/* Variables */
:root {
  --color-primary: #f59e0b;
  --color-primary-light: #fbbf24;
  --color-primary-dark: #d97706;
  --color-background: #fafafa;
  --color-white: #ffffff;
  --color-text: #1a1a1a;
  --color-text-light: #666666;
  --color-border: #e5e5e5;
  --color-success: #22c55e;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
  --radius: 12px;
  --radius-lg: 16px;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--color-background);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */
.header {
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.95);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 700;
  font-size: 1.25rem;
}

.logo-icon {
  font-size: 1.75rem;
}

.nav {
  display: flex;
  gap: 2rem;
}

.nav a {
  text-decoration: none;
  color: var(--color-text-light);
  font-weight: 500;
  transition: color 0.2s;
}

.nav a:hover {
  color: var(--color-primary);
}

/* Hero */
.hero {
  background: linear-gradient(135deg, #d97706 0%, #f59e0b 50%, #fbbf24 100%);
  color: white;
  padding: 4rem 0;
  text-align: center;
}

.hero-content {
  max-width: 700px;
  margin: 0 auto;
}

.badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.2);
  padding: 0.5rem 1rem;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.1;
}

.hero-subtitle {
  font-size: 1.25rem;
  opacity: 0.95;
  line-height: 1.6;
}

/* Section */
.section {
  padding: 4rem 0;
}

.section-alt {
  background: var(--color-white);
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 3rem;
}

/* Calculator */
.calculator-layout {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 2rem;
  align-items: start;
}

.calculator-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
}

.calculator-card h2 {
  font-size: 1.875rem;
  margin-bottom: 2rem;
}

/* Form Elements */
.form-group {
  margin-bottom: 2rem;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.select-input {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: inherit;
  background: white;
  cursor: pointer;
  transition: all 0.2s;
}

.select-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.1);
}

.tariff-info {
  margin-top: 0.75rem;
  font-size: 0.9rem;
  color: var(--color-text-light);
}

.tariff-info strong {
  color: var(--color-primary);
  font-weight: 700;
}

/* Appliance Adder */
.appliance-adder {
  margin-bottom: 2rem;
}

.appliance-adder h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

.add-form {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.usage-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr auto;
  gap: 0.75rem;
  align-items: center;
}

.usage-inputs input {
  padding: 0.875rem 1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: inherit;
}

.usage-inputs input:focus {
  outline: none;
  border-color: var(--color-primary);
}

.select-input-small {
  padding: 0.875rem 0.75rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-family: inherit;
  background: white;
  cursor: pointer;
  transition: all 0.2s;
}

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

.btn-add {
  padding: 0.875rem 1.5rem;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.btn-add:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
}

.usage-hint {
  margin-top: 0.5rem;
  padding: 0.75rem 1rem;
  background: #fef3c7;
  border-left: 3px solid var(--color-primary);
  border-radius: var(--radius);
  font-size: 0.875rem;
  color: #92400e;
  display: none;
}

.usage-hint.show {
  display: block;
}

/* Appliance List */
.appliance-list {
  margin-bottom: 2rem;
  max-height: 400px;
  overflow-y: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem;
}

.appliance-list:empty::before {
  content: "No appliances added yet. Select one above and click 'Add'.";
  display: block;
  text-align: center;
  color: var(--color-text-light);
  padding: 2rem;
}

.appliance-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem;
  background: var(--color-background);
  border-radius: var(--radius);
  margin-bottom: 0.75rem;
}

.appliance-item:last-child {
  margin-bottom: 0;
}

.appliance-info {
  flex: 1;
}

.appliance-name {
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.appliance-details {
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.appliance-cost {
  font-weight: 700;
  color: var(--color-primary);
  margin-right: 1rem;
}

.btn-remove {
  background: none;
  border: none;
  color: var(--color-danger);
  cursor: pointer;
  font-size: 1.25rem;
  padding: 0.25rem 0.5rem;
  transition: all 0.2s;
}

.btn-remove:hover {
  transform: scale(1.2);
}

/* Buttons */
.btn-primary {
  width: 100%;
  padding: 1rem 2rem;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* Calculator Credit (visible in screenshots) */
.calculator-credit {
  text-align: center;
  font-size: 0.85rem;
  color: #666;
  margin-top: 0.75rem;
  padding: 0.5rem;
  font-weight: 500;
}

/* Results Panel */
.results-panel {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.results-summary,
.priority-list,
.optimization-section {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
}

.results-summary.hidden,
.priority-list.hidden,
.optimization-section.hidden {
  display: none;
}

.results-summary h3,
.priority-list h3,
.optimization-section h3 {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
}

