/* ================= LIGHT (default) ================= */
:root,
html[data-theme="light"] {
  --bg: #f7f9fd;
  --bg-2: #eef2fb;
  --panel: #ffffff;
  --panel-2: #f5f7fd;
  --border: #e3e8f3;
  --neon: #6941e8;
  --neon-2: #0099c6;
  --accent: #e58200;
  --success: #0ea968;
  --danger: #e5484d;
  --text: #141a2e;
  --muted: #6b7392;
  --gold: #c58e00;

  --shadow-sm: 0 1px 2px rgba(20, 26, 46, 0.06);
  --shadow-md: 0 4px 14px rgba(105, 65, 232, 0.14);
  --shadow-lg: 0 10px 28px rgba(105, 65, 232, 0.18);

  --hero-gradient: linear-gradient(135deg, #0099c6, #6941e8, #e58200);
  --title-gradient: linear-gradient(135deg, #0099c6, #6941e8);

  --terminal-bg: #141a2e;
  --terminal-fg: #8fffa0;
  --terminal-border: #2a3458;

  --font-en: 'SF Mono', 'Menlo', 'Monaco', 'Courier New', ui-monospace, monospace;
  --font-ar: 'SF Arabic', 'Tajawal', 'Cairo', 'Noto Sans Arabic', 'Amiri',
             'Geeza Pro', system-ui, -apple-system, sans-serif;
  --font-code: 'SF Mono', 'Menlo', 'Monaco', 'Courier New', ui-monospace, monospace;
}

/* ================= DARK (opt-in) ================= */
html[data-theme="dark"] {
  --bg: #0a0e1a;
  --bg-2: #0f1528;
  --panel: #151c32;
  --panel-2: #1c2440;
  --border: #2a3458;
  --neon: #7c4dff;
  --neon-2: #00e5ff;
  --accent: #ffb74d;
  --success: #00e676;
  --danger: #ff5252;
  --text: #e6ecff;
  --muted: #8b94b8;
  --gold: #ffd54f;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 14px rgba(124, 77, 255, 0.4);
  --shadow-lg: 0 10px 28px rgba(124, 77, 255, 0.35);

  --hero-gradient: linear-gradient(135deg, #00e5ff, #7c4dff, #ffb74d);
  --title-gradient: linear-gradient(135deg, #00e5ff, #7c4dff);

  --terminal-bg: #000;
  --terminal-fg: #8fffa0;
  --terminal-border: #2a3458;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background:
    radial-gradient(ellipse at top left, rgba(0, 153, 198, 0.10), transparent 55%),
    radial-gradient(ellipse at bottom right, rgba(105, 65, 232, 0.10), transparent 55%),
    var(--bg);
  color: var(--text);
  font-family: var(--font-en);
  min-height: 100vh;
  line-height: 1.55;
  transition: background 0.3s, color 0.3s;
}

html[data-theme="dark"] body {
  background:
    radial-gradient(ellipse at top, #1a1f3a 0%, var(--bg) 60%);
}

html[lang="ar"] body {
  font-family: var(--font-ar);
  line-height: 1.75;
}

/* Keyword-safe zones: code, commands, file paths, regex. Always LTR + mono. */
.kw,
pre, code,
.terminal, .terminal-input,
.blank-input, .fixbug-input,
html[lang="ar"] pre,
html[lang="ar"] code,
html[lang="ar"] .terminal,
html[lang="ar"] .terminal-input,
html[lang="ar"] .blank-input,
html[lang="ar"] .fixbug-input,
html[lang="ar"] .kw {
  font-family: var(--font-code) !important;
  direction: ltr !important;
  unicode-bidi: isolate;
  text-align: left;
}

html[dir="rtl"] .hud-title,
html[dir="rtl"] .level-card h3,
html[dir="rtl"] .lesson h3 {
  text-align: right;
}

a { color: var(--neon); text-decoration: none; }
a:hover { text-decoration: underline; }

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  padding: 10px 18px;
  border-radius: 10px;
  font-weight: 600;
  transition: transform 0.1s, box-shadow 0.2s, background 0.15s, border-color 0.15s;
}
button:active { transform: translateY(1px); }

.btn-primary {
  background: linear-gradient(135deg, var(--neon), var(--neon-2));
  color: #ffffff;
  box-shadow: var(--shadow-md);
}
.btn-primary:hover { box-shadow: var(--shadow-lg); transform: translateY(-1px); }
.btn-primary:disabled { opacity: 0.45; cursor: not-allowed; transform: none; box-shadow: none; }

.btn-ghost {
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.btn-ghost:hover { background: var(--panel-2); border-color: var(--neon); }

.lang-btn { min-width: 40px; font-weight: 700; letter-spacing: 1px; }

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px;
}

/* ---------- HUD ---------- */
.hud {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
html[data-theme="dark"] .hud { background: rgba(15, 21, 40, 0.88); }

