/* ═══════════════════════════════════════════════
   CryptSolve — style.css
   Aesthetic: Dark cyberpunk meets editorial grid
   Fonts: Syne (display) + JetBrains Mono (code)
═══════════════════════════════════════════════ */

/* ── TOKENS ── */
:root {
  --bg:         #09090f;
  --surface:    #111118;
  --surface2:   #18181f;
  --border:     rgba(255,255,255,0.07);
  --border2:    rgba(255,255,255,0.14);
  --text:       #e8e8f0;
  --muted:      #6b6b82;
  --accent:     #7fff6b;
  --accent2:    #6beeff;
  --accent3:    #ff6bab;
  --warn:       #ffcc6b;
  --danger:     #ff6b6b;
  --card-bg:    rgba(255,255,255,0.035);
  --card-glow:  rgba(127,255,107,0.06);
  --radius:     16px;
  --radius-sm:  8px;
  --mono:       'JetBrains Mono', monospace;
  --sans:       'Syne', sans-serif;
  --transition: 0.22s cubic-bezier(0.4,0,0.2,1);
}

[data-theme="light"] {
  --bg:         #f0f0f7;
  --surface:    #ffffff;
  --surface2:   #f7f7ff;
  --border:     rgba(0,0,0,0.08);
  --border2:    rgba(0,0,0,0.15);
  --text:       #14141f;
  --muted:      #888899;
  --card-bg:    rgba(0,0,0,0.025);
  --card-glow:  rgba(127,255,107,0.08);
}

/* ── RESET ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

/* ── BACKGROUND ── */
.bg-grid {
  position: fixed; inset: 0; pointer-events: none; z-index: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black, transparent);
}

[data-theme="light"] .bg-grid {
  background-image:
    linear-gradient(rgba(0,0,0,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,0,0,0.04) 1px, transparent 1px);
}

.bg-orb {
  position: fixed; pointer-events: none; z-index: 0;
  border-radius: 50%; filter: blur(120px); opacity: 0.25;
}
.orb-1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, #7fff6b33, transparent 70%);
  top: -200px; right: -200px;
  animation: orbFloat 14s ease-in-out infinite;
}
.orb-2 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, #6beeff22, transparent 70%);
  bottom: -150px; left: -150px;
  animation: orbFloat 18s ease-in-out infinite reverse;
}

@keyframes orbFloat {
  0%,100% { transform: translate(0,0); }
  50%      { transform: translate(30px, -40px); }
}

/* ── HEADER ── */
.site-header {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; gap: 20px;
  padding: 0 40px;
  height: 64px;
  background: rgba(9,9,15,0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

[data-theme="light"] .site-header {
  background: rgba(240,240,247,0.88);
}

.logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 1.25rem; font-weight: 800; letter-spacing: -0.03em;
}
.logo-icon {
  font-size: 1.4rem; color: var(--accent);
  animation: spinHex 8s linear infinite;
}
@keyframes spinHex {
  to { transform: rotate(360deg); }
}
.logo-text em { color: var(--accent); font-style: normal; }

.header-nav {
  display: flex; gap: 4px; margin-left: auto;
}
.nav-btn {
  background: none; border: 1px solid transparent;
  color: var(--muted); font-family: var(--sans);
  font-size: 0.82rem; font-weight: 600; letter-spacing: 0.04em;
  padding: 6px 16px; border-radius: var(--radius-sm);
  cursor: pointer; transition: var(--transition);
  text-transform: uppercase;
}
.nav-btn:hover { color: var(--text); border-color: var(--border2); }
.nav-btn.active {
  color: var(--accent); border-color: rgba(127,255,107,0.35);
  background: rgba(127,255,107,0.08);
}

.theme-toggle {
  width: 36px; height: 36px;
  border-radius: 50%; border: 1px solid var(--border2);
  background: var(--card-bg); color: var(--text);
  font-size: 1.1rem; cursor: pointer; transition: var(--transition);
  display: flex; align-items: center; justify-content: center;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }

/* ── MAIN ── */
.main-container {
  position: relative; z-index: 1;
  max-width: 860px; margin: 0 auto;
  padding: 48px 24px 80px;
}

