:root {
  --bg-dark: #f8fafc;
  --bg-sidebar: #ffffff;
  --bg-card: #ffffff;
  --bg-input: #f1f5f9;
  --bg-hover: #e2e8f0;
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #94a3b8;
  
  --accent-purple: #6d28d9;
  --accent-blue: #0284c7;
  --accent-cyan: #0891b2;
  --accent-glow: rgba(109, 40, 217, 0.2);

  --reasoning-bg: #f3f0ff;
  --reasoning-border: rgba(109, 40, 217, 0.25);
  --reasoning-text: #4c1d95;

  --border-color: #e2e8f0;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --font-family: 'Noto Sans KR', 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  --sidebar-width: 280px;

  --user-bubble-bg: #e2e8f0;
  --user-bubble-text: #0f172a;
  --user-avatar-bg: #475569;
  --header-bg: rgba(255, 255, 255, 0.85);
  --code-bg: #1e293b;
  --code-header-bg: #0f172a;
  --code-header-text: #94a3b8;
  --code-text: #e2e8f0;
  --login-screen-bg: radial-gradient(circle at 50% 30%, rgba(109, 40, 217, 0.08), transparent 65%),
                      radial-gradient(circle at 80% 80%, rgba(2, 132, 199, 0.08), transparent 50%),
                      #f1f5f9;
  --login-card-bg: rgba(255, 255, 255, 0.92);
  --login-card-border: rgba(0, 0, 0, 0.08);
  --login-card-shadow: 0 20px 60px rgba(0, 0, 0, 0.08), 0 0 30px rgba(109, 40, 217, 0.1);
  --modal-card-bg: #ffffff;
  --modal-footer-bg: #f8fafc;
  --quick-card-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  --footer-gradient-start: rgba(248, 250, 252, 0);
  --footer-gradient-end: rgba(248, 250, 252, 0.95);
}

[data-theme="dark"] {
  --bg-dark: #0b0f19;
  --bg-sidebar: #111726;
  --bg-card: #182035;
  --bg-input: #1b243b;
  --bg-hover: #222d4a;
  
  --text-main: #f0f4fc;
  --text-muted: #8c9bba;
  --text-dim: #5c6b8c;
  
  --accent-purple: #7c4dff;
  --accent-blue: #00b0ff;
  --accent-cyan: #00e5ff;
  --accent-glow: rgba(124, 77, 255, 0.35);

  --reasoning-bg: #141b2d;
  --reasoning-border: rgba(124, 77, 255, 0.4);
  --reasoning-text: #b8c7e6;

  --border-color: rgba(255, 255, 255, 0.08);

  --user-bubble-bg: #1f2b45;
  --user-bubble-text: #f0f4fc;
  --user-avatar-bg: #3a4866;
  --header-bg: rgba(11, 15, 25, 0.8);
  --code-bg: #151b28;
  --code-header-bg: #1c2436;
  --code-header-text: #8c9bba;
  --code-text: #f0f4fc;
  --login-screen-bg: radial-gradient(circle at 50% 30%, rgba(124, 77, 255, 0.18), transparent 65%),
                      radial-gradient(circle at 80% 80%, rgba(0, 176, 255, 0.12), transparent 50%),
                      #0b0f19;
  --login-card-bg: rgba(17, 23, 38, 0.85);
  --login-card-border: rgba(255, 255, 255, 0.1);
  --login-card-shadow: 0 20px 60px rgba(0, 0, 0, 0.6), 0 0 30px rgba(124, 77, 255, 0.15);
  --modal-card-bg: #111726;
  --modal-footer-bg: rgba(0, 0, 0, 0.2);
  --quick-card-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
  --footer-gradient-start: rgba(11, 15, 25, 0);
  --footer-gradient-end: rgba(11, 15, 25, 0.95);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  overflow: hidden;
  height: 100vh;
  width: 100vw;
}

/* Utility Helper */
.hidden {
  display: none !important;
}

/* App Layout */
.app-layout {
  display: flex;
  height: 100vh;
  width: 100vw;
  position: relative;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  padding: 1.25rem 1rem;
  z-index: 100;
  flex-shrink: 0;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), margin-left 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sidebar.collapsed {
  margin-left: calc(-1 * var(--sidebar-width));
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
}

.sidebar-close-btn {
  display: flex;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo {
  width: 44px;
  height: 44px;
  border-radius: 4px;
  background: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.brand-logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 4px;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.5px;
}

