@import url('https://fonts.googleapis.com/css2?family=Google+Sans:wght@400;500;700&family=Roboto:wght@400;500;700&display=swap');

:root {
  --md-primary: #9c1a5c;
  --md-on-primary: #ffffff;
  --md-primary-container: #ffd8ea;
  --md-on-primary-container: #3f0025;
  --md-secondary: #74565f;
  --md-surface: #fff8f8;
  --md-surface-dim: #f2dee3;
  --md-on-surface: #22191b;
  --md-on-surface-variant: #524346;
  --md-surface-container: #fdedf1;
  --md-surface-container-high: #f7e2e8;
  --md-outline: #85747a;
  --md-outline-variant: #d7c1c8;
  --md-scrim: rgba(0, 0, 0, 0.6);
  --md-viewer-scrim: rgba(255, 248, 248, 0.72);
  --md-elevation-1: 0 1px 2px rgba(0,0,0,.30), 0 1px 3px 1px rgba(0,0,0,.15);
  --md-elevation-2: 0 1px 2px rgba(0,0,0,.30), 0 2px 6px 2px rgba(0,0,0,.15);
  --md-elevation-3: 0 4px 8px 3px rgba(0,0,0,.15), 0 1px 3px rgba(0,0,0,.30);
  --md-motion-emphasized: cubic-bezier(0.2, 0, 0, 1);
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --md-primary: #ffaed3;
    --md-on-primary: #5c0f3c;
    --md-primary-container: #7a2d55;
    --md-on-primary-container: #ffd8ea;
    --md-secondary: #e2bdc7;
    --md-surface: #181112;
    --md-surface-dim: #181112;
    --md-on-surface: #ecdfe1;
    --md-on-surface-variant: #d5c2c6;
    --md-surface-container: #251d1f;
    --md-surface-container-high: #302729;
    --md-outline: #9f8c90;
    --md-outline-variant: #524346;
    --md-viewer-scrim: rgba(15, 10, 11, 0.72);
    color-scheme: dark;
  }
}

/* Explicit user override via the top bar toggle, regardless of system setting */
:root[data-theme="dark"] {
  --md-primary: #ffaed3;
  --md-on-primary: #5c0f3c;
  --md-primary-container: #7a2d55;
  --md-on-primary-container: #ffd8ea;
  --md-secondary: #e2bdc7;
  --md-surface: #181112;
  --md-surface-dim: #181112;
  --md-on-surface: #ecdfe1;
  --md-on-surface-variant: #d5c2c6;
  --md-surface-container: #251d1f;
  --md-surface-container-high: #302729;
  --md-outline: #9f8c90;
  --md-outline-variant: #524346;
  --md-viewer-scrim: rgba(15, 10, 11, 0.72);
  color-scheme: dark;
}

:root[data-theme="light"] {
  --md-viewer-scrim: rgba(255, 248, 248, 0.72);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--md-surface);
  color: var(--md-on-surface);
  font-family: 'Roboto', 'Google Sans', system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--md-surface-container);
  border-bottom: 1px solid var(--md-outline-variant);
  backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--md-surface-container) 92%, transparent);
}

.topbar-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 14px 12px 14px 20px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.topbar-text {
  flex-shrink: 0;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.topbar-icon-btn {
  color: var(--md-on-surface-variant);
  background: var(--md-surface-container-high);
  flex-shrink: 0;
}

#theme-toggle.topbar-icon-btn:hover,
#lang-toggle.topbar-icon-btn:hover {
  background: color-mix(in srgb, var(--md-surface-container-high) 70%, var(--md-on-surface) 12%);
}

#lang-toggle {
  width: auto;
  padding: 0 14px;
  border-radius: 20px;
  font-family: 'Google Sans', 'Roboto', sans-serif;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.searchbar-wrap {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 12px;
  flex: 1 1 200px;
  min-width: 160px;
  justify-content: center;
}

.searchbar {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--md-surface-container-high);
  border-radius: 28px;
  padding: 10px 16px;
  width: 100%;
  max-width: 360px;
  box-shadow: var(--md-elevation-1);
}

.searchbar-icon {
  color: var(--md-on-surface-variant);
  flex-shrink: 0;
}

.searchbar-input {
  border: none;
  background: transparent;
  outline: none;
  color: var(--md-on-surface);
  font-family: 'Roboto', sans-serif;
  font-size: 14px;
  width: 100%;
  -moz-appearance: textfield;
}

