:root {
  --primary-color: #e74c3c;
  --primary-hover: #c0392b;
  --secondary-color: #2c3e50;
  --bg-color: #f8f9fa;
  --text-color: #333;
  --text-light: #7f8c8d;
  --white: #fff;
  --border-color: #eaeaea;
  --success: #27ae60;
  --warning: #f39c12;
  --danger: #e74c3c;
  
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 24px rgba(0,0,0,0.12);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
}

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

html, body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  scroll-behavior: smooth;
}

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.2s ease;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Button Utility */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  font-size: 15px;
  gap: 8px;
}

.btn-primary {
  background-color: var(--primary-color);
  color: var(--white);
  box-shadow: 0 4px 10px rgba(231, 76, 60, 0.3);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 15px rgba(231, 76, 60, 0.4);
}

.btn-outline {
  background-color: transparent;
  color: var(--primary-color);
  border: 1.5px solid var(--primary-color);
}

.btn-outline:hover {
  background-color: var(--primary-color);
  color: var(--white);
}

/* Form Styles */
.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  color: var(--secondary-color);
}

.form-group input, 
.form-group select, 
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 15px;
  transition: border-color 0.2s;
  background-color: var(--white);
}

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

/* Modal Overlay */
.modal-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  backdrop-filter: blur(4px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-box {
  background: var(--white);
  padding: 40px;
  border-radius: var(--radius-lg);
  text-align: center;
  max-width: 400px;
  width: 90%;
  box-shadow: var(--shadow-lg);
  transform: translateY(20px);
  transition: transform 0.3s ease;
}

.modal-overlay.active .modal-box {
  transform: translateY(0);
}

/* Shared page wrapper */
.page-wrapper {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

/* Loader */
.loader {
  border: 3px solid rgba(0,0,0,0.1);
  border-radius: 50%;
  border-top: 3px solid var(--primary-color);
  width: 24px;
  height: 24px;
  animation: spin 1s linear infinite;
  display: inline-block;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Alert Boxes */
.alert {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 10px;
}

.alert.error {
  background-color: #fdf2f2;
  color: var(--danger);
  border: 1px solid #f9d8d8;
}

.alert.success {
  background-color: #f0fdf4;
  color: var(--success);
  border: 1px solid #dcfce7;
}