:root {
  --bg: #f8f8fb;
  --panel: #ffffff;
  --sidebar: #f1f1f5;
  --text: #19191d;
  --muted: #6f7079;
  --line: #e3e3e9;
  --accent: #6557e8;
  --accent-soft: #efedff;
  --accent-strong: #5546d6;
  --danger: #b54949;
  --shadow: 0 14px 36px rgba(30, 28, 54, 0.08);
  --radius-md: 16px;
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: Pretendard, "Noto Sans KR", Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  word-break: keep-all;
}
button, textarea { font: inherit; }
button { color: inherit; }
button:focus-visible, textarea:focus-visible, a:focus-visible {
  outline: 3px solid rgba(101, 87, 232, .24);
  outline-offset: 2px;
}
button:disabled { opacity: .55; cursor: not-allowed; }

.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 264px minmax(0, 1fr);
}
.sidebar {
  position: fixed;
  inset: 0 auto 0 0;
  width: 264px;
  z-index: 20;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 20px 16px 18px;
  background: var(--sidebar);
  border-right: 1px solid var(--line);
}
.brand-row { display: flex; align-items: center; min-height: 44px; }
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  text-decoration: none;
  font-weight: 750;
  letter-spacing: -.02em;
}
.brand-mark, .assistant-avatar {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 10px;
  color: #fff;
  background: linear-gradient(135deg, #7768ee, #4f40ce);
  font-size: 15px;
  font-weight: 800;
  box-shadow: 0 6px 18px rgba(85,70,214,.18);
}
.mobile-close { display: none; }
.new-chat, .side-item, .recent-item {
  border: 0;
  background: transparent;
  cursor: pointer;
  text-align: left;
}
.new-chat {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
  font-weight: 700;
  box-shadow: 0 3px 10px rgba(33,33,49,.03);
}
.side-nav { display: grid; gap: 4px; }
.side-item {
  min-height: 44px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 12px;
  border-radius: 12px;
}
.side-item:not(:disabled):hover, .recent-item:hover { background: rgba(255,255,255,.72); }
.side-icon { width: 22px; text-align: center; font-size: 18px; }
.mini-badge {
  margin-left: auto;
  padding: 2px 7px;
  border-radius: 999px;
  color: var(--muted);
  background: rgba(255,255,255,.72);
  font-size: 11px;
  font-weight: 700;
}
.recent-section { min-height: 0; overflow: auto; }
.recent-section h2 {
  margin: 12px 10px 8px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}
.recent-item {
  width: 100%;
  min-height: 40px;
  padding: 8px 10px;
  border-radius: 10px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 14px;
}
.sidebar-footer {
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px;
  color: var(--muted);
  font-size: 12px;
}
.preview-dot { width: 8px; height: 8px; border-radius: 50%; background: #8b7ff0; }

.main-panel {
  grid-column: 2;
  min-width: 0;
  min-height: 100vh;
  position: relative;
  display: flex;
  flex-direction: column;
}
.topbar {
  min-height: 68px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 24px;
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(248,248,251,.86);
  backdrop-filter: blur(18px);
}
.mobile-menu { display: none; }
.model-pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 40px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255,255,255,.78);
  color: #50515a;
  font-size: 14px;
  font-weight: 650;
}
.status-spark { color: var(--accent); }
.login-button {
  margin-left: auto;
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  font-weight: 700;
  cursor: pointer;
}

