel: #12151c;
  --panel2: #1a1f29;
  --panel3: #212734;
  --sidebar: #0d0f15;
  --border: #242a37;
  --border-soft: #1c212c;
  --text: #eef1f6;
  --muted: #8b93a3;
  --muted-dim: #626a7a;
  --accent: #6d8dff;
  --accent2: #a26dff;
  --accent-soft: rgba(109, 141, 255, 0.12);
  --user-bubble: linear-gradient(135deg, #2c3a66, #29325c);
  --bot-bubble: #161b25;
  --tool-bg: #0d1017;
  --tool-border: #232a38;
  --ok: #3ddc84;
  --err: #ff6b81;
  --warn: #f0a938;
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --shadow-soft: 0 8px 30px rgba(0,0,0,0.35);
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { height: 100%; overscroll-behavior: none; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  height: 100dvh; display: flex; flex-direction: column; overflow: hidden;
  -webkit-font-smoothing: antialiased;
}
.hidden { display: none !important; }
.muted { color: var(--muted); font-size: 0.85rem; }
.err { color: var(--err); font-size: 0.85rem; margin: 6px 0; }

::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 8px; }
::-webkit-scrollbar-thumb:hover { background: var(--muted-dim); }
* { scrollbar-width: thin; scrollbar-color: var(--border) transparent; }

.icon-btn {
  width: 38px; height: 38px; display: inline-flex; align-items: center; justify-content: center;
  background: var(--panel2); border: 1px solid var(--border); color: var(--muted);
  border-radius: var(--radius-sm); cursor: pointer; font-size: 0.95rem; flex-shrink: 0;
  transition: background .15s, color .15s, border-color .15s, transform .1s;
}
.icon-btn:hover { color: var(--text); border-color: var(--muted-dim); background: var(--panel3); }
.icon-btn:active { transform: scale(0.94); }

/* ---------- Login ---------- */
.login-wrap {
  flex: 1; display: grid; place-items: center; padding: 24px;
  padding-top: calc(24px + var(--safe-top)); padding-bottom: calc(24px + var(--safe-bottom));
  position: relative; overflow: hidden;
}
.login-bg-glow {
  position: absolute; inset: 0; pointer-events: none; z-index: 0;
  background:
    radial-gradient(600px circle at 20% 15%, rgba(109,141,255,0.16), transparent 60%),
    radial-gradient(500px circle at 85% 85%, rgba(162,109,255,0.14), transparent 60%);
}
.login-card {
  position: relative; z-index: 1;
  width: 100%; max-width: 380px; background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 36px 30px; text-align: center; box-shadow: var(--shadow-soft);
}
.login-logo {
  font-size: 36px; color: #fff; margin: 0 auto 14px; width: 64px; height: 64px; border-radius: 18px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  box-shadow: 0 8px 24px rgba(109,141,255,0.35);
}
.login-card h1 { font-size: 1.35rem; margin: 0 0 4px; letter-spacing: -0.02em; }
.login-card label { display: block; text-align: left; font-size: 0.82rem; color: var(--muted); margin-top: 16px; font-weight: 500; }
.login-card input {
  width: 100%; margin-top: 7px; padding: 13px 14px; border: 1px solid var(--border);
  border-radius: var(--radius-sm); background: var(--panel2); color: var(--text); font-size: 1rem;
  transition: border-color .15s, background .15s;
}
.login-card input:focus { outline: none; border-color: var(--accent); background: var(--panel3); }
.login-card button {
  width: 100%; margin-top: 22px; padding: 13px; border: 0; border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--accent), var(--accent2)); color: #fff;
  font-size: 0.98rem; font-weight: 600; cursor: pointer; transition: filter .15s, transform .1s;
  min-height: 48px;
}
.login-card button:hover { filter: brightness(1.08); }
.login-card button:active { transform: scale(0.98); }
.login-card button:disabled { opacity: 0.5; cursor: default; }

/* ---------- App shell ---------- */
.app { flex: 1; display: flex; min-height: 0; position: relative; }

.sidebar-overlay {
  display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.55);
  z-index: 15; backdrop-filter: blur(2px);
}
.sidebar-overlay.show { display: block; }

