/* ═══════════════════════════════════════════════════════
   ZEROday — Solver Styles
   Uses only CSS variables defined in css/themes.css
   so it automatically inherits all 6 themes.
   ═══════════════════════════════════════════════════════ */

/* ── Page layout override ───────────────────────────── */
.solver-main-content {
  padding: 1.5rem 1.8rem;
}

/* ── Top bar ────────────────────────────────────────── */
.solver-topbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.4rem;
  flex-wrap: wrap;
}
.solver-page-title {
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
  margin: 0 0 0.2rem;
}
.solver-page-sub {
  font-size: 0.82rem;
  color: var(--text2);
  margin: 0;
}

.solver-score-pill {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.35rem 0.9rem;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--accent);
  font-family: 'DM Mono', monospace;
  white-space: nowrap;
}
.solver-score-label {
  font-size: 0.72rem;
  font-weight: 400;
  color: var(--text3);
  font-family: 'DM Sans', sans-serif;
}

/* ── Mode tabs ──────────────────────────────────────── */
.solver-mode-tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0;
}
.solver-mode-tab {
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  padding: 0.55rem 1.1rem;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text3);
  cursor: pointer;
  transition: all 0.18s;
  margin-bottom: -1px;
  border-radius: 4px 4px 0 0;
}
.solver-mode-tab:hover { color: var(--text2); }
.solver-mode-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  background: rgba(var(--accent-rgb, 124, 111, 255), 0.06);
}

/* ── Mode panels ────────────────────────────────────── */
.solver-mode-panel { animation: solverFadeIn 0.22s ease; }
.solver-mode-panel.hidden { display: none; }
@keyframes solverFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: none; }
}

/* ── Two-column layout ──────────────────────────────── */
.solver-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 1.2rem;
  align-items: start;
}

/* ── Shared panel card ──────────────────────────────── */
.solver-panel-card {
  background: var(--surface, var(--bg2));
  border: 1px solid var(--border);
  border-radius: var(--radius, 14px);
  padding: 1.1rem 1.1rem;
}

/* ── Left panel ─────────────────────────────────────── */
.solver-left .solver-panel-card {
  position: sticky;
  top: calc(var(--topbar-h, 56px) + 0.8rem);
}

.solver-panel-label {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--text3);
  margin-bottom: 0.55rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--border);
}

.solver-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  margin-right: 0.55rem;
  flex-shrink: 0;
}

.solver-subject-btn {
  display: flex;
  align-items: center;
  width: 100%;
  text-align: left;
  padding: 0.55rem 0.7rem;
  background: none;
  border: 1px solid transparent;
  border-radius: var(--radius-sm, 8px);
  color: var(--text2);
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.16s;
  margin-bottom: 0.2rem;
}
.solver-subject-btn:hover { color: var(--text); background: var(--bg3); }
.solver-subject-btn.active {
  color: var(--accent);
  background: rgba(var(--accent-rgb, 124,111,255), 0.08);
  border-color: rgba(var(--accent-rgb, 124,111,255), 0.22);
}

.solver-divider {
  height: 1px;
  background: var(--border);
  margin: 0.8rem 0;
}

.solver-chapter-list {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  max-height: calc(100vh - 380px);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
.solver-chapter-btn {
  display: block;
  width: 100%;
  text-align: left;
  padding: 0.5rem 0.7rem;
  background: none;
  border: 1px solid transparent;
  border-radius: var(--radius-sm, 8px);
  color: var(--text2);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.82rem;
  cursor: pointer;
  transition: all 0.14s;
}
.solver-chapter-btn:hover { color: var(--text); background: var(--bg3); }
.solver-chapter-btn.active {
  color: var(--text);
  background: var(--bg3);
  border-color: var(--border-hover, var(--border));
}

/* ── Right panel ────────────────────────────────────── */
.solver-right { display: flex; flex-direction: column; gap: 1rem; }

