:root {
  --bg: #0f1419;
  --card: #1a2332;
  --accent: #3d8bfd;
  --accent-hover: #5ca0ff;
  --text: #e7ecf3;
  --muted: #8b9cb3;
  --border: #2a3a52;
  --success: #3dd68c;
  --error: #f07178;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: linear-gradient(160deg, #0a0e14 0%, #121c2a 50%, #0f1419 100%);
  color: var(--text);
}

.header {
  padding: 2rem 1.5rem 1rem;
  text-align: center;
}

.header h1 {
  margin: 0;
  font-size: 1.75rem;
  font-weight: 700;
}

.subtitle {
  color: var(--muted);
  margin: 0.5rem 0 0;
}

.upload-card,
.board-card {
  max-width: 960px;
  margin: 1rem auto 1.5rem;
  padding: 1.25rem 1.5rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
}

.upload-card h2,
.board-card h2 {
  margin: 0 0 1rem;
  font-size: 1.1rem;
}

#upload-form {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

#file-input {
  flex: 1;
  min-width: 200px;
  color: var(--muted);
}

button {
  padding: 0.55rem 1.2rem;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}

button:hover {
  background: var(--accent-hover);
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.status {
  margin: 0.75rem 0 0;
  font-size: 0.9rem;
  color: var(--muted);
}

.status.ok {
  color: var(--success);
}

.status.err {
  color: var(--error);
}

.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  padding: 0.65rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  color: var(--muted);
  font-weight: 600;
  font-size: 0.85rem;
}

.replay-link {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}

.replay-link:hover {
  text-decoration: underline;
}

.empty-row td {
  color: var(--muted);
  text-align: center;
  padding: 2rem;
}