:root {
  color-scheme: light;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  background: #f5f6f7;
  color: #1c1f23;
}

* {
  box-sizing: border-box;
}

body {
  height: 100vh;
  margin: 0;
  overflow: hidden;
}

button {
  font: inherit;
}

.app-shell {
  display: flex;
  flex-direction: column;
  height: 100vh;
  width: 100%;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-shrink: 0;
  height: 60px;
  padding: 0 24px;
  border-bottom: 1px solid #e0e4e8;
  background: #ffffff;
  box-shadow: 0 1px 3px rgba(28, 31, 35, 0.06);
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.room-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 10px 0 12px;
  height: 42px;
  border: 1px solid #cfd6dd;
  border-radius: 8px;
  background: #f9fafb;
  font-size: 0.9rem;
}

.room-label {
  color: #59616b;
}

.room-id {
  font-size: 1rem;
  font-weight: 720;
  letter-spacing: 0.08em;
  color: #1f2328;
}

.copy-btn {
  height: 26px;
  padding: 0 10px;
  border: 1px solid #cfd6dd;
  border-radius: 5px;
  background: #ffffff;
  color: #374151;
  font: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 100ms ease;
}

.copy-btn:hover {
  background: #f3f4f6;
}

h1 {
  margin: 0;
  font-size: clamp(1.45rem, 3vw, 2rem);
  font-weight: 720;
}

.status {
  margin: 5px 0 0;
  color: #59616b;
  font-size: 0.95rem;
}

.status.is-online {
  color: #16705f;
}

.status.is-offline {
  color: #b23434;
}

.history-btn {
  min-height: 42px;
  padding: 0 14px;
  border: 1px solid #cfd6dd;
  border-radius: 8px;
  background: #ffffff;
  color: #252a30;
  cursor: pointer;
  font-weight: 650;
  font-size: 0.88rem;
  transition:
    border-color 120ms ease,
    background 120ms ease,
    opacity 120ms ease;
}

.history-btn:hover:not(:disabled) {
  border-color: #89939f;
  background: #f9fafb;
}

.history-btn:disabled {
  opacity: 0.38;
  cursor: default;
}

.clear-button {
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid #cfd6dd;
  border-radius: 8px;
  background: #ffffff;
  color: #252a30;
  cursor: pointer;
  font-weight: 650;
  transition:
    border-color 120ms ease,
    background 120ms ease,
    transform 120ms ease;
}

.clear-button:hover {
  border-color: #89939f;
  background: #f9fafb;
}

.clear-button:active {
  transform: translateY(1px);
}

.board-wrap {
  position: relative;
  flex: 1;
  overflow: hidden;
  background: #ffffff;
  touch-action: none;
}

#whiteboard {
  display: block;
  width: 100%;
  height: 100%;
  cursor: crosshair;
}

.cursor-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.remote-cursor {
  position: absolute;
  left: 0;
  top: 0;
  width: 18px;
  height: 18px;
  transform: translate(-100px, -100px);
  transition: transform 70ms linear;
}

.remote-cursor::before {
  position: absolute;
  left: 0;
  top: 0;
  width: 0;
  height: 0;
  border-top: 15px solid var(--cursor-color, #e05252);
  border-right: 10px solid transparent;
  content: "";
  filter: drop-shadow(0 2px 2px rgba(28, 31, 35, 0.22));
}

.remote-cursor::after {
  position: absolute;
  left: 8px;
  top: 12px;
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--cursor-color, #e05252);
  content: "";
  box-shadow: 0 0 0 2px #ffffff;
}

.cursor-name {
  position: absolute;
  left: 16px;
  top: -2px;
  padding: 2px 7px;
  border-radius: 4px;
  background: var(--cursor-color, #e05252);
  color: #ffffff;
  font-size: 11px;
  font-weight: 650;
  line-height: 18px;
  white-space: nowrap;
  pointer-events: none;
}

.name-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(28, 31, 35, 0.45);
  backdrop-filter: blur(4px);
}

.name-overlay.hidden {
  display: none;
}

.name-modal {
  width: min(92%, 480px);
  padding: 32px 28px;
  border-radius: 14px;
  background: #ffffff;
  box-shadow: 0 24px 60px rgba(28, 31, 35, 0.22);
}

.name-modal h2 {
  margin: 0 0 6px;
  font-size: 1.25rem;
  font-weight: 720;
}

.name-modal p {
  margin: 0 0 20px;
  color: #59616b;
  font-size: 0.9rem;
}

.name-modal form {
  display: flex;
  gap: 8px;
}

.name-modal input {
  flex: 1;
  min-width: 0;
  height: 42px;
  padding: 0 12px;
  border: 1px solid #cfd6dd;
  border-radius: 8px;
  font: inherit;
  font-size: 0.95rem;
  outline: none;
  transition: border-color 120ms ease;
}

.name-modal input:focus {
  border-color: #4e9af1;
}

.name-modal form button {
  height: 42px;
  padding: 0 18px;
  border: none;
  border-radius: 8px;
  background: #1f2328;
  color: #ffffff;
  font: inherit;
  font-weight: 650;
  cursor: pointer;
  white-space: nowrap;
  transition: background 120ms ease;
}

.name-modal form button:hover {
  background: #373d46;
}

/* Room ID input — bigger digits, centered */
#roomIdInput {
  font-size: 1.4rem;
  font-weight: 720;
  letter-spacing: 0.2em;
  text-align: center;
}

/* Action cards */
.action-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 4px;
}

.action-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
  padding: 18px 16px;
  border: 1.5px solid #cfd6dd;
  border-radius: 10px;
  background: #ffffff;
  cursor: pointer;
  text-align: left;
  transition: border-color 120ms ease, background 120ms ease, transform 120ms ease;
}

.action-card:hover {
  border-color: #1f2328;
  background: #f9fafb;
}

.action-card:active {
  transform: translateY(1px);
}

.action-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: #1f2328;
}

.action-desc {
  font-size: 0.8rem;
  color: #59616b;
  line-height: 1.4;
}

/* Error + back */
.modal-error {
  margin: 10px 0 0;
  font-size: 0.85rem;
  color: #b23434;
  min-height: 1.2em;
}

.link-btn {
  margin-top: 14px;
  padding: 0;
  border: none;
  background: none;
  color: #59616b;
  font: inherit;
  font-size: 0.88rem;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.link-btn:hover {
  color: #1f2328;
}

@media (max-width: 640px) {
  .topbar {
    height: auto;
    flex-wrap: wrap;
    padding: 10px 16px;
    gap: 8px;
  }

  .clear-button {
    width: 100%;
  }
}