/*
  Styles for the standalone /sudoku-cards page.
  Reuses CSS variables from ../styles.css and theme variables from the game palette.
  Card design is a web port of the Flutter FirstScreen CardsRibbon / MyCard widgets.
*/

.site-main--cards {
  display: block;
  align-items: initial;
  justify-content: initial;
  padding: 0;
}

.cards-page {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 20px 64px;
  width: 100%;
}

.cards-page__head {
  margin-bottom: 24px;
}

.cards-page__title {
  margin: 0 0 8px;
  font-size: 28px;
  font-weight: 700;
  color: var(--text);
}

.cards-page__intro {
  margin: 0;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 640px;
}

/* ---------- Difficulty tabs ---------- */

.difficulty-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 28px;
  overflow-x: auto;
}

.difficulty-tab {
  appearance: none;
  border: none;
  background: transparent;
  font: inherit;
  font-size: 15px;
  color: var(--text-muted);
  padding: 10px 16px;
  cursor: pointer;
  border-bottom: 3px solid transparent;
  white-space: nowrap;
}

.difficulty-tab:hover {
  color: var(--text);
}

.difficulty-tab.is-active {
  color: var(--text);
  font-weight: 700;
  border-bottom-color: var(--accent);
}

/* ---------- Cards ribbon ---------- */

.cards-ribbon-wrap {
  position: relative;
  width: 100%;
  overflow: hidden;
  border-radius: 16px;
  background: var(--panel);
  border: 1px solid var(--border);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.4) inset,
    0 6px 16px rgba(43, 51, 63, 0.06);
}

.cards-ribbon {
  display: flex;
  gap: 12px;
  padding: 20px 24px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.cards-ribbon::-webkit-scrollbar {
  height: 8px;
}

.cards-ribbon::-webkit-scrollbar-track {
  background: transparent;
}

.cards-ribbon::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

/* ---------- Flip card container ---------- */

.flip-card {
  flex: 0 0 auto;
  width: 160px;
  height: 220px;
  perspective: 800px;
  scroll-snap-align: start;
  cursor: pointer;
  user-select: none;
}

.flip-card__inner {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 16px;
  transition: transform 500ms cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
}

.flip-card.is-face .flip-card__inner {
  transform: rotateY(180deg);
}

.flip-card__face,
.flip-card__back {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border-radius: 16px;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  overflow: hidden;
}

.flip-card__face {
  transform: rotateY(180deg);
}

/* ---------- Card neumorphic base ---------- */

.card-neu {
  background: var(--bg);
  border-radius: 16px;
  box-shadow:
    6px 6px 12px var(--shadow-dark-color, rgba(0, 0, 0, 0.12)),
    -6px -6px 12px var(--shadow-light-color, rgba(255, 255, 255, 0.7));
}

.theme-dark .card-neu {
  box-shadow:
    6px 6px 12px var(--shadow-dark-color, rgba(0, 0, 0, 0.4)),
    -4px -4px 10px var(--shadow-light-color, rgba(255, 255, 255, 0.05));
}

/* ---------- Front card (real level) ---------- */

.sudoku-card {
  display: flex;
  flex-direction: column;
  padding: 12px;
  height: 100%;
  box-sizing: border-box;
}

.sudoku-card__header {
  display: flex;
  align-items: flex-start;
  gap: 6px;
  margin-bottom: 6px;
}

.sudoku-card__difficulty-icon {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.sudoku-card__difficulty-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.sudoku-card__difficulty-name {
  flex: 1;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.02em;
  line-height: 1.2;
  margin-top: 4px;
}

.sudoku-card__level-badge {
  flex-shrink: 0;
  min-width: 46px;
  padding: 5px 8px;
  border-radius: 8px 0 8px 0;
  background: var(--highlight-color);
  color: var(--tone-minus-one, #fff);
  font-size: 12px;
  font-weight: 700;
  text-align: center;
}

.sudoku-card__title {
  text-align: center;
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  margin: 0 0 10px;
}

.sudoku-card__progress {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  margin: auto 0 8px;
}

.sudoku-card__progress-ring {
  position: relative;
  width: 88px;
  height: 88px;
  border-radius: 50%;
  background: var(--bg);
  box-shadow:
    inset 4px 4px 8px var(--shadow-dark-color, rgba(0, 0, 0, 0.12)),
    inset -4px -4px 8px var(--shadow-light-color, rgba(255, 255, 255, 0.7));
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-dark .sudoku-card__progress-ring {
  box-shadow:
    inset 4px 4px 8px var(--shadow-dark-color, rgba(0, 0, 0, 0.4)),
    inset -2px -2px 6px var(--shadow-light-color, rgba(255, 255, 255, 0.05));
}

.sudoku-card__progress-ring svg {
  position: absolute;
  inset: 0;
  transform: rotate(-90deg);
}

.sudoku-card__progress-ring circle {
  fill: none;
  stroke-width: 8;
}

.sudoku-card__progress-ring .track {
  stroke: var(--border);
}

.sudoku-card__progress-ring .fill {
  stroke: var(--accent);
  transition: stroke-dashoffset 300ms ease;
}

.sudoku-card__progress-ring .fill.is-complete {
  stroke: var(--green-color, #4caf50);
}

.sudoku-card__progress-text {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  z-index: 1;
}

.sudoku-card__status-badge {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--panel);
  color: var(--text-muted);
}

.sudoku-card__status-badge.is-complete {
  background: var(--green-color, #4caf50);
  color: #fff;
}

.sudoku-card__status-badge.is-in-progress {
  background: var(--yellow-color, #dea01e);
  color: var(--tone-minus-one, #fff);
}

.sudoku-card__stats {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-size: 11px;
  color: var(--text-muted);
  margin-top: auto;
}

.sudoku-card__stat {
  display: flex;
  align-items: center;
  gap: 4px;
}

.sudoku-card__stat svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

/* ---------- Back card (placeholder) ---------- */

.placeholder-card {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  border-radius: 16px;
}

.placeholder-card__image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 16px;
}

.placeholder-card__overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: rgba(0, 0, 0, 0.22);
  border-radius: 16px;
}

.placeholder-card__icon {
  width: 36px;
  height: 36px;
  color: rgba(255, 255, 255, 0.9);
}

.placeholder-card__label {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: rgba(255, 255, 255, 0.9);
}

/* ---------- Selection highlight ---------- */

.flip-card.is-selected .flip-card__inner {
  box-shadow: 0 0 0 3px var(--accent), 0 12px 28px rgba(38, 90, 194, 0.22);
}

/* ---------- Hint ---------- */

.cards-hint {
  margin: 20px 0 0;
  font-size: 14px;
  color: var(--text-muted);
  text-align: center;
}

/* ---------- Responsive ---------- */

@media (max-width: 480px) {
  .cards-page {
    padding: 20px 16px 48px;
  }

  .cards-page__title {
    font-size: 24px;
  }

  .flip-card {
    width: 138px;
    height: 190px;
  }

  .cards-ribbon {
    padding: 16px;
    gap: 10px;
  }

  .sudoku-card__progress-ring {
    width: 72px;
    height: 72px;
  }

  .sudoku-card__progress-text {
    font-size: 15px;
  }
}