/* ==========================================================================
   ProjectSolar — Vibrant Modern Aesthetic Landing Page
   - Single unified canvas (header completely merged with home page)
   - Solid solar palette (no gradients), soft blurred glow orbs for depth
   - Live interactive solar system preview deck with animated energy beams
   - Clean, professional typography & high-converting layout
   ========================================================================== */

/* ─── Global Background & Ambient Solar Aura ─────────────────────────────── */
body {
  font-family: 'Plus Jakarta Sans', 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  letter-spacing: -0.01em;
  background-color: var(--bg-body);
  color: var(--text-main);
  position: relative;
  overflow-x: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Light theme warm luminous solar palette */
[data-theme="light"] {
  --bg-body: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-subtle: #f1f5f9;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
}

[data-theme="light"] body {
  background: var(--bg-body);
}

/* Dark theme deep cosmic solar palette */
[data-theme="dark"] {
  --bg-body: #0b0f19;
  --bg-card: #131c2e;
  --bg-card-subtle: #1e293b;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --border-color: #1e293b;
}

[data-theme="dark"] body {
  background: var(--bg-body);
}

/* Dynamic Ambient Glow Behind Hero */
.landing-ambient-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.ambient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  animation: floatOrb 20s ease-in-out infinite alternate;
}

.ambient-orb-1 {
  width: 620px;
  height: 620px;
  background: rgba(245, 158, 11, 0.16);
  top: -160px;
  left: 50%;
  transform: translateX(-50%);
  animation-duration: 18s;
}

.ambient-orb-2 {
  width: 520px;
  height: 520px;
  background: rgba(2, 132, 199, 0.10);
  top: 35%;
  left: -140px;
  animation-duration: 24s;
  animation-delay: -4s;
}

.ambient-orb-3 {
  width: 480px;
  height: 480px;
  background: rgba(16, 185, 129, 0.10);
  top: 55%;
  right: -120px;
  animation-duration: 22s;
  animation-delay: -8s;
}

[data-theme="light"] .ambient-orb-1 {
  background: rgba(245, 158, 11, 0.14);
}

[data-theme="light"] .ambient-orb-2 {
  background: rgba(2, 132, 199, 0.07);
}

[data-theme="light"] .ambient-orb-3 {
  background: rgba(16, 185, 129, 0.07);
}

@keyframes floatOrb {
  0% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(30px, 40px) scale(1.08);
  }
  100% {
    transform: translate(-30px, 20px) scale(0.96);
  }
}

header, main, footer {
  position: relative;
  z-index: 1;
}

/* ─── Integrated Header (One Seamless Piece with Page) ───────────────────── */
.app-header {
  background: transparent !important;
  border: none !important;
  box-shadow: none !important;
  padding: 1.75rem 2.5rem 0.5rem !important;
  position: relative;
  width: 100%;
}

.header-container {
  max-width: 1240px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  color: var(--text-main);
  transition: transform 0.2s ease;
}

.brand:hover {
  transform: scale(1.02);
}

.brand-icon {
  width: 42px;
  height: 42px;
  background: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  flex-shrink: 0;
}

.brand-icon img.brand-logo-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: drop-shadow(0 4px 10px rgba(245, 158, 11, 0.4));
  transition: filter 0.3s ease;
}

.brand:hover .brand-icon {
  transform: rotate(8deg) scale(1.1);
}

.brand:hover .brand-icon img.brand-logo-img {
  filter: drop-shadow(0 8px 18px rgba(245, 158, 11, 0.65));
}

.brand-title {
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.brand-subtitle {
  font-size: 0.7rem;
  color: var(--text-muted);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* Clean Inline Header Navigation (No Floating Container) */
.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
  background: transparent;
  padding: 0;
  margin: 0;
  border: none;
  box-shadow: none;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.885rem;
  font-weight: 600;
  transition: color 0.15s ease, transform 0.15s ease;
  display: inline-block;
}

.nav-link:hover {
  color: var(--primary-solar);
  transform: translateY(-1px);
}

@media (max-width: 920px) {
  .nav-links { display: none; }
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.header-cta {
  padding: 0.65rem 1.35rem;
  font-size: 0.885rem;
  font-weight: 700;
  text-decoration: none;
  background: var(--primary-solar);
  color: #ffffff;
  border-radius: var(--radius-full);
  box-shadow: 0 6px 18px rgba(245, 158, 11, 0.35);
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.header-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(245, 158, 11, 0.5);
}

