:root {
  --bg: #0e0f13;
  --bg-elev: #13141a;
  --panel: #161922;
  --muted: #a3a8b7;
  --text: #e8eaf1;
  --accent: #26a17b;
  --accent-weak: rgba(38, 161, 123, 0.2);
  --border: #2a2f3a;
  --glow: 0 10px 30px rgba(38,161,123,.12);
  --danger: #ff5555;
  --danger-weak: rgba(255, 85, 85, 0.2);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
html { color-scheme: dark; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(38,161,123,.18), transparent 50%),
    radial-gradient(900px 500px at 0% 110%, rgba(86,120,255,.12), transparent 50%),
    linear-gradient(180deg, #0b0c10, #0f1117 40%, #0e0f13);
  color: var(--text);
}

#app { display: grid; grid-template-columns: 280px 1fr; height: 100%; }

/* Sidebar */
.sidebar {
  background: var(--bg-elev);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  min-height: 100%;
}
.sidebar__header { padding: 14px; border-bottom: 1px solid var(--border); }
.brand { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; cursor: pointer; border-radius: 10px; padding: 4px; }
.brand:hover { background: rgba(255,255,255,0.03); }
.brand:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.avatar { width: 34px; height: 34px; border-radius: 50%; background: var(--accent); display:flex; align-items:center; justify-content:center; color:#081611; font-weight:700; }
.brand__title { font-weight: 600; }
.brand__subtitle { color: var(--muted); font-size: 12px; }
.new-chat { width: 100%; background: var(--panel); color: var(--text); border: 1px solid var(--border); border-radius: 12px; padding: 10px 12px; cursor: pointer; box-shadow: var(--glow); transition: border-color .15s ease, transform .06s ease; }
.new-chat:hover { border-color: var(--accent); box-shadow: var(--glow), 0 0 0 2px var(--accent-weak) inset; }
.new-chat:active { transform: translateY(1px); }
.clear-chats { width: 100%; margin-top: 8px; background: transparent; color: var(--muted); border: 1px solid var(--border); border-radius: 12px; padding: 8px 12px; cursor: pointer; transition: border-color .15s ease, color .15s ease; }
.clear-chats:hover { color: #ffd6d6; border-color: var(--danger); box-shadow: 0 0 0 2px var(--danger-weak) inset; }
.clear-chats:active { transform: translateY(1px); }

.sidebar__section { padding: 10px; overflow-y: auto; overflow-x: hidden; flex: 1; scrollbar-gutter: stable both-edges; padding-right: 12px; }
.section__title { font-size: 12px; color: var(--muted); margin: 4px 6px 8px; text-transform: uppercase; letter-spacing: .04em; }
.chat-list { display: grid; gap: 6px; overflow-x: hidden; }
.chat-item { display:flex; align-items:center; gap:10px; padding: 10px 12px; border-radius: 12px; background: transparent; border: 1px solid transparent; cursor: pointer; color: var(--text); text-decoration: none; transition: background .15s ease, border-color .15s ease; width: 100%; max-width: 100%; text-align: left; box-sizing: border-box; overflow: hidden; min-width: 0; }
.chat-item:hover { background: #171a22; border-color: var(--border); }
.chat-item__icon { width: 26px; height: 26px; border-radius: 6px; background: #202431; display:flex; align-items:center; justify-content:center; color: var(--muted); font-size: 14px; flex: 0 0 26px; }
.chat-item__title { font-size: 14px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; flex: 1 1 auto; min-width: 0; max-width: 100%; }

.sidebar__footer { border-top: 1px solid var(--border); padding: 10px; display:flex; gap:10px; }
.sidebar__link { color: var(--muted); text-decoration: none; font-size: 13px; }
.sidebar__link:hover { color: var(--text); }

/* Main */
.main { display: grid; grid-template-rows: 1fr auto; min-height: 100%; }
.topbar { display:flex; align-items:center; gap:12px; padding: 14px 18px; border-bottom: 1px solid var(--border); background: linear-gradient(180deg, rgba(255,255,255,0.03), transparent); backdrop-filter: blur(6px); }
.topbar__title { font-weight: 600; }
.theme-toggle { background: transparent; border: 1px solid var(--border); color: var(--text); border-radius: 10px; padding: 8px 10px; cursor: pointer; }
.theme-toggle:hover { border-color: var(--accent); }
.topbar__spacer { flex:1; }

.content { padding: 28px 24px 10px; overflow: auto; scroll-behavior: smooth; }
.content.hide-welcome .welcome { display: none; }
.welcome { text-align: center; margin: 6vh auto 2rem; max-width: 700px; }
.welcome .headshot { width: 128px; height: 128px; border-radius: 50%; object-fit: cover; display: block; margin: 0 auto 14px; border: 2px solid var(--border); box-shadow: 0 10px 28px rgba(0,0,0,.28), 0 0 0 3px rgba(255,255,255,0.03) inset; background: #222; }
.welcome h1 { margin: 0 0 6px; font-size: 36px; letter-spacing: -0.02em; }
.welcome p { margin: 0 0 18px; color: var(--muted); }
.suggestions { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 12px; margin: 0 auto; max-width: 560px; }
.suggestion { padding: 12px 14px; border-radius: 14px; border: 1px solid var(--border); background: var(--panel); color: var(--text); cursor: pointer; text-align:left; box-shadow: 0 6px 20px rgba(0,0,0,.15); transition: transform .06s ease, border-color .15s ease; font-size: 17px; line-height: 1.3; }
.suggestion:hover { border-color: var(--accent); box-shadow: 0 6px 22px rgba(0,0,0,.2), 0 0 0 2px var(--accent-weak) inset; transform: translateY(-1px); }

