/* ============================================================
   Math Blitz — Design v2
   ============================================================ */

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

:root {
  --purple: #a855f7;
  --cyan:   #06b6d4;
  --pink:   #ec4899;
  --gold:   #f59e0b;
  --green:  #22c55e;
  --red:    #ef4444;
  --glass-bg:     rgba(255,255,255,0.04);
  --glass-border: rgba(255,255,255,0.08);
}

html, body { height: 100%; background: #080810; }

body {
  font-family: system-ui, -apple-system, sans-serif;
  color: #e2e8f0;
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  overflow-x: hidden;
}

#app {
  width: 100%;
  max-width: 500px;
  min-height: 100vh;
  position: relative;
}

/* ── Background ───────────────────────────────────────────── */
.bg-glow {
  position: fixed; top: 50%; left: 50%;
  transform: translate(-50%,-50%);
  width: 900px; height: 900px;
  background: radial-gradient(circle, rgba(168,85,247,0.1) 0%, transparent 65%);
  pointer-events: none; z-index: 0;
}

#particle-canvas {
  position: fixed; top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none; z-index: 0;
}

/* ── Screens ──────────────────────────────────────────────── */
.screen         { display: none; flex-direction: column; gap: 14px; position: relative; z-index: 1; padding: 36px 20px 40px; }
.screen.active  { display: flex; }

/* ── Glass card ───────────────────────────────────────────── */
.card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: 1.5rem;
  text-align: center;
}

/* ── HUD ──────────────────────────────────────────────────── */
.hud { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 10px; }
.hud-box {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  padding: 10px 8px;
  text-align: center;
}
.hud-label { font-size: 9px; color: #64748b; text-transform: uppercase; letter-spacing: .1em; }
.hud-val   { font-size: 18px; font-weight: 700; margin-top: 2px; font-family: 'Orbitron', sans-serif; }

/* ── Timer bar ────────────────────────────────────────────── */
#timer-wrap {
  height: 6px;
  background: rgba(255,255,255,.05);
  border-radius: 3px;
  overflow: hidden;
}
#timer-bar {
  height: 100%; width: 100%;
  background: var(--green);
  transition: width .1s linear, background .5s ease;
  border-radius: 3px;
  box-shadow: 0 0 8px var(--green), 0 0 18px rgba(34,197,94,.55);
}
#timer-bar.urgent { animation: timerUrgent .38s ease-in-out infinite; }

/* ── Question ─────────────────────────────────────────────── */
#question  { font-size: clamp(28px,8vw,48px); font-weight: 700; margin: 8px 0 4px; font-family: 'Orbitron', sans-serif; letter-spacing: .04em; }
#level-tag { font-size: 9px; color: var(--purple); letter-spacing: .14em; text-transform: uppercase; margin-bottom: 6px; font-family: 'Orbitron', sans-serif; font-weight: 700; }
#timer-num { position: absolute; top: 10px; right: 14px; font-family: 'Orbitron', sans-serif; font-weight: 700; font-size: 20px; }

/* ── Answer choices ───────────────────────────────────────── */
#choices { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; }

.choice {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 14px;
  padding: 20px 8px;
  font-size: 22px;
  font-weight: 700;
  cursor: pointer;
  color: #fff;
  text-align: center;
  transition: all .15s ease;
  user-select: none;
  font-family: 'Orbitron', sans-serif;
}
.choice:hover                { border-color: rgba(168,85,247,.55); box-shadow: 0 0 16px rgba(168,85,247,.2); transform: scale(1.04); }
.choice.correct              { border-color: var(--green) !important; background: rgba(34,197,94,.1) !important; color: var(--green); animation: correctBurst .7s ease; }
.choice.wrong                { border-color: var(--red) !important; background: rgba(239,68,68,.1) !important; color: var(--red); animation: shake .45s ease; }
.choice.show-correct         { border-color: var(--green) !important; background: rgba(34,197,94,.06) !important; animation: glowPulse .8s ease; }

/* ── Feedback & progress ──────────────────────────────────── */
#feedback   { text-align: center; font-size: 14px; font-weight: 700; min-height: 22px; color: #aaa; font-family: 'Orbitron', sans-serif; letter-spacing: .08em; }
#prog-wrap  { height: 4px; background: rgba(255,255,255,.05); border-radius: 2px; overflow: hidden; }
#prog-bar   { height: 100%; background: var(--cyan); transition: width .3s; border-radius: 2px; width: 0%; box-shadow: 0 0 8px var(--cyan), 0 0 18px rgba(6,182,212,.35); }
#prog-label { font-size: 10px; color: #64748b; text-align: right; font-family: 'Orbitron', sans-serif; }

