/* ============================================================================
   AddMath Mudah — Mobile-First Gamified Educational UI Styles
   ============================================================================ */
:root {
  --bg: #f4f7fe;
  --surface: #ffffff;
  --surface-alt: #f8fafc;
  --text: #0f172a;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --primary: #4f46e5;
  --primary-soft: #eef2ff;
  --accent: #10b981;
  --accent-soft: #ecfdf5;
  --warn: #f59e0b;
  --warn-soft: #fffbeb;
  --danger: #ef4444;
  --danger-soft: #fef2f2;
  --shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
  --radius: 16px;
}

[data-theme="dark"] {
  --bg: #0b1120;
  --surface: #1e293b;
  --surface-alt: #0f172a;
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --border: #334155;
  --primary: #818cf8;
  --primary-soft: rgba(99, 102, 241, 0.16);
  --accent: #34d399;
  --accent-soft: rgba(16, 185, 129, 0.15);
  --warn: #fbbf24;
  --warn-soft: rgba(245, 158, 11, 0.15);
  --danger: #f87171;
  --danger-soft: rgba(239, 68, 68, 0.16);
  --shadow: 0 10px 28px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  width: 100%;
  max-width: 100%;
  overflow-x: clip;
}

body {
  font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  padding-bottom: 106px; /* ample space so mobile bottom nav never overlaps buttons */
  -webkit-tap-highlight-color: transparent;
}

/* Top App Header */
.top-bar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 10px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  max-width: 100%;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  min-width: 0;
}

@media (max-width: 540px) {
  .brand-sub { display: none; }
  .brand-title { font-size: 0.94rem; }
  .brand-logo { width: 34px; height: 34px; font-size: 14px; flex-shrink: 0; }
  .stat-pill { padding: 4px 8px; font-size: 0.74rem; }
  .lang-btn { padding: 4px 8px; font-size: 0.72rem; }
  .icon-btn { width: 32px; height: 32px; font-size: 0.9rem; }
  .top-actions { gap: 5px; flex-wrap: nowrap; }
  .app-shell { padding: 12px; gap: 14px; }
  .card { padding: 14px; }
}

.brand-logo {
  width: 38px;
  height: 38px;
  border-radius: 11px;
  background: linear-gradient(135deg, #4f46e5, #9333ea);
  color: #fff;
  font-weight: 800;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.35);
}

.brand-title { font-weight: 800; font-size: 1.02rem; line-height: 1.15; }
.brand-sub { font-size: 0.72rem; color: var(--text-muted); font-weight: 600; }

.top-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.stat-pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  padding: 5px 10px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
}

.lang-toggle {
  display: inline-flex;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 2px;
}

.lang-btn {
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-weight: 700;
  font-size: 0.75rem;
  padding: 5px 10px;
  border-radius: 999px;
  cursor: pointer;
  transition: 0.2s;
}

.lang-btn.active {
  background: var(--primary);
  color: #fff;
}

.icon-btn {
  border: 1px solid var(--border);
  background: var(--surface-alt);
  color: var(--text);
  width: 36px;
  height: 36px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 1rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* Main Responsive Shell */
.app-shell {
  max-width: 1240px;
  width: 100%;
  margin: 0 auto;
  padding: 16px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

#main-view,
.sidebar,
.card,
.grid-2,
.grid-2 > *,
.step-item,
.formula-box,
.tip-box,
.trap-box,
.coach-panel,
.guided-step-card {
  min-width: 0;
  max-width: 100%;
}

@media (min-width: 900px) {
  body { padding-bottom: 24px; }
  .app-shell { grid-template-columns: 280px minmax(0, 1fr); padding: 22px; }
  .bottom-nav { display: none !important; }
}

/* Desktop Sidebar */
.sidebar {
  display: none;
}

@media (min-width: 900px) {
  .sidebar {
    display: flex;
    flex-direction: column;
    gap: 12px;
    position: sticky;
    top: 76px;
    align-self: start;
  }
}

.nav-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
  box-shadow: var(--shadow);
}

.side-link {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: none;
  background: transparent;
  color: var(--text);
  font-weight: 600;
  font-size: 0.9rem;
  border-radius: 12px;
  cursor: pointer;
  text-align: left;
  transition: 0.18s;
}

.side-link:hover { background: var(--surface-alt); }
.side-link.active { background: var(--primary-soft); color: var(--primary); font-weight: 700; }

