/* ─── RESET & TOKENS ─────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #080c14;
  --bg2:       #0e1420;
  --surface:   #131c2e;
  --surface2:  #1a2540;
  --border:    #1f2e4a;
  --accent:    #00e5ff;
  --accent2:   #7c3aed;
  --green:     #22c55e;
  --red:       #ef4444;
  --yellow:    #f59e0b;
  --text:      #e2e8f0;
  --text-muted:#7a8fa6;
  --hw:        #f97316;
  --sw-py:     #3b82f6;
  --sw-html:   #e11d48;
  --sw-js:     #eab308;
  --net:       #06b6d4;

  --radius:    14px;
  --radius-sm: 8px;
  --shadow:    0 8px 32px rgba(0,0,0,.5);
  --font-brand:'Orbitron', sans-serif;
  --font:      'Inter', sans-serif;
}

html, body {
  height: 100%;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
}

/* ─── SCREENS ─────────────────────────────────────────────── */
.screen {
  position: fixed; inset: 0;
  display: none;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}
.screen.active { display: flex; flex-direction: column; align-items: center; }

/* ─── HOME ────────────────────────────────────────────────── */
#screen-home {
  justify-content: center;
  min-height: 100vh;
  padding: 24px 16px;
}

.home-bg-grid {
  position: fixed; inset: 0; z-index: 0;
  background-image:
    linear-gradient(rgba(0,229,255,.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,229,255,.04) 1px, transparent 1px);
  background-size: 40px 40px;
  animation: gridMove 20s linear infinite;
}
@keyframes gridMove { to { background-position: 40px 40px; } }

.home-content {
  position: relative; z-index: 1;
  width: 100%; max-width: 480px;
  display: flex; flex-direction: column; align-items: center; gap: 28px;
}

.logo-wrap { text-align: center; }
.logo-icon { font-size: 3.5rem; display: block; animation: float 3s ease-in-out infinite; }
@keyframes float { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-10px)} }

.logo-title {
  font-family: var(--font-brand);
  font-size: clamp(2rem, 8vw, 3.2rem);
  font-weight: 900;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 4px;
}
.logo-sub { color: var(--text-muted); font-size: .9rem; margin-top: 4px; letter-spacing: 2px; text-transform: uppercase; }

.home-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  width: 100%;
  box-shadow: var(--shadow);
  display: flex; flex-direction: column; gap: 20px;
}

.badge-row { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }
.badge {
  padding: 4px 12px; border-radius: 20px; font-size: .75rem; font-weight: 600;
  letter-spacing: 1px; text-transform: uppercase;
}
.badge-hw  { background: rgba(249,115,22,.15); color: var(--hw);    border: 1px solid rgba(249,115,22,.3); }
.badge-py  { background: rgba(59,130,246,.15); color: var(--sw-py); border: 1px solid rgba(59,130,246,.3); }
.badge-html{ background: rgba(225,29,72,.15);  color: var(--sw-html);border: 1px solid rgba(225,29,72,.3); }
.badge-js  { background: rgba(234,179,8,.15);  color: var(--sw-js); border: 1px solid rgba(234,179,8,.3); }
.badge-net { background: rgba(6,182,212,.15);  color: var(--net);   border: 1px solid rgba(6,182,212,.3); }

.home-desc { color: var(--text-muted); font-size: .88rem; line-height: 1.6; text-align: center; }

.input-group { display: flex; flex-direction: column; gap: 8px; }
.input-group label { font-size: .8rem; font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; }
.input-group input {
  background: var(--bg2); border: 1px solid var(--border); border-radius: var(--radius-sm);
  color: var(--text); font-family: var(--font); font-size: 1rem;
  padding: 12px 16px; outline: none; transition: border-color .2s, box-shadow .2s;
}
.input-group input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(0,229,255,.12); }
.input-group input::placeholder { color: var(--text-muted); }

/* ─── BUTTONS ─────────────────────────────────────────────── */
.btn {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  border: none; border-radius: var(--radius-sm);
  font-family: var(--font-brand); font-size: .85rem; font-weight: 600; letter-spacing: 1px;
  padding: 14px 20px; cursor: pointer; transition: all .2s; text-transform: uppercase;
}
.btn svg { width: 20px; height: 20px; fill: currentColor; }

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #0099cc);
  color: #000; box-shadow: 0 4px 20px rgba(0,229,255,.3);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 28px rgba(0,229,255,.45); }
.btn-primary:active { transform: translateY(0); }

.btn-ghost {
  background: transparent; color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }


.btn-back {
  background: none; border: none; color: var(--text-muted);
  font-family: var(--font); font-size: .9rem; cursor: pointer; padding: 4px 0;
  display: inline-flex; align-items: center; gap: 6px;
}
.btn-back:hover { color: var(--accent); }

/* ─── GAME SCREEN ─────────────────────────────────────────── */
#screen-game {
  justify-content: flex-start;
  padding: 0 0 32px;
  min-height: 100vh;
}

.game-header {
  width: 100%; max-width: 700px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 20px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.hud-block { display: flex; flex-direction: column; align-items: flex-start; gap: 2px; }
.hud-block.center { align-items: center; }
.hud-block.right { align-items: flex-end; }
.hud-label { font-size: .65rem; font-weight: 700; color: var(--text-muted); letter-spacing: 2px; text-transform: uppercase; }
.hud-value { font-family: var(--font-brand); font-size: 1.4rem; color: var(--accent); }

.level-pips { display: flex; gap: 6px; margin-top: 2px; }
.pip {
  width: 28px; height: 10px; border-radius: 4px;
  background: var(--border); transition: background .4s, box-shadow .4s;
}
.pip.active-1 { background: var(--green); box-shadow: 0 0 8px var(--green); }
.pip.active-2 { background: var(--yellow); box-shadow: 0 0 8px var(--yellow); }
.pip.active-3 { background: var(--red); box-shadow: 0 0 8px var(--red); }

/* Timer */
.timer-track {
  width: 100%; height: 6px; background: var(--surface2); flex-shrink: 0;
}
.timer-fill {
  height: 100%; width: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width .1s linear, background .5s;
  transform-origin: left;
}
.timer-fill.warning { background: linear-gradient(90deg, var(--yellow), var(--red)); }
.timer-fill.danger  { background: var(--red); animation: pulse-bar .5s infinite alternate; }
@keyframes pulse-bar { to { opacity: .6; } }

.timer-row {
  display: flex; align-items: baseline; gap: 4px;
  padding: 6px 20px 0;
  width: 100%; max-width: 700px; margin: 0 auto;
}
.timer-num {
  font-family: var(--font-brand); font-size: 2.2rem; color: var(--accent);
  transition: color .3s;
  min-width: 2.5ch;
}
.timer-num.warning { color: var(--yellow); }
.timer-num.danger  { color: var(--red); }
.timer-sec { font-size: .8rem; color: var(--text-muted); }

/* Category */
.q-category-row {
  width: 100%; max-width: 700px; margin: 10px auto 0;
  padding: 0 20px;
}
.q-category-tag {
  display: inline-block; padding: 4px 14px; border-radius: 20px;
  font-size: .72rem; font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase;
}
.cat-hw   { background: rgba(249,115,22,.15); color: var(--hw);     border: 1px solid rgba(249,115,22,.3); }
.cat-py   { background: rgba(59,130,246,.15);  color: var(--sw-py);  border: 1px solid rgba(59,130,246,.3); }
.cat-html { background: rgba(225,29,72,.15);   color: var(--sw-html);border: 1px solid rgba(225,29,72,.3); }
.cat-js   { background: rgba(234,179,8,.15);   color: var(--sw-js);  border: 1px solid rgba(234,179,8,.3); }
.cat-net  { background: rgba(6,182,212,.15);   color: var(--net);    border: 1px solid rgba(6,182,212,.3); }

/* Question card */
.question-card {
  width: 100%; max-width: 700px; margin: 12px auto 0;
  padding: 0 20px;
}
.question-text {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 22px;
  font-size: clamp(.95rem, 2.5vw, 1.1rem);
  line-height: 1.65;
  font-weight: 500;
  min-height: 90px;
}

/* Options */
.options-grid {
  width: 100%; max-width: 700px; margin: 14px auto 0;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
@media (max-width: 480px) {
  .options-grid { grid-template-columns: 1fr; }
}

.option-btn {
  display: flex; align-items: center; gap: 12px;
  background: var(--surface); border: 1.5px solid var(--border);
  border-radius: var(--radius); padding: 14px 16px;
  color: var(--text); font-family: var(--font); font-size: .92rem;
  cursor: pointer; text-align: left; transition: all .18s;
  min-height: 64px;
}
.option-btn:hover:not(:disabled) {
  border-color: var(--accent); background: rgba(0,229,255,.06);
  transform: translateY(-2px); box-shadow: 0 4px 16px rgba(0,229,255,.15);
}
.option-btn:disabled { cursor: not-allowed; }