/* ── Q navigator ────────────────────────────────────── */
.solver-qnav-card { padding: 0.9rem 1rem; }
.solver-qnav-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.7rem;
}
.solver-qnav-title {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text3);
}
.solver-qnav-legend {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  font-size: 0.7rem;
  color: var(--text3);
}
.legend-pip {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 2px;
  margin-right: 0.18rem;
}
.solver-qnav-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.solver-q-box {
  width: 30px;
  height: 30px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg3);
  color: var(--text3);
  font-size: 0.72rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.14s;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'DM Mono', monospace;
}
.solver-q-box:hover { border-color: var(--accent); color: var(--accent); }
.solver-q-box.current {
  border-color: var(--accent);
  background: rgba(var(--accent-rgb,124,111,255), 0.18);
  color: var(--accent);
}
.solver-q-box.correct {
  background: rgba(74,222,128,0.15);
  border-color: var(--green);
  color: var(--green);
}
.solver-q-box.wrong {
  background: rgba(248,113,113,0.15);
  border-color: var(--red);
  color: var(--red);
}
.solver-q-box.skipped {
  background: rgba(251,146,60,0.12);
  border-color: var(--orange);
  color: var(--orange);
}

/* ── Question card ──────────────────────────────────── */
.solver-q-card { min-height: 300px; }

.solver-empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 3.5rem 1.5rem;
  color: var(--text3);
}
.solver-empty-state h3 { font-size: 1rem; font-weight: 600; margin-bottom: 0.4rem; color: var(--text2); }
.solver-empty-state p  { font-size: 0.82rem; }

/* ── Meta badges ────────────────────────────────────── */
.solver-q-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1rem;
}
.solver-badge {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.18rem 0.55rem;
  border-radius: 5px;
}
.solver-badge-chapter { background: var(--bg3); color: var(--text2); border: 1px solid var(--border); }
.solver-badge-easy    { background: rgba(74,222,128,0.1); color: var(--green); }
.solver-badge-medium  { background: rgba(251,146,60,0.1); color: var(--orange); }
.solver-badge-hard    { background: rgba(248,113,113,0.1); color: var(--red); }
.solver-badge-mcq     { background: rgba(96,165,250,0.1); color: var(--blue); }
.solver-badge-integer { background: rgba(192,132,252,0.1); color: var(--purple); }
.solver-badge-year    { background: var(--bg3); color: var(--text3); border: 1px solid var(--border); }

/* ── Question text ──────────────────────────────────── */
.solver-q-text {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--text);
  margin-bottom: 1.4rem;
}
.solver-q-image {
  width: 100%;
  max-height: 260px;
  object-fit: contain;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg3);
  margin-bottom: 1rem;
}

/* ── MCQ Options ────────────────────────────────────── */
.solver-options-grid {
  display: grid;
  gap: 0.55rem;
  margin-bottom: 1.4rem;
}
.solver-option-btn {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  text-align: left;
  padding: 0.8rem 1rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.93rem;
  cursor: pointer;
  transition: all 0.17s;
}
.solver-option-btn:hover:not(.disabled) {
  border-color: var(--accent);
  background: rgba(var(--accent-rgb,124,111,255), 0.05);
  transform: translateX(2px);
}
.solver-option-key {
  min-width: 24px;
  height: 24px;
  border-radius: 6px;
  background: var(--bg3);
  border: 1px solid var(--border);
  font-size: 0.75rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--text2);
  font-family: 'DM Mono', monospace;
}
.solver-option-btn.correct {
  border-color: var(--green);
  background: rgba(74,222,128,0.08);
}
.solver-option-btn.correct .solver-option-key {
  background: rgba(74,222,128,0.2);
  border-color: var(--green);
  color: var(--green);
}
.solver-option-btn.wrong {
  border-color: var(--red);
  background: rgba(248,113,113,0.08);
}
.solver-option-btn.wrong .solver-option-key {
  background: rgba(248,113,113,0.2);
  border-color: var(--red);
  color: var(--red);
}
.solver-option-btn.disabled { cursor: not-allowed; }

