:root {
  --bg: #0f1410;
  --panel: #1a221c;
  --grid: #243028;
  --snake: #6fbf73;
  --snake-head: #a8e6a1;
  --food: #e85d4c;
  --text: #e8efe6;
  --muted: #8a9a88;
  --accent: #c4e87a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(ellipse at 20% 0%, #1c2a1e 0%, transparent 50%),
    radial-gradient(ellipse at 80% 100%, #1a2420 0%, transparent 45%),
    var(--bg);
}

.app {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  padding: 1.5rem;
}

.header {
  text-align: center;
}

.header h1 {
  margin: 0;
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--accent);
}

.hint {
  margin: 0.4rem 0 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.panel {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 0.65rem 1rem;
  background: var(--panel);
  border: 1px solid #2e3a32;
}

.stat {
  font-size: 0.95rem;
  color: var(--muted);
}

.stat span {
  color: var(--text);
  font-weight: 600;
  margin-left: 0.25rem;
}

#btn-start {
  border: none;
  padding: 0.45rem 1rem;
  background: var(--accent);
  color: #1a2210;
  font-weight: 600;
  cursor: pointer;
}

#btn-start:hover {
  filter: brightness(1.08);
}

#board {
  display: block;
  background: var(--grid);
  border: 3px solid #3a4a3e;
  image-rendering: pixelated;
  max-width: min(90vw, 480px);
  height: auto;
}

.status {
  margin: 0;
  min-height: 1.25rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.status.over {
  color: var(--food);
}

.status.pause {
  color: var(--accent);
}

.back-showcase {
  position: fixed;
  top: 1rem;
  right: 1rem;
  z-index: 20;
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 0.95rem;
  border: 1px solid #3a4a3e;
  border-radius: 999px;
  background: rgba(26, 34, 28, 0.92);
  color: var(--text);
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  backdrop-filter: blur(8px);
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}

.back-showcase:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(36, 48, 40, 0.95);
}