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

:root {
  --bg-base: #f6f8fa;
  --bg-surface: #ffffff;
  --bg-elevated: #eaeef2;
  --border: #d0d7de;
  --border-hover: #b0bac5;
  --text-primary: #1f2328;
  --text-secondary: #636c76;
  --text-muted: #9198a1;
  --accent: #0969da;
  --accent-hover: #0550ae;
  --accent-soft: rgba(9, 105, 218, 0.1);
  --user-bubble: #0969da;
  --danger: #cf222e;
  --danger-soft: rgba(207, 34, 46, 0.1);
  --purple: #6c63ff;
}

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-base);
  color: var(--text-primary);
  font-size: 15px;
  line-height: 1.6;
}

.hidden {
  display: none !important;
}

/* ─── Auth Screen ─────────────────────────────── */

#auth-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  background: linear-gradient(135deg, #e8f0fe 0%, #dce8fb 50%, #c8dcf8 100%);
}

#auth-card {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 44px 40px;
  width: 100%;
  max-width: 380px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.6);
}

.auth-logo {
  width: 52px;
  height: 52px;
  background: var(--accent-soft);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.auth-logo svg {
  width: 28px;
  height: 28px;
  color: var(--accent-hover);
}

#auth-card h1 {
  font-size: 26px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
  letter-spacing: -0.3px;
}

.auth-subtitle {
  color: var(--text-secondary);
  font-size: 14px;
  margin-bottom: 28px;
}

#password-input {
  width: 100%;
  padding: 11px 15px;
  background: var(--bg-base);
  border: 1px solid var(--border-hover);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 15px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  margin-bottom: 12px;
}

#password-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

#login-btn {
  width: 100%;
  padding: 11px;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
  letter-spacing: 0.2px;
}

#login-btn:hover {
  background: var(--accent-hover);
}

#login-btn:active {
  transform: scale(0.98);
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  10%, 50%, 90% { transform: translateX(-10px); }
  30%, 70% { transform: translateX(10px); }
}

#auth-card.shake {
  animation: shake 0.45s cubic-bezier(0.36, 0.07, 0.19, 0.97);
}

/* ─── Chat Screen ─────────────────────────────── */

#chat-screen {
  display: flex;
  flex-direction: column;
  height: 100vh;
  position: relative;
  overflow: hidden;
}

/* Header */

#chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  z-index: 10;
}

.header-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
}

.header-icon {
  width: 20px;
  height: 20px;
  color: var(--accent-hover);
}

#reset-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: transparent;
  border: 1px solid var(--border-hover);
  color: var(--text-secondary);
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  transition: all 0.2s;
}

#reset-btn svg {
  width: 15px;
  height: 15px;
}

#reset-btn:hover {
  border-color: var(--danger);
  color: var(--danger);
  background: var(--danger-soft);
}

/* Messages Area */

#messages-area {
  flex: 1;
  overflow-y: auto;
  padding: 28px 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  scroll-behavior: smooth;
}

#messages-area::-webkit-scrollbar {
  width: 5px;
}

#messages-area::-webkit-scrollbar-track {
  background: transparent;
}

#messages-area::-webkit-scrollbar-thumb {
  background: var(--border-hover);
  border-radius: 3px;
}

/* Empty state */

#empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin: auto;
  padding: 40px;
  color: var(--text-muted);
  text-align: center;
}

#empty-state svg {
  width: 40px;
  height: 40px;
  opacity: 0.3;
}

#empty-state p {
  font-size: 16px;
  color: var(--text-secondary);
  font-weight: 500;
}

#empty-state span {
  font-size: 13px;
  color: var(--text-muted);
}

/* Messages */

.message {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  max-width: 80%;
  animation: msg-in 0.2s ease;
}

@keyframes msg-in {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.message.user {
  align-self: flex-end;
  flex-direction: row-reverse;
}

.message.assistant {
  align-self: flex-start;
}

.message.error {
  align-self: center;
  max-width: 90%;
}

.bubble {
  padding: 12px 16px;
  border-radius: 14px;
  word-break: break-word;
  overflow-wrap: break-word;
}

.message.user .bubble {
  background: var(--user-bubble);
  color: #fff;
  border-bottom-right-radius: 4px;
}

.message.assistant .bubble {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  color: var(--text-primary);
  border-bottom-left-radius: 4px;
}

.error-bubble {
  background: var(--danger-soft);
  border: 1px solid rgba(229, 83, 75, 0.3);
  color: var(--danger);
  border-radius: 10px;
  padding: 10px 16px;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* User message text */

.text-content {
  white-space: pre-wrap;
}

/* Message images (in bubble) */

.message-images {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 8px;
}

.message-image {
  max-width: 220px;
  max-height: 180px;
  border-radius: 8px;
  object-fit: cover;
  cursor: pointer;
  transition: opacity 0.2s;
}