.sidebar {
  width: 272px; flex-shrink: 0; background: var(--sidebar); border-right: 1px solid var(--border-soft);
  display: flex; flex-direction: column; padding: 14px;
  padding-top: calc(14px + var(--safe-top)); padding-left: calc(14px + var(--safe-left));
}
.sidebar-top { display: none; align-items: center; justify-content: space-between; margin-bottom: 14px; }
.sidebar-brand { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 1.05rem; }
.sidebar-brand-icon {
  width: 30px; height: 30px; border-radius: 9px; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, var(--accent), var(--accent2)); color: #fff; font-size: 0.95rem;
}
.sidebar-close-btn { display: none; }

.new-conv-btn {
  padding: 12px 14px; border: 1px solid var(--border); border-radius: var(--radius-md);
  background: var(--panel2); color: var(--text); cursor: pointer; font-size: 0.9rem; font-weight: 600;
  text-align: left; display: flex; align-items: center; gap: 8px; min-height: 46px;
  transition: background .15s, border-color .15s;
}
.new-conv-btn .plus {
  width: 20px; height: 20px; border-radius: 6px; background: var(--accent-soft); color: var(--accent);
  display: inline-flex; align-items: center; justify-content: center; font-size: 1rem; flex-shrink: 0;
}
.new-conv-btn:hover { border-color: var(--accent); background: var(--panel3); }
.new-conv-btn:active { transform: scale(0.99); }

.model-select-sidebar {
  margin-top: 8px; width: 100%; padding: 9px 10px; border: 1px solid var(--border);
  border-radius: var(--radius-sm); background: var(--panel2); color: var(--muted); font-size: 0.8rem;
  cursor: pointer; min-height: 40px;
}
.model-select-sidebar:focus { outline: none; border-color: var(--accent); }

.conv-list { flex: 1; overflow-y: auto; margin-top: 14px; display: flex; flex-direction: column; gap: 3px; }
.conv-item {
  padding: 10px 12px; border-radius: var(--radius-sm); cursor: pointer; font-size: 0.86rem;
  color: var(--muted); border: 1px solid transparent; transition: background .12s, border-color .12s;
}
.conv-item-title { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: var(--text); font-weight: 500; }
.conv-item-meta {
  display: flex; align-items: center; justify-content: space-between;
  margin-top: 4px; font-size: 0.68rem; color: var(--muted-dim);
}
.conv-badge {
  background: var(--panel3); padding: 2px 7px; border-radius: 6px; white-space: nowrap; font-weight: 500;
}
.conv-item:hover { background: var(--panel2); }
.conv-item.active { background: var(--accent-soft); border-color: rgba(109,141,255,0.3); }
.conv-item.active .conv-item-title { color: var(--accent); }

.sidebar-footer {
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
  padding-top: 12px; border-top: 1px solid var(--border-soft); margin-top: 10px;
  padding-bottom: var(--safe-bottom);
}
.user-chip { display: flex; align-items: center; gap: 8px; min-width: 0; }
.user-avatar {
  width: 28px; height: 28px; border-radius: 50%; background: var(--panel2); flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; font-size: 0.85rem;
}
.user-name { font-size: 0.82rem; color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

.topbar {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 18px; padding-top: calc(12px + var(--safe-top));
  padding-right: calc(18px + var(--safe-right));
  border-bottom: 1px solid var(--border-soft); background: rgba(18,21,28,0.85);
  backdrop-filter: blur(12px); position: sticky; top: 0; z-index: 5;
}
.sidebar-toggle-btn { display: none; }
.hamburger { width: 16px; height: 12px; position: relative; display: block; }
.hamburger span {
  position: absolute; left: 0; width: 100%; height: 2px; background: var(--muted); border-radius: 2px;
  transition: background .15s;
}
.hamburger span:nth-child(1) { top: 0; }
.hamburger span:nth-child(2) { top: 5px; }
.hamburger span:nth-child(3) { top: 10px; }
.icon-btn:hover .hamburger span { background: var(--text); }

