:root {
  --primary: #004d40;
  --accent: #80cbc4;
  --bg: #e0f2f1;
  --text: #0a1f1e;
  --light-gray: #f5f5f5;
  --border: #b2dfdb;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  background: #fff;
  color: var(--text);
  line-height: 1.6;
}

/* Demo Bar */
.demo-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--primary);
  color: #fff;
  padding: 8px 16px;
  font-size: 13px;
  text-align: center;
  z-index: 1000;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.demo-bar a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}

.demo-bar a:hover {
  text-decoration: underline;
}

body {
  padding-top: 36px;
}

/* Header & Navigation */
header {
  background: #fff;
  border-bottom: 2px solid var(--border);
  padding: 16px;
  position: sticky;
  top: 36px;
  z-index: 100;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
}

.nav-toggle {
  display: none;
}

.menu-icon {
  display: none;
  cursor: pointer;
  font-size: 24px;
  background: none;
  border: none;
  color: var(--primary);
}

nav ul {
  list-style: none;
  display: flex;
  gap: 24px;
}

nav a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  font-size: 14px;
  transition: color 0.2s;
}

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

/* Mobile Navigation */
@media (max-width: 640px) {
  .menu-icon {
    display: block;
  }

  nav ul {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: #fff;
    border-bottom: 2px solid var(--border);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    gap: 0;
  }

  nav li {
    border-bottom: 1px solid var(--border);
  }

  nav a {
    display: block;
    padding: 12px 16px;
  }

  .nav-toggle:checked ~ nav ul {
    max-height: 300px;
  }
}

/* Main Content */
main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 16px;
}

section {
  padding: 40px 0;
}

h1, h2, h3 {
  color: var(--primary);
  margin-bottom: 16px;
}

h1 {
  font-size: 32px;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

p {
  margin-bottom: 12px;
  color: var(--text);
}

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, #00695c 100%);
  color: #fff;
  padding: 60px 16px;
  text-align: center;
  margin-bottom: 0;
}

.hero h1 {
  color: #fff;
  font-size: 36px;
  margin-bottom: 16px;
}

.hero p {
  color: #fff;
  font-size: 18px;
  margin-bottom: 24px;
}

.btn {
  display: inline-block;
  padding: 12px 28px;
  background: var(--accent);
  color: var(--primary);
  text-decoration: none;
  border-radius: 4px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  font-size: 14px;
  transition: background 0.3s;
}

.btn:hover {
  background: #4db8a8;
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 2px solid #fff;
}

.btn-outline:hover {
  background: rgba(255,255,255,0.1);
}

/* Cards & Grid */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin: 32px 0;
}

.card {
  background: #fff;
  border: 2px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0,0,0,0.1);
}

.card-title {
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 12px;
  font-size: 16px;
}

.card-price {
  color: var(--primary);
  font-size: 20px;
  font-weight: 700;
  margin: 12px 0;
}

.card-desc {
  font-size: 13px;
  color: #666;
  line-height: 1.5;
}

/* Feature List */
.features {
  list-style: none;
  margin: 20px 0;
}

.features li {
  padding: 8px 0;
  padding-left: 28px;
  position: relative;
}

.features li:before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: bold;
  font-size: 18px;
}

/* Form */
form {
  background: var(--bg);
  padding: 32px;
  border-radius: 8px;
  max-width: 500px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 20px;
}

label {
  display: block;
  margin-bottom: 6px;
  font-weight: 500;
  color: var(--text);
}

input, textarea, select {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: inherit;
  font-size: 14px;
  transition: border-color 0.2s;
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(0,77,64,0.1);
}

textarea {
  resize: vertical;
  min-height: 120px;
}

/* Table */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
}

th {
  background: var(--bg);
  color: var(--primary);
  padding: 12px;
  text-align: left;
  font-weight: 600;
  border-bottom: 2px solid var(--border);
}

td {
  padding: 12px;
  border-bottom: 1px solid var(--border);
}

tr:hover {
  background: #fafafa;
}

/* Listing Page */
.listing-item {
  background: #fff;
  border: 2px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  margin-bottom: 20px;
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.listing-icon {
  width: 120px;
  height: 120px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--bg) 100%);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 48px;
}

.listing-content h3 {
  margin-top: 0;
}

.listing-meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
  color: #666;
  margin: 12px 0;
}

/* Detail Page */
.detail-hero {
  background: linear-gradient(135deg, var(--accent) 0%, var(--bg) 100%);
  padding: 60px 16px;
  text-align: center;
  border-radius: 8px;
  margin-bottom: 32px;
}

.detail-hero h1 {
  color: var(--primary);
  margin-bottom: 8px;
}

.detail-price {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 16px;
}

.detail-sections {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

@media (min-width: 768px) {
  .detail-sections {
    grid-template-columns: 2fr 1fr;
  }
}

.detail-box {
  background: var(--bg);
  padding: 24px;
  border-radius: 8px;
}

.detail-box h3 {
  margin-top: 0;
}

/* Simulator */
.calculator {
  background: var(--bg);
  padding: 32px;
  border-radius: 8px;
  max-width: 600px;
  margin: 0 auto 32px;
}

.calculator h2 {
  text-align: center;
  margin-bottom: 32px;
}

.input-group {
  margin-bottom: 24px;
}

.input-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
}

.input-group input,
.input-group select {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 14px;
}

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

.range-display {
  text-align: center;
  margin: 16px 0;
  font-size: 20px;
  font-weight: 600;
  color: var(--primary);
}

.result-box {
  background: #fff;
  border-left: 4px solid var(--primary);
  padding: 20px;
  border-radius: 4px;
  margin-top: 32px;
}

.result-row {
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}

.result-row:last-child {
  border-bottom: none;
}

.result-label {
  font-weight: 500;
  color: var(--text);
}

.result-value {
  font-weight: 700;
  color: var(--primary);
}

/* Footer */
footer {
  background: var(--primary);
  color: #fff;
  padding: 40px 16px;
  margin-top: 60px;
  text-align: center;
}

footer h3 {
  color: #fff;
  margin-bottom: 16px;
}

footer p {
  color: #fff;
  margin-bottom: 8px;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
  margin: 20px 0;
}

.footer-links a {
  color: var(--accent);
  text-decoration: none;
}

.footer-links a:hover {
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
  h1 {
    font-size: 24px;
  }

  h2 {
    font-size: 20px;
  }

  section {
    padding: 32px 0;
  }

  .hero {
    padding: 48px 16px;
  }

  .hero h1 {
    font-size: 28px;
  }

  .grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .listing-item {
    flex-direction: column;
  }

  .listing-icon {
    width: 100%;
    height: 200px;
  }

  form {
    padding: 20px;
  }

  .header-container {
    gap: 12px;
  }

  nav ul {
    gap: 12px;
  }

  .detail-sections {
    grid-template-columns: 1fr;
  }
}

/* Utility */
.text-center {
  text-align: center;
}

.mt-0 {
  margin-top: 0;
}

.mb-0 {
  margin-bottom: 0;
}

.mt-2 {
  margin-top: 16px;
}

.mb-2 {
  margin-bottom: 16px;
}

.highlight {
  background: var(--bg);
  padding: 2px 6px;
  border-radius: 3px;
}