/* ─── Hero Section ───────────────────────────────────────────────────────── */
.hero-section {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 3.5rem 1.5rem 4.5rem;
  max-width: 1040px;
  margin: 0 auto;
  position: relative;
  box-sizing: border-box;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.42rem 1.15rem;
  background: rgba(245, 158, 11, 0.10);
  border: 1px solid rgba(245, 158, 11, 0.3);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary-solar);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 1.75rem;
}

.hero-pill svg {
  flex-shrink: 0;
  color: var(--primary-solar);
}

.hero-h1 {
  font-size: clamp(2.5rem, 5.5vw, 4.25rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.04em;
  color: var(--text-main);
  margin: 0 auto 1.35rem;
  max-width: 940px;
}

/* Radiant Text Accent */
.hero-h1 .highlight {
  color: var(--primary-solar);
  display: inline-block;
}

.hero-sub {
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  line-height: 1.68;
  color: var(--text-muted);
  max-width: 740px;
  margin: 0 auto 2.5rem;
  font-weight: 400;
  font-family: 'Inter', sans-serif;
}

.hero-actions {
  display: flex;
  gap: 0.9rem;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  margin-top: 0.25rem;
}

.hero-btn-primary {
  padding: 0.72rem 1.6rem;
  font-size: 0.935rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  background: var(--primary-solar);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(245, 158, 11, 0.35);
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  justify-content: center;
  text-decoration: none;
}

.hero-btn-primary:hover {
  background: #d97706;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(245, 158, 11, 0.45);
}

.hero-btn-secondary {
  padding: 0.7rem 1.45rem;
  font-size: 0.935rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  justify-content: center;
  text-decoration: none;
}

[data-theme="light"] .hero-btn-secondary {
  background: #ffffff;
  border: 1px solid rgba(0, 0, 0, 0.12);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.03);
}

.hero-btn-secondary:hover {
  background: var(--bg-card);
  border-color: var(--primary-solar);
  color: var(--primary-solar);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

/* ─── Hero Key Highlights & Action Layout ────────────────────────────────── */

/* ─── Section Generic ────────────────────────────────────────────────────── */
.landing-section {
  padding: 6rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--primary-solar);
  margin-bottom: 0.75rem;
  padding: 0.25rem 0.75rem;
  background-color: var(--primary-solar-subtle);
  border: 1px solid rgba(245, 158, 11, 0.3);
  border-radius: var(--radius-full);
}

.section-h2 {
  font-size: clamp(1.9rem, 3.5vw, 2.7rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-main);
  line-height: 1.2;
  margin-bottom: 1rem;
}

.section-lead {
  font-size: 1.075rem;
  line-height: 1.68;
  color: var(--text-muted);
  max-width: 700px;
  font-family: 'Inter', sans-serif;
}

.section-header {
  margin-bottom: 3.5rem;
}

.section-header.centered {
  text-align: center;
}

.section-header.centered .section-lead {
  margin: 0 auto;
}

/* ─── Interactive Quick Estimator Card ────────────────────────────────────── */
.estimator-wrap {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 3rem;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem;
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.06);
  position: relative;
  overflow: hidden;
}

.estimator-wrap::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--primary-solar);
}

.estimator-art-backdrop {
  position: absolute;
  right: -30px;
  bottom: -30px;
  pointer-events: none;
  opacity: 0.10;
  color: var(--primary-solar);
  z-index: 0;
  transition: opacity 0.3s ease;
}

[data-theme="light"] .estimator-art-backdrop {
  opacity: 0.16;
}

.estimator-inputs {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  position: relative;
  z-index: 1;
}

/* Mode Switcher: Monthly Bill vs Monthly Consumption */
.estimator-mode-toggle {
  display: inline-flex;
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  padding: 0.25rem;
  gap: 0.25rem;
  align-self: flex-start;
}

[data-theme="light"] .estimator-mode-toggle {
  background: rgba(0, 0, 0, 0.04);
  border: 1px solid rgba(0, 0, 0, 0.08);
}

.mode-tab-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.825rem;
  font-weight: 600;
  padding: 0.45rem 1rem;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: inherit;
}

.mode-tab-btn:hover {
  color: var(--text-main);
}

.mode-tab-btn.active {
  background: var(--primary-solar);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(245, 158, 11, 0.35);
}

