/* =========================================================
   Sambung Kata (Shiritori) Quiz — CSS
   ========================================================= */

/* ── Hero Banner ── */
.sambung-hero {
  background: linear-gradient(135deg, #7c3aed 0%, #a855f7 50%, #ec4899 100%);
  border-radius: var(--radius-xl, 16px);
  padding: 1.5rem 1.25rem 1.25rem;
  text-align: center;
  margin-bottom: 1rem;
  position: relative;
  overflow: hidden;
}
.sambung-hero::before {
  content: 'つ な い で';
  position: absolute;
  top: 8px; left: 0; right: 0;
  font-size: 3rem;
  font-weight: 900;
  color: rgba(255,255,255,.08);
  letter-spacing: .5em;
  pointer-events: none;
}
.sambung-hero-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: .3rem;
}
.sambung-hero-sub {
  font-size: .85rem;
  color: rgba(255,255,255,.85);
}

/* ── Chain Display ── */
.sk-chain-wrap {
  display: flex;
  align-items: center;
  gap: .4rem;
  overflow-x: auto;
  padding: .5rem .25rem;
  margin-bottom: .75rem;
  scrollbar-width: thin;
  scrollbar-color: var(--purple, #7c3aed) transparent;
  scroll-behavior: smooth;
}
.sk-chain-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  flex-shrink: 0;
}
.sk-chain-bubble {
  background: linear-gradient(135deg, #7c3aed, #a855f7);
  color: #fff;
  border-radius: 999px;
  padding: .3rem .75rem;
  font-size: .8rem;
  font-weight: 700;
  white-space: nowrap;
  box-shadow: 0 2px 8px rgba(124,58,237,.3);
  animation: sk-pop .25s cubic-bezier(.34,1.56,.64,1);
}
.sk-chain-arrow {
  color: var(--gray-400, #9ca3af);
  font-size: 1rem;
  align-self: center;
  flex-shrink: 0;
}
.sk-chain-dot {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--gray-100, #f3f4f6);
  border: 2px dashed var(--gray-300, #d1d5db);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .65rem;
  color: var(--gray-400);
}

/* ── Current Word Card ── */
.sk-current-card {
  background: var(--white, #fff);
  border: 2.5px solid #a855f7;
  border-radius: var(--radius-xl, 16px);
  padding: 1.25rem;
  text-align: center;
  margin-bottom: 1rem;
  box-shadow: 0 4px 20px rgba(168,85,247,.15);
  position: relative;
}
.sk-current-label {
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: #a855f7;
  margin-bottom: .4rem;
}
.sk-current-jp {
  font-size: 2rem;
  font-weight: 800;
  color: var(--gray-900, #111);
  line-height: 1.2;
}
.sk-current-hira {
  font-size: 1rem;
  color: #7c3aed;
  font-weight: 600;
  margin-top: .15rem;
}
.sk-current-id {
  font-size: .82rem;
  color: var(--gray-500, #6b7280);
  margin-top: .2rem;
}
.sk-next-hint {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  margin-top: .75rem;
  background: linear-gradient(135deg, #fdf4ff, #fce7f3);
  border: 1.5px solid #f0abfc;
  border-radius: 999px;
  padding: .35rem .9rem;
  font-size: .85rem;
  font-weight: 700;
  color: #86198f;
}
.sk-next-char {
  font-size: 1.2rem;
  font-weight: 900;
  color: #a855f7;
  background: rgba(168,85,247,.12);
  border-radius: 6px;
  padding: 0 .35rem;
}

/* ── Score Bar ── */
.sk-score-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--gray-50, #f9fafb);
  border: 1px solid var(--gray-200, #e5e7eb);
  border-radius: var(--radius-lg, 12px);
  padding: .6rem 1rem;
  margin-bottom: .75rem;
  gap: .5rem;
}
.sk-score-pill {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  flex: 1;
  text-align: center;
}
.sk-score-val {
  font-size: 1.3rem;
  font-weight: 800;
  color: #7c3aed;
  line-height: 1;
}
.sk-score-lbl {
  font-size: .65rem;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: .06em;
  font-weight: 600;
}
.sk-score-divider {
  width: 1px;
  height: 32px;
  background: var(--gray-200);
}

/* ── Timer ── */
.sk-timer-bar {
  height: 6px;
  background: var(--gray-100, #f3f4f6);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: .75rem;
}
.sk-timer-fill {
  height: 100%;
  background: linear-gradient(90deg, #7c3aed, #ec4899);
  border-radius: 999px;
  transition: width .1s linear;
}
.sk-timer-fill.warning {
  background: linear-gradient(90deg, #f59e0b, #ef4444);
}

