* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #0f0f1a;
  --surface: #16213e;
  --surface2: #1a2a4a;
  --border: #0f3460;
  --accent: #e94560;
  --accent2: #4ecca3;
  --text: #e0e0f0;
  --muted: #7a7a9a;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  min-height: 100vh;
}

header {
  text-align: center;
  padding: 2.5rem 1rem 1.5rem;
  background: linear-gradient(180deg, #16213e 0%, transparent 100%);
  border-bottom: 1px solid var(--border);
  margin-bottom: 2rem;
}

header h1 {
  font-size: 2.2rem;
  letter-spacing: 3px;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}

header p {
  color: var(--muted);
  font-size: 0.95rem;
}

main {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Card */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.8rem 2rem;
}

.card.hidden {
  display: none;
}

.step-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 3px;
  color: var(--accent2);
  margin-bottom: 1.2rem;
  font-weight: 600;
}

/* Drop Zone */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 2.5rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.drop-zone.drag-over {
  border-color: var(--accent);
  background: rgba(233, 69, 96, 0.07);
}

.drop-icon {
  font-size: 2.8rem;
  margin-bottom: 0.3rem;
}

.drop-zone p {
  color: var(--muted);
  font-size: 0.95rem;
}

.drop-zone span {
  color: var(--muted);
  font-size: 0.85rem;
}

.file-info {
  margin-top: 1rem;
  font-size: 0.88rem;
  color: var(--accent2);
  font-weight: 600;
  min-height: 1.2rem;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.6rem 1.6rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  letter-spacing: 0.5px;
  transition: background 0.2s, transform 0.1s;
  text-decoration: none;
}

.btn:hover {
  background: #c73652;
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--border);
  color: var(--muted);
}

.btn-secondary:hover {
  background: var(--surface2);
  color: var(--text);
}

.btn-generate {
  margin-top: 1.5rem;
  padding: 0.75rem 2.5rem;
  font-size: 1rem;
}

/* Table */
.table-wrapper {
  overflow-x: auto;
  border-radius: 10px;
  border: 1px solid var(--border);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

thead tr {
  background: var(--border);
}

thead th {
  padding: 0.7rem 1rem;
  text-align: left;
  color: var(--accent2);
  font-weight: 600;
  letter-spacing: 0.5px;
  white-space: nowrap;
}

tbody tr:nth-child(even) {
  background: rgba(15, 52, 96, 0.3);
}

tbody td {
  padding: 0.55rem 1rem;
  color: var(--text);
  white-space: nowrap;
  max-width: 200px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.row-count {
  margin-top: 0.8rem;
  font-size: 0.82rem;
  color: var(--muted);
}

/* Config */
.config-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.2rem;
}

.config-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.config-group label {
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
}

.config-group select,
.config-group input[type="color"] {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  padding: 0.5rem 0.8rem;
  font-size: 0.9rem;
  outline: none;
  cursor: pointer;
  transition: border-color 0.2s;
}

.config-group select:focus,
.config-group select:hover {
  border-color: var(--accent);
}

.config-group input[type="color"] {
  height: 40px;
  padding: 2px 6px;
}

/* Auto-suggest badge */
.suggest-badge {
  margin-top: 0.4rem;
  font-size: 0.75rem;
  background: rgba(78, 204, 163, 0.12);
  border: 1px solid var(--accent2);
  color: var(--accent2);
  border-radius: 6px;
  padding: 0.3rem 0.6rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  animation: fadeIn 0.3s ease;
}

.suggest-badge.hidden {
  display: none;
}

.suggest-badge .suggest-icon {
  font-size: 0.9rem;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Chart */
.chart-container {
  position: relative;
  max-height: 450px;
  display: flex;
  justify-content: center;
}

.chart-container canvas {
  max-height: 420px;
}

.chart-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-top: 1.5rem;
}