.chap-mini-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 10px;
  margin-top: 4px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  font-size: 0.83rem;
  text-align: left;
}
.chap-mini-btn:hover { background: var(--surface-alt); }
.chap-mini-btn.active { border-color: var(--primary); background: var(--primary-soft); font-weight: 700; }

/* Mobile Bottom Navigation */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 60;
  background: var(--surface);
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  padding: 6px 4px env(safe-area-inset-bottom, 6px);
  box-shadow: 0 -4px 18px rgba(0, 0, 0, 0.06);
}

.bnav-btn {
  border: none;
  background: transparent;
  color: var(--text-muted);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  font-size: 0.68rem;
  font-weight: 700;
  padding: 6px 2px;
  cursor: pointer;
}
.bnav-btn .bnav-ico { font-size: 1.18rem; }
.bnav-btn.active { color: var(--primary); }

/* Cards & Grids */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
  margin-bottom: 16px;
}

.hero-banner {
  background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 60%, #db2777 100%);
  color: #fff;
  border-radius: 20px;
  padding: 22px;
  margin-bottom: 18px;
  box-shadow: 0 12px 28px rgba(79, 70, 229, 0.28);
}

.hero-banner h1 { font-size: 1.42rem; font-weight: 800; margin-bottom: 6px; }
.hero-banner p { font-size: 0.92rem; opacity: 0.93; margin-bottom: 14px; }

.xp-bar-wrap {
  background: rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  height: 10px;
  overflow: hidden;
  margin-top: 6px;
}
.xp-bar-fill {
  height: 100%;
  background: #34d399;
  border-radius: 999px;
  transition: width 0.4s ease;
}

.grid-2 { display: grid; grid-template-columns: 1fr; gap: 14px; }
@media (min-width: 680px) { .grid-2 { grid-template-columns: repeat(2, 1fr); } }

.chap-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 16px;
  cursor: pointer;
  transition: transform 0.18s, border-color 0.18s;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 10px;
}
.chap-card:hover { transform: translateY(-2px); border-color: var(--primary); }
.chap-card.locked { opacity: 0.72; cursor: default; }
.chap-card.locked:hover { transform: none; border-color: var(--border); }

.chap-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  color: #fff;
  font-weight: 800;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* Sub-tabs inside a Chapter */
.mode-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.mode-tab {
  flex: 1 1 auto;
  text-align: center;
  padding: 9px 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  font-weight: 700;
  font-size: 0.84rem;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.mode-tab.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}
@media (max-width: 680px) {
  .mode-tabs {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }
  .mode-tab {
    padding: 9px 8px;
    font-size: 0.78rem;
    line-height: 1.25;
  }
}

/* Formula & Step Boxes */
.formula-box {
  background: var(--surface-alt);
  border-left: 4px solid var(--primary);
  padding: 10px 14px;
  border-radius: 10px;
  margin: 8px 0;
  overflow-x: auto;
}

.tip-box {
  background: var(--warn-soft);
  border: 1px solid rgba(245, 158, 11, 0.35);
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 0.86rem;
  margin-top: 10px;
}

.trap-box {
  background: var(--danger-soft);
  border: 1px solid rgba(239, 68, 68, 0.35);
  padding: 12px 14px;
  border-radius: 12px;
  margin-top: 10px;
  font-size: 0.87rem;
}

.step-item {
  border: 1px solid var(--border);
  background: var(--surface-alt);
  border-radius: 12px;
  padding: 12px 14px;
  margin-bottom: 10px;
  overflow-x: auto;
}

/* Keep KaTeX equations left-aligned and contained so they NEVER push off-screen */
.katex-display {
  display: block !important;
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 6px 2px;
  margin: 4px 0 !important;
  text-align: left !important;
}
.katex-display > .katex {
  text-align: left !important;
}
.katex {
  font-size: 1.02em;
}
@media (max-width: 640px) {
  .katex { font-size: 0.94em; }
}

@keyframes inputFlashPulse {
  0% { border-color: var(--accent); background: var(--accent-soft); box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.28); }
  100% { border-color: var(--border); background: var(--surface-alt); box-shadow: none; }
}

.inp-flash {
  animation: inputFlashPulse 0.75s ease;
}

.spm-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 6px;
  font-size: 0.74rem;
  font-weight: 800;
  margin-right: 6px;
}
.spm-P1 { background: #dbeafe; color: #1d4ed8; }
.spm-K1 { background: #fef3c7; color: #b45309; }
.spm-J1, .spm-N1 { background: #d1fae5; color: #047857; }

