/* --- Start screen --- */
#start-screen {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 18px;
  width: min(720px, calc(100vw - 32px));
  padding: 34px;
  border: 1px solid rgba(132,153,166,0.34);
  border-radius: 8px;
  background:
    linear-gradient(180deg, rgba(17,25,34,0.96), rgba(9,14,19,0.97)),
    radial-gradient(circle at 18% 0%, rgba(98,209,200,0.18), transparent 36%);
  box-shadow: 0 26px 80px rgba(0,0,0,0.52), inset 0 1px 0 rgba(255,255,255,0.05);
  overflow: hidden;
}
#start-screen::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(90deg, transparent, rgba(98,209,200,0.12), transparent),
    linear-gradient(rgba(240,179,90,0.08) 1px, transparent 1px);
  background-size: 100% 100%, 100% 42px;
  animation: tactical-scan 6s ease-in-out infinite;
}
#start-screen > * { position: relative; z-index: 1; }
#start-screen h1 {
  font-family: var(--font-display);
  font-size: 42px;
  color: var(--accent);
  letter-spacing: 4px;
  text-align: center;
  text-shadow: 0 0 22px rgba(240,179,90,0.22);
}
#start-screen .subtitle {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent-2);
  letter-spacing: 1px;
  text-align: center;
  margin-top: -8px;
  margin-bottom: 6px;
}
.mode-group {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  align-items: stretch;
  gap: 10px;
  width: 100%;
}
.mode-group-title {
  grid-column: 1 / -1;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 1px;
  color: var(--text-dim);
  text-transform: none;
  display: flex;
  align-items: center;
  gap: 10px;
}
.mode-group-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, rgba(132,153,166,0.42), transparent);
}
.mode-btn {
  width: 100%;
  min-height: 54px;
  padding: 12px 14px;
  border: 1px solid rgba(132,153,166,0.34);
  border-radius: 4px;
  background: linear-gradient(180deg, rgba(23,35,45,0.96), rgba(13,20,27,0.98));
  color: var(--text);
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0;
  transition: transform 0.18s ease, border-color 0.18s ease, color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease;
  position: relative;
  overflow: hidden;
}
.mode-btn:hover {
  border-color: var(--accent-2);
  background: linear-gradient(180deg, rgba(29,47,58,0.98), rgba(14,26,32,0.98));
  color: var(--text);
  transform: translateY(-1px);
  box-shadow: 0 12px 28px rgba(0,0,0,0.28), 0 0 0 1px rgba(98,209,200,0.12);
}
.mode-btn.primary { border-color: rgba(240,179,90,0.58); color: var(--accent); }
.mode-btn.primary:hover { border-color: var(--accent); background: linear-gradient(180deg, rgba(44,35,24,0.98), rgba(20,24,27,0.98)); }
.mode-btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 38%, rgba(255,255,255,0.11) 50%, transparent 62%);
  opacity: 0;
  transform: translateX(-60%);
  transition: opacity 0.2s, transform 0.42s ease;
}
.mode-btn:hover::after { opacity: 1; transform: translateX(60%); }
.mode-btn:disabled {
  cursor: not-allowed;
  opacity: 0.46;
  transform: none;
  box-shadow: none;
}

#room-setup {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  margin-top: 8px;
  padding: 20px;
  background: rgba(7,11,16,0.72);
  border: 1px solid rgba(132,153,166,0.3);
  border-radius: 4px;
  width: min(420px, 100%);
  align-self: center;
}
#p2p-submode-select {
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 100%;
}
#room-setup .room-code-display {
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 900;
  letter-spacing: 8px;
  color: var(--accent);
}
#room-setup input {
  width: min(260px, 100%);
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg);
  color: var(--text);
  font-size: 18px;
  text-align: center;
  letter-spacing: 4px;
  font-family: var(--font-mono);
  text-transform: uppercase;
  transition: border-color 0.2s;
}
#room-setup input:focus { outline: none; border-color: var(--accent); }
#room-setup button {
  padding: 8px 24px;
  border: 1px solid var(--border);
  border-radius: 4px;
  cursor: pointer;
  font-family: var(--font-display);
  font-size: 14px;
  letter-spacing: 2px;
  transition: all 0.2s;
}
.btn-host { background: var(--red); color: white; border-color: var(--red); }
.btn-host:hover { background: #ff7470; }
.btn-join { background: var(--accent-blue); color: white; border-color: var(--accent-blue); }
.btn-join:hover { background: #79a2ff; }
.btn-back { background: transparent; color: var(--text-dim); margin-top: 8px; }
.btn-back:hover { color: var(--text); border-color: var(--text-dim); }

.conn-status { font-size: 12px; color: var(--text-dim); }
.conn-status .dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; margin-right: 4px; }
.conn-status .dot.red { background: var(--red); }
.conn-status .dot.yellow { background: var(--amber); }
.conn-status .dot.green { background: var(--jade); }

#room-error { font-size: 12px; color: var(--red); min-height: 16px; }

@media (max-width: 720px) {
  #start-screen {
    width: calc(100vw - 20px);
    padding: 22px;
  }
  #start-screen h1 { font-size: 32px; }
  .mode-group { grid-template-columns: 1fr; }
}