/* ── Integer input ──────────────────────────────────── */
.solver-integer-box {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.1rem;
  margin-bottom: 1rem;
}
.solver-integer-box label {
  display: block;
  font-size: 0.8rem;
  color: var(--text2);
  margin-bottom: 0.6rem;
}
.solver-integer-row {
  display: flex;
  gap: 0.7rem;
  align-items: center;
  flex-wrap: wrap;
}
.solver-integer-input {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: 'DM Mono', monospace;
  font-size: 1.05rem;
  padding: 0.55rem 0.9rem;
  width: 190px;
  outline: none;
  transition: border-color 0.16s;
}
.solver-integer-input:focus   { border-color: var(--accent); }
.solver-integer-input.correct { border-color: var(--green); }
.solver-integer-input.wrong   { border-color: var(--red); }
.solver-integer-feedback {
  font-size: 0.84rem;
  margin-top: 0.5rem;
  min-height: 1.2em;
  font-weight: 600;
}
.solver-integer-feedback.correct { color: var(--green); }
.solver-integer-feedback.wrong   { color: var(--red); }

/* ── Explanation ────────────────────────────────────── */
.solver-explanation {
  background: rgba(74,222,128,0.04);
  border: 1px solid rgba(74,222,128,0.18);
  border-radius: 10px;
  padding: 1.1rem 1.2rem;
  margin-bottom: 1.2rem;
  display: none;
}
.solver-explanation.show { display: block; animation: solverFadeIn 0.25s ease; }
.solver-explanation-label {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--green);
  font-weight: 700;
  margin-bottom: 0.55rem;
}
.solver-explanation-text {
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--text);
}

/* ── Action buttons ─────────────────────────────────── */
.solver-q-actions {
  display: flex;
  gap: 0.65rem;
  align-items: center;
}
.solver-q-progress {
  margin-left: auto;
  font-family: 'DM Mono', monospace;
  font-size: 0.78rem;
  color: var(--text3);
}
.solver-btn {
  padding: 0.55rem 1.3rem;
  border-radius: 9px;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.17s;
  border: 1px solid var(--border);
}
.solver-btn:hover:not(:disabled) { transform: translateY(-1px); }
.solver-btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }
.solver-btn-primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.solver-btn-primary:hover:not(:disabled) {
  box-shadow: 0 4px 16px rgba(var(--accent-rgb,124,111,255), 0.4);
}
.solver-btn-ghost   { background: transparent; color: var(--text2); }
.solver-btn-ghost:hover { background: var(--bg3); color: var(--text); }
.solver-btn-check   {
  background: rgba(74,222,128,0.1);
  color: var(--green);
  border-color: rgba(74,222,128,0.28);
}

/* ── Booklet landing ────────────────────────────────── */
.booklet-landing-wrap { padding: 0; }
.booklet-landing-hdr  { margin-bottom: 1.4rem; }
.booklet-landing-hdr h2 { font-size: 1.15rem; font-weight: 700; margin-bottom: 0.25rem; }
.booklet-landing-hdr p  { font-size: 0.82rem; color: var(--text2); }

.booklet-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 1rem;
}
.booklet-card {
  background: var(--surface, var(--bg2));
  border: 1px solid var(--border);
  border-radius: var(--radius, 14px);
  padding: 1.5rem;
  cursor: pointer;
  transition: all 0.22s;
}
.booklet-card:hover {
  border-color: var(--border-hover, var(--accent));
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0,0,0,0.35);
}
.booklet-card-icon  { font-size: 2rem; margin-bottom: 0.7rem; }
.booklet-card-title { font-weight: 700; font-size: 1rem; margin-bottom: 0.3rem; }
.booklet-card-desc  { font-size: 0.8rem; color: var(--text2); line-height: 1.5; }
.booklet-card-tags  { display: flex; gap: 0.4rem; flex-wrap: wrap; margin-top: 0.9rem; }
.booklet-tag {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.55rem;
  border-radius: 5px;
  background: var(--bg3);
  color: var(--text3);
  border: 1px solid var(--border);
}
.booklet-tag.live { background: rgba(74,222,128,0.1); color: var(--green); border-color: rgba(74,222,128,0.25); }

