:root {
  --bg: #120c07;
  --bg-elevated: #1a120b;
  --bg-panel: #1e150d;
  --ink: #f7efe4;
  --ink-muted: #b7a690;
  --ink-faint: #7d6d58;
  --accent: #f0a01a;
  --accent-soft: color-mix(in srgb, #f0a01a 18%, transparent);
  --accent-line: color-mix(in srgb, #f0a01a 28%, transparent);
  --user-bg: #2a1d10;
  --danger: #e85d4c;
  --ok: #6fbf73;
  --radius: 18px;
  --font: "Instrument Sans", system-ui, sans-serif;
  --display: "Syne", "Instrument Sans", sans-serif;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}

*, *::before, *::after { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
}

body {
  background-image:
    radial-gradient(ellipse 80% 50% at 10% -10%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 0%, color-mix(in srgb, #ff6b2c 10%, transparent), transparent 50%),
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 2px,
      color-mix(in srgb, var(--accent) 3%, transparent) 2px,
      color-mix(in srgb, var(--accent) 3%, transparent) 3px
    );
  background-attachment: fixed;
}

button, textarea { font: inherit; color: inherit; }

.app {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  height: 100dvh;
  max-width: 1400px;
  margin: 0 auto;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding: 1.25rem 1rem 1rem;
  border-right: 1px solid var(--accent-line);
  background: color-mix(in srgb, var(--bg-panel) 88%, transparent);
  backdrop-filter: blur(12px);
  animation: rise 0.55s ease both;
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 0.35rem 0.4rem;
}

.brand-mark {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 0.85rem;
  background:
    linear-gradient(145deg, #ffc14d, #e8890a 55%, #b34e00);
  box-shadow: 0 0 0 1px color-mix(in srgb, #fff 12%, transparent), 0 10px 24px rgba(240, 160, 26, 0.28);
  position: relative;
  overflow: hidden;
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 22% 28% 28% 22%;
  border: 2px solid rgba(18, 12, 7, 0.55);
  border-radius: 999px 999px 40% 40%;
  border-bottom-width: 0;
}

.brand-copy h1 {
  margin: 0;
  font-family: var(--display);
  font-size: 1.35rem;
  letter-spacing: -0.03em;
  line-height: 1;
}

.brand-sub {
  margin: 0.2rem 0 0;
  color: var(--ink-muted);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.btn-new {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  width: 100%;
  border: 1px solid var(--accent-line);
  background: var(--accent-soft);
  color: var(--ink);
  border-radius: 999px;
  padding: 0.72rem 1rem;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.btn-new:hover {
  background: color-mix(in srgb, var(--accent) 28%, transparent);
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  transform: translateY(-1px);
}

.btn-new .plus { font-size: 1.15rem; line-height: 1; }

.session-list {
  flex: 1;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding-right: 0.15rem;
  scrollbar-width: thin;
  scrollbar-color: var(--accent-line) transparent;
}

.session-item {
  width: 100%;
  text-align: left;
  border: 0;
  background: transparent;
  border-radius: 12px;
  padding: 0.7rem 0.8rem;
  cursor: pointer;
  color: var(--ink-muted);
  transition: background 0.15s ease, color 0.15s ease;
}

.session-item:hover { background: color-mix(in srgb, #fff 4%, transparent); color: var(--ink); }
.session-item.active {
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  color: var(--ink);
  box-shadow: inset 0 0 0 1px var(--accent-line);
}

.session-item .title {
  display: block;
  font-size: 0.92rem;
  font-weight: 560;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.session-item .meta {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.72rem;
  color: var(--ink-faint);
}

.sidebar-foot { padding-top: 0.4rem; }

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.4rem 0.7rem;
  border-radius: 999px;
  background: color-mix(in srgb, #fff 4%, transparent);
  border: 1px solid var(--accent-line);
  color: var(--ink-muted);
  font-size: 0.75rem;
}

.status-pill .dot {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: var(--ink-faint);
}

.status-pill.ok .dot { background: var(--ok); box-shadow: 0 0 0 3px color-mix(in srgb, var(--ok) 25%, transparent); }
.status-pill.bad .dot { background: var(--danger); }

.main {
  display: grid;
  grid-template-rows: auto 1fr auto;
  min-width: 0;
  animation: rise 0.65s ease 0.05s both;
}

.topbar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.25rem 0.75rem;
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 12%, transparent);
}

.topbar-title { flex: 1; min-width: 0; }
.topbar-title h2 {
  margin: 0;
  font-family: var(--display);
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.topbar-title p {
  margin: 0.15rem 0 0;
  color: var(--ink-faint);
  font-size: 0.78rem;
}

.icon-btn {
  border: 1px solid var(--accent-line);
  background: color-mix(in srgb, #fff 3%, transparent);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 0.75rem;
  cursor: pointer;
  display: grid;
  place-items: center;
}
.icon-btn:hover { background: var(--accent-soft); }
.mobile-only { display: none; }

.messages {
  overflow: auto;
  padding: 1.25rem 1.25rem 0.5rem;
  scroll-behavior: smooth;
}

.empty {
  max-width: 34rem;
  margin: 12vh auto 0;
  text-align: center;
  animation: rise 0.7s ease both;
}