/* Master SPM Bank (180 Questions: Examples, Common Mistakes & K1/N1 Scheme) */
.mbank-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
  margin-bottom: 14px;
  min-width: 0;
  max-width: 100%;
  transition: border-color 0.2s;
}
.mbank-card.mastered {
  border-color: var(--accent);
}
.mbank-qbox {
  font-size: 0.96rem;
  font-weight: 600;
  background: var(--surface-alt);
  padding: 13px 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  margin: 10px 0 12px;
  white-space: pre-line;
  overflow-x: auto;
}
.mbank-mistake-panel {
  background: var(--danger-soft);
  border: 1px solid rgba(239, 68, 68, 0.38);
  border-left: 4px solid var(--danger);
  border-radius: 12px;
  padding: 12px 14px;
  margin-top: 10px;
  font-size: 0.88rem;
  overflow-x: auto;
}
.mbank-scheme-panel {
  background: var(--accent-soft);
  border: 1px solid rgba(16, 185, 129, 0.38);
  border-left: 4px solid var(--accent);
  border-radius: 12px;
  padding: 12px 14px;
  margin-top: 10px;
  font-size: 0.89rem;
  overflow-x: auto;
}
.mbank-scheme-row {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 12px;
  margin-top: 8px;
  overflow-x: auto;
}

/* Buttons & Inputs */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 16px;
  border-radius: 12px;
  border: 1px solid transparent;
  font-weight: 700;
  font-size: 0.88rem;
  cursor: pointer;
  min-height: 42px;
  transition: 0.16s;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { filter: brightness(1.07); }
.btn-accent { background: var(--accent); color: #fff; }
.btn-outline { background: var(--surface); border-color: var(--border); color: var(--text); }
.btn-outline:hover { background: var(--surface-alt); }
.btn-sm { padding: 6px 12px; min-height: 34px; font-size: 0.8rem; }

.math-input {
  width: 100%;
  padding: 12px 14px;
  font-size: 1rem;
  border: 2px solid var(--border);
  border-radius: 12px;
  background: var(--surface-alt);
  color: var(--text);
  outline: none;
}
.math-input:focus { border-color: var(--primary); }

.keypad-row {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin: 8px 0 12px;
}
.key-chip {
  padding: 5px 11px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface-alt);
  color: var(--text);
  font-weight: 700;
  font-size: 0.84rem;
  cursor: pointer;
}

/* Visual Lab Canvas */
.lab-canvas {
  width: 100%;
  height: 290px;
  border-radius: 14px;
  border: 1px solid var(--border);
  display: block;
}

.slider-row {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-top: 10px;
}
.slider-row input[type="range"] { width: 100%; accent-color: var(--primary); height: 26px; }

/* Intent Coach Box */
.coach-panel {
  margin-top: 16px;
  border: 2px solid var(--primary);
  background: var(--primary-soft);
  border-radius: 16px;
  padding: 14px;
}

.intent-chips {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin: 8px 0;
}

.intent-chip {
  border: 1px solid var(--primary);
  background: var(--surface);
  color: var(--primary);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
}

.guided-step-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  margin-top: 10px;
}

/* Chat Tutor */
.chat-stream {
  max-height: 400px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 8px 4px;
}
.msg-bubble {
  max-width: 88%;
  padding: 11px 14px;
  border-radius: 14px;
  font-size: 0.9rem;
  white-space: pre-line;
}
.msg-user { align-self: flex-end; background: var(--primary); color: #fff; }
.msg-bot { align-self: flex-start; background: var(--surface-alt); border: 1px solid var(--border); }

/* Offline Fallback Math & Inline Code Formatting */
.m-code {
  font-family: 'JetBrains Mono', Consolas, monospace;
  background: var(--primary-soft);
  color: var(--primary);
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 0.86em;
  font-weight: 700;
}
.m-frac { display: inline-flex; flex-direction: column; vertical-align: middle; text-align: center; font-size: 0.88em; padding: 0 3px; }
.m-num { border-bottom: 1px solid currentColor; padding: 0 2px; }
.m-den { padding: 0 2px; }

@keyframes fadeSlideIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.anim-in {
  animation: fadeSlideIn 0.28s ease forwards;
}

