:root {
  /* rendering optimizations */
  color-scheme: light dark;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;

  /* sizes */
  --avatar-size: 48px;

  /* light theme */
  --bg-primary: #f5f0f8;
  --bg-secondary: #e8dff0;
  --text-primary: #2d1b3d;
  --text-secondary: #6b5573;
  --text-muted: rgba(45, 27, 61, 0.5);
  --border: #d4c5de;
  --accent: #e6613c;
  --accent-hover: #e49424;
  --error: #c0392b;
}

[data-theme="lighter"] {
    /* lighter theme */
  --bg-primary: #fdf8fc;
  --bg-secondary: #f5ecf3;
  --text-primary: #1a1a2e;
  --text-secondary: #4a5568;
  --text-muted: rgba(26, 26, 46, 0.5);
  --border: #e5dfe8;
  --accent: #5c64ff;
  --accent-hover: #5295ff;
  --error: #e63946;
}

@media (prefers-color-scheme: dark) {
  :root {
    /* dark theme */
    --bg-primary: #2a1f3d;
    --bg-secondary: #3d2f54;
    --text-primary: #f5e6ff;
    --text-secondary: #d4b5e0;
    --text-muted: rgba(245, 230, 255, 0.6);
    --border: #4a3a5f;
    --accent: #fcbb6c;
    --accent-hover: #ff8a7a;
    --error: #e74c3c;
  }
}

[data-theme="darker"] {
    /* darker theme */
  --bg-primary: #1a0f24;
  --bg-secondary: #2d1b3d;
  --text-primary: #fef5f0;
  --text-secondary: #e8b5a0;
  --text-muted: rgba(254, 245, 240, 0.6);
  --border: #3d2750;
  --accent: #fcbb6c;
  --accent-hover: #ff8a7a;
  --error: #e74c3c;
}

#login-container {
  max-width: 400px;
  margin: 2rem auto;
  padding: 2rem;
}

#handle-input {
  width: 100%;
  padding: 0.5rem;
  margin-bottom: 1rem;
}

#login-error {
  color: var(--error);
  margin-top: 1rem;
}

a {
  font-weight: 500;
  color: var(--accent);
  text-decoration: inherit;
}
a:hover {
  color: var(--accent-hover);
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  margin: 0;
  display: flex;
  min-height: 100vh;

  font-family: system-ui, Avenir, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  font-weight: 400;
}

h1 {
  font-size: 3.2em;
  line-height: 1.1;
}

#app {
  max-width: 1280px;
  margin: 0 auto;
  padding: 2rem;
}

.note {
  display: flex;
  gap: 10px;
  padding: 16px;
  margin-bottom: 16px;
}

/* standalone notes (not in a chain) */
.note:not(.reply-chain .note) {
  background: var(--bg-primary);
  border: 2px solid var(--border);
  border-radius: 8px;
}

/* reply chains container */
.reply-chain {
  background: var(--bg-primary);
  border: 2px solid var(--border);
  border-radius: 8px;
  margin-bottom: 16px;
  overflow: hidden;
}

/* notes inside chains */
.reply-chain .note {
  background: transparent;
  border: none;
  border-radius: 0;
  margin: 0;
}

/* separator between notes in chain */
.reply-chain .note + .note {
  border-top: 2px solid var(--border);
}

.note-avatar {
  width: var(--avatar-size);
  height: var(--avatar-size);
  flex-shrink: 0;
}

.note-content {
  flex: 1;
}

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

.note-media {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(45%, 1fr));
  grid-auto-rows: 200px;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.note-media:has(> :only-child) {
  grid-auto-rows: auto;
  justify-content: start;
}

.note-media:has(> :only-child) img {
  width: auto;
  max-width: 100%;
  height: auto;
  max-height: 400px;
  object-fit: contain;
}

.note-media img,
.note-media-error {
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  overflow: hidden;
  border-radius: 8px;
}

.note-media img {
  object-fit: cover;
}

.note-media img.has-alt {
  border: 2px solid var(--accent);
}

.note-media img.no-alt {
  border: 2px solid var(--error);
}

.note-media-error {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.25rem;
  padding: 1rem;
  background: var(--bg-secondary);
  border: 2px solid var(--error);
  text-align: center;
  font-size: 0.85rem;
}

.note-media-error img {
  width: 48px;
  height: 48px;
  border: none !important;
  object-fit: contain;
  height: auto;
  max-height: unset;
  grid-auto-rows: unset;
}

#lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  flex-direction: column;
  gap: 1rem;
  padding: 2rem;
}

#lightbox-img {
  max-width: 90vw;
  max-height: 80vh;
  object-fit: contain;
  border-radius: 8px;
  border: none !important;
}

#lightbox-alt {
  color: white;
  background: rgba(0, 0, 0, 0.6);
  padding: 0.5rem 1rem;
  border-radius: 8px;
  max-width: 60ch;
  text-align: center;
  font-size: 0.9rem;
}

#lightbox-prev,
#lightbox-next {
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(0, 0, 0, 0.5);
  color: white;
  border: none;
  font-size: 2rem;
  padding: 0.5rem 1rem;
  cursor: pointer;
  border-radius: 4px;
}

#lightbox-prev { left: 1rem; }
#lightbox-next { right: 1rem; }

#lightbox-prev:hover,
#lightbox-next:hover {
  background: rgba(0, 0, 0, 0.8);
}

#lightbox-close {
  position: fixed;
  top: 1rem;
  right: 1rem;
  background: rgba(0, 0, 0, 0.5);
  color: white;
  border: none;
  font-size: 1.5rem;
  width: 2rem;
  height: 2rem;
  cursor: pointer;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.muted {
  color: var(--text-muted);
  font-size: 12px;
}

.info {
  color: var(--text-muted);
  font-style: italic;
  text-align: center;
}

.spinner {
  border: 8px solid var(--border);
  border-top: 8px solid var(--accent);
  border-radius: 50%;
  width: 64px;
  height: 64px;
  animation: spin 2s linear infinite;
  margin: 20px auto;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}