.opt-letter {
  font-family: var(--font-brand); font-size: .8rem; font-weight: 700;
  width: 28px; height: 28px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: var(--surface2); color: var(--accent);
  flex-shrink: 0; transition: background .2s;
}
.opt-text { flex: 1; line-height: 1.4; }

.option-btn.correct { border-color: var(--green); background: rgba(34,197,94,.12); }
.option-btn.correct .opt-letter { background: var(--green); color: #000; }
.option-btn.wrong   { border-color: var(--red); background: rgba(239,68,68,.12); animation: shake .35s; }
.option-btn.wrong .opt-letter { background: var(--red); color: #fff; }

@keyframes shake {
  0%,100%{transform:translateX(0)}
  20%{transform:translateX(-8px)}
  40%{transform:translateX(8px)}
  60%{transform:translateX(-5px)}
  80%{transform:translateX(5px)}
}

/* ─── ANSWER FLASH OVERLAY ────────────────────────────────── */
.answer-flash {
  position: fixed; inset: 0; z-index: 100; pointer-events: none;
  transition: opacity .3s;
}
.answer-flash.hidden { display: none; }
.answer-flash.correct-flash { background: rgba(34,197,94,.08); }
.answer-flash.wrong-flash   { background: rgba(239,68,68,.10); }

/* ─── GAME OVER ───────────────────────────────────────────── */
#screen-gameover {
  justify-content: center; align-items: center;
  padding: 24px 16px; min-height: 100vh;
}
.gameover-content {
  width: 100%; max-width: 480px;
  display: flex; flex-direction: column; align-items: center; gap: 24px;
  text-align: center;
}
.go-icon { font-size: 4rem; animation: pop .4s cubic-bezier(.36,1.5,.5,1); }
@keyframes pop { from{transform:scale(0)} to{transform:scale(1)} }
.go-title { font-family: var(--font-brand); font-size: clamp(1.8rem,6vw,2.8rem); }
.go-subtitle { color: var(--text-muted); font-size: .9rem; }
.go-player-name { font-size: .95rem; color: var(--accent); font-weight: 600; letter-spacing: 1px; }

.go-stats {
  display: flex; gap: 12px; width: 100%; justify-content: center; flex-wrap: wrap;
}
.stat-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 20px;
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  flex: 1; min-width: 100px;
}
.stat-label { font-size: .7rem; text-transform: uppercase; letter-spacing: 1px; color: var(--text-muted); }
.stat-value { font-family: var(--font-brand); font-size: 1.8rem; }
.stat-value.accent { color: var(--accent); }

.go-rank-msg {
  background: rgba(0,229,255,.08); border: 1px solid rgba(0,229,255,.2);
  border-radius: var(--radius-sm); padding: 12px 20px;
  font-size: .88rem; color: var(--accent); width: 100%;
  display: none;
}
.go-rank-msg.show { display: block; }
.go-actions { display: flex; gap: 12px; width: 100%; }
.go-actions .btn { flex: 1; }

/* ─── LEADERBOARD ─────────────────────────────────────────── */
#screen-leaderboard {
  justify-content: flex-start; align-items: center;
  padding: 32px 16px; min-height: 100vh;
}
.lb-content {
  width: 100%; max-width: 520px;
  display: flex; flex-direction: column; gap: 16px;
}
.lb-title { font-family: var(--font-brand); font-size: clamp(1.6rem,5vw,2.2rem); text-align: center; }
.lb-sub { color: var(--text-muted); font-size: .85rem; text-align: center; }

.lb-list { display: flex; flex-direction: column; gap: 8px; }
.lb-item {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 14px 18px;
  display: flex; align-items: center; gap: 14px;
  animation: slideIn .3s ease both;
}
@keyframes slideIn { from{opacity:0;transform:translateX(-16px)} to{opacity:1;transform:none} }

.lb-rank {
  font-family: var(--font-brand); font-size: 1.1rem;
  width: 36px; text-align: center; flex-shrink: 0;
}
.lb-rank.gold   { color: #fbbf24; text-shadow: 0 0 12px #fbbf24; }
.lb-rank.silver { color: #94a3b8; }
.lb-rank.bronze { color: #b45309; }

.lb-name { flex: 1; font-weight: 600; }
.lb-meta { display: flex; flex-direction: column; align-items: flex-end; gap: 2px; }
.lb-score { font-family: var(--font-brand); font-size: 1.1rem; color: var(--accent); }
.lb-detail { font-size: .7rem; color: var(--text-muted); }

.lb-empty { color: var(--text-muted); text-align: center; padding: 40px 0; font-size: .9rem; }

.lb-item.highlight { border-color: var(--accent); background: rgba(0,229,255,.06); }

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