:root {
  --bg: #0f1116;
  --panel: #171a22;
  --card: #1e2230;
  --ink: #eef2f7;
  --muted: #a6afbf;
  --accent: #48c6ef;
  --radius: 16px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--ink);
  background: radial-gradient(circle at top, #1e2433 0%, #0e1117 60%, #0b0e13 100%);
  min-height: 100vh;
}

.app {
  max-width: 1200px;
  margin: 0 auto;
  padding: 28px 20px 60px;
  display: grid;
  gap: 20px;
}

.header {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.06);
  padding: 16px 18px;
  border-radius: var(--radius);
}

.header h1 {
  margin: 0;
  font-size: 26px;
}

.header p {
  margin: 6px 0 0;
  color: var(--muted);
}

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

button {
  border: none;
  background: var(--card);
  color: var(--ink);
  padding: 10px 16px;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 600;
  transition: transform 0.15s ease, background 0.2s ease;
}

button:hover {
  background: #2b3042;
  transform: translateY(-1px);
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 16px;
}

.sheet {
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
  padding: 16px;
  display: grid;
  gap: 8px;
}

#ice {
  width: 100%;
  height: auto;
  display: block;
  touch-action: none;
}

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

.panel {
  display: grid;
  gap: 16px;
}

.panel-block {
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
  padding: 14px;
  display: grid;
  gap: 10px;
}

.panel-block h2 {
  margin: 0;
  font-size: 16px;
}

#logList {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: 13px;
  display: grid;
  gap: 6px;
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  display: grid;
  place-items: center;
}

.overlay[hidden] {
  display: none;
}

.overlay-card {
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius);
  padding: 24px 30px;
  text-align: center;
  display: grid;
  gap: 12px;
}

@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .panel {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  }
}