:root {
  --bg: #000;
  --bg-elev: #0a140a;
  --bg-card: #061206;
  --fg: #4ade80;
  --fg-bright: #86efac;
  --fg-dim: #2a5a2a;
  --fg-mute: #d4f4d4;
  --border: #1a3a1a;
  --border-bright: #2d6b2d;
  --err: #ff5555;
  --glow: 0 0 12px rgba(74, 222, 128, 0.35);
  --glow-soft: 0 0 8px rgba(74, 222, 128, 0.18);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.6), 0 0 0 1px var(--border);
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 20px;
  --radius-pill: 999px;
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  font-family: 'SF Mono', 'JetBrains Mono', 'Fira Code', Menlo, Consolas, monospace;
  font-size: 14px;
  line-height: 1.55;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; height: 100%; background: var(--bg); color: var(--fg-mute); }

/* subtle scanline + radial glow on page bg */
body::before {
  content: ""; position: fixed; inset: 0; pointer-events: none; z-index: 0;
  background:
    radial-gradient(ellipse at 20% 0%, rgba(74, 222, 128, 0.07), transparent 50%),
    radial-gradient(ellipse at 80% 100%, rgba(74, 222, 128, 0.04), transparent 50%);
}

button, input, textarea {
  font: inherit; color: inherit;
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease), background 0.15s var(--ease), transform 0.1s var(--ease);
}
button { cursor: pointer; color: var(--fg); }
button:hover:not(:disabled) { background: var(--bg-elev); border-color: var(--border-bright); box-shadow: var(--glow-soft); }
button:active:not(:disabled) { transform: scale(0.97); }
button:disabled { opacity: 0.4; cursor: not-allowed; }
input:focus, textarea:focus { outline: none; border-color: var(--fg); box-shadow: var(--glow-soft); background: var(--bg-elev); }

/* ===== login ===== */
#login {
  position: relative; z-index: 1;
  display: flex; align-items: center; justify-content: center;
  min-height: 100vh; padding: 20px;
}
.login-box {
  width: 100%; max-width: 380px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  box-shadow: var(--shadow-card), 0 0 60px rgba(74, 222, 128, 0.08);
  animation: fadeUp 0.45s var(--ease);
}
@keyframes fadeUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.login-box h1 { color: var(--fg); margin: 0 0 6px; font-size: 18px; letter-spacing: 0.1em; }
.login-box .hint { color: var(--fg-dim); margin: 0 0 24px; font-size: 12px; }
.login-box .hint.small { font-size: 11px; margin-top: 18px; line-height: 1.5; }
.login-box form { display: flex; flex-direction: column; gap: 14px; }
.login-box label { display: flex; flex-direction: column; gap: 6px; font-size: 11px; color: var(--fg-dim); letter-spacing: 0.05em; text-transform: uppercase; }
.login-box input { padding: 10px 14px; border-radius: var(--radius-sm); }
.login-box button[type=submit] {
  background: var(--fg); color: var(--bg);
  border-color: var(--fg); margin-top: 6px;
  padding: 11px; font-weight: 600;
  border-radius: var(--radius-sm);
}
.login-box button[type=submit]:hover {
  background: var(--fg-bright); border-color: var(--fg-bright);
  box-shadow: var(--glow);
}
.err { color: var(--err); font-size: 12px; margin: 0; }

/* ===== app shell ===== */
#app {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 260px 1fr;
  height: 100vh;
  gap: 12px; padding: 12px;
}

/* sidebar */
#sidebar {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex; flex-direction: column; padding: 14px; gap: 10px;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}
.brand { color: var(--fg-dim); font-size: 11px; letter-spacing: 0.12em; margin-bottom: 4px; }
#new-chat {
  border-style: dashed; color: var(--fg);
  padding: 10px 12px; text-align: left;
  border-radius: var(--radius-sm);
  background: transparent;
}
#new-chat:hover { background: var(--bg-elev); }
#chat-list { list-style: none; padding: 0; margin: 0; overflow-y: auto; flex: 1; display: flex; flex-direction: column; gap: 4px; }
#chat-list li {
  padding: 9px 12px; border-radius: var(--radius-sm); cursor: pointer; color: var(--fg-mute);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 13px;
  display: flex; justify-content: space-between; align-items: center; gap: 6px;
  border: 1px solid transparent;
  transition: background 0.12s var(--ease), border-color 0.12s var(--ease);
}
#chat-list li:hover { background: var(--bg-elev); }
#chat-list li.active {
  background: rgba(74, 222, 128, 0.10);
  color: var(--fg-bright);
  border-color: rgba(74, 222, 128, 0.25);
  box-shadow: var(--glow-soft);
}
#chat-list li .del { opacity: 0; font-size: 11px; color: var(--err); cursor: pointer; transition: opacity 0.12s; }
#chat-list li:hover .del { opacity: 0.7; }
#chat-list li:hover .del:hover { opacity: 1; }
#sidebar .footer {
  margin-top: auto; padding-top: 10px; border-top: 1px solid var(--border);
  display: flex; justify-content: space-between; align-items: center;
  font-size: 11px; color: var(--fg-dim);
}
#sidebar .footer #who { padding: 4px 10px; background: var(--bg-elev); border-radius: var(--radius-pill); }
#sidebar .footer button { padding: 4px 10px; font-size: 13px; border-radius: var(--radius-pill); }

