/* ─── Reset & Variables ───────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
.hidden { display: none !important; }

:root {
  --bg:       #0f0e17;
  --surface:  #1a1928;
  --surface2: #252436;
  --border:   #33314f;
  --accent:   #7c6af8;
  --accent2:  #5e50d4;
  --danger:   #e95a5a;
  --success:  #4ade80;
  --warn:     #fbbf24;
  --text:     #e8e6f0;
  --muted:    #8e8ba8;
  --card-r:   12px;
  --nav-h:    56px;
  --shadow:   0 4px 24px rgba(0,0,0,.4);
}

html, body { height: 100%; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, sans-serif;
  font-size: 15px;
  line-height: 1.5;
  overflow-x: hidden;
}

/* ─── Top Panel ───────────────────────────────────────────────────────────── */

#top-panel {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  height: var(--nav-h);
}

.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 100%; padding: 0 16px; gap: 12px;
}

.nav-left  { display: flex; gap: 4px; }
.nav-center { flex: 1; text-align: center; min-width: 0; }
.nav-right { display: flex; align-items: center; gap: 10px; }

.nav-btn {
  background: none; border: none; color: var(--text);
  font-size: 14px; font-weight: 600; cursor: pointer;
  padding: 6px 12px; border-radius: 8px; transition: background .15s;
}
.nav-btn:hover { background: var(--surface2); }

.lang-btn {
  background: none; border: none; cursor: pointer;
  font-size: 20px; line-height: 1; padding: 4px;
}

.room-badge {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: 20px; padding: 3px 12px; font-size: 13px;
  max-width: 280px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.room-dot {
  width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0;
  background: var(--success); box-shadow: 0 0 6px var(--success);
  animation: pulse 2s infinite;
}
@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:.5} }

.status-dot {
  width: 8px; height: 8px; border-radius: 50%; display: inline-block;
}
.status-dot.ok  { background: var(--success); }
.status-dot.err { background: var(--danger); animation: pulse 1s infinite; }

/* ─── Dropdown ────────────────────────────────────────────────────────────── */

.dropdown {
  position: absolute; top: var(--nav-h); left: 8px;
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: var(--card-r); min-width: 220px;
  box-shadow: var(--shadow); z-index: 200; overflow: hidden;
}
.dropdown.hidden { display: none; }

.dd-header {
  padding: 10px 16px; font-size: 11px; font-weight: 700;
  text-transform: uppercase; letter-spacing: .06em; color: var(--muted);
  border-bottom: 1px solid var(--border);
}

.dd-item {
  display: block; width: 100%; background: none; border: none;
  color: var(--text); text-align: left; cursor: pointer;
  padding: 12px 16px; font-size: 14px; transition: background .12s;
}
.dd-item:hover { background: var(--border); }
.dd-item.danger { color: var(--danger); }

.dd-item-title { font-weight: 600; }
.dd-item-desc  { font-size: 12px; color: var(--muted); margin-top: 2px; }
.dd-badges     { display: flex; gap: 6px; margin-top: 6px; }

.badge-solo, .badge-multi {
  font-size: 10px; font-weight: 700; padding: 1px 7px;
  border-radius: 10px; text-transform: uppercase; letter-spacing: .04em;
}
.badge-solo  { background: #2d4a7a; color: #7eb8ff; }
.badge-multi { background: #3d2d6e; color: #b09aff; }

/* ─── Main Content ────────────────────────────────────────────────────────── */

#main {
  margin-top: var(--nav-h);
  min-height: calc(100vh - var(--nav-h));
  padding: 32px 20px;
  max-width: 900px;
  margin-left: auto; margin-right: auto;
}

/* ─── Hero ────────────────────────────────────────────────────────────────── */

.hero {
  display: flex; flex-direction: column; align-items: center;
  justify-content: center; text-align: center;
  min-height: calc(100vh - var(--nav-h) - 64px);
  padding: 40px 16px;
}

.hero-title {
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 800; letter-spacing: -.02em;
  background: linear-gradient(135deg, var(--accent), #c084fc);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  margin-bottom: 16px;
}

.hero-sub {
  color: var(--muted); font-size: 1.1rem; margin-bottom: 40px; max-width: 400px;
}

.hero-btns { display: flex; gap: 14px; flex-wrap: wrap; justify-content: center; }

/* ─── Buttons ─────────────────────────────────────────────────────────────── */

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  border: none; border-radius: 10px; cursor: pointer; font-weight: 600;
  font-size: 14px; padding: 10px 20px; transition: filter .15s, transform .1s;
  white-space: nowrap;
}
.btn:active { transform: scale(.97); }
.btn:disabled { opacity: .5; cursor: default; }