.estimator-view-pane {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.estimator-note {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.55;
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  margin: 0;
}

.estimator-note svg {
  flex-shrink: 0;
  margin-top: 0.18rem;
  color: var(--primary-solar);
}

.estimator-btn-container {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  margin-top: 0.25rem;
}

.estimator-action-btn {
  width: auto;
  max-width: max-content;
  padding: 0.68rem 1.4rem;
  font-size: 0.895rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--primary-solar);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(245, 158, 11, 0.35);
  text-decoration: none;
  transition: all 0.2s ease;
}

.estimator-action-btn:hover {
  background: #d97706;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(245, 158, 11, 0.45);
}

.estimator-results {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.15rem;
  position: relative;
  z-index: 1;
}

.est-metric {
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.2rem 1.15rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.est-metric:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
}

.est-metric-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.45rem;
}

.est-metric-label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.est-metric-art-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.est-metric:hover .est-metric-art-icon {
  transform: scale(1.08);
}

.est-metric-amber .est-metric-art-icon {
  background: rgba(245, 158, 11, 0.12);
  color: var(--primary-solar);
  border: 1px solid rgba(245, 158, 11, 0.25);
}

.est-metric-amber:hover {
  border-color: rgba(245, 158, 11, 0.4);
}

.est-metric-cyan .est-metric-art-icon {
  background: rgba(14, 165, 233, 0.12);
  color: #0ea5e9;
  border: 1px solid rgba(14, 165, 233, 0.25);
}

.est-metric-cyan:hover {
  border-color: rgba(14, 165, 233, 0.4);
}

.est-metric-green .est-metric-art-icon {
  background: rgba(16, 185, 129, 0.12);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.est-metric-green:hover {
  border-color: rgba(16, 185, 129, 0.4);
}

.est-metric-blue .est-metric-art-icon {
  background: rgba(99, 102, 241, 0.12);
  color: var(--accent-blue);
  border: 1px solid rgba(99, 102, 241, 0.25);
}

.est-metric-blue:hover {
  border-color: rgba(99, 102, 241, 0.4);
}

.est-metric-value {
  font-size: 1.55rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-main);
  line-height: 1.15;
  margin: 0.25rem 0 0.45rem;
}

.est-metric-footer {
  margin-top: auto;
  display: flex;
  align-items: center;
}

.est-metric-caption {
  font-size: 0.775rem;
  color: var(--text-muted);
  font-weight: 500;
}

.est-metric-pill {
  font-size: 0.725rem;
  font-weight: 600;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.05);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  display: inline-block;
}

[data-theme="light"] .est-metric-pill {
  background: rgba(0, 0, 0, 0.04);
  border-color: rgba(0, 0, 0, 0.06);
}

.est-metric-pill.green-pill {
  color: var(--accent-green);
  background: rgba(16, 185, 129, 0.1);
  border-color: rgba(16, 185, 129, 0.2);
}

.est-metric-value.clr-green  { color: var(--accent-green); }
.est-metric-value.clr-blue   { color: var(--accent-blue); }
.est-metric-value.clr-amber  { color: var(--primary-solar); }

/* ─── Features Grid ──────────────────────────────────────────────────────── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.6rem;
}

@media (max-width: 960px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
  .features-grid { grid-template-columns: 1fr; }
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.35rem 1.85rem;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  border-color: var(--primary-solar);
  transform: translateY(-5px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.09);
}

.feature-icon-wrap {
  width: 50px;
  height: 50px;
  border-radius: var(--radius-md);
  background: var(--primary-solar-subtle);
  color: var(--primary-solar);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.4rem;
  transition: transform 0.3s ease;
}

.feature-card:hover .feature-icon-wrap {
  transform: scale(1.1);
}

.feature-h3 {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.65rem;
  letter-spacing: -0.02em;
}

.feature-p {
  font-size: 0.9rem;
  line-height: 1.68;
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
}

/* ─── How It Works (Steps Grid) ─────────────────────────────────────────── */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.6rem;
}

@media (max-width: 800px) {
  .steps-grid { grid-template-columns: 1fr; }
}

.step-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.4rem 1.85rem;
  position: relative;
  transition: all 0.25s ease;
}

.step-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary-solar);
  box-shadow: 0 14px 32px rgba(0, 0, 0, 0.08);
}