.message-image:hover {
  opacity: 0.9;
}

/* Markdown */

.markdown-content { line-height: 1.7; }
.markdown-content > *:first-child { margin-top: 0; }
.markdown-content > *:last-child { margin-bottom: 0; }
.markdown-content h1,
.markdown-content h2,
.markdown-content h3,
.markdown-content h4 {
  margin: 16px 0 8px;
  color: var(--text-primary);
  line-height: 1.3;
}
.markdown-content h1 { font-size: 1.4em; }
.markdown-content h2 { font-size: 1.2em; }
.markdown-content h3 { font-size: 1.05em; }
.markdown-content p { margin: 8px 0; }
.markdown-content ul,
.markdown-content ol {
  padding-left: 22px;
  margin: 8px 0;
}
.markdown-content li { margin: 4px 0; }
.markdown-content a { color: var(--accent-hover); text-decoration: underline; }
.markdown-content blockquote {
  border-left: 3px solid var(--border-hover);
  padding-left: 14px;
  color: var(--text-secondary);
  margin: 10px 0;
}
.markdown-content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 16px 0;
}
.markdown-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 14px;
}
.markdown-content th,
.markdown-content td {
  border: 1px solid var(--border);
  padding: 8px 12px;
  text-align: left;
}
.markdown-content th {
  background: var(--bg-elevated);
  font-weight: 600;
}
.markdown-content code {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
  font-size: 0.875em;
  color: #6639ba;
}
.markdown-content pre {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  overflow-x: auto;
  margin: 12px 0;
}
.markdown-content pre code {
  background: none;
  border: none;
  padding: 0;
  color: var(--text-primary);
  font-size: 0.875em;
}
.markdown-content pre::-webkit-scrollbar { height: 4px; }
.markdown-content pre::-webkit-scrollbar-thumb {
  background: var(--border-hover);
  border-radius: 2px;
}

/* Loading dots */

.loading-dots {
  display: flex;
  gap: 5px;
  align-items: center;
  padding: 4px 2px;
}

.loading-dots span {
  width: 7px;
  height: 7px;
  background: var(--text-muted);
  border-radius: 50%;
  display: inline-block;
  animation: dot-bounce 1.3s infinite ease-in-out both;
}

.loading-dots span:nth-child(1) { animation-delay: -0.32s; }
.loading-dots span:nth-child(2) { animation-delay: -0.16s; }
.loading-dots span:nth-child(3) { animation-delay: 0s; }

@keyframes dot-bounce {
  0%, 80%, 100% { transform: scale(0.7); opacity: 0.4; }
  40%            { transform: scale(1); opacity: 1; }
}

/* ─── Image Preview Zone ──────────────────────── */

#image-preview-zone {
  display: flex;
  gap: 10px;
  padding: 10px 20px;
  overflow-x: auto;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

#image-preview-zone::-webkit-scrollbar { height: 3px; }
#image-preview-zone::-webkit-scrollbar-thumb {
  background: var(--border-hover);
  border-radius: 2px;
}

.preview-wrapper {
  position: relative;
  flex-shrink: 0;
}

.preview-image {
  width: 68px;
  height: 68px;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid var(--border);
  display: block;
}

.remove-image {
  position: absolute;
  top: -7px;
  right: -7px;
  width: 20px;
  height: 20px;
  background: var(--danger);
  border: 2px solid var(--bg-base);
  border-radius: 50%;
  color: white;
  cursor: pointer;
  font-size: 13px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s;
}

.remove-image:hover {
  transform: scale(1.15);
}

/* ─── Input Zone ──────────────────────────────── */

#input-zone {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  padding: 14px 20px;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

#message-input {
  flex: 1;
  padding: 10px 14px;
  background: var(--bg-base);
  border: 1px solid var(--border-hover);
  border-radius: 10px;
  color: var(--text-primary);
  font-size: 15px;
  font-family: inherit;
  resize: none;
  outline: none;
  min-height: 42px;
  max-height: 200px;
  line-height: 1.55;
  transition: border-color 0.2s, box-shadow 0.2s;
  overflow-y: auto;
}

#message-input::-webkit-scrollbar { width: 4px; }
#message-input::-webkit-scrollbar-thumb {
  background: var(--border-hover);
  border-radius: 2px;
}

#message-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

#message-input:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#message-input::placeholder {
  color: var(--text-muted);
}

#send-btn {
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  background: var(--accent);
  border: none;
  border-radius: 10px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s, transform 0.1s;
}

#send-btn:hover:not(:disabled) {
  background: var(--accent-hover);
}

#send-btn:active:not(:disabled) {
  transform: scale(0.95);
}

#send-btn:disabled {
  background: var(--bg-elevated);
  cursor: not-allowed;
}

#send-btn svg {
  width: 17px;
  height: 17px;
}

/* ─── Drop Overlay ────────────────────────────── */

#drop-overlay {
  position: absolute;
  inset: 0;
  background: rgba(246, 248, 250, 0.88);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 50;
  pointer-events: none;
}

.drop-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  border: 2px dashed var(--accent);
  border-radius: 16px;
  padding: 48px 64px;
  color: var(--accent-hover);
}

.drop-content svg {
  width: 48px;
  height: 48px;
}

.drop-content span {
  font-size: 18px;
  font-weight: 600;
}