/* style.css - 1A NRG */

:root {
  /* Light theme (default) */
  --color-bg: #F9F9F6; /* off-white */
  --color-bg-alt: #F0F0EB;
  --color-text: #111827; /* dark gray */
  --color-primary: #1D4A3D; /* deep green */
  --color-accent: #E5A91E; /* warm yellow */
  --color-border: #D1D5DB;
  --color-bg-card: #FFFFFF;
  --color-text-muted: #4B5563;
  --color-error: #B91C1C;
  --font-base: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-heading: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Dark theme */
    --color-bg: #111827; /* dark gray */
    --color-bg-alt: #1F2937;
    --color-text: #F9F9F6; /* off-white */
    --color-primary: #29745E; /* lighter deep green for contrast */
    --color-accent: #FDE047; /* bright warm yellow */
    --color-border: #374151;
    --color-bg-card: #1F2937;
    --color-text-muted: #9CA3AF;
    --color-error: #F87171;
  }
}

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

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-base);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  font-size: 16px;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main {
  flex: 1;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--color-primary);
}

h1 { font-size: 2.5rem; letter-spacing: -0.025em; }
h2 { font-size: 2rem; margin-top: 2rem; }
h3 { font-size: 1.5rem; margin-top: 1.5rem; }

p { margin-bottom: 1.25rem; }

a {
  color: var(--color-primary);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}

a:hover, a:focus {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
}

a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* Layout */
.container {
  width: 100%;
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.container-sm {
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header & Nav */
header {
  background-color: var(--color-primary);
  color: #fff;
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.logo-link {
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-link:hover, .logo-link:focus {
  color: var(--color-accent);
}

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

.main-nav {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.main-nav a {
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
}

.main-nav a:hover, .main-nav a:focus {
  color: var(--color-accent);
}

/* Hero Section */
.hero {
  background-color: var(--color-primary);
  color: #fff;
  padding: 4rem 0 5rem;
  text-align: center;
}

.hero h1 {
  color: #fff;
  font-size: 3rem;
  max-width: 800px;
  margin: 0 auto 1.5rem;
}

.hero p {
  font-size: 1.25rem;
  max-width: 600px;
  margin: 0 auto 2rem;
  color: #e5e7eb;
}

.btn-primary {
  display: inline-block;
  background-color: var(--color-accent);
  color: #000;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.125rem;
  padding: 0.75rem 2rem;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: background-color 0.2s;
}

.btn-primary:hover {
  background-color: #d19a16;
}

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

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

/* Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

.card {
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 2rem;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.card-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 1rem;
  color: var(--color-primary);
}

/* Comparison Table */
.table-responsive {
  overflow-x: auto;
  margin-top: 2rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
}

th, td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

th {
  background-color: var(--color-primary);
  color: #fff;
  font-weight: 600;
}

tr:last-child td {
  border-bottom: none;
}

tr:nth-child(even) {
  background-color: var(--color-bg);
}

/* Estimator Form */
.estimator-wrapper {
  background-color: var(--color-bg-card);
  border: 2px solid var(--color-primary);
  border-radius: 12px;
  padding: 2.5rem;
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
}

.estimator-wrapper h2 {
  margin-top: 0;
}

.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--color-text);
}

input[type="number"], select {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  font-size: 1rem;
  background-color: var(--color-bg);
  color: var(--color-text);
}

.error-msg {
  color: var(--color-error);
  font-size: 0.875rem;
  margin-top: 0.25rem;
  display: none;
}
.error-msg.active {
  display: block;
}
.has-error input {
  border-color: var(--color-error);
}

.btn-submit {
  width: 100%;
  margin-top: 1rem;
}

/* Estimator Results */
.result {
  margin-top: 2rem;
  padding: 1.5rem;
  background-color: var(--color-bg);
  border-radius: 8px;
  border-left: 4px solid var(--color-primary);
  display: none;
}

.result.active {
  display: block;
}

.result-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin: 1.5rem 0;
}

.result-item {
  background-color: var(--color-bg-card);
  padding: 1rem;
  border-radius: 6px;
  border: 1px solid var(--color-border);
  text-align: center;
}

.result-item .label {
  display: block;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  font-weight: 600;
}

.result-item .value {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-top: 0.25rem;
}

.assumptions {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-top: 1rem;
}

/* FAQ */
.faq-item {
  margin-bottom: 2rem;
}
.faq-item h3 {
  margin-bottom: 0.5rem;
}

/* Footer */
footer {
  background-color: var(--color-bg-card);
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
  text-align: center;
}

footer nav {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

footer nav a {
  color: var(--color-text-muted);
  text-decoration: none;
}

footer nav a:hover, footer nav a:focus {
  text-decoration: underline;
  color: var(--color-text);
}

/* Responsive */
@media (min-width: 768px) {
  .hero h1 { font-size: 4rem; }
  .cards-grid { grid-template-columns: repeat(2, 1fr); }
  .result-grid { grid-template-columns: repeat(2, 1fr); }
  .estimator-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }
}

@media (min-width: 1024px) {
  .cards-grid { grid-template-columns: repeat(3, 1fr); }
  .result-grid { grid-template-columns: repeat(4, 1fr); }
}