.searchbar-input::-webkit-outer-spin-button,
.searchbar-input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.searchbar-input::placeholder {
  color: var(--md-on-surface-variant);
}

.searchbar-status {
  font-size: 13px;
  color: var(--md-on-surface-variant);
}

.searchbar-status.error {
  color: var(--md-primary);
}

.material-title {
  display: block;
  font-family: 'Google Sans', 'Roboto', sans-serif;
  font-size: 22px;
  font-weight: 500;
  color: var(--md-on-surface);
}

.topbar-subtitle {
  display: block;
  margin-top: 2px;
  font-size: 13px;
  color: var(--md-on-surface-variant);
}

/*
  Real masonry, built in JS (app.js): a fixed number of column divs, each
  photo appended to exactly one column and never moved again. This is what
  fixes the "auto scrolls up" jump — CSS `column-count` looked the same but
  rebalances every tile across columns whenever the DOM child count
  changes, which visibly shifts already-visible content on every batch load.
*/
.gallery {
  max-width: 1400px;
  margin: 0 auto;
  padding: 16px;
  display: flex;
  gap: 10px;
}

.gallery-col {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.tile {
  display: block;
  position: relative;
  width: 100%;
  border: none;
  padding: 0;
  border-radius: 16px;
  overflow: hidden;
  cursor: pointer;
  background: var(--md-surface-container-high);
  box-shadow: var(--md-elevation-1);
  content-visibility: auto;
  contain-intrinsic-size: 280px;
  transition: box-shadow 200ms var(--md-motion-emphasized), transform 200ms var(--md-motion-emphasized);
}

.tile:hover {
  box-shadow: var(--md-elevation-2);
  transform: translateY(-2px) scale(1.01);
}

.tile-id {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 3px 10px;
  border-radius: 10px;
  background: color-mix(in srgb, var(--md-on-surface) 55%, transparent);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  color: #fff;
  font-family: 'Google Sans', 'Roboto', sans-serif;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.02em;
  pointer-events: none;
  opacity: 0;
  transition: opacity 300ms ease;
}

.tile img.loaded ~ .tile-id {
  opacity: 1;
}

/* A tile whose image failed even after the automatic retries — a clearly
   visible, clickable-to-retry marker instead of a silent, permanent blank
   hole in the grid. */
.tile-failed {
  min-height: 160px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  background: var(--md-surface-container);
  border: 1px dashed var(--md-outline-variant);
}

.tile-failed::before {
  content: "⟳";
  color: var(--md-primary);
  font-size: 28px;
  line-height: 1;
}

.tile-failed::after {
  content: "Chạm để tải lại";
  color: var(--md-on-surface-variant);
  font-size: 11px;
}

/*
  The image reveals only once BOTH it has decoded and it has scrolled into
  view (gated together in app.js as one combined signal) — never two
  separately-timed animations on the same tile, which is what caused the
  flicker/jank before. Only the <img> moves, never the .tile container
  itself, so the masonry column flow (break-inside, box-shadow, hover)
  stays untouched by the reveal.
*/
.tile img {
  display: block;
  width: 100%;
  height: auto;
  background: var(--md-surface-dim);
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 480ms var(--md-motion-emphasized), transform 480ms var(--md-motion-emphasized);
}

.tile img.loaded {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .tile img {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

.sentinel {
  display: flex;
  justify-content: center;
  padding: 32px 0 64px;
}

.loader {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 3px solid var(--md-primary-container);
  border-top-color: var(--md-primary);
  animation: spin 850ms linear infinite;
}

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

.fab-group {
  position: fixed;
  right: 20px;
  bottom: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: 20;
}

.fab {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  border: none;
  background: var(--md-primary-container);
  color: var(--md-on-primary-container);
  box-shadow: var(--md-elevation-3);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px) scale(0.9);
  transition: opacity 240ms var(--md-motion-emphasized), transform 240ms var(--md-motion-emphasized);
}

.fab.show {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0) scale(1);
}

.fab:active {
  transform: scale(0.92);
}

/* Full-screen viewer — Material 3 full-screen dialog pattern */
.viewer {
  position: fixed;
  inset: 0;
  z-index: 100;
}