.btn-primary   { background: var(--accent);  color: #fff; }
.btn-primary:hover:not(:disabled)   { filter: brightness(1.15); }
.btn-secondary { background: var(--surface2); color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover { filter: brightness(1.2); }
.btn-ghost     { background: none; color: var(--muted); border: 1px solid var(--border); }
.btn-ghost:hover { color: var(--text); border-color: var(--muted); }
.btn-danger    { background: var(--danger); color: #fff; }
.btn-danger:hover { filter: brightness(1.15); }
.btn-sm        { font-size: 12px; padding: 5px 11px; border-radius: 7px; }
.btn-lg        { padding: 13px 28px; font-size: 16px; border-radius: 12px; }
.btn-wide      { width: 100%; margin-top: 8px; }

/* ─── Room Lobby ──────────────────────────────────────────────────────────── */

.room-lobby h2 { font-size: 1.6rem; margin-bottom: 24px; }

.lobby-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 20px;
}
@media (max-width: 600px) { .lobby-grid { grid-template-columns: 1fr; } }

.players-card, .share-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--card-r); padding: 20px;
}

.players-card h3 { font-size: .9rem; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); margin-bottom: 14px; }

.player-list { list-style: none; }
.player-item { display: flex; align-items: center; gap: 8px; padding: 8px 0; border-bottom: 1px solid var(--border); }
.player-item:last-child { border-bottom: none; }
.player-name { flex: 1; }

.badge {
  font-size: 10px; font-weight: 700; padding: 2px 7px;
  border-radius: 10px; text-transform: uppercase;
}
.badge.you    { background: #1e3a5f; color: #7eb8ff; }
.badge.owner  { background: #3d2d6e; color: #c084fc; }

.share-row {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 0; border-bottom: 1px solid var(--border); flex-wrap: wrap;
}
.share-row:last-child { border-bottom: none; }
.share-label { font-size: 11px; color: var(--muted); flex-shrink: 0; }
.code-val { font-family: 'Courier New', monospace; font-size: 13px; background: var(--bg); padding: 3px 8px; border-radius: 6px; }
.share-url { flex-direction: column; align-items: flex-start; }
.url-input { width: 100%; background: var(--bg); border: 1px solid var(--border); border-radius: 7px; color: var(--muted); font-size: 11px; padding: 5px 8px; font-family: monospace; }

.qr-wrap { margin-top: 14px; display: flex; justify-content: center; }

.tip-box {
  background: rgba(124,106,248,.15); border: 1px solid rgba(124,106,248,.4);
  border-radius: var(--card-r); padding: 14px 18px; color: var(--accent);
  font-size: 14px; margin-top: 4px;
}
.waiting-msg { color: var(--muted); font-style: italic; }

/* ─── Config Screen ───────────────────────────────────────────────────────── */

.config-screen { max-width: 480px; margin: 0 auto; }
.config-screen h2 { margin-bottom: 28px; }

.config-form, .modal-body { display: flex; flex-direction: column; gap: 14px; }

.field { display: flex; flex-direction: column; gap: 5px; }
.field > span { font-size: 13px; font-weight: 600; color: var(--muted); }

input, select, textarea {
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: 8px; color: var(--text); font-size: 14px;
  padding: 9px 12px; outline: none; width: 100%;
  transition: border-color .15s;
}
input:focus, select:focus { border-color: var(--accent); }
input[type=number] { max-width: 140px; }

.waiting-screen {
  display: flex; align-items: center; justify-content: center;
  min-height: 300px; text-align: center;
}

/* ─── Math Game ───────────────────────────────────────────────────────────── */

.game-screen { display: flex; flex-direction: column; gap: 18px; }

.hud {
  display: flex; align-items: center; gap: 24px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--card-r); padding: 14px 20px;
}
.hud-item { display: flex; align-items: center; gap: 8px; }
.hud-lbl  { font-size: 12px; font-weight: 600; color: var(--muted); text-transform: uppercase; }
.hud-val  { font-size: 1.3rem; font-weight: 700; font-family: monospace; }
.hud-msg  { margin-left: auto; font-weight: 700; font-size: 15px; }
.hud-msg.success { color: var(--success); }
.hud-msg.error   { color: var(--danger); }

.find-hint { color: var(--muted); font-size: 13px; }

.eq-grid {
  display: grid;
  grid-template-columns: repeat(var(--cols, 4), 1fr);
  gap: 10px;
}
@media (max-width: 600px) {
  .eq-grid { grid-template-columns: repeat(2, 1fr); }
}