/* ── Buttons ──────────────────────────────────────────────── */
.btn {
  width: 100%; padding: 15px;
  font-size: 15px; font-weight: 700;
  cursor: pointer; border: none;
  border-radius: 12px; color: #fff;
  transition: all .18s ease;
  font-family: 'Orbitron', sans-serif;
  letter-spacing: .08em;
  display: flex; align-items: center; justify-content: center;
}
.btn:active { transform: scale(.97) !important; }
.btn i[data-lucide],
.btn svg {
  width: 20px; height: 20px;
  vertical-align: middle;
  margin-right: 8px;
  flex-shrink: 0;
  display: inline-block;
  stroke-width: 2;
}

.btn-primary {
  background: linear-gradient(135deg, #6d28d9, #a855f7);
  border: 1px solid rgba(168,85,247,.35);
  box-shadow: 0 0 24px rgba(168,85,247,.25), 0 4px 16px rgba(0,0,0,.3);
}
.btn-primary:hover { box-shadow: 0 0 40px rgba(168,85,247,.55), 0 4px 20px rgba(0,0,0,.4); transform: translateY(-2px); border-color: var(--purple); }

.btn-danger {
  background: linear-gradient(135deg, #b91c1c, #f97316);
  border: 1px solid rgba(239,68,68,.3);
  box-shadow: 0 0 20px rgba(239,68,68,.18), 0 4px 16px rgba(0,0,0,.3);
}
.btn-danger:hover { box-shadow: 0 0 36px rgba(239,68,68,.45), 0 4px 20px rgba(0,0,0,.4); transform: translateY(-2px); }

.btn-dark {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  color: #94a3b8;
  border: 1px solid var(--glass-border);
}
.btn-dark:hover { background: rgba(255,255,255,.07); border-color: rgba(255,255,255,.14); color: white; }

.btn-sm  { padding: 10px; font-size: 13px; }
.row2    { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.back-btn { background: none; border: none; color: #475569; cursor: pointer; font-size: 13px; padding: 0; display: flex; align-items: center; gap: 4px; }
.back-btn:hover { color: #94a3b8; }
.top-bar  { display: flex; justify-content: space-between; align-items: center; }

/* ── Input ────────────────────────────────────────────────── */
input[type="text"], input[type="password"] {
  width: 100%; padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,.1);
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(20px);
  color: #fff; font-size: 15px; outline: none;
  transition: border-color .18s;
}
input[type="text"]:focus, input[type="password"]:focus { border-color: var(--purple); box-shadow: 0 0 0 3px rgba(168,85,247,.15); }
input::placeholder { color: #475569; }

/* ── Level selector ───────────────────────────────────────── */
.level-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.level-card {
  background: rgba(255,255,255,.03);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255,255,255,.07);
  border-left-width: 3px;
  border-radius: 14px;
  padding: 1rem;
  cursor: pointer;
  transition: all .2s ease;
  text-align: left;
  position: relative;
}
.level-card.selected, .level-card:hover { background: rgba(255,255,255,.06); }
.level-card .lc-num   { font-size: 28px; font-weight: 900; margin-bottom: 4px; font-family: 'Orbitron', sans-serif; line-height: 1; }
.level-card .lc-title { font-size: 11px; font-weight: 700; color: #e2e8f0; margin-bottom: 4px; font-family: 'Orbitron', sans-serif; letter-spacing: .1em; }
.level-card .lc-desc  { font-size: 11px; color: #64748b; line-height: 1.5; }
.lc-diff  { display: flex; gap: 4px; margin-top: 6px; align-items: center; }
.lc-dot   { width: 7px; height: 7px; border-radius: 50%; background: rgba(255,255,255,.07); transition: all .2s; }
.lc-timer {
  position: absolute; top: 10px; right: 10px;
  background: rgba(0,0,0,.45); border-radius: 6px;
  padding: 2px 8px; font-size: 10px;
  font-family: 'Orbitron', sans-serif; font-weight: 600; letter-spacing: .06em;
}