/* ── PANELS ── */
.panel { display: none; }
.panel.active { display: block; animation: fadeUp 0.4s ease both; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── HERO ── */
.panel-hero { margin-bottom: 40px; }
.hero-title {
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 800; line-height: 0.95;
  letter-spacing: -0.04em;
}
.hero-title em {
  color: var(--accent); font-style: normal;
  -webkit-text-stroke: 1px var(--accent);
  text-shadow: 0 0 40px rgba(127,255,107,0.4);
}
.hero-sub {
  margin-top: 12px; color: var(--muted);
  font-size: 0.95rem; font-family: var(--mono);
}

/* ── CARDS ── */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 20px;
  transition: border-color var(--transition);
  position: relative; overflow: hidden;
}
.card::before {
  content: '';
  position: absolute; inset: 0;
  background: var(--card-glow);
  opacity: 0; transition: opacity var(--transition);
  pointer-events: none;
}
.card:hover::before { opacity: 1; }

/* ── PRESETS ── */
.presets-strip {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  margin-bottom: 20px;
}
.presets-label {
  font-size: 0.78rem; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--muted);
}
.preset-chip {
  font-family: var(--mono); font-size: 0.74rem;
  padding: 6px 12px; border-radius: 100px;
  border: 1px solid; cursor: pointer;
  transition: var(--transition); background: transparent;
  font-weight: 600;
}
.preset-chip.easy   { color: var(--accent);  border-color: rgba(127,255,107,0.3); }
.preset-chip.medium { color: var(--warn);     border-color: rgba(255,204,107,0.3); }
.preset-chip.hard   { color: var(--danger);   border-color: rgba(255,107,107,0.3); }
.preset-chip.easy:hover   { background: rgba(127,255,107,0.1); }
.preset-chip.medium:hover { background: rgba(255,204,107,0.1); }
.preset-chip.hard:hover   { background: rgba(255,107,107,0.1); }

/* ── INPUT CARD ── */
.input-label {
  display: block; font-size: 0.72rem; font-weight: 700;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--muted); margin-bottom: 12px;
}
.puzzle-input-row {
  display: flex; gap: 12px; align-items: stretch;
}
.puzzle-input {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border2);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-family: var(--mono);
  font-size: 1.1rem; font-weight: 600;
  padding: 14px 18px;
  outline: none; transition: var(--transition);
  letter-spacing: 0.04em;
}
.puzzle-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(127,255,107,0.12);
}
.puzzle-input::placeholder { color: var(--muted); }

.solve-btn {
  display: flex; align-items: center; gap: 8px;
  padding: 14px 28px;
  background: var(--accent); color: #0a0f0a;
  font-family: var(--sans); font-size: 0.95rem; font-weight: 800;
  border: none; border-radius: var(--radius-sm);
  cursor: pointer; transition: var(--transition);
  letter-spacing: 0.02em; white-space: nowrap;
}
.solve-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(127,255,107,0.3); }
.solve-btn:active { transform: translateY(0); }
.solve-btn.secondary {
  background: var(--surface2); color: var(--text);
  border: 1px solid var(--border2);
}
.solve-btn.secondary:hover { box-shadow: 0 8px 24px rgba(255,255,255,0.08); }
.solve-btn.loading .btn-text::after {
  content: ''; display: inline-block;
  width: 12px; height: 12px;
  border: 2px solid rgba(10,15,10,0.3);
  border-top-color: #0a0f0a;
  border-radius: 50%; margin-left: 8px;
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.btn-icon { font-size: 1.1rem; }

.input-hint {
  font-size: 0.75rem; color: var(--muted); margin-top: 10px;
  font-family: var(--mono);
}

/* ── EQUATION DISPLAY ── */
.equation-card { text-align: center; }
.eq-label {
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--muted); margin-bottom: 16px;
}
.eq-display {
  font-family: var(--mono); font-size: 1.6rem; font-weight: 700;
  letter-spacing: 0.08em; color: var(--accent2);
  display: flex; align-items: center; justify-content: center;
  gap: 16px; flex-wrap: wrap;
}
.eq-word { color: var(--text); }
.eq-op   { color: var(--muted); }
.eq-eq   { color: var(--accent); }