.step-num {
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--primary-solar);
  margin-bottom: 1.15rem;
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.step-num::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border-color);
}

.step-h3 {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.65rem;
  letter-spacing: -0.02em;
}

.step-p {
  font-size: 0.9rem;
  line-height: 1.68;
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
}

/* ─── System Topologies (3 Architecture Cards in a Row) ─────────────────── */
.topologies-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.6rem;
  align-items: stretch;
}

@media (max-width: 900px) {
  .topologies-grid { grid-template-columns: 1fr; }
}

.topology-card {
  background: var(--bg-card);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.4rem 1.85rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.topology-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.1);
}

.topology-card.featured {
  border-color: var(--primary-solar);
  box-shadow: 0 0 0 1px var(--primary-solar), 0 16px 38px rgba(245, 158, 11, 0.18);
  background-color: var(--bg-card);
}

.topo-badge {
  display: inline-flex;
  align-items: center;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.28rem 0.7rem;
  border-radius: var(--radius-full);
  margin-bottom: 1.15rem;
}

.topo-badge.blue   { background: var(--accent-blue-subtle);  color: var(--accent-blue); }
.topo-badge.green  { background: var(--accent-green-subtle); color: var(--accent-green); }
.topo-badge.amber  { background: var(--primary-solar-subtle); color: var(--primary-solar-hover); }

.topo-h3 {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.65rem;
  letter-spacing: -0.025em;
}

.topo-desc {
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--text-muted);
  margin-bottom: 1.6rem;
  font-family: 'Inter', sans-serif;
}

.topo-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  margin-bottom: 2.2rem;
}

.topo-item {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  font-size: 0.9rem;
  color: var(--text-main);
  font-weight: 500;
  line-height: 1.5;
}

.topo-item svg {
  color: var(--accent-green);
  flex-shrink: 0;
  margin-top: 0.2rem;
}



/* ─── FAQ Accordion ──────────────────────────────────────────────────────── */
.faq-list {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.95rem;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.faq-item:hover {
  border-color: rgba(245, 158, 11, 0.45);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.35rem 1.75rem;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.025rem;
  font-weight: 700;
  cursor: pointer;
  text-align: left;
  letter-spacing: -0.015em;
  gap: 1.25rem;
  transition: color 0.15s ease;
}

.faq-question:hover {
  color: var(--primary-solar);
}

.faq-chevron {
  flex-shrink: 0;
  color: var(--text-muted);
  transition: transform 0.25s ease;
}

.faq-item.open .faq-chevron {
  transform: rotate(180deg);
  color: var(--primary-solar);
}

.faq-answer {
  display: none;
  padding: 0 1.75rem 1.5rem;
  font-size: 0.94rem;
  line-height: 1.72;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  padding-top: 1.2rem;
  font-family: 'Inter', sans-serif;
}

.faq-item.open .faq-answer {
  display: block;
}

/* ─── Call to Action Block ───────────────────────────────────────────────── */
.cta-section {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 5rem 2.25rem;
  text-align: center;
  max-width: 880px;
  margin: 0 auto;
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.08);
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--primary-solar);
}

.cta-h2 {
  font-size: clamp(1.9rem, 3.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-main);
  margin-bottom: 0.95rem;
}

.cta-p {
  font-size: 1.075rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 2.5rem;
  line-height: 1.68;
  font-family: 'Inter', sans-serif;
}

/* ─── Footer ─────────────────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-card);
  padding: 2.75rem 2rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-top: 5rem;
}

.site-footer-inner {
  max-width: 1240px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.35rem;
}

.footer-brand {
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.footer-links {
  display: flex;
  gap: 1.85rem;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.875rem;
  transition: color 0.15s ease;
}

.footer-links a:hover {
  color: var(--primary-solar);
}

.footer-links a.active {
  color: var(--primary-solar);
}

.footer-disclaimer {
  max-width: 1240px;
  margin: 1.35rem auto 0;
  font-size: 0.8rem;
  color: var(--text-dim);
  line-height: 1.65;
  font-family: 'Inter', sans-serif;
}

/* Solid hover states (replace former gradient shifts) */
.header-cta:hover,
.hero-btn-primary:hover {
  background: var(--primary-solar-hover);
}

/* Energy-flow SVG icons use the solar accent colour */
.flow-icon {
  display: inline-flex;
  align-items: center;
  color: var(--primary-solar);
}