.brand-badge {
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}



.btn-new-chat {
  width: 100%;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-md);
  border: none;
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
  color: #ffffff;
  font-family: var(--font-family);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: all 0.25s ease;
  margin-bottom: 1.5rem;
  box-shadow: 0 4px 14px var(--accent-glow);
}

.btn-new-chat:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--accent-glow);
  filter: brightness(1.1);
}

.sidebar-section {
  margin-bottom: 1.25rem;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-dim);
  letter-spacing: 0.8px;
}

.preset-chips {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.preset-chip {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 0.6rem 0.85rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-family);
  font-size: 0.85rem;
  text-align: left;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  transition: all 0.2s ease;
}

.preset-chip i {
  color: var(--accent-blue);
}

.preset-chip:hover {
  background: var(--bg-hover);
  color: var(--text-main);
  border-color: rgba(255, 255, 255, 0.15);
}

.history-section {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.chat-history-list {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding-right: 0.25rem;
}

.history-item {
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: all 0.15s ease;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.history-item span {
  overflow: hidden;
  text-overflow: ellipsis;
}

.history-item:hover, .history-item.active {
  background: var(--bg-hover);
  color: var(--text-main);
}

.history-item.active {
  font-weight: 600;
  border-left: 3px solid var(--accent-purple);
}

.history-item .btn-del-item {
  opacity: 0;
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  transition: color 0.2s;
}

.history-item:hover .btn-del-item {
  opacity: 1;
}

.history-item .btn-del-item:hover {
  color: #ff5252;
}

.sidebar-footer {
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

.sidebar-footer-btn {
  width: 100%;
  padding: 0.75rem;
  border-radius: var(--radius-sm);
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-family: var(--font-family);
  font-size: 0.9rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  transition: all 0.2s ease;
}

.sidebar-footer-btn:hover {
  background: var(--bg-hover);
  color: var(--text-main);
}

/* Main Content */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-dark);
  position: relative;
  overflow: hidden;
}

/* Top Header */
.top-header {
  height: 64px;
  padding: 0 1.5rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--header-bg);
  backdrop-filter: blur(10px);
  z-index: 10;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.sidebar-toggle-btn {
  display: none;
}

.model-info-pill {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--bg-card);
  padding: 0.4rem 0.85rem;
  border-radius: 30px;
  border: 1px solid var(--border-color);
  font-size: 0.85rem;
}

.model-info-pill i {
  color: var(--accent-purple);
}

.model-name {
  font-weight: 600;
}

.thinking-badge {
  font-size: 0.72rem;
  padding: 0.15rem 0.5rem;
  border-radius: 20px;
  background: rgba(124, 77, 255, 0.15);
  color: var(--accent-cyan);
  border: 1px solid rgba(0, 229, 255, 0.3);
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

/* Chat Feed */
.chat-feed-container {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Welcome Screen */
.welcome-container {
  margin: auto;
  max-width: 680px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  padding: 2rem 1rem;
}

.welcome-icon-glow {
  width: 72px;
  height: 72px;
  border-radius: 24px;
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-cyan));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  color: #fff;
  box-shadow: 0 0 30px var(--accent-glow);
  animation: pulse-glow 3s infinite alternate;
}

@keyframes pulse-glow {
  0% { transform: scale(1); box-shadow: 0 0 20px var(--accent-glow); }
  100% { transform: scale(1.05); box-shadow: 0 0 40px rgba(0, 229, 255, 0.5); }
}

.welcome-container h1 {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.welcome-subtitle {
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 500px;
}

.quick-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  width: 100%;
  margin-top: 1rem;
}

.quick-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.1rem;
  text-align: left;
  cursor: pointer;
  transition: all 0.25 ease;
}

.quick-card:hover {
  background: var(--bg-hover);
  border-color: rgba(124, 77, 255, 0.4);
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.card-icon {
  font-size: 1.25rem;
  color: var(--accent-cyan);
  margin-bottom: 0.5rem;
}

.card-title {
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 0.2rem;
}

.card-desc {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* Chat Messages */
.message-row {
  display: flex;
  gap: 1rem;
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.message-row.user {
  justify-content: flex-end;
}

.avatar {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
  flex-shrink: 0;
}

.avatar.user-avatar {
  background: var(--user-avatar-bg);
  color: #fff;
}

.avatar.ai-avatar {
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
  color: #fff;
  box-shadow: 0 0 10px var(--accent-glow);
}