.conversation {
  width: min(840px, calc(100% - 40px));
  margin: 0 auto;
  flex: 1;
  padding: clamp(54px, 9vh, 100px) 0 230px;
}
.empty-state { text-align: center; }
.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .13em;
}
.empty-state h1 {
  margin: 0;
  font-size: clamp(32px, 4vw, 48px);
  line-height: 1.2;
  letter-spacing: -.045em;
  font-weight: 770;
}
.empty-copy {
  max-width: 560px;
  margin: 18px auto 0;
  color: var(--muted);
  font-size: 17px;
}
.starter-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 38px auto 0;
  max-width: 680px;
}
.starter {
  min-height: 88px;
  display: flex;
  align-items: center;
  gap: 13px;
  padding: 15px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(255,255,255,.74);
  cursor: pointer;
  text-align: left;
  transition: border-color .16s ease, transform .16s ease, background .16s ease;
}
.starter:hover { transform: translateY(-1px); border-color: #ccc9e9; background: #fff; }
.starter-icon {
  flex: 0 0 38px;
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 18px;
}
.starter span:last-child { display: grid; gap: 2px; }
.starter strong { font-size: 14px; }
.starter small { color: var(--muted); font-size: 12px; }

.message-list { display: grid; gap: 28px; padding-top: 6px; }
.message { width: 100%; }
.user-message { display: flex; justify-content: flex-end; }
.message-bubble {
  max-width: min(620px, 86%);
  padding: 11px 15px;
  border-radius: 18px 18px 5px 18px;
  background: #eae8f7;
  white-space: pre-wrap;
}
.assistant-message {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr);
  gap: 12px;
}
.assistant-avatar { width: 34px; height: 34px; border-radius: 11px; }
.assistant-body { min-width: 0; }
.assistant-meta {
  min-height: 30px;
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 13px;
  font-weight: 750;
}
.demo-label {
  padding: 2px 7px;
  border-radius: 999px;
  background: #f1f0f7;
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
}
.assistant-content { color: #2f3037; font-size: 16px; }
.assistant-content p { margin: 0 0 12px; }
.assistant-content p:last-child { margin-bottom: 0; }
.source-list { display: grid; gap: 8px; margin-top: 16px; }
.source-card {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: #fff;
}
.source-index {
  flex: 0 0 28px;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 12px;
  font-weight: 800;
}
.source-card strong { display: block; font-size: 13px; }
.source-card small { display: block; color: var(--muted); font-size: 12px; }
.error-box {
  padding: 14px;
  border: 1px solid #e6caca;
  border-radius: 14px;
  background: #fff8f8;
}
.retry-button {
  margin-top: 10px;
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid #debdbd;
  border-radius: 11px;
  background: #fff;
  color: var(--danger);
  font-weight: 750;
  cursor: pointer;
}
.typing {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  min-height: 28px;
}
.typing i { width: 6px; height: 6px; border-radius: 50%; background: #aaa7b9; animation: pulse 1s infinite ease-in-out; }
.typing i:nth-child(2) { animation-delay: .14s; }
.typing i:nth-child(3) { animation-delay: .28s; }
@keyframes pulse { 0%, 70%, 100% { opacity: .35; transform: translateY(0); } 35% { opacity: 1; transform: translateY(-2px); } }