.brand { font-weight: 600; display: flex; align-items: center; gap: 8px; min-width: 0; flex: 1; }
.brand .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--ok); flex-shrink: 0; box-shadow: 0 0 8px rgba(61,220,132,0.6); }
.brand .dot.busy { background: var(--warn); animation: pulse 1s infinite; box-shadow: 0 0 8px rgba(240,169,56,0.6); }
.brand .dot.err { background: var(--err); }
#conv-title { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 0.92rem; }
@keyframes pulse { 50% { opacity: 0.35; } }
.topbar-actions { display: flex; gap: 6px; align-items: center; flex-shrink: 0; }
.model-select {
  padding: 8px 10px; border: 1px solid var(--border); border-radius: var(--radius-sm);
  background: var(--panel2); color: var(--text); font-size: 0.8rem; cursor: pointer; min-height: 38px;
  max-width: 150px;
}
.model-select:focus { outline: none; border-color: var(--accent); }
.model-select:disabled { opacity: 0.5; cursor: default; }

.messages {
  flex: 1; overflow-y: auto; padding: 22px 18px; min-height: 0;
  display: flex; flex-direction: column; gap: 16px; scroll-behavior: smooth;
}
.empty-state { margin: auto; text-align: center; color: var(--muted); max-width: 400px; padding: 20px; }
.empty-icon {
  font-size: 2rem; margin: 0 auto 16px; width: 64px; height: 64px; border-radius: 20px;
  display: flex; align-items: center; justify-content: center; color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  box-shadow: 0 8px 24px rgba(109,141,255,0.3);
}
.empty-state h2 { color: var(--text); font-size: 1.1rem; margin: 0 0 8px; }
.empty-state p { line-height: 1.6; font-size: 0.9rem; margin: 0; }

.msg { max-width: 84%; display: flex; align-items: flex-start; gap: 8px; animation: slideIn .2s ease-out; }
@keyframes slideIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }
.msg.user { align-self: flex-end; flex-direction: row-reverse; }
.msg.assistant { align-self: flex-start; }
.avatar {
  width: 26px; height: 26px; border-radius: 50%; font-size: 12px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; margin-top: 2px;
  background: var(--panel2); border: 1px solid var(--border);
}
.msg.assistant .avatar { background: linear-gradient(135deg, var(--accent), var(--accent2)); border: none; color: #fff; }
.bubble-col { display: flex; flex-direction: column; gap: 8px; min-width: 0; }
.bubble {
  padding: 11px 15px; border-radius: var(--radius-md); line-height: 1.55; word-break: break-word; font-size: 0.95rem;
}
.msg.user .bubble { background: var(--user-bubble); border-top-right-radius: 4px; white-space: pre-wrap; }
.msg.assistant .bubble { background: var(--bot-bubble); border: 1px solid var(--border-soft); border-top-left-radius: 4px; }
.bubble p:first-child { margin-top: 0; }
.bubble p:last-child { margin-bottom: 0; }
.bubble pre {
  background: #070910; border: 1px solid var(--border-soft); border-radius: var(--radius-sm); padding: 12px;
  overflow-x: auto; font-size: 0.83rem; position: relative;
}
.bubble code { font-family: "SF Mono", Menlo, Consolas, monospace; }
.bubble :not(pre) > code { background: var(--panel3); padding: 2px 6px; border-radius: 5px; font-size: 0.85em; }
.bubble img { max-width: 100%; border-radius: var(--radius-sm); margin-top: 6px; display: block; }
.copy-btn {
  position: absolute; top: 6px; right: 6px; font-size: 0.7rem; padding: 4px 9px;
  border-radius: 6px; border: 1px solid var(--border); background: var(--panel2);
  color: var(--muted); cursor: pointer; opacity: 0; transition: opacity .15s;
}
.bubble pre:hover .copy-btn, .bubble pre:active .copy-btn { opacity: 1; }
.cursor { display: inline-block; width: 7px; height: 1.05em; background: var(--accent); border-radius: 1px;
  vertical-align: text-bottom; animation: blink 1s steps(2) infinite; margin-left: 2px; }
@keyframes blink { 50% { opacity: 0; } }