.message-bubble {
  max-width: 80%;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.message-row.user .message-bubble {
  background: var(--user-bubble-bg);
  border: 1px solid var(--border-color);
  padding: 0.85rem 1.15rem;
  border-radius: 18px 18px 4px 18px;
  color: var(--user-bubble-text);
  font-size: 0.98rem;
}

.message-row.assistant .message-bubble {
  background: transparent;
  width: 100%;
}

/* Reasoning Thought Box */
.thought-accordion {
  background: var(--reasoning-bg);
  border: 1px solid var(--reasoning-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all 0.3s ease;
}

.thought-header {
  padding: 0.6rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
  font-size: 0.85rem;
  color: var(--accent-cyan);
  font-weight: 600;
  background: rgba(124, 77, 255, 0.05);
}

.thought-header-left {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.thought-header i.fa-chevron-down {
  transition: transform 0.2s ease;
}

.thought-accordion.collapsed .thought-header i.fa-chevron-down {
  transform: rotate(-90deg);
}

.thought-body {
  padding: 0.85rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--reasoning-text);
  line-height: 1.5;
  white-space: pre-wrap;
  border-top: 1px solid rgba(124, 77, 255, 0.2);
  max-height: 400px;
  overflow-y: auto;
}

.thought-accordion.collapsed .thought-body {
  display: none;
}

/* Streaming Pulse Animation */
.thinking-spinner {
  display: inline-block;
  animation: spin 1.2s linear infinite;
}

@keyframes spin {
  100% { transform: rotate(360deg); }
}

.status-loading-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.5rem 0.9rem;
  background: var(--bg-card);
  border: 1px solid var(--reasoning-border);
  border-radius: 20px;
  font-size: 0.85rem;
  color: var(--accent-cyan);
  box-shadow: 0 0 12px var(--accent-glow);
}

.response-timer-pill {
  font-weight: 600;
  font-family: var(--font-mono);
  color: var(--accent-purple);
  background: rgba(124, 77, 255, 0.15);
  padding: 0.15rem 0.55rem;
  border-radius: 12px;
  font-size: 0.8rem;
  border: 1px solid rgba(124, 77, 255, 0.3);
  margin-left: 0.2rem;
}

/* Assistant Content Box */
.assistant-content {
  font-size: 0.98rem;
  line-height: 1.7;
  color: var(--text-main);
}

.assistant-content p {
  margin-bottom: 0.85rem;
}

.assistant-content p:last-child {
  margin-bottom: 0;
}

.assistant-content pre {
  margin: 1rem 0;
  border-radius: var(--radius-sm);
  background: var(--code-bg) !important;
  border: 1px solid var(--border-color);
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.assistant-content code {
  font-family: var(--font-mono);
  font-size: 0.88rem;
}

.assistant-content pre code {
  color: var(--code-text);
  background: transparent !important;
  display: block;
  padding: 1rem;
  overflow-x: auto;
  line-height: 1.6;
}

.assistant-content :not(pre) > code {
  background: rgba(109, 40, 217, 0.08);
  color: var(--accent-purple);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  border: 1px solid rgba(109, 40, 217, 0.15);
}

[data-theme="dark"] .assistant-content :not(pre) > code {
  background: rgba(124, 77, 255, 0.15);
  color: #a78bfa;
  border-color: rgba(124, 77, 255, 0.3);
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--code-header-bg);
  padding: 0.45rem 1rem;
  font-size: 0.75rem;
  color: var(--code-header-text);
  font-family: var(--font-mono);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.btn-copy-code {
  background: transparent;
  border: none;
  color: var(--code-header-text);
  cursor: pointer;
  font-size: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  transition: color 0.2s, opacity 0.2s;
  opacity: 0.85;
}

.btn-copy-code:hover {
  color: var(--accent-cyan);
  opacity: 1;
}

/* Input Footer */
.input-footer {
  padding: 1rem 1.5rem 1.25rem 1.5rem;
  background: linear-gradient(180deg, var(--footer-gradient-start) 0%, var(--footer-gradient-end) 40%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  z-index: 5;
}

.input-box-wrapper {
  max-width: 900px;
  width: 100%;
  background: var(--bg-input);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-lg);
  padding: 0.75rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  transition: all 0.2s ease;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.input-box-wrapper:focus-within {
  border-color: var(--accent-purple);
  box-shadow: 0 0 20px var(--accent-glow);
}

