src/index.css

:root {
  --primary-color: #6366f1;
  /* Indigo 500 */
  --primary-hover: #4f46e5;
  /* Indigo 600 */
  --background-dark: #0f172a;
  /* Slate 900 */
  --surface-dark: #1e293b;
  /* Slate 800 */
  --text-primary: #f8fafc;
  /* Slate 50 */
  --text-secondary: #94a3b8;
  /* Slate 400 */
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
}

body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--background-dark);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  justify-content: center;
}

#root {
  width: 100%;
  max-width: 1280px;
  /* Increased from 480px */
  padding: 1rem;
  box-sizing: border-box;
}

/* Typography */
h1 {
  font-size: 2rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 2rem;
  background: var(--accent-gradient);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.025em;
}

/* Card Container */
.card {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: 1.5rem;
  padding: 1.5rem;
  box-shadow: var(--shadow-lg);
  margin-bottom: 1.5rem;
}

/* Input Group */
.input-group {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

input[type="text"] {
  width: 100%;
  padding: 1rem;
  border-radius: 1rem;
  border: 1px solid var(--glass-border);
  background: rgba(15, 23, 42, 0.6);
  color: white;
  font-size: 1rem;
  transition: all 0.3s ease;
  box-sizing: border-box;
}

input[type="text"]:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.3);
}

/* Modern File Input */
.file-input-wrapper {
  position: relative;
  width: 100%;
  height: 3rem;
  border: 1px dashed var(--glass-border);
  border-radius: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(15, 23, 42, 0.3);
  transition: all 0.3s ease;
  cursor: pointer;
  overflow: hidden;
}

.file-input-wrapper:hover {
  border-color: var(--primary-color);
  background: rgba(15, 23, 42, 0.5);
}

.file-input {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.file-input-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
  pointer-events: none;
}

.file-input-label span {
  color: var(--primary-color);
  font-weight: 600;
}

/* Button */
button {
  width: 100%;
  padding: 1rem;
  border-radius: 1rem;
  border: none;
  background: var(--accent-gradient);
  color: white;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
}

button:active {
  transform: scale(0.98);
}

button:disabled {
  opacity: 0.7;
  cursor: not-allowed;
  filter: grayscale(0.5);
}

/* Table Styles */
.table-container {
  overflow-x: auto;
  border-radius: 1rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

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

th {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-secondary);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

tr:last-child td {
  border-bottom: none;
}

/* Loading Animation */
.loading-spinner {
  width: 24px;
  height: 24px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 1s ease-in-out infinite;
  margin: 0 auto;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Error Message */
.error-message {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
  color: #fca5a5;
  padding: 1rem;
  border-radius: 1rem;
  text-align: center;
  margin-top: 1rem;
  font-size: 0.9rem;
}

/* Success Message */
.success-message {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.2);
  color: #4ade80;
  padding: 1rem;
  border-radius: 1rem;
  text-align: center;
  margin-bottom: 1.5rem;
  font-weight: 500;
}