/* ---------- tool call card ---------- */
.tool-card {
  background: var(--tool-bg); border: 1px solid var(--tool-border); border-radius: var(--radius-sm);
  font-size: 0.83rem; overflow: hidden;
}
.tool-head {
  display: flex; align-items: center; gap: 8px; padding: 10px 12px; cursor: pointer;
  user-select: none; min-height: 40px;
}
.tool-head:hover { background: rgba(255,255,255,0.025); }
.tool-emoji { font-size: 0.95rem; }
.tool-name { font-weight: 600; color: var(--text); }
.tool-label { color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; flex: 1; min-width: 0; font-size: 0.8rem; }
.tool-status { font-size: 0.68rem; padding: 3px 9px; border-radius: 10px; flex-shrink: 0; font-weight: 500; }
.tool-status.running { background: rgba(240,169,56,0.15); color: var(--warn); }
.tool-status.completed { background: rgba(61,220,132,0.15); color: var(--ok); }
.tool-status.error { background: rgba(255,107,129,0.15); color: var(--err); }
.tool-caret { color: var(--muted); font-size: 0.7rem; transition: transform .15s; flex-shrink: 0; }
.tool-card.open .tool-caret { transform: rotate(90deg); }
.tool-body { display: none; padding: 0 12px 12px; border-top: 1px solid var(--tool-border); }
.tool-card.open .tool-body { display: block; }
.tool-section { margin-top: 10px; }
.tool-section-label { color: var(--muted-dim); font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 5px; font-weight: 600; }
.tool-pre {
  background: #030405; border-radius: var(--radius-sm); padding: 10px 12px; font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.8rem; overflow-x: auto; white-space: pre-wrap; word-break: break-word; max-height: 320px; overflow-y: auto;
}

.composer {
  padding: 12px; padding-bottom: calc(12px + var(--safe-bottom));
  padding-left: calc(12px + var(--safe-left)); padding-right: calc(12px + var(--safe-right));
  border-top: 1px solid var(--border-soft); background: var(--panel);
}
.composer-inner { display: flex; gap: 8px; align-items: flex-end; max-width: 900px; margin: 0 auto; }
.composer textarea {
  flex: 1; resize: none; padding: 13px 14px; border: 1px solid var(--border); border-radius: var(--radius-md);
  background: var(--panel2); color: var(--text); font-size: 1rem; font-family: inherit; line-height: 1.4;
  transition: border-color .15s;
}
.composer textarea:focus { outline: none; border-color: var(--accent); }
.composer textarea:disabled { opacity: 0.5; }
.composer button[type="submit"] {
  width: 46px; height: 46px; border: 0; border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff; font-size: 1.1rem; cursor: pointer; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; transition: filter .15s, transform .1s;
}
.composer button[type="submit"]:hover { filter: brightness(1.08); }
.composer button[type="submit"]:active { transform: scale(0.94); }
.composer button:disabled { opacity: 0.45; cursor: default; }
.stop-btn {
  width: 46px; height: 46px; border: 1px solid var(--err); border-radius: var(--radius-md); background: transparent;
  color: var(--err); cursor: pointer; flex-shrink: 0; display: flex; align-items: center; justify-content: center;
}
.stop-square { width: 13px; height: 13px; background: var(--err); border-radius: 3px; display: block; }

/* =========================================================
   MOBILE
   ========================================================= */
@media (max-width: 860px) {
  .sidebar-toggle-btn { display: inline-flex; }
  .sidebar-top { display: flex; }
  .sidebar-close-btn { display: inline-flex; }

  .sidebar {
    position: fixed; z-index: 20; top: 0; left: 0; bottom: 0; height: 100dvh;
    width: min(300px, 85vw); transform: translateX(-100%); transition: transform .25s cubic-bezier(.2,.8,.2,1);
    box-shadow: 0 0 40px rgba(0,0,0,0.5);
  }
  .sidebar.open { transform: translateX(0); }

  .topbar { padding: 10px 12px; padding-top: calc(10px + var(--safe-top)); gap: 8px; }
  #conv-title { font-size: 0.86rem; }
  .model-select { max-width: 108px; font-size: 0.74rem; padding: 7px 8px; }
  .topbar-actions .icon-btn { width: 36px; height: 36px; font-size: 0.85rem; }

  .messages { padding: 16px 12px; gap: 14px; }
  .msg { max-width: 92%; }
  .bubble { font-size: 0.94rem; padding: 10px 13px; }

  .composer { padding: 10px; padding-bottom: calc(10px + var(--safe-bottom)); }
  .composer textarea { font-size: 16px; padding: 12px 13px; } /* 16px prevents iOS auto-zoom */
  .composer button[type="submit"], .stop-btn { width: 44px; height: 44px; }

  .empty-state h2 { font-size: 1rem; }
  .empty-state p { font-size: 0.85rem; }
}

@media (max-width: 420px) {
  .model-select { display: none; } /* keep topbar uncluttered on very small screens */
}