:root {
  --bg-color: #121212;
  --surface-color: #1e1e1e;
  --surface-hover: #2c2c2c;
  --text-primary: #e0e0e0;
  --text-secondary: #a0a0a0;
  --primary-color: #bb86fc;
  --primary-hover: #9965f4;
  --success-color: #03dac6;
  --error-color: #cf6679;
  --border-color: #333333;
  --font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-color);
}

nav a {
  color: var(--text-primary);
  text-decoration: none;
  margin-left: 1rem;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  transition: background-color 0.2s;
}

nav a:hover, nav a.active {
  background-color: var(--surface-hover);
  color: var(--primary-color);
}

.card {
  background-color: var(--surface-color);
  border-radius: 8px;
  padding: 1.5rem;
  margin-bottom: 1rem;
  box-shadow: 0 4px 6px rgba(0,0,0,0.3);
  transition: transform 0.2s;
}

.card:hover {
  transform: translateY(-2px);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.stat-item {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.5rem;
}

.delta.positive { color: var(--success-color); }
.delta.negative { color: var(--error-color); }

button {
  background-color: var(--primary-color);
  color: #000;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  font-weight: 600;
  transition: background-color 0.2s;
}

button:hover {
  background-color: var(--primary-hover);
}

button.secondary {
  background-color: transparent;
  color: var(--primary-color);
  border: 1px solid var(--primary-color);
}

button.secondary:hover {
  background-color: rgba(187, 134, 252, 0.1);
}

input, select {
  width: 100%;
  padding: 0.75rem;
  margin-bottom: 1rem;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  border-radius: 4px;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--primary-color);
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

/* Login Modal */
#login-modal {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}
.hidden {
  display: none !important;
}

/* Scroll to top button */
#scroll-top-btn {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  background: var(--primary-color);
  color: #000;
  font-size: 1.3rem;
  font-weight: 700;
  cursor: pointer;
  border: none;
  box-shadow: 0 4px 12px rgba(187, 134, 252, 0.4);
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.3s, transform 0.3s, background-color 0.2s;
  pointer-events: none;
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
}

#scroll-top-btn.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

#scroll-top-btn:hover {
  background: var(--primary-hover);
  box-shadow: 0 6px 16px rgba(187, 134, 252, 0.6);
}