#userInput {
  width: 100%;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text-main);
  font-family: var(--font-family);
  font-size: 0.98rem;
  resize: none;
  max-height: 200px;
  line-height: 1.5;
}

#userInput::placeholder {
  color: var(--text-dim);
}

.input-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.token-counter {
  font-size: 0.75rem;
  color: var(--text-dim);
}

.btn-send, .btn-stop {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition: all 0.2s ease;
}

.btn-send {
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
  color: #fff;
}

.btn-send:hover {
  transform: scale(1.05);
  box-shadow: 0 0 15px var(--accent-glow);
}

.btn-send:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-stop {
  background: #ff5252;
  color: #fff;
}

.btn-stop:hover {
  background: #ff1744;
}

.disclaimer {
  font-size: 0.72rem;
  color: var(--text-dim);
  text-align: center;
}

/* Modal */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 1;
  transition: opacity 0.2s ease;
}

.modal-backdrop.hidden {
  display: none;
}

.modal-card {
  background: var(--modal-card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  width: 90%;
  max-width: 520px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.3);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.modal-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-header h3 {
  font-size: 1.1rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.modal-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  max-height: 70vh;
  overflow-y: auto;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.label-hint {
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--text-dim);
}

.form-group input[type="text"],
.form-group input[type="password"],
.form-group textarea,
.form-group select {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.85rem;
  color: var(--text-main);
  font-family: var(--font-family);
  font-size: 0.9rem;
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: var(--accent-purple);
}

.form-row {
  display: flex;
  gap: 1rem;
}

.flex-1 { flex: 1; }

.toggle-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  margin-top: 0.5rem;
}

.toggle-label input {
  display: none;
}

.toggle-switch {
  width: 44px;
  height: 24px;
  background: var(--bg-card);
  border-radius: 20px;
  position: relative;
  border: 1px solid var(--border-color);
  transition: background 0.2s;
}

.toggle-switch::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--text-muted);
  transition: transform 0.2s;
}

.toggle-label input:checked + .toggle-switch {
  background: var(--accent-purple);
}

.toggle-label input:checked + .toggle-switch::after {
  transform: translateX(20px);
  background: #fff;
}

.slider-header {
  display: flex;
  justify-content: space-between;
}

.slider-value {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-cyan);
}

.modal-footer {
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  background: var(--modal-footer-bg);
}

.footer-right-btns {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Common Buttons */
.btn-icon {
  background: transparent;
  border: none;
  color: var(--text-muted);
  width: 32px;
  height: 32px;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-icon:hover {
  background: var(--bg-hover);
  color: var(--text-main);
}

.btn-secondary {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-family);
  font-size: 0.85rem;
  cursor: pointer;
}

.btn-secondary:hover {
  background: var(--bg-hover);
  color: var(--text-main);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
  border: none;
  color: #fff;
  padding: 0.5rem 1.1rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-family);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
}

.btn-primary:hover {
  box-shadow: 0 0 12px var(--accent-glow);
}

.btn-text-icon {
  background: transparent;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.8rem;
}

.btn-text-icon:hover {
  color: #ff5252;
}

.hidden {
  display: none !important;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  .sidebar {
    position: absolute;
    left: 0;
    top: 0;
    height: 100vh;
    transform: translateX(-100%);
    box-shadow: 10px 0 30px rgba(0, 0, 0, 0.5);
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .sidebar-close-btn, .sidebar-toggle-btn {
    display: flex;
  }
  
  .chat-feed-container {
    padding: 1rem;
  }
  
  .quick-cards {
    grid-template-columns: 1fr;
  }

  .login-container {
    width: 90%;
    padding: 2rem 1.25rem;
  }
}

/* ==========================================================================
   Login Screen Styles
   ========================================================================== */
.login-top-actions {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  z-index: 1001;
}

.login-theme-toggle {
  position: static;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: all 0.2s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.login-theme-toggle:hover {
  transform: scale(1.08);
  border-color: var(--accent-purple);
}

/* Language Toggle Switch (Bilingual KO / EN) */
.lang-toggle-container {
  display: inline-flex;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 22px;
  padding: 3px;
  gap: 3px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.lang-toggle-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 600;
  font-family: inherit;
  padding: 4px 11px;
  border-radius: 16px;
  cursor: pointer;
  transition: all 0.22s cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  user-select: none;
}