/* ── Options ── */
.sk-options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .6rem;
  margin-bottom: 1rem;
}
.sk-option-btn {
  background: var(--white, #fff);
  border: 2px solid var(--gray-200, #e5e7eb);
  border-radius: var(--radius-lg, 12px);
  padding: .75rem .6rem;
  cursor: pointer;
  text-align: center;
  transition: all .2s cubic-bezier(.34,1.56,.64,1);
  display: flex;
  flex-direction: column;
  gap: 3px;
  align-items: center;
}
.sk-option-btn:hover:not(:disabled) {
  border-color: #a855f7;
  background: #fdf4ff;
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(168,85,247,.2);
}
.sk-option-btn:disabled { cursor: not-allowed; opacity: .7; }
.sk-option-btn.correct {
  border-color: #16a34a !important;
  background: #f0fdf4 !important;
  animation: sk-bounce .4s cubic-bezier(.34,1.56,.64,1);
}
.sk-option-btn.wrong {
  border-color: #dc2626 !important;
  background: #fef2f2 !important;
  animation: sk-shake .35s ease;
}
.sk-option-jp {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--gray-900, #111);
}
.sk-option-hira {
  font-size: .75rem;
  color: #7c3aed;
  font-weight: 600;
}
.sk-option-romaji {
  font-size: .7rem;
  color: var(--gray-400);
}

/* ── Feedback Toast ── */
.sk-feedback {
  position: fixed;
  bottom: 90px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: #111;
  color: #fff;
  border-radius: 999px;
  padding: .6rem 1.4rem;
  font-size: .88rem;
  font-weight: 700;
  opacity: 0;
  pointer-events: none;
  transition: all .3s ease;
  z-index: 9999;
  white-space: nowrap;
  max-width: 90vw;
}
.sk-feedback.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.sk-feedback.ok  { background: #16a34a; }
.sk-feedback.err { background: #dc2626; }

/* ── Result Screen ── */
.sk-result-wrap {
  text-align: center;
  padding: 2rem 1rem;
}
.sk-result-emoji {
  font-size: 4rem;
  margin-bottom: .5rem;
  animation: sk-pop .5s cubic-bezier(.34,1.56,.64,1);
}
.sk-result-score {
  font-size: 3rem;
  font-weight: 900;
  background: linear-gradient(135deg, #7c3aed, #ec4899);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.sk-result-label {
  font-size: 1rem;
  color: var(--gray-600);
  margin-bottom: 1.5rem;
}
.sk-chain-review {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  justify-content: center;
  max-height: 180px;
  overflow-y: auto;
  padding: .5rem;
  margin-bottom: 1.5rem;
  background: var(--gray-50);
  border-radius: var(--radius-lg);
}
.sk-chain-review-item {
  background: #f5f3ff;
  border: 1.5px solid #ddd6fe;
  border-radius: 999px;
  padding: .25rem .7rem;
  font-size: .78rem;
  font-weight: 700;
  color: #6d28d9;
}

/* ── Combo Badge ── */
.sk-combo {
  position: fixed;
  top: 80px;
  right: 16px;
  background: linear-gradient(135deg, #f59e0b, #ef4444);
  color: #fff;
  border-radius: 999px;
  padding: .3rem .8rem;
  font-size: .8rem;
  font-weight: 800;
  box-shadow: 0 4px 16px rgba(245,158,11,.4);
  animation: sk-pop .3s cubic-bezier(.34,1.56,.64,1);
  z-index: 200;
  pointer-events: none;
}

/* ── Animations ── */
@keyframes sk-pop {
  0%   { transform: scale(.6); opacity: .5; }
  100% { transform: scale(1);  opacity: 1; }
}
@keyframes sk-bounce {
  0%   { transform: scale(1); }
  40%  { transform: scale(1.08); }
  100% { transform: scale(1); }
}
@keyframes sk-shake {
  0%, 100% { transform: translateX(0); }
  20%      { transform: translateX(-6px); }
  60%      { transform: translateX(6px); }
}

/* ── Loading State ── */
.sk-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  padding: 3rem 1rem;
  color: var(--gray-500);
}
.sk-spinner {
  width: 36px; height: 36px;
  border: 3px solid var(--gray-200);
  border-top-color: #7c3aed;
  border-radius: 50%;
  animation: spin .7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Dark Mode ── */
.dark-mode .sk-current-card {
  background: var(--card-dark, #1e1b2e);
  border-color: #7c3aed;
}
.dark-mode .sk-current-jp { color: #f3e8ff; }
.dark-mode .sk-current-id { color: #a1a1aa; }
.dark-mode .sk-score-bar {
  background: #1e1b2e;
  border-color: #3f3f46;
}
.dark-mode .sk-option-btn {
  background: #1e1b2e;
  border-color: #3f3f46;
  color: #f3e8ff;
}
.dark-mode .sk-option-btn:hover:not(:disabled) {
  background: #2d1b4e;
  border-color: #a855f7;
}
.dark-mode .sk-option-jp { color: #f3e8ff; }
.dark-mode .sk-chain-review { background: #18181b; }
.dark-mode .sk-chain-dot {
  background: #27272a;
  border-color: #52525b;
}
.dark-mode .sk-next-hint {
  background: linear-gradient(135deg, #2d1b4e, #3b1c3b);
  border-color: #7c3aed;
  color: #e9d5ff;
}