.eq-card {
  position: relative; background: var(--surface); border: 2px solid var(--border);
  border-radius: var(--card-r); padding: 14px 10px;
  cursor: pointer; transition: border-color .15s, background .15s, transform .1s;
  display: flex; align-items: center; justify-content: center; text-align: center;
  min-height: 60px; color: var(--text);
}
.eq-card:hover { background: var(--surface2); border-color: var(--muted); transform: scale(1.02); }
.eq-card.marked { background: rgba(233,90,90,.15); border-color: var(--danger); }

.eq-x {
  position: absolute; top: 4px; left: 7px;
  font-size: 13px; font-weight: 900; color: var(--danger);
  opacity: 0; transition: opacity .15s;
}
.eq-card.marked .eq-x { opacity: 1; }

.eq-text { font-family: 'Courier New', monospace; font-size: 14px; font-weight: 600; }

.game-btns {
  display: flex; gap: 12px; justify-content: center;
}

/* ─── Scoreboard ──────────────────────────────────────────────────────────── */

.score-screen { display: flex; flex-direction: column; gap: 24px; }
.score-screen h2 { font-size: 1.6rem; }

.scoreboard {
  width: 100%; border-collapse: collapse;
  background: var(--surface); border-radius: var(--card-r);
  overflow: hidden; border: 1px solid var(--border);
}
.scoreboard th, .scoreboard td {
  padding: 12px 16px; text-align: left;
  border-bottom: 1px solid var(--border);
}
.scoreboard th { font-size: 12px; color: var(--muted); font-weight: 700; text-transform: uppercase; letter-spacing: .06em; background: var(--surface2); }
.scoreboard tr:last-child td { border-bottom: none; }
.scoreboard tr.winner td { background: rgba(74,222,128,.07); }
.scoreboard tr.winner td:first-child::before { content: '🏆 '; }

.score-btns { display: flex; gap: 10px; flex-wrap: wrap; }

.solo-result {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--card-r); padding: 24px; max-width: 360px;
}
.result-row {
  display: flex; justify-content: space-between; align-items: center;
  padding: 10px 0; border-bottom: 1px solid var(--border); font-size: 15px;
}
.result-row:last-child { border-bottom: none; }
.result-row strong { font-size: 1.2rem; font-family: monospace; }
.total-row { background: rgba(124,106,248,.1); border-radius: 8px; padding: 12px; margin-top: 4px; }

/* ─── Modal ───────────────────────────────────────────────────────────────── */

#modal-overlay {
  position: fixed; inset: 0; z-index: 500;
  background: rgba(0,0,0,.65); backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center; padding: 20px;
}
#modal-overlay.hidden { display: none; }

#modal-box {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 16px; padding: 28px; max-width: 440px; width: 100%;
  position: relative; box-shadow: var(--shadow);
  max-height: 90vh; overflow-y: auto;
}
#modal-box h2 { margin-bottom: 20px; font-size: 1.3rem; }

.modal-close {
  position: absolute; top: 14px; right: 14px;
  background: none; border: none; color: var(--muted); cursor: pointer;
  font-size: 18px; line-height: 1; padding: 4px 8px;
  border-radius: 6px; transition: color .15s;
}
.modal-close:hover { color: var(--text); }

.modal-row { display: flex; gap: 10px; margin-top: 8px; }

.form-error { color: var(--danger); font-size: 13px; margin-top: -4px; }
.form-error.hidden { display: none; }

.or-sep { color: var(--muted); font-size: 13px; text-align: center; margin: 4px 0; }

.owner-warn {
  background: rgba(233,90,90,.1); border: 1px solid rgba(233,90,90,.3);
  border-radius: 8px; padding: 10px 14px; font-size: 14px; margin-bottom: 8px;
}
.transfer-block { border-top: 1px solid var(--border); margin-top: 12px; padding-top: 12px; }

/* ─── Toast ───────────────────────────────────────────────────────────────── */

.toast {
  position: fixed; bottom: 24px; right: 24px; z-index: 999;
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px 18px; font-size: 14px;
  box-shadow: var(--shadow); opacity: 0; transform: translateY(8px);
  transition: opacity .25s, transform .25s; pointer-events: none;
}
.toast.show { opacity: 1; transform: translateY(0); }
.toast-error { border-color: var(--danger); color: var(--danger); }
.toast-warn  { border-color: var(--warn); color: var(--warn); }