:root {
  color-scheme: light;
  --bg: #f4f1ea;
  --bg-accent: #e7ded0;
  --surface: rgba(255, 252, 246, 0.84);
  --surface-strong: #fffdf8;
  --border: rgba(110, 87, 54, 0.16);
  --text: #1f1a14;
  --muted: #756754;
  --accent: #155e63;
  --accent-strong: #0d4347;
  --accent-soft: rgba(21, 94, 99, 0.11);
  --warning: #8b5e22;
  --shadow: 0 24px 60px rgba(51, 37, 19, 0.12);
  --radius: 18px;
  --sidebar-width: 308px;
  font-family: "Segoe UI Variable", "SF Pro Text", "IBM Plex Sans", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(21, 94, 99, 0.1), transparent 36%),
    radial-gradient(circle at bottom right, rgba(139, 94, 34, 0.12), transparent 34%),
    linear-gradient(180deg, #f7f3ec 0%, var(--bg) 100%);
  color: var(--text);
}

.app-shell {
  display: grid;
  grid-template-columns: minmax(0, var(--sidebar-width)) minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: auto;
  padding: 22px 18px 20px;
  border-right: 1px solid var(--border);
  background:
    linear-gradient(180deg, rgba(255, 250, 243, 0.92), rgba(246, 239, 228, 0.86));
  backdrop-filter: blur(18px);
}

.sidebar-top,
.thread-header,
.composer-toolbar,
.brand,
.message {
  display: flex;
  align-items: center;
}

.sidebar-top,
.thread-header,
.composer-toolbar {
  justify-content: space-between;
}

.brand {
  gap: 12px;
}

.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  color: white;
  background: linear-gradient(135deg, var(--accent), #2a8b92);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.32);
  font-weight: 700;
}

.brand-title {
  font-size: 15px;
  font-weight: 700;
}

.brand-subtitle,
.thread-subtitle,
.micro-copy {
  color: var(--muted);
  font-size: 12px;
}

.import-card,
.hero-card,
.composer-shell,
.message,
.kb-item {
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.import-card,
.kb-item,
.hero-card,
.composer-shell,
.message {
  border-radius: var(--radius);
}

.import-card,
.kb-section {
  margin-top: 18px;
}

.import-card {
  padding: 14px;
}

.section-title {
  margin-bottom: 12px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.field {
  display: block;
  margin-bottom: 10px;
}

.field span {
  display: block;
  margin-bottom: 6px;
  font-size: 12px;
  color: var(--muted);
}

input,
textarea,
button {
  font: inherit;
}

input,
textarea {
  width: 100%;
  border: 1px solid rgba(118, 97, 65, 0.16);
  background: rgba(255, 255, 255, 0.7);
  color: var(--text);
  border-radius: 14px;
  padding: 11px 13px;
  transition: border-color 140ms ease, box-shadow 140ms ease, transform 140ms ease;
}

input:focus,
textarea:focus {
  outline: none;
  border-color: rgba(21, 94, 99, 0.5);
  box-shadow: 0 0 0 4px rgba(21, 94, 99, 0.12);
}

textarea {
  resize: vertical;
  min-height: 104px;
}

button {
  cursor: pointer;
}

.primary-button,
.ghost-button {
  border-radius: 999px;
  padding: 10px 14px;
  transition: transform 140ms ease, background 140ms ease, color 140ms ease, border-color 140ms ease;
}

.primary-button {
  border: 1px solid transparent;
  color: white;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
}

.ghost-button {
  border: 1px solid rgba(118, 97, 65, 0.16);
  color: var(--text);
  background: rgba(255, 255, 255, 0.58);
}

.primary-button:hover,
.ghost-button:hover,
.kb-item:hover {
  transform: translateY(-1px);
}

.kb-list {
  display: grid;
  gap: 12px;
}

.kb-item {
  width: 100%;
  text-align: left;
  padding: 14px;
}

.kb-item.active {
  border-color: rgba(21, 94, 99, 0.34);
  background: linear-gradient(180deg, rgba(21, 94, 99, 0.1), rgba(255, 252, 246, 0.9));
}

.kb-name {
  font-size: 14px;
  font-weight: 700;
}

.kb-meta,
.kb-summary {
  margin-top: 6px;
  font-size: 12px;
  color: var(--muted);
}

.thread-shell {
  min-width: 0;
  display: flex;
  flex-direction: column;
  padding: 22px;
  gap: 18px;
}

.thread-header {
  gap: 16px;
}

.thread-title {
  font-size: 24px;
  font-weight: 700;
}

.runtime-badges,
.composer-toolbar {
  gap: 10px;
  flex-wrap: wrap;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border-radius: 999px;
  padding: 7px 11px;
  font-size: 12px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.7);
}

.badge.accent {
  background: var(--accent-soft);
  border-color: rgba(21, 94, 99, 0.2);
  color: var(--accent-strong);
}

.badge.subtle {
  color: var(--warning);
}

.message-list {
  flex: 1;
  min-height: 0;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding-right: 4px;
}

.hero-card {
  padding: 24px;
  animation: slide-up 360ms ease both;
}

.hero-card h1 {
  margin: 10px 0 10px;
  font-size: clamp(28px, 5vw, 48px);
  line-height: 1.05;
  font-weight: 700;
}

.hero-card p,
.message-body,
.message-activity {
  line-height: 1.6;
}

.hero-eyebrow {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.message {
  gap: 14px;
  align-items: flex-start;
  padding: 16px 18px;
  animation: slide-up 220ms ease both;
}

.message.user {
  background: linear-gradient(180deg, rgba(21, 94, 99, 0.08), rgba(255, 252, 246, 0.86));
}

.message-role {
  flex: 0 0 auto;
  width: 38px;
  height: 38px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 700;
  color: white;
  background: linear-gradient(135deg, #4f4130, #8b5e22);
}

.message.assistant .message-role {
  background: linear-gradient(135deg, var(--accent), #2a8b92);
}

.message-body {
  white-space: pre-wrap;
  word-break: break-word;
  flex: 1;
}

.message-activity {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--border);
  font-size: 12px;
  color: var(--muted);
}

.composer-shell {
  padding: 14px;
}

.composer-box {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  align-items: end;
}

.composer-box .primary-button {
  height: 48px;
}

@keyframes slide-up {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 980px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: relative;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .thread-shell {
    padding: 16px;
  }

  .composer-box {
    grid-template-columns: 1fr;
  }
}