/* ── Booklet subject grid ───────────────────────────── */
.booklet-subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}
.booklet-subject-card {
  background: var(--surface, var(--bg2));
  border: 1px solid var(--border);
  border-radius: var(--radius, 14px);
  padding: 1.5rem 1.2rem;
  cursor: pointer;
  text-align: center;
  transition: all 0.2s;
}
.booklet-subject-card:hover:not([style*="cursor:default"]) {
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(0,0,0,0.3);
}
.bsc-icon { font-size: 2.2rem; margin-bottom: 0.6rem; }
.bsc-name { font-weight: 700; font-size: 1rem; margin-bottom: 0.3rem; }
.bsc-desc { font-size: 0.78rem; color: var(--text2); line-height: 1.5; }
.bsc-badge {
  display: inline-block;
  margin-top: 0.7rem;
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 0.18rem 0.5rem;
  border-radius: 4px;
}
.bsc-badge.live { background: rgba(74,222,128,0.12); color: var(--green); }
.bsc-badge.soon { background: rgba(192,132,252,0.12); color: var(--purple); }

/* ── Booklet chapter grid ───────────────────────────── */
.booklet-chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}
.booklet-chapter-card {
  background: var(--surface, var(--bg2));
  border: 1px solid var(--border);
  border-radius: var(--radius, 14px);
  padding: 1.3rem;
  cursor: pointer;
  transition: all 0.2s;
}
.booklet-chapter-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  background: var(--bg3);
}
.bcc-icon { font-size: 1.6rem; margin-bottom: 0.5rem; }
.bcc-name { font-weight: 700; font-size: 0.92rem; margin-bottom: 0.25rem; }
.bcc-desc { font-size: 0.76rem; color: var(--text3); }

/* ── Booklet solver (full solver inside booklet mode) ─ */
.booklet-solver-wrap { display: grid; grid-template-columns: 220px 1fr; gap: 1.2rem; }
.booklet-solver-info {
  background: var(--surface, var(--bg2));
  border: 1px solid var(--border);
  border-radius: var(--radius, 14px);
  padding: 1rem;
  position: sticky;
  top: calc(var(--topbar-h, 56px) + 0.8rem);
  height: fit-content;
}
.booklet-stat-row {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  flex-wrap: wrap;
  padding: 0.4rem 0;
}
.booklet-stat-val {
  font-size: 1.3rem;
  font-weight: 700;
  font-family: 'DM Mono', monospace;
}
.booklet-stat-lbl {
  font-size: 0.67rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text3);
  margin-top: 1px;
}
.booklet-stat-sep { color: var(--border); font-size: 1.1rem; }

/* ── Shared back button ─────────────────────────────── */
.solver-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text2);
  background: none;
  border: none;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.84rem;
  cursor: pointer;
  padding: 0.4rem 0;
  margin-bottom: 1rem;
  transition: color 0.16s;
}
.solver-back-btn:hover { color: var(--text); }

/* ── Loading / spinner ──────────────────────────────── */
.solver-loading {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text3);
  font-size: 0.82rem;
  padding: 0.8rem 0.3rem;
}
.solver-loading::before {
  content: '';
  width: 14px; height: 14px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: solverSpin 0.75s linear infinite;
  flex-shrink: 0;
}
@keyframes solverSpin { to { transform: rotate(360deg); } }

/* ── Correct animation ──────────────────────────────── */
@keyframes solverPop {
  0%   { transform: scale(1); }
  40%  { transform: scale(1.015); }
  100% { transform: scale(1); }
}
.solver-pop { animation: solverPop 0.32s ease; }

/* ── Responsive ─────────────────────────────────────── */
@media (max-width: 900px) {
  .solver-layout          { grid-template-columns: 1fr; }
  .solver-left .solver-panel-card { position: static; }
  .booklet-solver-wrap    { grid-template-columns: 1fr; }
  .booklet-solver-info    { position: static; }
  .solver-main-content    { padding: 1rem; }
}
@media (max-width: 600px) {
  .booklet-subject-grid   { grid-template-columns: 1fr 1fr; }
  .booklet-chapter-grid   { grid-template-columns: 1fr; }
  .solver-q-text          { font-size: 0.94rem; }
}