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

  :root {
    /* Light mode (default) */
    --cream: #faf8f5;
    --ink: #1a1814;
    --ink-light: #6b6560;
    --accent: #c8783a;
    --border: #e8e4de;
    --user-bg: #fff;
    --coach-bg: #f5f1eb;
    --header-bg: #fff;
    --input-area-bg: #fff;
    --radius: 3px;
  }

  @media (prefers-color-scheme: dark) {
    :root {
      --cream: #1a1814;
      --ink: #f5f1eb;
      --ink-light: #a89f97;
      --accent: #e8a862;
      --border: #3d3934;
      --user-bg: #2a2520;
      --coach-bg: #1a1814;
      --header-bg: #1a1814;
      --input-area-bg: #1a1814;
    }
  }

  [data-theme="dark"] {
    --cream: #1a1814;
    --ink: #f5f1eb;
    --ink-light: #a89f97;
    --accent: #e8a862;
    --border: #3d3934;
    --user-bg: #2a2520;
    --coach-bg: #1a1814;
    --header-bg: #1a1814;
    --input-area-bg: #1a1814;
    --radius: 3px;
  }

  [data-theme="light"] {
    --cream: #faf8f5;
    --ink: #1a1814;
    --ink-light: #6b6560;
    --accent: #c8783a;
    --border: #e8e4de;
    --user-bg: #fff;
    --coach-bg: #f5f1eb;
    --header-bg: #fff;
    --input-area-bg: #fff;
  }

  body {
    background: var(--cream);
    color: var(--ink);
    font-family: 'DM Sans', sans-serif;
    height: 100dvh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
  }

  /* Header */
  header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border);
    background: var(--header-bg);
    flex-shrink: 0;
    transition: background-color 0.2s, border-color 0.2s;
  }

  .wordmark {
    font-family: 'Lora', serif;
    font-size: 20px;
    font-weight: 400;
    letter-spacing: -0.02em;
  }

  .wordmark span { color: var(--accent); font-style: italic; }

  .header-right {
    display: flex;
    align-items: center;
    gap: 16px;
  }

  .user-email {
    font-size: 12px;
    color: var(--ink-light);
  }

  .logout {
    font-size: 12px;
    color: var(--ink-light);
    text-decoration: none;
    padding: 6px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: all 0.15s;
  }

  .logout:hover { border-color: var(--ink-light); color: var(--ink); }

  /* Messages */
  #messages {
    flex: 1;
    overflow-y: auto;
    padding: 32px 24px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    max-width: 760px;
    width: 100%;
    margin: 0 auto;
  }

  .message {
    display: flex;
    flex-direction: column;
    gap: 6px;
    animation: fadeIn 0.2s ease;
  }

  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(6px); }
    to   { opacity: 1; transform: translateY(0); }
  }

  .message-label {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--ink-light);
  }

  .message-bubble {
    padding: 16px 18px;
    border-radius: var(--radius);
    font-size: 15px;
    line-height: 1.7;
    white-space: pre-wrap;
  }

  .message.user .message-bubble {
    background: var(--user-bg);
    border: 1px solid var(--border);
  }

  .message.coach .message-bubble {
    background: var(--coach-bg);
    border: 1px solid #ded9d1;
    font-family: 'Lora', serif;
    font-size: 15px;
  }

  .message.coach .message-bubble strong {
    font-weight: 600;
    color: var(--ink);
  }

  .sources {
    font-size: 11px;
    color: var(--ink-light);
    font-style: italic;
    margin-top: 4px;
    padding-left: 2px;
  }

  /* Thinking indicator */
  .thinking .message-bubble {
    display: flex;
    gap: 6px;
    align-items: center;
    padding: 18px;
  }

  .dot {
    width: 7px; height: 7px;
    background: var(--ink-light);
    border-radius: 50%;
    animation: pulse 1.2s ease-in-out infinite;
  }

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

  @keyframes pulse {
    0%, 60%, 100% { opacity: 0.3; transform: scale(1); }
    30% { opacity: 1; transform: scale(1.2); }
  }

  /* Welcome */
  .welcome {
    text-align: center;
    padding: 48px 24px;
    color: var(--ink-light);
  }

  .welcome h2 {
    font-family: 'Lora', serif;
    font-size: 22px;
    font-weight: 400;
    color: var(--ink);
    margin-bottom: 10px;
  }

  .welcome p {
    font-size: 14px;
    line-height: 1.6;
    max-width: 400px;
    margin: 0 auto 28px;
  }

  .suggestions {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    max-width: 560px;
    margin: 0 auto;
  }

  .suggestion {
    padding: 9px 16px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 13px;
    color: var(--ink);
    cursor: pointer;
    transition: all 0.15s;
    font-family: 'DM Sans', sans-serif;
  }

  .suggestion:hover {
    border-color: var(--accent);
    color: var(--accent);
  }

  /* Input area */
  .input-area {
    border-top: 1px solid var(--border);
    padding: 16px 24px;
    padding-bottom: max(20px, env(safe-area-inset-bottom, 20px));
    background: var(--input-area-bg);
    flex-shrink: 0;
    position: sticky;
    bottom: 0;
    z-index: 10;
    transition: background-color 0.2s, border-color 0.2s;
  }

  .input-inner {
    max-width: 760px;
    margin: 0 auto;
    display: flex;
    gap: 10px;
    align-items: flex-end;
  }

  textarea {
    flex: 1;
    padding: 12px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-family: 'DM Sans', sans-serif;
    font-size: 15px;
    color: var(--ink);
    background: var(--cream);
    resize: none;
    outline: none;
    line-height: 1.5;
    max-height: 120px;
    transition: border-color 0.15s;
  }

  textarea:focus { border-color: var(--accent); }
  textarea::placeholder { color: var(--ink-light); }

  #send-btn {
    padding: 12px 20px;
    background: var(--ink);
    color: #fff;
    border: none;
    border-radius: var(--radius);
    font-family: 'DM Sans', sans-serif;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.15s;
    white-space: nowrap;
    height: 46px;
  }

  #send-btn:hover:not(:disabled) { background: #2d2a25; }
  #send-btn:disabled { background: #ccc; cursor: not-allowed; }

  .disclaimer {
    text-align: center;
    font-size: 11px;
    color: var(--ink-light);
    margin-top: 10px;
  }

  /* Scrollbar */
  #messages::-webkit-scrollbar { width: 4px; }
  #messages::-webkit-scrollbar-track { background: transparent; }
  #messages::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

  /* Dark mode toggle */
  .dark-mode-toggle {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--ink-light);
    padding: 4px 10px;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    transition: all 0.15s;
    margin-right: 8px;
  }

  .dark-mode-toggle:hover {
    border-color: var(--accent);
    color: var(--accent);
  }

  /* Smooth transitions for theme changes */
  body, header, .input-area, textarea, #send-btn, .logout, .suggestion {
    transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  }
</style>