:root {
  color-scheme: dark;
  --bg: #0d0d10;
  --surface: #16161b;
  --border: #27272e;
  --text: #ededf0;
  --text-dim: #9a9aa2;
  --accent: #5b8cff;
  --danger: #ff6b6b;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

[hidden] {
  display: none !important;
}

button {
  font-family: inherit;
  cursor: pointer;
}

/* ---------- Login ---------- */

.login-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.login-form {
  width: 100%;
  max-width: 320px;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  text-align: center;
}

.login-form h1 {
  margin: 0 0 0.5rem;
  font-size: 1.5rem;
  font-weight: 600;
}

.login-form input {
  padding: 0.75rem 1rem;
  border-radius: 0.5rem;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 1rem;
}

.login-form input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.login-form button {
  padding: 0.75rem 1rem;
  border-radius: 0.5rem;
  border: none;
  background: var(--accent);
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
}

.login-form button:hover {
  filter: brightness(1.08);
}

.error {
  color: var(--danger);
  font-size: 0.875rem;
  margin: 0;
}

/* ---------- Gallery ---------- */

.gallery-screen {
  min-height: 100vh;
  max-width: 1400px; /* caps columns on wide desktops so fewer thumbnails load at once */
  margin: 0 auto;
  padding: 1rem 1.25rem 3rem;
}

.gallery-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0 1rem;
}

.gallery-header h1 {
  font-size: 1.25rem;
  margin: 0;
  font-weight: 600;
}

.text-button {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 0.4rem 0.85rem;
  border-radius: 999px;
  font-size: 0.85rem;
}

.text-button:hover {
  color: var(--text);
  border-color: var(--text-dim);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 6px;
}

@media (min-width: 1024px) {
  .grid {
    grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  }
}

.thumb {
  position: relative;
  aspect-ratio: 1 / 1;
  border: none;
  padding: 0;
  margin: 0;
  overflow: hidden;
  border-radius: 6px;
  background: var(--surface);
}

.thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.15s ease;
}

.thumb:hover img {
  transform: scale(1.04);
}

.thumb:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem 0.5rem;
  padding: 0 0 0.75rem;
  font-size: 0.9rem;
  color: var(--text-dim);
}

.breadcrumb-link {
  background: none;
  border: none;
  padding: 0.2rem 0;
  color: var(--accent);
  font-size: inherit;
}

.breadcrumb-link:hover {
  text-decoration: underline;
}

.breadcrumb-current {
  color: var(--text);
  word-break: break-all;
}

.thumb.folder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem;
  border: 1px solid var(--border);
  color: var(--text);
}

.thumb.folder:hover {
  border-color: var(--text-dim);
}

.folder-icon {
  font-size: 2.5rem;
  line-height: 1;
}

.folder-name {
  max-width: 100%;
  font-size: 0.85rem;
  text-align: center;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sentinel {
  height: 1px;
}

.status {
  text-align: center;
  color: var(--text-dim);
  padding: 2rem 0;
}

/* ---------- Full-screen viewer ---------- */

.viewer {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.94);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 100;
}

.viewer-stage {
  position: relative;
  width: 100%;
  flex: 1;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.viewer-image {
  max-width: 92vw;
  max-height: 100%;
  object-fit: contain;
  user-select: none;
}

.viewer-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-self: stretch;
  padding: 1rem 4rem 0.5rem 1rem; /* right padding keeps clear of the close button */
}

.viewer-tool {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: rgba(255, 255, 255, 0.08);
  border: none;
  border-radius: 999px;
  color: #fff;
  padding: 0.45rem 0.85rem;
  font-size: 0.85rem;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
}

.viewer-tool:hover {
  background: rgba(255, 255, 255, 0.18);
}

.viewer-switch {
  gap: 0.6rem;
}

.switch-track {
  position: relative;
  width: 2.2rem;
  height: 1.25rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.3);
  transition: background 0.2s ease;
}

.switch-thumb {
  position: absolute;
  top: 0.15rem;
  left: 0.15rem;
  width: 0.95rem;
  height: 0.95rem;
  border-radius: 50%;
  background: #fff;
  transition: transform 0.2s ease;
}

.viewer-switch[aria-checked="true"] .switch-track {
  background: #3b82f6;
}

.viewer-switch[aria-checked="true"] .switch-thumb {
  transform: translateX(0.95rem);
}

.viewer-caption {
  color: var(--text-dim);
  font-size: 0.8rem;
  height: 3rem;
  display: flex;
  align-items: center;
  margin: 0;
  padding: 0 1rem;
  text-align: center;
  word-break: break-all;
}

.viewer-control {
  position: absolute;
  background: rgba(255, 255, 255, 0.08);
  border: none;
  color: #fff;
  border-radius: 999px;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 101;
}

.viewer-control:hover {
  background: rgba(255, 255, 255, 0.18);
}

.viewer-close {
  top: 1rem;
  right: 1rem;
  width: 2.5rem;
  height: 2.5rem;
  font-size: 1.5rem;
  line-height: 1;
}

.viewer-prev,
.viewer-next {
  top: 50%;
  transform: translateY(-50%);
  width: 3rem;
  height: 3rem;
  font-size: 1.1rem;
}

.viewer-prev {
  left: 1rem;
}

.viewer-next {
  right: 1rem;
}

.viewer-control:disabled {
  opacity: 0.3;
  cursor: default;
}

.spinner {
  position: absolute;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  border: 3px solid rgba(255, 255, 255, 0.2);
  border-top-color: #fff;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (max-width: 640px) {
  .grid {
    grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
    gap: 4px;
  }

  .viewer-toolbar {
    padding: 0.75rem 3.75rem 0.25rem 0.75rem;
  }

  .viewer-tool {
    padding: 0.4rem 0.7rem;
    font-size: 0.8rem;
  }

  .viewer-prev,
  .viewer-next {
    width: 2.5rem;
    height: 2.5rem;
  }
}