/* Reset & Variables */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --sidebar-width: 260px;
  --bg-primary: #212121;
  --bg-secondary: #171717;
  --bg-tertiary: #2f2f2f;
  --bg-hover: #3a3a3a;
  --text-primary: #ececec;
  --text-secondary: #b4b4b4;
  --text-muted: #8e8e8e;
  --border-color: #3a3a3a;
  --accent: #10a37f;
  --accent-hover: #0d8a6a;
  --user-bubble: #2f2f2f;
  --code-bg: #1e1e1e;
  --scrollbar-bg: transparent;
  --scrollbar-thumb: #565656;
}

html, body {
  height: 100%;
}

body {
  font-family: 'Söhne', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow: hidden;
}

/* App Layout */
.app {
  display: flex;
  height: 100vh;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease, width 0.3s ease;
  position: relative;
  z-index: 100;
}

.sidebar.hidden {
  transform: translateX(-100%);
  width: 0;
  overflow: hidden;
}

.sidebar-header {
  padding: 12px;
  display: flex;
  gap: 8px;
}

.new-chat-btn {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-primary);
  font-size: 14px;
  cursor: pointer;
  transition: background 0.2s;
}

.new-chat-btn:hover {
  background: var(--bg-tertiary);
}

.sidebar-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-primary);
  cursor: pointer;
  transition: background 0.2s;
}

.sidebar-toggle:hover {
  background: var(--bg-tertiary);
}

/* Chat List */
.chat-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px 12px;
}

.chat-list::-webkit-scrollbar {
  width: 6px;
}

.chat-list::-webkit-scrollbar-track {
  background: transparent;
}

.chat-list::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 3px;
}

.chat-item {
  display: flex;
  align-items: center;
  padding: 10px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s;
  margin-bottom: 2px;
}

.chat-item:hover {
  background: var(--bg-tertiary);
}

.chat-item.active {
  background: var(--bg-tertiary);
}

.chat-item-title {
  flex: 1;
  font-size: 14px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.chat-item-delete {
  opacity: 0;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  transition: opacity 0.2s, color 0.2s;
}

.chat-item:hover .chat-item-delete {
  opacity: 1;
}

.chat-item-delete:hover {
  color: #ef4444;
}

/* Sidebar Footer */
.sidebar-footer {
  padding: 12px;
  border-top: 1px solid var(--border-color);
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s;
}

.user-info:hover {
  background: var(--bg-tertiary);
}

.user-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, #10a37f, #1a7f5a);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 600;
}

.user-info span {
  font-size: 14px;
}

/* Main Content */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

/* Header */
.header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-color);
}

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

.sidebar.hidden + .main .header .sidebar-toggle {
  display: flex;
}

.model-selector {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s;
}

.model-selector:hover {
  background: var(--bg-tertiary);
}

.model-name {
  font-size: 16px;
  font-weight: 600;
}

/* Chat Container */
.chat-container {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.chat-container::-webkit-scrollbar {
  width: 8px;
}

.chat-container::-webkit-scrollbar-track {
  background: transparent;
}

.chat-container::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 4px;
}

/* Welcome Screen */
.welcome {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 20px;
  text-align: center;
}

.welcome.hidden {
  display: none;
}

.logo {
  width: 72px;
  height: 72px;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.welcome h1 {
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 32px;
}

.suggestions {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  max-width: 600px;
}

.suggestion {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  color: var(--text-primary);
  font-size: 14px;
  text-align: left;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
}

.suggestion:hover {
  background: var(--bg-hover);
  border-color: var(--text-muted);
}

.suggestion span {
  font-size: 20px;
}

/* Messages */
.messages {
  flex: 1;
  padding: 24px 0;
}

.message {
  padding: 24px 0;
  animation: fadeIn 0.3s ease;
}

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

.message-content {
  max-width: 768px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  gap: 16px;
}

.message-avatar {
  width: 28px;
  height: 28px;
  border-radius: 4px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 600;
}

.message.user .message-avatar {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
}

.message.assistant .message-avatar {
  background: var(--accent);
  color: white;
}

.message-text {
  flex: 1;
  min-width: 0;
  line-height: 1.7;
}

.message-text p {
  margin-bottom: 16px;
}

.message-text p:last-child {
  margin-bottom: 0;
}

.message-text code {
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'Söhne Mono', Monaco, monospace;
  font-size: 14px;
}

.message-text pre {
  background: var(--code-bg);
  border-radius: 8px;
  margin: 16px 0;
  overflow: hidden;
}

.message-text pre code {
  display: block;
  padding: 16px;
  overflow-x: auto;
  background: transparent;
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 16px;
  background: #333;
  font-size: 12px;
  color: var(--text-muted);
}

.copy-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 12px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.copy-btn:hover {
  color: var(--text-primary);
}

.message-text ul, .message-text ol {
  margin: 16px 0;
  padding-left: 24px;
}

.message-text li {
  margin-bottom: 8px;
}

.message-text a {
  color: var(--accent);
  text-decoration: none;
}

.message-text a:hover {
  text-decoration: underline;
}

/* Typing Indicator */
.typing-indicator {
  display: flex;
  gap: 4px;
  padding: 8px 0;
}

.typing-indicator span {
  width: 8px;
  height: 8px;
  background: var(--text-muted);
  border-radius: 50%;
  animation: bounce 1.4s ease-in-out infinite;
}

.typing-indicator span:nth-child(1) { animation-delay: 0s; }
.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

@keyframes bounce {
  0%, 60%, 100% { transform: translateY(0); }
  30% { transform: translateY(-6px); }
}

/* Input Area */
.input-area {
  padding: 16px 24px 24px;
  background: var(--bg-primary);
}

.input-container {
  max-width: 768px;
  margin: 0 auto;
  display: flex;
  align-items: flex-end;
  gap: 12px;
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  transition: border-color 0.2s;
}

.input-container:focus-within {
  border-color: var(--text-muted);
}

.input-container textarea {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 16px;
  font-family: inherit;
  line-height: 1.5;
  resize: none;
  max-height: 200px;
  outline: none;
}

.input-container textarea::placeholder {
  color: var(--text-muted);
}

.send-btn {
  width: 32px;
  height: 32px;
  background: var(--text-primary);
  border: none;
  border-radius: 8px;
  color: var(--bg-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.2s, transform 0.2s;
}

.send-btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.send-btn:not(:disabled):hover {
  transform: scale(1.05);
}

.disclaimer {
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 12px;
}

/* Mobile */
@media (max-width: 768px) {
  .sidebar {
    position: absolute;
    height: 100%;
    z-index: 1000;
  }
  
  .sidebar.hidden {
    transform: translateX(-100%);
  }
  
  .header .sidebar-toggle {
    display: flex !important;
  }
  
  .suggestions {
    grid-template-columns: 1fr;
  }
  
  .message-content {
    padding: 0 16px;
  }
  
  .input-area {
    padding: 12px 16px 16px;
  }
}