/* ── SOLVING CARD ── */
.solving-header {
  display: flex; align-items: center; gap: 12px; margin-bottom: 16px;
}
.pulse-ring {
  width: 16px; height: 16px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 0 rgba(127,255,107,0.6);
  animation: pulse 1.2s ease-in-out infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0   rgba(127,255,107,0.6); }
  70%  { box-shadow: 0 0 0 12px rgba(127,255,107,0); }
  100% { box-shadow: 0 0 0 0   rgba(127,255,107,0); }
}
.solving-title {
  font-weight: 700; letter-spacing: 0.02em; color: var(--accent);
}
.backtrack-log {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 14px 16px;
  font-family: var(--mono); font-size: 0.78rem; color: var(--muted);
  height: 130px; overflow-y: auto;
  line-height: 1.7;
}
.backtrack-log .log-assign { color: var(--accent2); }
.backtrack-log .log-fail   { color: var(--danger); }
.backtrack-log .log-ok     { color: var(--accent); }

.stats-row {
  display: flex; gap: 20px; margin-top: 14px; flex-wrap: wrap;
}
.stat-item {
  font-family: var(--mono); font-size: 0.8rem; color: var(--muted);
}
.stat-item strong { color: var(--text); font-size: 1rem; display: block; }

/* ── RESULT CARD ── */
.result-card { border-color: rgba(127,255,107,0.25); }
.result-card::before { opacity: 1; }

.result-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 24px;
}
.result-badge {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--accent); color: #0a0f0a;
  font-size: 0.8rem; font-weight: 800; letter-spacing: 0.1em;
  text-transform: uppercase; padding: 6px 14px; border-radius: 100px;
}
.result-time {
  font-family: var(--mono); font-size: 0.78rem; color: var(--muted);
}

.mapping-grid {
  display: flex; flex-wrap: wrap; gap: 12px;
  margin-bottom: 24px;
}
.map-chip {
  display: flex; flex-direction: column; align-items: center;
  background: var(--surface2); border: 1px solid var(--border2);
  border-radius: var(--radius-sm);
  padding: 12px 18px; min-width: 60px;
  animation: popIn 0.4s cubic-bezier(0.34,1.56,0.64,1) both;
}
.map-chip .letter {
  font-family: var(--mono); font-size: 1.1rem; font-weight: 700;
  color: var(--accent2);
}
.map-chip .equals { font-size: 0.65rem; color: var(--muted); margin: 2px 0; }
.map-chip .digit  {
  font-family: var(--mono); font-size: 1.5rem; font-weight: 800;
  color: var(--accent);
}

@keyframes popIn {
  from { opacity: 0; transform: scale(0.7) translateY(10px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}

.verified-eq {
  font-family: var(--mono); font-size: 1rem;
  background: var(--surface); border-radius: var(--radius-sm);
  padding: 16px 20px; text-align: center;
  color: var(--accent); font-weight: 700;
  letter-spacing: 0.04em;
}

/* ── NO SOLUTION ── */
.no-solution-card { text-align: center; border-color: rgba(255,107,107,0.25); }
.nosol-icon { font-size: 2.5rem; margin-bottom: 12px; }
.nosol-text { font-size: 1.1rem; font-weight: 700; color: var(--danger); }
.nosol-hint { font-size: 0.85rem; color: var(--muted); margin-top: 8px; }

/* ── PLAY MODE ── */
.play-controls {
  display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 20px;
}

.play-meta-row {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 20px; flex-wrap: wrap; gap: 10px;
}
.play-puzzle-label {
  font-family: var(--mono); font-weight: 700; font-size: 1rem;
  color: var(--accent2);
}
.play-stats { display: flex; gap: 10px; }
.stat-chip {
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: 100px; padding: 4px 14px;
  font-family: var(--mono); font-size: 0.78rem; color: var(--muted);
}
.stat-chip strong { color: var(--text); }

.play-eq {
  font-family: var(--mono); font-size: 1.4rem; font-weight: 700;
  text-align: center; color: var(--text);
  margin-bottom: 24px; letter-spacing: 0.06em;
  line-height: 2;
}

.play-inputs {
  display: flex; flex-wrap: wrap; gap: 10px;
  margin-bottom: 20px;
}
.play-input-group {
  display: flex; flex-direction: column; align-items: center; gap: 4px;
}
.play-letter {
  font-family: var(--mono); font-size: 0.8rem; font-weight: 700;
  color: var(--accent2); letter-spacing: 0.08em;
}
.play-digit-input {
  width: 52px; height: 52px; text-align: center;
  background: var(--surface); border: 2px solid var(--border2);
  border-radius: var(--radius-sm); color: var(--text);
  font-family: var(--mono); font-size: 1.4rem; font-weight: 800;
  outline: none; transition: var(--transition);
}
.play-digit-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(127,255,107,0.15);
}
.play-digit-input.correct { border-color: var(--accent); background: rgba(127,255,107,0.1); }
.play-digit-input.wrong   { border-color: var(--danger); background: rgba(255,107,107,0.1); }
.play-digit-input.hinted  { border-color: var(--warn);   background: rgba(255,204,107,0.1); color: var(--warn); }