.composer-wrap {
  position: fixed;
  left: calc(264px + (100vw - 264px) / 2);
  bottom: 0;
  transform: translateX(-50%);
  z-index: 12;
  width: min(800px, calc(100vw - 264px - 40px));
  padding: 14px 0 20px;
  background: linear-gradient(to bottom, transparent, var(--bg) 28%, var(--bg));
}
.composer {
  position: relative;
  padding: 10px 11px 9px;
  border: 1px solid #d9d9e2;
  border-radius: 22px;
  background: #fff;
  box-shadow: var(--shadow);
}
.composer:focus-within { border-color: #b9b3e9; box-shadow: 0 14px 40px rgba(55,50,95,.10), 0 0 0 3px rgba(101,87,232,.07); }
.composer textarea {
  display: block;
  width: 100%;
  max-height: 180px;
  min-height: 50px;
  padding: 8px 8px 4px;
  border: 0;
  outline: 0;
  resize: none;
  background: transparent;
  color: var(--text);
  font-size: 16px;
  line-height: 1.55;
}
.composer textarea::placeholder { color: #9b9ca5; }
.composer-actions { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.composer-tools { display: flex; align-items: center; gap: 6px; }
.tool-button {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0 11px;
  border: 0;
  border-radius: 11px;
  background: transparent;
  color: #55565f;
  cursor: pointer;
  font-size: 14px;
  font-weight: 650;
}
.tool-button:hover { background: #f5f5f8; }
.tool-button[aria-pressed="true"] { background: var(--accent-soft); color: var(--accent-strong); }
.send-button {
  flex: 0 0 42px;
  width: 42px;
  height: 42px;
  border: 0;
  border-radius: 13px;
  color: #fff;
  background: var(--accent);
  cursor: pointer;
  font-size: 21px;
  font-weight: 800;
}
.send-button:not(:disabled):hover { background: var(--accent-strong); }
.attachment-chip {
  width: fit-content;
  max-width: 100%;
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr) 28px;
  align-items: center;
  gap: 9px;
  margin: 0 0 8px 8px;
  padding: 8px 9px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: #fff;
  box-shadow: 0 5px 16px rgba(40,40,60,.05);
}
.attachment-chip .file-icon { width: 30px; height: 30px; display: grid; place-items: center; border-radius: 9px; background: #f3f2f8; }
.attachment-chip strong, .attachment-chip small { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.attachment-chip strong { font-size: 12px; }
.attachment-chip small { color: var(--muted); font-size: 10px; }
.attachment-chip button { width: 28px; height: 28px; border: 0; border-radius: 8px; background: transparent; cursor: pointer; }
.composer-note { margin: 8px 8px 0; color: #888993; font-size: 11px; text-align: center; }
.sidebar-scrim { position: fixed; inset: 0; z-index: 18; background: rgba(16,16,24,.28); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

@media (max-width: 920px) {
  .app-shell { display: block; }
  .sidebar { transform: translateX(-100%); transition: transform .2s ease; box-shadow: 18px 0 40px rgba(20,20,30,.12); }
  .app-shell.sidebar-open .sidebar { transform: translateX(0); }
  .mobile-close { display: inline-grid; place-items: center; width: 38px; height: 38px; margin-right: 4px; border: 0; border-radius: 11px; background: transparent; cursor: pointer; font-size: 26px; }
  .topbar { padding: 10px 14px; min-height: 62px; }
  .mobile-menu { display: inline-grid; place-items: center; width: 42px; height: 42px; border: 0; border-radius: 12px; background: transparent; cursor: pointer; font-size: 20px; }
  .conversation { width: min(760px, calc(100% - 28px)); padding-top: clamp(40px, 8vh, 76px); }
  .composer-wrap { left: 50%; width: calc(100vw - 28px); }
}

@media (max-width: 620px) {
  .topbar { background: rgba(248,248,251,.94); }
  .model-pill { min-height: 38px; padding: 0 10px; font-size: 13px; }
  .login-button { min-height: 40px; padding: 0 13px; font-size: 14px; }
  .conversation { width: calc(100% - 24px); padding-top: 42px; padding-bottom: 218px; }
  .empty-state h1 { font-size: 32px; line-height: 1.24; }
  .empty-copy { margin-top: 14px; font-size: 15px; }
  .starter-grid { grid-template-columns: 1fr; gap: 8px; margin-top: 28px; }
  .starter { min-height: 76px; padding: 12px 13px; }
  .composer-wrap { width: calc(100vw - 20px); padding-bottom: max(12px, env(safe-area-inset-bottom)); }
  .composer { border-radius: 20px; padding: 8px; }
  .composer textarea { min-height: 48px; padding: 7px 7px 2px; font-size: 16px; }
  .tool-button { min-height: 42px; padding: 0 9px; }
  .send-button { width: 44px; height: 44px; flex-basis: 44px; }
  .composer-note { font-size: 10px; margin-inline: 2px; }
  .message-list { gap: 24px; }
  .assistant-message { grid-template-columns: 34px minmax(0, 1fr); gap: 10px; }
  .message-bubble { max-width: 92%; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
}