.viewer[hidden] {
  display: none;
}

.viewer-backdrop {
  position: absolute;
  inset: -4px;
  background: var(--md-viewer-scrim);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  animation: fadeIn 200ms ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.viewer-content {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  animation: viewerIn 220ms var(--md-motion-emphasized);
}

@keyframes viewerIn {
  from { opacity: 0; transform: scale(0.98); }
  to { opacity: 1; transform: scale(1); }
}

.viewer-appbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 16px;
  flex-shrink: 0;
}

.viewer-icon-btn {
  border: none;
  background: transparent;
  color: var(--md-on-surface);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  text-decoration: none;
  transition: background 150ms ease;
}

.viewer-icon-btn:hover {
  background: color-mix(in srgb, var(--md-on-surface) 10%, transparent);
}

.viewer-position {
  color: var(--md-on-surface);
  opacity: 0.85;
  font-size: 14px;
  font-weight: 500;
  font-family: 'Google Sans', 'Roboto', sans-serif;
}

.viewer-id {
  margin-left: auto;
  padding: 4px 12px;
  border-radius: 10px;
  background: var(--md-primary-container);
  color: var(--md-on-primary-container);
  font-family: 'Google Sans', 'Roboto', sans-serif;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.viewer-stage {
  position: relative;
  z-index: 0;
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 0;
  padding: 0 16px;
  overflow: hidden;
}

#viewer-img {
  max-width: min(92vw, 1400px);
  max-height: 100%;
  border-radius: 16px;
  box-shadow: var(--md-elevation-3);
  background: color-mix(in srgb, var(--md-on-surface) 15%, transparent);
  transition: opacity 200ms ease, transform 200ms var(--md-motion-emphasized);
  touch-action: none;
  user-select: none;
}

.viewer-btn {
  position: absolute;
  z-index: 2;
  border: none;
  background: color-mix(in srgb, var(--md-on-surface) 55%, transparent);
  color: var(--md-on-primary);
  border-radius: 50%;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 150ms ease, transform 150ms ease;
}

.viewer-btn:hover {
  background: color-mix(in srgb, var(--md-on-surface) 80%, transparent);
  transform: scale(1.06);
}

.viewer-prev {
  left: 16px;
}

.viewer-next {
  right: 16px;
}

.zoombar {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  padding: 6px;
  background: var(--md-surface-container-high);
  border-radius: 24px;
  box-shadow: var(--md-elevation-1);
  width: fit-content;
}

.zoombar-btn {
  border: none;
  background: transparent;
  color: var(--md-on-surface-variant);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 150ms ease;
}

.zoombar-btn:hover {
  background: color-mix(in srgb, var(--md-on-surface) 10%, transparent);
}

.zoombar-btn:active {
  transform: scale(0.92);
}

.zoombar-btn:disabled {
  opacity: 0.35;
  cursor: default;
}

.zoombar-btn:disabled:hover {
  background: transparent;
}

.zoombar-level {
  min-width: 52px;
  text-align: center;
  font-family: 'Google Sans', 'Roboto', sans-serif;
  font-size: 13px;
  font-weight: 600;
  color: var(--md-on-surface);
}

.viewer-toolbar {
  position: relative;
  z-index: 1;
  flex-shrink: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px 10px;
  padding: 16px;
}

.toolbar-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  border: none;
  background: var(--md-primary-container);
  color: var(--md-on-primary-container);
  font-family: 'Google Sans', 'Roboto', sans-serif;
  font-size: 14px;
  font-weight: 500;
  padding: 12px 20px;
  border-radius: 20px;
  cursor: pointer;
  box-shadow: var(--md-elevation-1);
  transition: box-shadow 150ms ease, transform 150ms ease;
}

.toolbar-btn:hover {
  box-shadow: var(--md-elevation-2);
  transform: translateY(-1px);
}

.toolbar-btn:active {
  transform: scale(0.97);
}

.snackbar {
  position: fixed;
  left: 50%;
  bottom: 32px;
  transform: translateX(-50%) translateY(20px);
  background: #322a2c;
  color: #fff;
  padding: 14px 24px;
  border-radius: 8px;
  font-size: 14px;
  box-shadow: var(--md-elevation-3);
  opacity: 0;
  pointer-events: none;
  transition: opacity 200ms ease, transform 200ms ease;
  z-index: 200;
}

.snackbar.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}