.hud-title {
  font-size: 18px;
  font-weight: 700;
  background: var(--title-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hud-stats { display: flex; gap: 10px; align-items: center; font-size: 14px; flex-wrap: wrap; }
.hud-stat { display: flex; align-items: center; gap: 6px; color: var(--text); }
.hud-stat .val { font-weight: 700; color: var(--accent); }
.hearts { letter-spacing: 2px; font-size: 16px; }

/* ---------- Home / level grid ---------- */
.hero {
  text-align: center;
  padding: 56px 24px 24px;
}
.hero h1 {
  font-size: 46px;
  margin: 0 0 14px;
  background: var(--hero-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: shimmer 3.2s ease-in-out infinite alternate;
  line-height: 1.15;
}
@keyframes shimmer {
  from { filter: brightness(1); }
  to { filter: brightness(1.08) saturate(1.1); }
}
.hero p {
  color: var(--muted);
  max-width: 640px;
  margin: 0 auto;
  font-size: 16px;
}

.level-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
  margin-top: 32px;
}
.level-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 22px;
  cursor: pointer;
  transition: transform 0.15s, border-color 0.2s, box-shadow 0.2s;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.level-card:hover:not(.locked) {
  transform: translateY(-3px);
  border-color: var(--neon);
  box-shadow: var(--shadow-lg);
}
.level-card.locked { opacity: 0.55; cursor: not-allowed; }
.level-card.completed { border-color: var(--success); }
.level-card.completed::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(14, 169, 104, 0.06), transparent 60%);
  pointer-events: none;
}
.level-card .num {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 2px;
  font-weight: 600;
}
.level-card h3 { margin: 6px 0 8px; font-size: 18px; }
.level-card p { margin: 0; color: var(--muted); font-size: 13px; }
.level-card .badge {
  position: absolute;
  top: 14px;
  inset-inline-end: 14px;
  font-size: 22px;
}
.level-card.boss { border-color: var(--gold); }
.level-card.boss::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top right, rgba(229, 130, 0, 0.14), transparent 60%);
  pointer-events: none;
}

/* ---------- Level page ---------- */
.level-header { text-align: center; padding: 28px 0 12px; }
.level-header .crumb { color: var(--muted); font-size: 13px; margin-bottom: 8px; }
.level-header h2 { font-size: 28px; margin: 0 0 8px; }
.level-header .intro { color: var(--muted); max-width: 640px; margin: 0 auto; }

.progress-bar {
  height: 10px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 5px;
  overflow: hidden;
  margin: 24px 0;
}
.progress-bar .fill {
  height: 100%;
  background: linear-gradient(90deg, var(--neon), var(--neon-2));
  transition: width 0.5s ease-out;
  box-shadow: 0 0 14px rgba(105, 65, 232, 0.35);
}
html[dir="rtl"] .progress-bar .fill {
  background: linear-gradient(-90deg, var(--neon), var(--neon-2));
}

.lesson {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
}
.lesson h3 { margin-top: 0; color: var(--neon); }
.lesson p { color: var(--text); }
.lesson pre {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px;
  overflow-x: auto;
  font-size: 13px;
  color: var(--text);
}
.lesson code {
  background: var(--bg-2);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 90%;
  color: var(--accent);
  border: 1px solid var(--border);
}
.lesson .power-up {
  background: linear-gradient(135deg, rgba(105, 65, 232, 0.08), rgba(229, 130, 0, 0.08));
  border-inline-start: 3px solid var(--neon);
  padding: 12px 16px;
  border-radius: 8px;
  margin-top: 16px;
  font-size: 14px;
  color: var(--text);
}

.svg-figure {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin: 16px 0;
  text-align: center;
}
.svg-figure svg { max-width: 100%; height: auto; }
.svg-figure .caption { color: var(--muted); font-size: 12px; margin-top: 8px; }

/* ---------- Puzzles ---------- */
.puzzle {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 20px;
  animation: slideIn 0.35s ease-out;
  box-shadow: var(--shadow-sm);
}
@keyframes slideIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.puzzle .tag {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--neon);
  background: rgba(105, 65, 232, 0.08);
  padding: 5px 12px;
  border-radius: 20px;
  margin-bottom: 12px;
  font-weight: 700;
}
.puzzle .q { font-size: 16px; margin: 8px 0 16px; line-height: 1.65; color: var(--text); }

