:root {
  --primary: #1a1a2e;
  --accent: #e94560;
  --bg: #f0f0f5;
  --text: #0a0a1a;
  --light: #ffffff;
  --border: #ddd;
  --success: #27ae60;
  --warning: #f39c12;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

/* ===== DEMO BAR ===== */
.demo-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--primary);
  color: var(--light);
  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;
}

/* ===== LAYOUT UTAMA ===== */
body {
  padding-top: 36px;
}

header {
  background: var(--light);
  border-bottom: 1px solid var(--border);
  padding: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.logo {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}

.nav-toggle {
  display: none;
}

.nav-toggle:checked ~ nav {
  display: block;
}

nav {
  display: none;
}

nav ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
}

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

nav a {
  display: block;
  padding: 12px 16px;
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  transition: background 0.2s;
}

nav a:hover {
  background: var(--bg);
  color: var(--accent);
}

.nav-label {
  cursor: pointer;
  padding: 8px 16px;
  font-size: 18px;
  color: var(--primary);
  display: flex;
  align-items: center;
}

/* Mobile-first: nav toggle visible on small screens */
@media (max-width: 640px) {
  nav {
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--light);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  }

  .nav-toggle:checked ~ .nav-label::before {
    content: "✕";
  }

  .nav-label::before {
    content: "☰";
  }
}

@media (min-width: 641px) {
  nav {
    display: block !important;
  }

  nav ul {
    flex-direction: row;
    gap: 0;
  }

  nav li {
    border-top: none;
    border-right: 1px solid var(--border);
  }

  nav li:last-child {
    border-right: none;
  }

  .nav-label {
    display: none;
  }
}

main {
  padding: 16px;
  max-width: 1200px;
  margin: 0 auto;
}

section {
  margin-bottom: 32px;
}

footer {
  background: var(--primary);
  color: var(--light);
  padding: 32px 16px;
  text-align: center;
  margin-top: 48px;
  font-size: 14px;
}

footer p {
  margin-bottom: 8px;
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3 {
  color: var(--primary);
  margin-bottom: 16px;
  line-height: 1.3;
}

h1 {
  font-size: 32px;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

p {
  margin-bottom: 12px;
}

/* ===== BUTTONS & FORMS ===== */
.btn {
  display: inline-block;
  padding: 12px 24px;
  background: var(--accent);
  color: var(--light);
  text-decoration: none;
  border: none;
  border-radius: 4px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn:hover {
  background: #d63a4e;
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

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

.btn-secondary:hover {
  background: #0d0d1a;
}

form {
  background: var(--light);
  padding: 24px;
  border-radius: 4px;
  border: 1px solid var(--border);
  max-width: 600px;
}

form label {
  display: block;
  margin-top: 16px;
  font-weight: 600;
  color: var(--primary);
}

form input,
form textarea,
form select {
  width: 100%;
  margin-top: 6px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: inherit;
  font-size: 14px;
}

form textarea {
  resize: vertical;
  min-height: 100px;
}

form input:focus,
form textarea:focus,
form select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(233, 69, 96, 0.1);
}

form button {
  margin-top: 20px;
}

/* ===== HERO SECTION ===== */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, #2d2d4a 100%);
  color: var(--light);
  padding: 48px 16px;
  border-radius: 4px;
  text-align: center;
  margin-bottom: 32px;
}

.hero h1 {
  color: var(--light);
  font-size: 28px;
  margin-bottom: 12px;
}

.hero p {
  font-size: 16px;
  margin-bottom: 24px;
}

.hero .btn {
  background: var(--accent);
}

/* ===== CARDS & LISTINGS ===== */
.card {
  background: var(--light);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 20px;
  margin-bottom: 16px;
  transition: box-shadow 0.2s, transform 0.2s;
}

.card:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  transform: translateY(-2px);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  margin-bottom: 12px;
}

.card-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}

.card-price {
  font-size: 16px;
  font-weight: 700;
  color: var(--accent);
}

.card-desc {
  font-size: 14px;
  color: #555;
  margin-bottom: 12px;
}

.card-specs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 13px;
}

.spec {
  display: flex;
  align-items: center;
  gap: 6px;
}

.spec-icon {
  width: 18px;
  height: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

/* ===== SIMULASI KPR ===== */
.simulator {
  background: var(--light);
  padding: 24px;
  border-radius: 4px;
  border: 1px solid var(--border);
}

.simulator-result {
  background: #f9f9f9;
  padding: 16px;
  border-radius: 4px;
  margin-top: 20px;
  border-left: 4px solid var(--accent);
}

.result-row {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}

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

.result-label {
  font-weight: 600;
  color: var(--primary);
}

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

.slider-container {
  margin: 16px 0;
}

.slider-label {
  display: flex;
  justify-content: space-between;
  margin-bottom: 8px;
  font-size: 13px;
  font-weight: 600;
}

input[type="range"] {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--border);
  outline: none;
  -webkit-appearance: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  transition: background 0.2s;
}

input[type="range"]::-webkit-slider-thumb:hover {
  background: #d63a4e;
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: none;
  transition: background 0.2s;
}

input[type="range"]::-moz-range-thumb:hover {
  background: #d63a4e;
}

/* ===== RESPONSIVE GRID ===== */
.grid {
  display: grid;
  gap: 16px;
  margin-bottom: 24px;
}

.grid-2 {
  grid-template-columns: 1fr;
}

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

  .hero {
    padding: 64px 32px;
  }

  .hero h1 {
    font-size: 36px;
  }

  h1 {
    font-size: 40px;
  }

  h2 {
    font-size: 28px;
  }

  main {
    padding: 32px;
  }
}

/* ===== UTILITIES ===== */
.text-center {
  text-align: center;
}

.text-muted {
  color: #888;
}

.mt-32 {
  margin-top: 32px;
}

.mb-24 {
  margin-bottom: 24px;
}

.highlight {
  background: #fff3cd;
  padding: 16px;
  border-left: 4px solid var(--warning);
  border-radius: 4px;
  margin-bottom: 20px;
  font-size: 14px;
}

.badge {
  display: inline-block;
  padding: 4px 12px;
  background: var(--accent);
  color: var(--light);
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  margin-right: 8px;
  margin-bottom: 8px;
}

.badge-success {
  background: var(--success);
}

/* ===== SVG ICONS ===== */
svg {
  display: inline-block;
  vertical-align: middle;
}

.icon-small {
  width: 16px;
  height: 16px;
}

.icon-medium {
  width: 24px;
  height: 24px;
}

.icon-large {
  width: 32px;
  height: 32px;
}