/* ========================================
   Structural Heart Radar — AI Chat
   ======================================== */

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

:root {
  --font-display: 'Cabinet Grotesk', 'General Sans', sans-serif;
  --font-body: 'General Sans', 'Helvetica Neue', sans-serif;

  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.8125rem);
  --text-sm:   clamp(0.8125rem, 0.78rem + 0.2vw, 0.875rem);
  --text-base: clamp(0.875rem, 0.85rem + 0.15vw, 0.9375rem);
  --text-lg:   clamp(1rem, 0.95rem + 0.3vw, 1.125rem);
  --text-xl:   clamp(1.125rem, 1rem + 0.5vw, 1.375rem);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  --sidebar-width: 280px;
}

/* ======== LIGHT MODE ======== */
:root, [data-theme="light"] {
  --color-bg: #f5f7fa;
  --color-surface: #ffffff;
  --color-surface-2: #f8f9fb;
  --color-surface-offset: #eef1f6;
  --color-divider: #e2e6ed;
  --color-border: #d0d5df;
  --color-text: #1a1f2e;
  --color-text-muted: #5c6478;
  --color-text-faint: #96a0b5;
  --color-accent: #0891b2;
  --color-accent-hover: #0e7490;
  --color-accent-light: rgba(8, 145, 178, 0.08);
  --color-accent-surface: rgba(8, 145, 178, 0.05);
  --color-user-bg: #0891b2;
  --color-user-text: #ffffff;
  --color-ai-bg: #ffffff;
  --color-ai-border: #e2e6ed;
  --color-success: #16a34a;
  --color-error: #dc2626;
  --shadow-sm: 0 1px 3px rgba(26, 31, 46, 0.06);
  --shadow-md: 0 4px 12px rgba(26, 31, 46, 0.08);
}

/* ======== DARK MODE ======== */
[data-theme="dark"] {
  --color-bg: #0c0f16;
  --color-surface: #141820;
  --color-surface-2: #1a1f2c;
  --color-surface-offset: #111520;
  --color-divider: #222938;
  --color-border: #2c3548;
  --color-text: #d0d6e4;
  --color-text-muted: #7c869c;
  --color-text-faint: #4a5268;
  --color-accent: #22d3ee;
  --color-accent-hover: #67e8f9;
  --color-accent-light: rgba(34, 211, 238, 0.1);
  --color-accent-surface: rgba(34, 211, 238, 0.04);
  --color-user-bg: #164e63;
  --color-user-text: #cffafe;
  --color-ai-bg: #1a1f2c;
  --color-ai-border: #2c3548;
  --color-success: #4ade80;
  --color-error: #f87171;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.35);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg: #0c0f16;
    --color-surface: #141820;
    --color-surface-2: #1a1f2c;
    --color-surface-offset: #111520;
    --color-divider: #222938;
    --color-border: #2c3548;
    --color-text: #d0d6e4;
    --color-text-muted: #7c869c;
    --color-text-faint: #4a5268;
    --color-accent: #22d3ee;
    --color-accent-hover: #67e8f9;
    --color-accent-light: rgba(34, 211, 238, 0.1);
    --color-accent-surface: rgba(34, 211, 238, 0.04);
    --color-user-bg: #164e63;
    --color-user-text: #cffafe;
    --color-ai-bg: #1a1f2c;
    --color-ai-border: #2c3548;
    --color-success: #4ade80;
    --color-error: #f87171;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.25);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.35);
  }
}

/* ======== BASE ======== */
html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  height: 100dvh;
  overflow: hidden;
}

button { cursor: pointer; background: none; border: none; font: inherit; color: inherit; }
a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ======== APP SHELL ======== */
.app-shell {
  display: flex;
  height: 100dvh;
  overflow: hidden;
}

/* ======== SIDEBAR ======== */
.sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  background: var(--color-surface);
  border-right: 1px solid var(--color-divider);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  overflow-x: hidden;
}

.sidebar-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-4);
  border-bottom: 1px solid var(--color-divider);
}

.sidebar-logo {
  color: var(--color-accent);
  flex-shrink: 0;
}

.sidebar-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--color-text);
  display: block;
  line-height: 1.2;
}

.sidebar-sub {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  display: block;
}

.sidebar-stats {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-divider);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.stat-value {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}

.sidebar-section {
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-divider);
}

.sidebar-section-title {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-3);
}

.suggestion-chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.chip {
  font-size: var(--text-xs);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
  color: var(--color-text-muted);
  transition: all var(--transition);
  white-space: nowrap;
}

.chip:hover {
  background: var(--color-accent-light);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.setting-row {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.setting-row label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.setting-row input {
  font-size: var(--text-xs);
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface-2);
  color: var(--color-text);
  outline: none;
  width: 100%;
}

.setting-row input:focus {
  border-color: var(--color-accent);
}

.sidebar-footer {
  margin-top: auto;
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.clear-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

.clear-btn:hover {
  background: var(--color-surface-offset);
  color: var(--color-error);
}

.footer-link {
  font-size: 10px;
  color: var(--color-text-faint);
  text-align: center;
}

/* ======== CHAT MAIN ======== */
.chat-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
}

.chat-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-divider);
  background: var(--color-surface);
  flex-shrink: 0;
}