.messages { display: grid; gap: 14px; margin: 24px auto 100px; max-width: 760px; }
.msg { display: grid; grid-template-columns: 36px 1fr; gap: 12px; padding: 14px 16px; background: #11141b; border: 1px solid var(--border); border-radius: 14px; box-shadow: 0 8px 24px rgba(0,0,0,.18); animation: pop .18s ease; }
.msg .bubble { white-space: normal; line-height: 1.5; }
.msg .bubble p { margin: 0 0 0.5em; }
.msg .bubble ul, .msg .bubble ol { padding-left: 1.2em; margin: 0.2em 0; }
/* Compress spacing within list items */
.msg .bubble li { margin: 0; }
.msg .bubble li + li { margin-top: 0.15em; }
.msg .bubble li > p { margin: 0; }
.msg .bubble li > p + p { margin-top: 0.2em; }
.msg .bubble p:last-child { margin-bottom: 0; }
.msg .bubble li > p:last-child { margin-bottom: 0; }
.msg .bubble code { font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; background: #0f1117; border: 1px solid #242938; padding: 0.1em 0.35em; border-radius: 6px; }
.msg .bubble pre { background: #0f1117; border: 1px solid #242938; padding: 12px 14px; border-radius: 10px; overflow: auto; box-shadow: inset 0 1px 0 rgba(255,255,255,0.02); }
.msg .bubble pre code { background: transparent; border: 0; padding: 0; }
.msg .bubble blockquote { margin: 0.6em 0; padding-left: 0.9em; border-left: 3px solid #2a2f3a; color: var(--muted); }
.msg .bubble h1, .msg .bubble h2, .msg .bubble h3 { margin: 0.6em 0 0.3em; line-height: 1.3; }
/* Preserve user-entered newlines without affecting Markdown block spacing */
.msg.user .bubble { white-space: pre-wrap; }
.msg .who { width: 36px; height: 36px; border-radius: 9px; display:flex; align-items:center; justify-content:center; font-size: 14px; }
.msg.user .who { background: #21324a; color: #9fc1ff; }
.msg.assistant .who { background: #1a2c27; color: #78e2be; }
.msg.assistant .bubble.thinking { white-space: normal; }
.msg.assistant .bubble.thinking .dot { display:inline-block; width: 0.5em; text-align:center; opacity: 0.2; animation: dotblink 1.2s infinite; }
.msg.assistant .bubble.thinking .dot:nth-child(2) { animation-delay: .2s; }
.msg.assistant .bubble.thinking .dot:nth-child(3) { animation-delay: .4s; }
@keyframes dotblink { 0%, 20% { opacity: .2; } 50% { opacity: 1; } 100% { opacity: .2; } }

@keyframes pop {
  from { transform: translateY(2px); opacity: .0; }
  to { transform: translateY(0); opacity: 1; }
}

/* Composer */
.composer { position: sticky; bottom: 0; border-top: 1px solid var(--border); padding: 12px 16px 16px; background: linear-gradient(180deg, rgba(14,15,19,0), rgba(14,15,19,0.92) 25%, rgba(14,15,19,1) 60%); backdrop-filter: blur(2px); }
.composer__form { max-width: 760px; margin: 0 auto; }
.input-wrap { position: relative; display:flex; align-items: flex-end; background: var(--bg-elev); border: 1px solid var(--border); border-radius: 14px; padding: 8px; gap: 8px; box-shadow: var(--glow); }
textarea#prompt { resize: none; flex: 1; border: 0; outline: none; color: var(--text); background: transparent; font: inherit; padding: 8px 10px; max-height: 160px; }
.send { background: var(--panel); border: 1px solid var(--border); color: var(--text); border-radius: 10px; padding: 8px 12px; cursor: pointer; transition: border-color .15s ease, transform .06s ease; box-shadow: 0 8px 22px rgba(0,0,0,.2); }
.send:disabled { opacity: .5; cursor: default; }
.send:not(:disabled):hover { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-weak) inset, 0 8px 26px rgba(0,0,0,.25); }
.send:active { transform: translateY(1px); }
.hint { color: var(--muted); font-size: 12px; margin-top: 8px; text-align: center; }

/* Responsive */
@media (max-width: 1000px) {
  #app { grid-template-columns: 72px 1fr; }
  .brand__text, .section__title, .sidebar__footer { display: none; }
  .new-chat { padding: 10px; font-size: 0; }
  .new-chat::after { content: "+"; font-size: 18px; }
  .chat-item__title { display: none; }
  .clear-chats { padding: 10px; font-size: 0; }
  .clear-chats::after { content: "🗑"; font-size: 18px; }
}

@media (max-width: 640px) {
  .suggestions { grid-template-columns: 1fr; }
  .welcome h1 { font-size: 28px; }
}

/* Light theme (togglable) */
.light {
  --bg: #f7f7fb;
  --bg-elev: #ffffff;
  --panel: #f2f4fa;
  --muted: #5b6273;
  --text: #0e0f13;
  --accent: #0e7c61;
  --accent-weak: rgba(14, 124, 97, 0.18);
  --border: #e6e8ee;
}