/* ── Rank banner ──────────────────────────────────────────── */
.rank-banner {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(168,85,247,.3);
  border-radius: 16px; padding: 1.25rem; text-align: center;
  box-shadow: 0 0 32px rgba(168,85,247,.15);
}
.rank-num   { font-size: 46px; font-weight: 900; color: var(--gold); line-height: 1; font-family: 'Orbitron', sans-serif; text-shadow: 0 0 24px rgba(245,158,11,.35); }
.rank-badge { display: inline-block; margin-top: 8px; padding: 5px 16px; border-radius: 20px; font-size: 11px; font-weight: 700; font-family: 'Orbitron', sans-serif; letter-spacing: .1em; }

/* ── Leaderboard screen layout ───────────────────────────── */
#s-lb {
  padding: 0;
  gap: 0;
  height: 100vh;
  overflow: hidden;
}
#s-lb .top-bar {
  padding: 20px 20px 14px;
  flex-shrink: 0;
  background: rgba(8,8,16,.96);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  position: sticky;
  top: 0;
  z-index: 10;
}
#lb-list {
  flex: 1;
  overflow-y: auto;
  padding: 14px 20px 40px;
}

/* ── Leaderboard ──────────────────────────────────────────── */
.lb-row {
  display: flex; align-items: center; gap: 12px;
  background: var(--glass-bg); backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 12px; padding: 12px 16px; margin-bottom: 8px;
}
.lb-medal {
  width: 28px; height: 28px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; font-weight: 800; flex-shrink: 0;
}

/* ── Tabs ─────────────────────────────────────────────────── */
.tab-bar { display: grid; grid-template-columns: 1fr 1fr; background: var(--glass-bg); border: 1px solid var(--glass-border); border-radius: 12px; overflow: hidden; }
.tab        { padding: 12px; border: none; background: transparent; color: #64748b; font-weight: 700; cursor: pointer; font-size: 14px; transition: all .18s; }
.tab.active { background: var(--purple); color: #fff; }

/* ── Share modal ──────────────────────────────────────────── */
#modal {
  display: none; position: fixed; inset: 0;
  background: rgba(0,0,0,.8); z-index: 100;
  align-items: center; justify-content: center;
  padding: 1rem; backdrop-filter: blur(4px);
}
#modal.open  { display: flex; }
#modal-box   { background: rgba(8,8,16,.97); border: 1px solid rgba(255,255,255,.1); border-radius: 20px; padding: 1.5rem; max-width: 380px; width: 100%; position: relative; max-height: 90vh; overflow-y: auto; }
#modal-close { position: absolute; top: 12px; right: 14px; background: none; border: none; color: #555; font-size: 20px; cursor: pointer; }
#modal-close:hover { color: #fff; }
.sc-inner    { background: linear-gradient(135deg, rgba(168,85,247,.1), rgba(6,182,212,.05)); border: 1px solid rgba(168,85,247,.3); border-radius: 16px; padding: 1.75rem; text-align: center; margin-bottom: 16px; }
.soc-grid    { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-bottom: 10px; }
.soc-btn     { padding: 11px 8px; border: none; border-radius: 11px; font-size: 13px; font-weight: 700; cursor: pointer; color: #fff; transition: opacity .15s; }
.soc-btn:hover { opacity: .85; }

/* ── Analytics ────────────────────────────────────────────── */
.an-grid    { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.an-box     { background: rgba(255,255,255,.03); border: 1px solid var(--glass-border); border-radius: 12px; padding: 12px; text-align: center; }
.an-val     { font-size: 24px; font-weight: 800; color: var(--gold); margin-bottom: 2px; font-family: 'Orbitron', sans-serif; }
.an-label   { font-size: 11px; color: #64748b; text-transform: uppercase; letter-spacing: .04em; }
.an-section { font-size: 11px; color: var(--purple); text-transform: uppercase; letter-spacing: .08em; margin: 4px 0 8px; font-weight: 700; font-family: 'Orbitron', sans-serif; }
.an-panel   { background: var(--glass-bg); border: 1px solid var(--glass-border); border-radius: 14px; padding: 14px; }
.bar-row    { display: flex; align-items: center; gap: 8px; margin-bottom: 6px; }
.bar-label  { font-size: 12px; color: #aaa; width: 80px; flex-shrink: 0; text-align: right; }
.bar-track  { flex: 1; height: 8px; background: rgba(255,255,255,.05); border-radius: 4px; overflow: hidden; }
.bar-fill   { height: 100%; border-radius: 4px; transition: width .5s; }
.bar-count  { font-size: 11px; color: #555; width: 36px; text-align: right; flex-shrink: 0; }
.summary-row { display: flex; justify-content: space-between; font-size: 13px; color: #aaa; margin-bottom: 6px; }