.lang-toggle-btn:hover {
  color: var(--text-main);
}

.lang-toggle-btn.active {
  background: var(--accent-purple);
  color: #ffffff;
  box-shadow: 0 2px 10px rgba(124, 77, 255, 0.4);
}

.flag-icon {
  font-size: 0.9rem;
  line-height: 1;
}

.btn-theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.login-screen {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--login-screen-bg);
  padding: 1.5rem;
  overflow-y: auto;
}

.login-container {
  width: 100%;
  max-width: 440px;
  background: var(--login-card-bg);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid var(--login-card-border);
  border-radius: 24px;
  padding: 2.75rem 2.25rem;
  box-shadow: var(--login-card-shadow);
  animation: loginCardFadeIn 0.4s ease-out;
}

@keyframes loginCardFadeIn {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.97);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.login-header {
  text-align: center;
  margin-bottom: 2rem;
}

.login-brand-logo {
  width: 72px;
  height: 72px;
  margin: 0 auto 1.25rem;
  border-radius: 6px;
  background: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.login-brand-logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 6px;
}

.login-title {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.login-subtitle {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.login-error-alert {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1rem;
  background: rgba(255, 82, 82, 0.12);
  border: 1px solid rgba(255, 82, 82, 0.3);
  border-radius: var(--radius-sm);
  color: #ff5252;
  font-size: 0.9rem;
  animation: shakeAlert 0.3s ease;
}

@keyframes shakeAlert {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

.input-icon-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  width: 100%;
}

.input-icon-wrapper .input-icon {
  position: static;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-size: 1.05rem;
  flex-shrink: 0;
  pointer-events: none;
  transition: all 0.2s ease;
}

.input-icon-wrapper input {
  flex: 1;
  width: 100%;
  padding: 0.85rem 2.8rem 0.85rem 1rem;
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  transition: all 0.2s ease;
}

.input-icon-wrapper input:focus {
  border-color: var(--accent-purple);
  box-shadow: 0 0 0 3px var(--accent-glow);
  background-color: var(--bg-card);
  color: var(--text-main);
}

.input-icon-wrapper:focus-within .input-icon {
  border-color: var(--accent-purple);
  color: var(--accent-purple);
  background-color: var(--bg-card);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-icon-wrapper input:-webkit-autofill,
.input-icon-wrapper input:-webkit-autofill:hover, 
.input-icon-wrapper input:-webkit-autofill:focus, 
.input-icon-wrapper input:-webkit-autofill:active {
  -webkit-text-fill-color: var(--text-main) !important;
  -webkit-box-shadow: 0 0 0 1000px var(--bg-card) inset !important;
  transition: background-color 5000s ease-in-out 0s;
}

.btn-toggle-pwd {
  position: absolute;
  right: 0.8rem;
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  padding: 0.4rem;
  font-size: 1rem;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.2s ease;
}

.btn-toggle-pwd:hover {
  color: var(--accent-purple);
}

.login-options {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.88rem;
}

.remember-me {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-muted);
  cursor: pointer;
  user-select: none;
}

.remember-me input[type="checkbox"] {
  accent-color: var(--accent-purple);
  width: 16px;
  height: 16px;
  cursor: pointer;
}

.btn-login-submit {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  width: 100%;
  padding: 0.95rem;
  margin-top: 0.5rem;
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
  border: none;
  border-radius: var(--radius-md);
  color: #ffffff;
  font-size: 1.05rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  box-shadow: 0 4px 20px var(--accent-glow);
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn-login-submit:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(124, 77, 255, 0.5);
  filter: brightness(1.1);
}

.btn-login-submit:active {
  transform: translateY(0);
}

.btn-login-submit:disabled {
  opacity: 0.65;
  cursor: not-allowed;
  transform: none;
}

.login-footer {
  margin-top: 2rem;
  text-align: center;
  border-top: 1px solid var(--border-color);
  padding-top: 1.25rem;
}

.dev-hint {
  font-size: 0.8rem;
  color: var(--text-dim);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.btn-logout {
  color: var(--text-muted);
}

.btn-logout:hover {
  background-color: rgba(255, 82, 82, 0.12) !important;
  color: #ff5252 !important;
}

.user-info-badge {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.6rem 0.8rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  margin-bottom: 0.5rem;
  color: var(--text-color);
  font-size: 0.85rem;
  font-weight: 500;
}