.empty-brand {
  margin: 0 0 0.6rem;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(2.4rem, 6vw, 3.6rem);
  letter-spacing: -0.05em;
  background: linear-gradient(120deg, #fff 20%, var(--accent) 70%, #ff7a1a);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.empty h3 {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 600;
}

.empty > p {
  margin: 0.55rem auto 1.4rem;
  color: var(--ink-muted);
  max-width: 28rem;
  line-height: 1.55;
}

.suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  justify-content: center;
}

.suggestions button {
  border: 1px solid var(--accent-line);
  background: color-mix(in srgb, var(--bg-elevated) 80%, transparent);
  border-radius: 999px;
  padding: 0.55rem 0.95rem;
  cursor: pointer;
  color: var(--ink-muted);
  transition: transform 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}
.suggestions button:hover {
  transform: translateY(-1px);
  color: var(--ink);
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
}

.msg {
  display: grid;
  grid-template-columns: 2.1rem minmax(0, 1fr);
  gap: 0.75rem;
  margin: 0 auto 1.15rem;
  max-width: 820px;
  animation: msg-in 0.35s ease both;
}

.msg-avatar {
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 0.7rem;
  display: grid;
  place-items: center;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin-top: 0.15rem;
}

.msg.user .msg-avatar {
  background: var(--user-bg);
  color: var(--accent);
  border: 1px solid var(--accent-line);
}

.msg.assistant .msg-avatar {
  background: linear-gradient(145deg, #ffc14d, #e8890a);
  color: #1a1006;
}

.msg-body { min-width: 0; }

.msg-role {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-faint);
  margin-bottom: 0.3rem;
}

.msg-content {
  line-height: 1.65;
  white-space: pre-wrap;
  word-break: break-word;
  font-size: 0.98rem;
}

.msg.user .msg-content {
  background: color-mix(in srgb, var(--user-bg) 90%, transparent);
  border: 1px solid var(--accent-line);
  border-radius: 14px 14px 14px 4px;
  padding: 0.75rem 0.9rem;
}

.msg.assistant .msg-content {
  padding: 0.15rem 0;
}

.msg-content code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: color-mix(in srgb, #fff 7%, transparent);
  padding: 0.1em 0.35em;
  border-radius: 0.35em;
}

.msg-content pre {
  margin: 0.7rem 0;
  padding: 0.85rem 1rem;
  overflow: auto;
  background: #0c0906;
  border: 1px solid var(--accent-line);
  border-radius: 12px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.84rem;
  line-height: 1.5;
}

.msg-content pre code { background: none; padding: 0; }

.tool-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0.55rem 0 0.2rem;
}

.tool-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.72rem;
  color: var(--ink-muted);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  border: 1px solid var(--accent-line);
  border-radius: 999px;
  padding: 0.28rem 0.6rem;
  max-width: 100%;
}

.tool-chip .name { font-weight: 600; color: var(--accent); }
.tool-chip .preview {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 22rem;
}

.typing::after {
  content: "▍
  animation: blink 1s steps(1) infinite;
  color: var(--accent);
}

.composer-wrap {
  padding: 0.6rem 1.25rem 1.1rem;
}

.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.55rem;
  align-items: end;
  max-width: 820px;
  margin: 0 auto;
  padding: 0.7rem 0.7rem 0.7rem 1rem;
  border-radius: calc(var(--radius) + 4px);
  background: color-mix(in srgb, var(--bg-elevated) 92%, transparent);
  border: 1px solid var(--accent-line);
  box-shadow: var(--shadow);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.composer:focus-within {
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  box-shadow: 0 0 0 3px var(--accent-soft), var(--shadow);
}

.composer textarea {
  resize: none;
  border: 0;
  outline: none;
  background: transparent;
  min-height: 1.5rem;
  max-height: 10rem;
  line-height: 1.5;
  padding: 0.45rem 0;
}

.btn-send {
  width: 2.6rem;
  height: 2.6rem;
  border: 0;
  border-radius: 0.95rem;
  background: linear-gradient(145deg, #ffc14d, #e8890a);
  color: #1a1006;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: transform 0.15s ease, filter 0.15s ease;
}

.btn-send:hover { transform: translateY(-1px); filter: brightness(1.05); }
.btn-send:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }

.composer-hint {
  max-width: 820px;
  margin: 0.45rem auto 0;
  color: var(--ink-faint);
  font-size: 0.72rem;
  text-align: center;
}

.backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  z-index: 20;
}

.error-banner {
  max-width: 820px;
  margin: 0 auto 1rem;
  padding: 0.75rem 0.9rem;
  border-radius: 12px;
  border: 1px solid color-mix(in srgb, var(--danger) 45%, transparent);
  background: color-mix(in srgb, var(--danger) 12%, transparent);
  color: #ffc7c0;
  font-size: 0.9rem;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

@keyframes msg-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}

@keyframes blink {
  50% { opacity: 0; }
}

@media (max-width: 860px) {
  .app { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(86vw, 300px);
    z-index: 30;
    transform: translateX(-105%);
    transition: transform 0.25s ease;
    box-shadow: var(--shadow);
  }
  .sidebar.open { transform: none; }
  .mobile-only { display: grid; }
}