.cost-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.cost-card {
  background: var(--color-background);
  padding: 1.5rem;
  border-radius: var(--radius);
  text-align: center;
}

.cost-card.highlight {
  background: linear-gradient(135deg, #d97706, #f59e0b);
  color: white;
}

.cost-label {
  font-size: 0.875rem;
  opacity: 0.8;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.cost-value {
  font-size: 2rem;
  font-weight: 700;
}

.total-kwh {
  text-align: center;
  padding: 1rem;
  background: #fef3c7;
  border-radius: var(--radius);
  color: #92400e;
}

/* Priority List */
.priority-intro {
  color: var(--color-text-light);
  margin-bottom: 1rem;
}

.priority-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background: var(--color-background);
  border-radius: var(--radius);
  margin-bottom: 0.75rem;
}

.priority-rank {
  width: 32px;
  height: 32px;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
}

.priority-info {
  flex: 1;
}

.priority-name {
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.priority-impact {
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.priority-cost {
  font-weight: 700;
  color: var(--color-danger);
  font-size: 1.125rem;
}

/* Load Shedding Section */
.optimization-savings {
  text-align: center;
  padding: 2rem;
  background: linear-gradient(135deg, #22c55e, #16a34a);
  color: white;
  border-radius: var(--radius);
  margin: 1rem 0;
}

.savings-amount {
  font-size: 2.5rem;
  font-weight: 800;
  display: block;
  margin-bottom: 0.5rem;
}

.savings-label {
  font-size: 1rem;
  opacity: 0.9;
}

.optimization-tips {
  margin-top: 1.5rem;
}

.optimization-note {
  font-size: 0.95rem;
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

.optimization-tips ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.optimization-tips li {
  padding: 0.75rem 1rem;
  background: var(--color-background);
  border-radius: var(--radius);
  margin-bottom: 0.5rem;
  border-left: 3px solid var(--color-primary);
}

/* Tips Grid */
.tips-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-bottom: 3rem;
}

.tip-card {
  background: var(--color-background);
  border-radius: var(--radius-lg);
  padding: 2rem;
  border: 1px solid var(--color-border);
}

.tip-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.tip-card h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

.tip-card ul {
  list-style: none;
  margin-bottom: 1.5rem;
}

.tip-card li {
  padding: 0.5rem 0;
  line-height: 1.5;
  font-size: 0.95rem;
}

.tip-card li::before {
  content: "→";
  color: var(--color-primary);
  font-weight: 700;
  margin-right: 0.5rem;
}

.savings-badge {
  background: linear-gradient(135deg, #22c55e, #16a34a);
  color: white;
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  font-weight: 600;
  text-align: center;
}

/* Pro Tips */
.pro-tips {
  background: linear-gradient(135deg, #d97706, #f59e0b);
  color: white;
  padding: 2.5rem;
  border-radius: var(--radius-lg);
}

.pro-tips h3 {
  font-size: 1.75rem;
  margin-bottom: 1.5rem;
}

.pro-tips-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.pro-tip {
  background: rgba(255, 255, 255, 0.15);
  padding: 1.5rem;
  border-radius: var(--radius);
  line-height: 1.6;
}

.pro-tip strong {
  display: block;
  margin-bottom: 0.5rem;
  font-size: 1.05rem;
}

/* FAQ */
.faq-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  max-width: 1000px;
  margin: 0 auto;
}

.faq-item {
  background: var(--color-white);
  padding: 2rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
}

.faq-item h4 {
  font-size: 1.125rem;
  margin-bottom: 0.75rem;
  color: var(--color-primary);
}

/* Footer */
.footer {
  background: var(--color-text);
  color: white;
  padding: 3rem 0 2rem;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2rem;
}

.footer-brand p {
  margin-top: 1rem;
  opacity: 0.8;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-links h4 {
  margin-bottom: 0.5rem;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: white;
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: 0.875rem;
  opacity: 0.7;
}

.disclaimer {
  margin-top: 0.5rem;
  font-size: 0.8rem;
}

/* Responsive */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }

  .calculator-layout {
    grid-template-columns: 1fr;
  }

  .cost-cards {
    grid-template-columns: 1fr;
  }

  .tips-grid {
    grid-template-columns: 1fr;
  }

  .pro-tips-grid {
    grid-template-columns: 1fr;
  }

  .faq-grid {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }

  .nav {
    gap: 1rem;
    font-size: 0.875rem;
  }

  .usage-inputs {
    grid-template-columns: 1fr 1fr;
  }
  
  .usage-inputs input[type="number"] {
    grid-column: span 1;
  }
  
  .btn-add {
    grid-column: span 2;
  }
}