.step-done-row {
  background: var(--accent-soft);
  border: 1px solid rgba(16, 185, 129, 0.35);
  border-radius: 10px;
  padding: 8px 12px;
  margin-bottom: 8px;
  font-size: 0.86rem;
}

/* Chapter Quick Switcher & Blitz Interactive Feedback */
.chap-select {
  padding: 8px 12px;
  border-radius: 10px;
  border: 2px solid var(--primary);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-weight: 700;
  font-size: 0.86rem;
  min-width: 0;
  flex: 1;
  cursor: pointer;
  outline: none;
}

.blitz-opt {
  justify-content: space-between !important;
  text-align: left;
  width: 100%;
  font-size: 0.95rem;
  padding: 12px 16px;
  transition: transform 0.14s, background 0.16s, border-color 0.16s;
}
.blitz-opt.blitz-correct {
  background: var(--accent) !important;
  border-color: var(--accent) !important;
  color: #fff !important;
  transform: scale(1.01);
}
.blitz-opt.blitz-wrong {
  background: var(--danger) !important;
  border-color: var(--danger) !important;
  color: #fff !important;
}

#confetti-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  max-width: 100vw;
  pointer-events: none;
  z-index: 200;
}

/* Teacher Pain-Killer Clinic & Visual Poster Infographics */
.clinic-card {
  border: 2px solid var(--primary);
  background: linear-gradient(180deg, var(--primary-soft) 0%, var(--surface) 140px);
}

.clinic-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  align-items: start;
}
@media (min-width: 720px) {
  .clinic-hero-grid {
    grid-template-columns: 220px 1fr;
  }
}

.poster-thumb-wrap {
  position: relative;
  border-radius: 14px;
  overflow: hidden;
  border: 2px solid var(--border);
  background: var(--surface-alt);
  cursor: pointer;
  max-width: 280px;
  margin: 0 auto;
  box-shadow: var(--shadow);
  transition: transform 0.18s ease, border-color 0.18s ease;
}
.poster-thumb-wrap:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
}
.poster-thumb-img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.poster-zoom-pill {
  position: absolute;
  bottom: 8px;
  left: 8px;
  right: 8px;
  background: rgba(15, 23, 42, 0.84);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  text-align: center;
  padding: 6px 8px;
  border-radius: 999px;
  backdrop-filter: blur(4px);
}

.mental-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 10px;
}
@media (min-width: 680px) {
  .mental-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
.mental-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 13px;
  padding: 12px 14px;
}
.mental-tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
  margin-bottom: 5px;
}

.trigger-row {
  background: var(--surface-alt);
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  padding: 10px 12px;
  margin-bottom: 8px;
  font-size: 0.86rem;
}

.rx-compare {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 10px;
}
@media (min-width: 640px) {
  .rx-compare {
    grid-template-columns: 1fr 1fr;
  }
}
.rx-wrong {
  background: var(--danger-soft);
  border: 1px solid rgba(239, 68, 68, 0.38);
  border-radius: 12px;
  padding: 11px 13px;
  font-size: 0.85rem;
}
.rx-right {
  background: var(--accent-soft);
  border: 1px solid rgba(16, 185, 129, 0.38);
  border-radius: 12px;
  padding: 11px 13px;
  font-size: 0.85rem;
}

/* Horizontal Poster Strip on Home */
.poster-strip {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(128px, 1fr));
  gap: 10px;
  margin-top: 10px;
}
.poster-mini-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  background: var(--surface);
  cursor: pointer;
  transition: transform 0.16s, border-color 0.16s;
  display: flex;
  flex-direction: column;
}
.poster-mini-card:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
}
.poster-mini-card img {
  width: 100%;
  aspect-ratio: 9 / 14;
  object-fit: cover;
  object-position: top center;
  display: block;
}
.poster-mini-lbl {
  padding: 6px 8px;
  font-size: 0.74rem;
  font-weight: 800;
  line-height: 1.25;
}

/* Fullscreen Poster Lightbox Modal */
.poster-modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.86);
  backdrop-filter: blur(5px);
  z-index: 300;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
}
.poster-modal-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  width: 100%;
  max-width: 620px;
  max-height: 92vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.45);
}
.poster-modal-hdr {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.poster-modal-body {
  padding: 12px;
  overflow-y: auto;
  text-align: center;
}
.poster-modal-body img {
  width: 100%;
  max-width: 540px;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--border);
}