/* main */
#main {
  display: flex; flex-direction: column; min-width: 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}
#main header {
  padding: 12px 18px; border-bottom: 1px solid var(--border);
  display: flex; justify-content: space-between; align-items: center;
  font-size: 12px; color: var(--fg);
  background: linear-gradient(180deg, var(--bg-elev) 0%, transparent 100%);
}
#main header #chat-title { font-weight: 500; }
#main header .right { display: flex; align-items: center; gap: 14px; }
#main header .status { display: flex; align-items: center; gap: 6px; color: var(--fg-dim); font-size: 11px; }
#main header .dot {
  width: 8px; height: 8px; border-radius: var(--radius-pill);
  background: var(--fg); box-shadow: var(--glow-soft);
  transition: background 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
#main header .status.busy .dot { background: #fbbf24; box-shadow: 0 0 10px rgba(251, 191, 36, 0.5); animation: pulse 1.2s infinite; }
#main header .status.down .dot { background: var(--err); box-shadow: 0 0 10px rgba(255, 85, 85, 0.6); }
@keyframes pulse { 0%,100% { transform: scale(1); opacity: 1; } 50% { transform: scale(0.85); opacity: 0.6; } }
#main header .icon-btn {
  background: transparent; border: 1px solid var(--border);
  padding: 4px 10px; border-radius: var(--radius-pill);
  font-size: 11px; color: var(--fg-dim);
}
#main header .icon-btn:hover { color: var(--fg); border-color: var(--border-bright); background: var(--bg-elev); }

#stream {
  flex: 1; overflow-y: auto;
  padding: 24px;
  display: flex; flex-direction: column; gap: 20px;
  scrollbar-width: thin; scrollbar-color: var(--border) transparent;
}
#stream::-webkit-scrollbar { width: 8px; }
#stream::-webkit-scrollbar-track { background: transparent; }
#stream::-webkit-scrollbar-thumb { background: var(--border); border-radius: var(--radius-pill); }
#stream::-webkit-scrollbar-thumb:hover { background: var(--border-bright); }

.msg {
  animation: msgIn 0.3s var(--ease);
  max-width: min(78ch, 100%);
}
.msg.user { align-self: flex-end; }
.msg.assistant { align-self: flex-start; }
@keyframes msgIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

.msg .who {
  font-size: 10px; letter-spacing: 0.1em; color: var(--fg-dim); margin-bottom: 6px;
  text-transform: uppercase;
}
.msg.user .who { color: var(--fg); text-align: right; }
.msg.assistant .who { color: var(--fg-bright); }

.msg .body {
  white-space: pre-wrap; word-wrap: break-word; line-height: 1.65;
  padding: 12px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.msg.user .body {
  background: rgba(74, 222, 128, 0.10);
  border-color: rgba(74, 222, 128, 0.22);
  border-bottom-right-radius: 4px;
}
.msg.assistant .body {
  background: var(--bg-elev);
  border-bottom-left-radius: 4px;
}
.msg.assistant .body .cursor {
  display: inline-block; width: 7px; height: 14px; background: var(--fg);
  vertical-align: text-bottom; margin-left: 2px; border-radius: 2px;
  animation: blink 1s infinite;
  box-shadow: var(--glow-soft);
}
@keyframes blink { 50% { opacity: 0; } }