.user-info-badge i {
  color: var(--accent-purple);
  font-size: 1.1rem;
}

.user-info-name {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Chat Error Message Card */
.error-msg-card {
  padding: 0.9rem 1.15rem;
  background: rgba(255, 82, 82, 0.1);
  border: 1px solid rgba(255, 82, 82, 0.35);
  border-radius: var(--radius-md);
  color: #ff5252;
  font-size: 0.92rem;
  margin: 0.4rem 0;
  box-shadow: 0 4px 15px rgba(255, 82, 82, 0.1);
}

.error-msg-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
  font-size: 0.95rem;
}

.error-msg-content {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  word-break: break-word;
  white-space: pre-wrap;
  opacity: 0.92;
  line-height: 1.5;
}

/* Document Knowledge Status Pill in Top Header */
.doc-knowledge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.75rem;
  background: rgba(168, 85, 247, 0.15);
  border: 1px solid rgba(168, 85, 247, 0.35);
  border-radius: 20px;
  color: #c084fc;
  font-size: 0.8rem;
  font-weight: 600;
  transition: all 0.2s ease;
}
.doc-knowledge-pill i {
  color: #a855f7;
  font-size: 0.85rem;
}

/* Upload Dropzone & Document Modal Styles */
.upload-dropzone {
  border: 2px dashed rgba(168, 85, 247, 0.4);
  background: rgba(168, 85, 247, 0.05);
  border-radius: var(--radius-md);
  padding: 1.5rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
}
.upload-dropzone:hover, .upload-dropzone.dragover {
  border-color: var(--accent-purple);
  background: rgba(168, 85, 247, 0.12);
  transform: translateY(-1px);
}
.dropzone-icon {
  font-size: 2.2rem;
  color: var(--accent-purple);
}
.dropzone-text {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}
.dropzone-subtext {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin: 0;
}

.upload-status-alert {
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  margin-top: 0.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  transition: all 0.3s ease;
}
.upload-status-alert.info {
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.35);
  color: #c7d2fe;
}
.upload-status-alert.success {
  background: rgba(34, 197, 94, 0.15);
  border: 1px solid rgba(34, 197, 94, 0.4);
  color: #4ade80;
}
.upload-status-alert.error {
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid rgba(239, 68, 68, 0.4);
  color: #f87171;
}

.upload-progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  font-weight: 600;
}
.upload-status-percent {
  font-family: var(--font-family);
  font-size: 0.82rem;
  background: rgba(255, 255, 255, 0.15);
  padding: 0.1rem 0.45rem;
  border-radius: 4px;
}
.upload-progress-track {
  width: 100%;
  height: 8px;
  background: rgba(0, 0, 0, 0.25);
  border-radius: 10px;
  overflow: hidden;
  position: relative;
}
.upload-progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #6366f1, #8b5cf6, #ec4899);
  border-radius: 10px;
  transition: width 0.3s ease;
}
.upload-status-subtext {
  font-size: 0.76rem;
  color: var(--text-muted);
}

/* Document List Items */
.doc-list-container {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-height: 220px;
  overflow-y: auto;
  padding-right: 4px;
}
.doc-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.65rem 0.9rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  transition: background 0.2s;
}
.doc-item:hover {
  background: rgba(255, 255, 255, 0.05);
}
.doc-item-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  overflow: hidden;
}
.doc-item-icon {
  font-size: 1.2rem;
  color: var(--accent-purple);
  flex-shrink: 0;
}
.doc-item-details {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.doc-item-name {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.doc-item-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  gap: 0.6rem;
}
.btn-doc-delete {
  background: transparent;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  transition: all 0.2s;
}
.btn-doc-delete:hover {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
}

/* RAG Citation Badges */
.citations-box {
  margin-top: 0.85rem;
  padding-top: 0.65rem;
  border-top: 1px dashed rgba(255, 255, 255, 0.12);
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.citations-header {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.citations-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.citation-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.3);
  color: #a5b4fc;
  border-radius: 6px;
  font-family: var(--font-family);
  transition: all 0.2s ease;
}
.citation-badge:hover {
  background: rgba(99, 102, 241, 0.22);
  border-color: rgba(99, 102, 241, 0.5);
}
.citation-badge .score-pill {
  font-size: 0.7rem;
  background: rgba(255, 255, 255, 0.1);
  padding: 0.05rem 0.35rem;
  border-radius: 4px;
  color: #e0e7ff;
}