/* ============================================================
   Reset & base
   ============================================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg:       #0a0a0f;
  --color-surface:  #13131a;
  --color-border:   #2a2a3a;
  --color-accent:   #4ade80;
  --color-accent2:  #22d3ee;
  --color-danger:   #f87171;
  --color-text:     #e2e8f0;
  --color-muted:    #64748b;
  --font-main:      'Segoe UI', system-ui, sans-serif;
  --font-mono:      'Courier New', monospace;
  --radius:         6px;
}

html, body {
  height: 100%;
  width: 100%;
  overflow: hidden;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-main);
  font-size: 16px;
}

/* ============================================================
   Screen management — only one screen visible at a time
   ============================================================ */
.screen {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
}

.screen.active {
  display: flex;
}

/* ============================================================
   Auth Screen
   ============================================================ */
#auth-screen {
  background:
    radial-gradient(ellipse at 20% 50%, rgba(74, 222, 128, 0.06) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 20%, rgba(34, 211, 238, 0.06) 0%, transparent 60%),
    var(--color-bg);
}

.auth-container {
  width: 100%;
  max-width: 400px;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.game-title {
  text-align: center;
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  text-shadow: 0 0 30px rgba(74, 222, 128, 0.4);
}

.auth-tabs {
  display: flex;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.tab-btn {
  flex: 1;
  padding: 0.6rem;
  background: transparent;
  border: none;
  color: var(--color-muted);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.tab-btn.active {
  background: var(--color-accent);
  color: #000;
}

.tab-btn:hover:not(.active) {
  background: var(--color-border);
  color: var(--color-text);
}

.auth-form {
  display: none;
  flex-direction: column;
  gap: 1rem;
}

.auth-form.active {
  display: flex;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.form-group label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-muted);
}

.form-group input {
  padding: 0.65rem 0.85rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text);
  font-size: 1rem;
  outline: none;
  transition: border-color 0.15s;
}

.form-group input:focus {
  border-color: var(--color-accent);
}

.form-error {
  min-height: 1.2em;
  font-size: 0.85rem;
  color: var(--color-danger);
  text-align: center;
}

.btn-primary {
  padding: 0.75rem 1.5rem;
  background: var(--color-accent);
  border: none;
  border-radius: var(--radius);
  color: #000;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s;
}

.btn-primary:hover {
  opacity: 0.88;
}

.btn-primary:active {
  transform: scale(0.97);
}

.btn-primary:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn-secondary {
  padding: 0.6rem 1.2rem;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-muted);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ============================================================
   Lobby Screen
   ============================================================ */
#lobby-screen {
  background:
    radial-gradient(ellipse at 50% 80%, rgba(74, 222, 128, 0.05) 0%, transparent 60%),
    var(--color-bg);
}

.lobby-container {
  width: 100%;
  max-width: 460px;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.player-card {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 1.25rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.player-avatar {
  flex-shrink: 0;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: rgba(74, 222, 128, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
}

.player-info {
  flex: 1;
  min-width: 0;
}

.player-info h2 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 0.6rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.stats-grid {
  display: flex;
  gap: 1.2rem;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
}

.stat-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-muted);
}

.stat-value {
  font-size: 1.1rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--color-text);
}

.lobby-error {
  min-height: 1.2em;
  font-size: 0.85rem;
  color: var(--color-danger);
  text-align: center;
}

.btn-large {
  width: 100%;
  padding: 1rem;
  font-size: 1.1rem;
  letter-spacing: 0.15em;
}

/* ============================================================
   Game Screen
   ============================================================ */
#game-screen {
  background: #000;
}

#game-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

/* ============================================================
   HUD
   ============================================================ */
#hud {
  position: absolute;
  inset: 0;
  pointer-events: none;
  user-select: none;
}

/* Lives — top left */
#hud-lives {
  position: absolute;
  top: 16px;
  left: 16px;
  font-size: 1.5rem;
  color: var(--color-danger);
  text-shadow: 0 0 8px rgba(248, 113, 113, 0.6);
  letter-spacing: 0.1em;
}

/* Player count — top left below lives */
#hud-players {
  position: absolute;
  top: 52px;
  left: 16px;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-muted);
}

/* Ping display — top right */
#hud-ping {
  position: absolute;
  top: 16px;
  right: 16px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-muted);
}

/* Kill feed — top right */
#kill-feed {
  position: absolute;
  top: 16px;
  right: 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: flex-end;
  min-width: 240px;
  max-width: 320px;
}

.kill-entry {
  padding: 4px 10px;
  background: rgba(0,0,0,0.55);
  border-left: 2px solid var(--color-accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--color-text);
  animation: fadeInRight 0.2s ease;
  white-space: nowrap;
}

.kill-entry .killer { color: var(--color-accent); }
.kill-entry .victim { color: var(--color-danger); }

@keyframes fadeInRight {
  from { opacity: 0; transform: translateX(12px); }
  to   { opacity: 1; transform: translateX(0); }
}

/* Crosshair */
#crosshair {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 20px;
  height: 20px;
}

.ch-h {
  position: absolute;
  top: 50%;
  left: 0;
  width: 100%;
  height: 2px;
  background: rgba(255,255,255,0.85);
  transform: translateY(-50%);
}

.ch-v {
  position: absolute;
  left: 50%;
  top: 0;
  width: 2px;
  height: 100%;
  background: rgba(255,255,255,0.85);
  transform: translateX(-50%);
}

/* Frozen overlay */
#frozen-overlay {
  position: absolute;
  inset: 0;
  background: rgba(10, 50, 100, 0.72);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: all;
}

#frozen-overlay.hidden {
  display: none;
}

.frozen-content {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.frozen-icon {
  font-size: 4rem;
  animation: pulse 1.5s ease-in-out infinite;
}

.frozen-title {
  font-size: 2.5rem;
  font-weight: 900;
  letter-spacing: 0.3em;
  color: var(--color-accent2);
  text-shadow: 0 0 30px rgba(34, 211, 238, 0.6);
}

.frozen-sub {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-muted);
}

.frozen-timer {
  font-size: 3rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: #fff;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.1); opacity: 0.8; }
}

/* Pointer-lock prompt */
#pointer-lock-prompt {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: rgba(0,0,0,0.6);
  pointer-events: auto;
  z-index: 10;
}

#pointer-lock-prompt p {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.1em;
}

#pointer-lock-prompt .hint {
  font-size: 0.85rem;
  color: var(--color-muted);
  letter-spacing: 0.04em;
}

#pointer-lock-prompt.hidden {
  display: none;
}

/* ============================================================
   Username labels (CSS2D / positioned elements)
   ============================================================ */
.player-label {
  position: absolute;
  pointer-events: none;
  white-space: nowrap;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: #fff;
  text-shadow: 0 1px 3px rgba(0,0,0,0.9);
  background: rgba(0,0,0,0.55);
  padding: 2px 6px;
  border-radius: 3px;
  transform: translateX(-50%);
  display: none;
}

/* ============================================================
   Responsive tweaks
   ============================================================ */
@media (max-width: 480px) {
  .auth-container,
  .lobby-container {
    padding: 1.25rem;
  }

  .game-title {
    font-size: 1.35rem;
  }
}