/* ── Utility ──────────────────────────────────────────────── */
.storage-note { font-size: 11px; color: var(--green); text-align: center; padding: 6px; border: 1px solid rgba(34,197,94,.2); border-radius: 8px; background: rgba(34,197,94,.05); }
.empty-state  { text-align: center; color: #475569; padding: 3rem; background: var(--glass-bg); border: 1px solid var(--glass-border); border-radius: 16px; }

/* ── Nightmare card glow ──────────────────────────────────── */
.card-nightmare { animation: borderNightmare 2.2s ease-in-out infinite !important; }

/* ── Level-up flash overlay ──────────────────────────────── */
#levelup-flash {
  display: none; position: fixed;
  top: 50%; left: 50%;
  font-family: 'Orbitron', sans-serif; font-weight: 900; font-size: 48px;
  color: var(--purple); text-shadow: 0 0 40px var(--purple), 0 0 80px rgba(168,85,247,.4);
  pointer-events: none; z-index: 200; white-space: nowrap;
}
#levelup-flash.show { display: block; animation: levelUpFlash 1.2s ease forwards; }

/* ── Animations ───────────────────────────────────────────── */
@keyframes pulse        { 0%,100%{transform:scale(1)} 50%{transform:scale(1.07)} }
@keyframes glowPulse    { 0%,100%{opacity:1;filter:brightness(1)} 50%{opacity:.7;filter:brightness(1.4)} }
@keyframes shake        { 0%,100%{transform:translateX(0)} 15%{transform:translateX(-9px)} 30%{transform:translateX(9px)} 45%{transform:translateX(-6px)} 60%{transform:translateX(6px)} 75%{transform:translateX(-3px)} 90%{transform:translateX(3px)} }
@keyframes fadeInUp     { from{opacity:0;transform:translateY(14px)} to{opacity:1;transform:translateY(0)} }
@keyframes fadeIn       { from{opacity:0} to{opacity:1} }
@keyframes timerUrgent  { 0%,100%{opacity:1;box-shadow:0 0 8px var(--red),0 0 16px rgba(239,68,68,.4)} 50%{opacity:.25;box-shadow:none} }
@keyframes borderNightmare { 0%,100%{box-shadow:0 0 8px var(--pink),0 0 20px rgba(236,72,153,.15);border-color:rgba(236,72,153,.4)} 50%{box-shadow:0 0 24px var(--pink),0 0 50px rgba(236,72,153,.3);border-color:var(--pink)} }
@keyframes correctBurst { 0%{box-shadow:0 0 0 0 rgba(34,197,94,.9)} 50%{box-shadow:0 0 30px 8px rgba(34,197,94,.4)} 100%{box-shadow:0 0 12px 2px rgba(34,197,94,.2)} }
@keyframes levelUpFlash { 0%{opacity:0;transform:translate(-50%,-50%) scale(.5)} 35%{opacity:1;transform:translate(-50%,-50%) scale(1.08)} 100%{opacity:0;transform:translate(-50%,-50%) scale(1.5)} }
@keyframes nightmareGlow { 0%,100%{text-shadow:0 0 12px rgba(239,68,68,.5)} 50%{text-shadow:0 0 30px rgba(239,68,68,.9),0 0 60px rgba(239,68,68,.3)} }
@keyframes gradientShift { 0%,100%{background-position:0% 50%} 50%{background-position:100% 50%} }
@keyframes slideUp      { from{opacity:0;transform:translateY(20px)} to{opacity:1;transform:translateY(0)} }
@keyframes scoreFloat   { 0%{opacity:0;transform:translateY(0)} 20%{opacity:1} 100%{opacity:0;transform:translateY(-32px)} }
@keyframes lifeFlash    { 0%,100%{opacity:.2;filter:grayscale(1)} 50%{opacity:1;color:var(--red);filter:none;text-shadow:0 0 16px var(--red)} }

::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(168,85,247,.3); border-radius: 2px; }