.menu-toggle {
  display: none;
  padding: var(--space-1);
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
}

.menu-toggle:hover { background: var(--color-surface-offset); }

.chat-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  flex: 1;
}

[data-theme-toggle] {
  padding: var(--space-2);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
}

[data-theme-toggle]:hover {
  background: var(--color-surface-offset);
  color: var(--color-text);
}

/* ======== MESSAGES ======== */
.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  scroll-behavior: smooth;
}

.welcome-message {
  text-align: center;
  padding: var(--space-8) var(--space-4);
  color: var(--color-text-muted);
  max-width: 480px;
  margin: auto;
}

.welcome-icon {
  color: var(--color-accent);
  margin-bottom: var(--space-4);
  display: inline-block;
}

.welcome-message h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-xl);
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.welcome-message p {
  font-size: var(--text-sm);
  margin-bottom: var(--space-2);
  max-width: none;
}

.welcome-hint {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* Message bubbles */
.message {
  display: flex;
  gap: var(--space-3);
  max-width: 800px;
  animation: fadeIn 0.3s ease;
}

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

.message.user {
  margin-left: auto;
  flex-direction: row-reverse;
}

.message-avatar {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: var(--text-sm);
  font-weight: 600;
}

.message.user .message-avatar {
  background: var(--color-user-bg);
  color: var(--color-user-text);
}

.message.ai .message-avatar {
  background: var(--color-accent-light);
  color: var(--color-accent);
}

.message-content {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  line-height: 1.65;
  min-width: 0;
}

.message.user .message-content {
  background: var(--color-user-bg);
  color: var(--color-user-text);
  border-bottom-right-radius: var(--radius-sm);
}

.message.ai .message-content {
  background: var(--color-ai-bg);
  border: 1px solid var(--color-ai-border);
  border-bottom-left-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

.message.ai .message-content p { margin-bottom: var(--space-2); max-width: none; }
.message.ai .message-content p:last-child { margin-bottom: 0; }
.message.ai .message-content strong { color: var(--color-text); font-weight: 600; }
.message.ai .message-content a { color: var(--color-accent); }
.message.ai .message-content ul, .message.ai .message-content ol {
  margin: var(--space-2) 0;
  padding-left: var(--space-5);
}
.message.ai .message-content li { margin-bottom: var(--space-1); max-width: none; }
.message.ai .message-content code {
  background: var(--color-surface-offset);
  padding: 0.1em 0.3em;
  border-radius: var(--radius-sm);
  font-size: 0.9em;
}

/* Sources */
.message-sources {
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-divider);
}

.message-sources-title {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-faint);
  margin-bottom: var(--space-2);
}

.source-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-accent);
  padding: var(--space-1) var(--space-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  margin-right: var(--space-1);
  margin-bottom: var(--space-1);
  text-decoration: none;
  transition: all var(--transition);
}

.source-link:hover {
  background: var(--color-accent-light);
  border-color: var(--color-accent);
  text-decoration: none;
}

/* Loading */
.typing-indicator {
  display: flex;
  gap: 4px;
  padding: var(--space-4);
}

.typing-dot {
  width: 8px;
  height: 8px;
  background: var(--color-text-faint);
  border-radius: var(--radius-full);
  animation: typingBounce 1.4s infinite ease-in-out;
}

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

@keyframes typingBounce {
  0%, 80%, 100% { transform: scale(0.6); opacity: 0.4; }
  40% { transform: scale(1); opacity: 1; }
}

/* Error */
.error-message {
  padding: var(--space-3) var(--space-4);
  background: rgba(220, 38, 38, 0.08);
  border: 1px solid rgba(220, 38, 38, 0.2);
  border-radius: var(--radius-md);
  color: var(--color-error);
  font-size: var(--text-sm);
}

/* ======== INPUT AREA ======== */
.chat-input-area {
  padding: var(--space-3) var(--space-6) var(--space-4);
  border-top: 1px solid var(--color-divider);
  background: var(--color-surface);
  flex-shrink: 0;
}

.chat-form {
  max-width: 800px;
  margin: 0 auto;
}

.input-wrapper {
  display: flex;
  align-items: flex-end;
  gap: var(--space-2);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-2) var(--space-3);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.input-wrapper:focus-within {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-light);
}

.input-wrapper textarea {
  flex: 1;
  border: none;
  background: none;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  line-height: 1.5;
  resize: none;
  outline: none;
  max-height: 120px;
  padding: var(--space-1) 0;
}

.input-wrapper textarea::placeholder {
  color: var(--color-text-faint);
}

.send-btn {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent);
  color: white;
  flex-shrink: 0;
  transition: all var(--transition);
}

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

.send-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.input-hint {
  display: block;
  text-align: center;
  font-size: 11px;
  color: var(--color-text-faint);
  margin-top: var(--space-1);
}

/* ======== MOBILE ======== */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    z-index: 200;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    box-shadow: var(--shadow-lg);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 199;
    display: none;
  }

  .sidebar-overlay.visible {
    display: block;
  }

  .menu-toggle {
    display: flex;
  }

  .chat-messages {
    padding: var(--space-3);
  }

  .chat-input-area {
    padding: var(--space-2) var(--space-3) var(--space-3);
  }

  .input-hint {
    display: none;
  }
}

/* ======== REDUCED MOTION ======== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}