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

:root {
  --color-primary: #01a5a5;
  --color-secondary: #000000;
  --color-background:hsl(0, 0%, 99%);
  --color-text: #333333;
  --color-text-light: #666666;
  --color-border: #d1d1d1;
  --color-success: #008080;
  --color-danger: #d32f2f;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --font-family-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", sans-serif;
}

html {
  scroll-behavior: smooth;
}

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

.banner {
    position: sticky;      /* or 'fixed' if you want it always visible */
    top: 0;                /* stick to top */
    left: 0;
    width: 100%;           /* full width */
    background: linear-gradient(90deg, #20c997, #8e44ad); /* teal to violet */
    color: white;
    padding: 12px 20px;
    text-align: center;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    z-index: 1000;         /* stay on top of other content */
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.banner:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.15);
}

.banner-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 12px;
    font-size: 16px;
}

.banner-link {
    color: #ffffff;
    font-weight: 600;
    text-decoration: underline;
    transition: color 0.3s;
}

.banner-link:hover {
    color: #ffe600; /* optional hover color for contrast */
}


/* Main Layout */
#app {
  margin-top: 60px;
  min-height: calc(100vh - 60px);
}

.page {
  display: none;
  animation: fadeIn 0.3s ease-in;
}

.page.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-xl);
}

/* Welcome Page */
.welcome-container {
  display: flex;
  align-items: center;
  justify-content: center;
 
}

.welcome-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
  width: 100%;
}

.welcome-text h1 {
  font-size: 2.8rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  color: var(--color-secondary);
}

.welcome-description {
  font-size: 1.1rem;
  color: var(--color-text-light);
  margin-bottom: var(--spacing-xl);
  line-height: 1.8;
}

.button-group {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.btn {
  padding: var(--spacing-md) var(--spacing-xl);
  border: none;
  border-radius: 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

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

.btn-primary:hover {
  background-color: #006666;
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

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

.welcome-image {
  text-align: center;
}

.welcome-image img {
  max-width: 100%;
  height: auto;
  border-radius: 0.5rem;
}

/* Form Page */
.form-container {
  max-width: 700px;
}

.form-header {
  margin-bottom: var(--spacing-2xl);
  position: relative;
}

.form-header h2 {
  font-size: 2rem;
  color: var(--color-secondary);
  margin-bottom: var(--spacing-md);
}

.form-header p {
  color: var(--color-text-light);
  margin-bottom: var(--spacing-lg);
}

.btn-back {
  background: none;
  border: none;
  color: var(--color-primary);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  margin-bottom: var(--spacing-lg);
  transition: color 0.2s;
}

.btn-back:hover {
  color: #006666;
}

.churn-form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.form-section {
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  padding: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.form-section legend {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-secondary);
  padding: 0 var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.form-group label {
  font-weight: 600;
  color: var(--color-text);
  font-size: 0.95rem;
}

.form-group input,
.form-group select {
  padding: var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: 0.375rem;
  font-family: var(--font-family-sans);
  font-size: 1rem;
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 128, 128, 0.1);
}

.form-actions {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
}

/* Result Page */
.result-container {
  max-width: 600px;
  min-height: calc(100vh - 60px);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.result-header {
  margin-bottom: var(--spacing-xl);
}

.result-content {
  display: flex;
  justify-content: center;
  margin-bottom: var(--spacing-2xl);
}

.prediction-card {
  width: 100%;
  padding: var(--spacing-2xl);
  border-radius: 0.5rem;
  text-align: center;
  background-color: var(--color-background);
  border: 2px solid var(--color-border);
}

.prediction-card h2 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-lg);
  color: var(--color-secondary);
}

.prediction-result {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.prediction-item {
  padding: var(--spacing-xl);
  border-radius: 0.5rem;
}

.prediction-label {
  font-size: 0.9rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-sm);
}

.prediction-value {
  font-size: 2.5rem;
  font-weight: 700;
}

.churn {
  background-color: #ffe5e5;
  color: var(--color-secondary);
  border-left: 4px solid var(--color-danger);
}

.churn .prediction-label {
  color: var(--color-danger);
}

.churn .prediction-value {
  color: var(--color-danger);
}

.no-churn {
  background-color: #e5f5f5;
  color: var(--color-secondary);
  border-left: 4px solid var(--color-primary);
}

.no-churn .prediction-label {
  color: var(--color-primary);
}

.no-churn .prediction-value {
  color: var(--color-primary);
}

.result-actions {
  display: flex;
  justify-content: center;
}

/* Responsive Design */
@media (max-width: 768px) {
  .banner-content {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .welcome-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  .welcome-text h1 {
    font-size: 2rem;
  }

  .welcome-description {
    font-size: 1rem;
  }

  .button-group {
    flex-direction: column;
  }

  .btn {
    width: 100%;
    text-align: center;
  }

  .form-container {
    padding: var(--spacing-md);
  }

  .form-section {
    padding: var(--spacing-md);
  }

  .prediction-card {
    padding: var(--spacing-lg);
  }

  .prediction-value {
    font-size: 2rem;
  }

  .container {
    padding: var(--spacing-lg);
  }
}

@media (max-width: 480px) {
  #app {
    margin-top: 80px;
  }

  .banner {
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .banner-content {
    font-size: 0.9rem;
    gap: var(--spacing-xs);
  }

  .banner-link {
    font-weight: 600;
  }

  .welcome-text h1 {
    font-size: 1.5rem;
  }

  .welcome-description {
    font-size: 0.95rem;
  }

  .form-section legend {
    font-size: 1rem;
  }

  .prediction-value {
    font-size: 1.5rem;
  }
}

/* How It Works Section */
.how-it-works {
    padding: 60px 20px;
    background: #f5f5f5;
    text-align: center;
}

.how-it-works .section-title {
    font-size: 2em;
    margin-bottom: 40px;
    color: #333;
}

.steps-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 50px;
}

.step {
    background: white;
    border-radius: 12px;
    padding: 30px 20px;
    width: 250px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.step:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 18px rgba(0,0,0,0.15);
}

.step-icon {
    font-size: 3em;
    margin-bottom: 15px;
}

.step h3 {
    font-size: 1.3em;
    margin-bottom: 10px;
}

.step p {
    font-size: 0.95em;
    color: #555;
}

/* Footer */
.footer {
    background: #111;
    color: white;
    text-align: center;
    padding: 30px 20px;
    margin-top: 40px;
}

.footer-links {
    margin-top: 10px;
}

.footer-links a {
    color: #20c997; /* teal accent */
    text-decoration: none;
    margin: 0 12px;
    font-weight: 600;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: #8e44ad; /* violet accent */
}

/* Responsive for small screens */
@media (max-width: 800px) {
    .steps-container {
        flex-direction: column;
        align-items: center;
    }

    .step {
        width: 80%;
    }
}

/* Hero section */
/* Hero section */
.welcome-hero .welcome-container {
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
    justify-content: center; /* <-- center horizontally */
    width: 100%;
    max-width: 1200px;       /* limit max width */
    margin: 0 auto;          /* center on screen */
    padding: var(--spacing-xl);
}


/* How It Works remains same but full-width */
.how-it-works {
    padding: 60px 20px;
    background: #f5f5f5;
    text-align: center;
    width: 100%;
}

.footer {
    width: 100%;
    background: #111;
    color: white;
    text-align: center;
    padding: 30px 20px;
}