.play-actions {
  display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 16px;
}
.hint-btn, .reveal-btn {
  font-family: var(--sans); font-size: 0.85rem; font-weight: 700;
  padding: 10px 18px; border-radius: var(--radius-sm);
  cursor: pointer; transition: var(--transition); border: 1px solid;
}
.hint-btn {
  background: rgba(255,204,107,0.08); color: var(--warn);
  border-color: rgba(255,204,107,0.3);
}
.hint-btn:hover { background: rgba(255,204,107,0.15); }
.reveal-btn {
  background: rgba(255,107,107,0.08); color: var(--danger);
  border-color: rgba(255,107,107,0.3);
}
.reveal-btn:hover { background: rgba(255,107,107,0.15); }

.play-feedback {
  font-family: var(--mono); font-size: 0.9rem;
  padding: 12px 16px; border-radius: var(--radius-sm);
  font-weight: 600; text-align: center;
  display: none;
}
.play-feedback.success {
  display: block; background: rgba(127,255,107,0.1);
  border: 1px solid rgba(127,255,107,0.25); color: var(--accent);
}
.play-feedback.fail {
  display: block; background: rgba(255,107,107,0.1);
  border: 1px solid rgba(255,107,107,0.25); color: var(--danger);
}
.play-feedback.info {
  display: block; background: rgba(107,238,255,0.08);
  border: 1px solid rgba(107,238,255,0.2); color: var(--accent2);
}

.play-idle-card { text-align: center; padding: 50px 28px; }
.idle-icon { font-size: 3rem; margin-bottom: 12px; }

/* ── LEARN GRID ── */
.learn-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 20px;
}
@media (max-width: 640px) { .learn-grid { grid-template-columns: 1fr; } }

.learn-card { padding: 28px; }
.learn-icon { font-size: 2rem; margin-bottom: 14px; }
.learn-card h2 {
  font-size: 1.15rem; font-weight: 800; margin-bottom: 12px;
  letter-spacing: -0.02em;
}
.learn-card p {
  font-size: 0.875rem; color: var(--muted); line-height: 1.7;
  margin-bottom: 14px;
}
.learn-list {
  font-size: 0.85rem; color: var(--muted); line-height: 1.8;
  padding-left: 0; list-style: none;
}
.learn-list li { display: flex; gap: 8px; }
.learn-list li::before { content: '▸'; color: var(--accent); flex-shrink: 0; }
.learn-list.numbered { counter-reset: steps; }
.learn-list.numbered li::before {
  content: counter(steps);
  counter-increment: steps;
  color: var(--accent); font-weight: 800;
  font-family: var(--mono); font-size: 0.8rem;
  min-width: 18px;
}
.learn-card strong { color: var(--text); }

.learn-example {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 14px 18px;
  margin: 14px 0;
}
.learn-example code {
  font-family: var(--mono); font-size: 0.9rem; color: var(--accent2);
  white-space: pre; display: block;
}

.learn-complexity {
  background: var(--surface); border-radius: var(--radius-sm);
  padding: 12px 16px; font-size: 0.78rem; color: var(--muted);
  display: flex; flex-direction: column; gap: 4px;
  font-family: var(--mono);
}
.learn-complexity code { color: var(--accent); }

/* ── FOOTER ── */
.site-footer {
  position: relative; z-index: 1;
  display: flex; justify-content: space-between; align-items: center;
  padding: 20px 40px;
  border-top: 1px solid var(--border);
  font-size: 0.75rem; color: var(--muted);
  font-family: var(--mono);
}

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--surface); }
::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--muted); }

/* ── RESPONSIVE ── */
@media (max-width: 640px) {
  .site-header { padding: 0 16px; }
  .main-container { padding: 28px 14px 60px; }
  .puzzle-input-row { flex-direction: column; }
  .solve-btn { width: 100%; justify-content: center; }
  .header-nav { gap: 2px; }
  .nav-btn { padding: 5px 10px; font-size: 0.72rem; }
  .hero-title { font-size: 2.4rem; }
  .site-footer { flex-direction: column; gap: 6px; text-align: center; }
}