.options { display: flex; flex-direction: column; gap: 10px; }
.option {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 13px 15px;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s, transform 0.1s, box-shadow 0.15s;
  text-align: start;
  color: var(--text);
  font-family: inherit;
  font-size: 14px;
}
.option:hover {
  border-color: var(--neon);
  background: var(--panel-2);
  transform: translateX(2px);
  box-shadow: var(--shadow-sm);
}
html[dir="rtl"] .option:hover { transform: translateX(-2px); }
.option.selected { border-color: var(--neon); background: rgba(105, 65, 232, 0.08); }
.option.correct { border-color: var(--success); background: rgba(14, 169, 104, 0.10); }
.option.wrong { border-color: var(--danger); background: rgba(229, 72, 77, 0.10); }

.blank-row {
  display: flex;
  gap: 8px;
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 4px 12px;
}
.blank-row .kw {
  color: var(--accent);
  padding: 6px 2px;
  font-size: 14px;
}
.blank-input, .terminal-input, .fixbug-input {
  flex: 1;
  background: transparent;
  border: none;
  padding: 12px 10px;
  color: var(--text);
  font-size: 14px;
  outline: none;
  width: 100%;
}
.fixbug-input {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
}
.fixbug-input:focus, .blank-input:focus, .terminal-input:focus { border-color: var(--neon); }
.blank-row:focus-within { border-color: var(--neon); }

.reorder-list { display: flex; flex-direction: column; gap: 10px; }
.reorder-item {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  cursor: grab;
  user-select: none;
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: var(--shadow-sm);
}
.reorder-item:hover { border-color: var(--neon); }
.reorder-item.dragging { opacity: 0.4; }
.reorder-item .handle { color: var(--muted); }
.reorder-text { flex: 1; color: var(--text); }

.terminal {
  background: var(--terminal-bg);
  border: 1px solid var(--terminal-border);
  border-radius: 10px;
  padding: 14px;
  font-size: 13px;
  color: var(--terminal-fg);
}
.terminal .prompt { color: #00e5ff; }
.terminal-input {
  background: transparent;
  color: var(--terminal-fg);
  padding: 6px 0;
  border: none;
  border-bottom: 1px dashed #2a3458;
}

.feedback {
  margin-top: 16px;
  padding: 12px 14px;
  border-radius: 10px;
  font-size: 14px;
  display: none;
  animation: fadeIn 0.25s ease-out;
}
@keyframes fadeIn { from { opacity: 0 } to { opacity: 1 } }
.feedback.show { display: block; }
.feedback.ok {
  background: rgba(14, 169, 104, 0.10);
  border: 1px solid var(--success);
  color: #0b6b44;
}
.feedback.bad {
  background: rgba(229, 72, 77, 0.10);
  border: 1px solid var(--danger);
  color: #b72a2f;
}
html[data-theme="dark"] .feedback.ok { color: var(--success); }
html[data-theme="dark"] .feedback.bad { color: var(--danger); }
.feedback .hint { color: var(--muted); margin-top: 6px; font-size: 13px; }

.actions { display: flex; gap: 10px; margin-top: 16px; flex-wrap: wrap; }

/* ---------- Victory ---------- */
.victory { text-align: center; padding: 60px 24px; }
.victory .trophy {
  font-size: 92px;
  animation: bounceTrophy 1.4s ease-in-out infinite;
}
@keyframes bounceTrophy {
  0%, 100% { transform: translateY(0) rotate(-3deg); }
  50% { transform: translateY(-10px) rotate(3deg); }
}
.victory h1 {
  font-size: 40px;
  background: linear-gradient(135deg, var(--gold), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.certificate {
  background: var(--panel);
  border: 2px solid var(--gold);
  border-radius: 16px;
  padding: 32px;
  max-width: 560px;
  margin: 24px auto;
  box-shadow: 0 0 48px rgba(197, 142, 0, 0.25), var(--shadow-md);
}

/* ---------- XP popup ---------- */
.xp-pop {
  position: fixed;
  top: 80px;
  inset-inline-end: 24px;
  background: var(--success);
  color: #ffffff;
  padding: 10px 16px;
  border-radius: 10px;
  font-weight: 700;
  animation: xpFly 1.2s ease-out forwards;
  z-index: 50;
  font-family: var(--font-en);
  box-shadow: var(--shadow-md);
}
html[lang="ar"] .xp-pop { font-family: var(--font-ar); }
@keyframes xpFly {
  0% { transform: translateY(0); opacity: 1; }
  100% { transform: translateY(-36px); opacity: 0; }
}

/* ---------- Shake ---------- */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-7px); }
  75% { transform: translateX(7px); }
}
.shake { animation: shake 0.32s; }

/* ---------- Mobile polish ---------- */
@media (max-width: 600px) {
  .hero h1 { font-size: 32px; }
  .hud { padding: 10px 14px; }
  .hud-stats { gap: 6px; font-size: 12px; }
  .hud-stats button { padding: 8px 12px; }
  .container { padding: 16px; }
  .level-card { padding: 18px; }
}