/* code blocks */
.codeblock {
  position: relative;
  margin: 10px 0;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: #000;
  overflow: hidden;
}
.codeblock .codehead {
  display: flex; justify-content: space-between; align-items: center;
  padding: 6px 10px 6px 14px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  font-size: 10px; letter-spacing: 0.1em; color: var(--fg-dim);
  text-transform: uppercase;
}
.codeblock .copy-btn {
  background: transparent; border: 1px solid var(--border);
  color: var(--fg-dim); padding: 3px 10px;
  font-size: 10px; letter-spacing: 0.05em;
  border-radius: var(--radius-pill); cursor: pointer;
  transition: all 0.12s var(--ease);
}
.codeblock .copy-btn:hover { color: var(--fg); border-color: var(--fg); background: var(--bg-elev); }
.codeblock .copy-btn.copied { color: var(--fg-bright); border-color: var(--fg-bright); background: rgba(74, 222, 128, 0.1); }
.codeblock pre {
  margin: 0; padding: 12px 14px;
  font-size: 12.5px; line-height: 1.55;
  color: var(--fg-mute);
  overflow-x: auto;
  scrollbar-width: thin; scrollbar-color: var(--border) transparent;
}
.codeblock pre::-webkit-scrollbar { height: 6px; }
.codeblock pre::-webkit-scrollbar-thumb { background: var(--border); border-radius: var(--radius-pill); }
.codeblock code { font-family: inherit; }

/* inline code */
.msg .body code:not(pre code) {
  background: rgba(74, 222, 128, 0.08);
  border: 1px solid rgba(74, 222, 128, 0.15);
  padding: 1px 6px;
  border-radius: 6px;
  font-size: 0.92em;
  color: var(--fg-bright);
}

.empty {
  margin: auto; text-align: center; color: var(--fg-dim); font-size: 13px;
  opacity: 0.7;
  animation: fadeUp 0.5s var(--ease);
}

#composer {
  border-top: 1px solid var(--border); padding: 14px 18px;
  display: flex; align-items: flex-end; gap: 10px;
  background: linear-gradient(0deg, var(--bg-elev) 0%, transparent 100%);
}
#composer .prompt { color: var(--fg); padding: 10px 0; font-weight: 600; }
#composer textarea {
  flex: 1; resize: none; max-height: 200px;
  padding: 10px 14px;
  border-radius: var(--radius);
  background: var(--bg-elev);
}
#composer button#send {
  padding: 10px 18px; color: var(--bg);
  background: var(--fg); border-color: var(--fg);
  border-radius: var(--radius);
  font-weight: 600;
}
#composer button#send:hover:not(:disabled) {
  background: var(--fg-bright); border-color: var(--fg-bright);
  box-shadow: var(--glow);
}
#composer button#cancel {
  color: var(--err); border-color: var(--err);
  border-radius: var(--radius);
  padding: 10px 14px;
}
#composer button#cancel:hover { background: rgba(255, 85, 85, 0.1); box-shadow: 0 0 8px rgba(255, 85, 85, 0.3); }

/* === modal (system prompt viewer) === */
.modal-backdrop {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center;
  padding: 20px;
  animation: fadeIn 0.2s var(--ease);
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.modal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  max-width: 640px; width: 100%;
  max-height: 80vh; overflow-y: auto;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.6), 0 0 0 1px var(--border-bright), 0 0 60px rgba(74, 222, 128, 0.15);
  animation: fadeUp 0.25s var(--ease);
}
.modal h3 { margin: 0 0 6px; color: var(--fg); font-size: 14px; letter-spacing: 0.05em; }
.modal .modal-sub { color: var(--fg-dim); font-size: 12px; margin: 0 0 18px; }
.modal pre {
  margin: 0; padding: 14px 16px;
  background: #000; border: 1px solid var(--border); border-radius: var(--radius-sm);
  color: var(--fg-mute); font-size: 12.5px; line-height: 1.6;
  white-space: pre-wrap; word-wrap: break-word;
}
.modal .modal-actions { margin-top: 16px; display: flex; justify-content: flex-end; gap: 8px; }
.modal .modal-actions button { padding: 7px 16px; border-radius: var(--radius-pill); }

/* === toast === */
.toast {
  position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%);
  background: var(--bg-card); border: 1px solid var(--border-bright);
  color: var(--fg-bright);
  padding: 10px 18px; border-radius: var(--radius-pill);
  font-size: 12px; letter-spacing: 0.05em;
  box-shadow: var(--shadow-card), var(--glow);
  z-index: 200;
  animation: toastIn 0.3s var(--ease);
}
@keyframes toastIn { from { opacity: 0; transform: translate(-50%, 10px); } to { opacity: 1; transform: translate(-50%, 0); } }

/* mobile */
@media (max-width: 720px) {
  #app { grid-template-columns: 1fr; padding: 6px; gap: 6px; }
  #sidebar {
    position: fixed; inset: 6px 30% 6px 6px; z-index: 10;
    transform: translateX(-110%); transition: transform 0.25s var(--ease);
  }
  #sidebar.open { transform: translateX(0); }
  #main header .icon-btn.menu { display: inline-flex; }
}
#main header .icon-btn.menu { display: none; }