/* ─── System Sizes Benchmarks Grid (SEO Content) ────────────────────────── */
.sizes-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  align-items: stretch;
}

@media (max-width: 1100px) {
  .sizes-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
  .sizes-grid { grid-template-columns: 1fr; }
}

.size-card {
  background: var(--bg-card);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.2rem 1.65rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
}

.size-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-solar);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.09);
}

.size-card.featured {
  border-color: var(--primary-solar);
  box-shadow: 0 0 0 1px var(--primary-solar), 0 16px 36px rgba(245, 158, 11, 0.15);
}

.size-badge {
  display: inline-flex;
  align-items: center;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
  align-self: flex-start;
}

.size-badge.amber  { background: var(--primary-solar-subtle); color: var(--primary-solar-hover); }
.size-badge.green  { background: var(--accent-green-subtle);  color: var(--accent-green); }
.size-badge.blue   { background: var(--accent-blue-subtle);   color: var(--accent-blue); }
.size-badge.purple { background: rgba(168, 85, 247, 0.14);    color: #c084fc; }

.size-h3 {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.35rem;
  letter-spacing: -0.02em;
}

.size-lead {
  font-size: 0.86rem;
  color: var(--text-muted);
  margin-bottom: 1.35rem;
  font-family: 'Inter', sans-serif;
  line-height: 1.5;
}

.size-specs {
  list-style: none;
  padding: 0;
  margin: 0 0 1.6rem;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.size-spec-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  padding-bottom: 0.45rem;
  border-bottom: 1px dashed var(--border-color);
}

.size-spec-label {
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.size-spec-val {
  color: var(--text-main);
  font-weight: 700;
}

/* ─── Methodology & Engineering Standards Cards ──────────────────────────── */
.methodology-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.6rem;
}

@media (max-width: 960px) {
  .methodology-grid { grid-template-columns: 1fr; }
}

.method-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.2rem 1.85rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.method-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 0;
}

.method-card p {
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--text-muted);
  margin: 0;
  font-family: 'Inter', sans-serif;
}

.method-code-badge {
  display: inline-block;
  background: var(--bg-card-subtle);
  border: 1px solid var(--border-color);
  padding: 0.55rem 0.85rem;
  border-radius: var(--radius-sm);
  font-family: 'Courier New', monospace;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary-solar);
  word-break: break-word;
}

/* ─── Subpage Hero & Content Styling ─────────────────────────────────────── */
.subpage-hero {
  padding: 4.5rem 1.5rem 2.5rem;
  max-width: 1240px;
  margin: 0 auto;
  text-align: center;
}

.subpage-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.95rem;
  background: var(--primary-solar-subtle);
  border: 1px solid rgba(245, 158, 11, 0.28);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary-solar);
  margin-bottom: 1.25rem;
}

.subpage-h1 {
  font-size: clamp(2.1rem, 4.2vw, 3.2rem);
  font-weight: 800;
  letter-spacing: -0.035em;
  color: var(--text-main);
  line-height: 1.15;
  margin-bottom: 1.15rem;
}

.subpage-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 2.2rem;
  line-height: 1.7;
  font-family: 'Inter', sans-serif;
}

.subpage-body {
  max-width: 1240px;
  margin: 0 auto 5rem;
  padding: 0 1.5rem;
}

/* Comparison Table */
.comparison-table-wrap {
  overflow-x: auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  margin: 2.5rem 0;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.9rem;
}

.comparison-table th {
  background: var(--bg-card-subtle);
  padding: 1.15rem 1.35rem;
  font-weight: 700;
  color: var(--text-main);
  border-bottom: 1.5px solid var(--border-color);
  white-space: nowrap;
}

.comparison-table td {
  padding: 1.1rem 1.35rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
}

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

.comparison-table tr:hover td {
  background: var(--bg-card-subtle);
}

.table-tag {
  display: inline-block;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.78rem;
}

.table-tag.amber { background: var(--primary-solar-subtle); color: var(--primary-solar); }
.table-tag.green { background: var(--accent-green-subtle); color: var(--accent-green); }
.table-tag.blue  { background: var(--accent-blue-subtle); color: var(--accent-blue); }

/* Explore Hub Cards on Homepage */
.hub-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

@media (max-width: 1100px) {
  .hub-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
  .hub-grid { grid-template-columns: 1fr; }
}

.hub-card {
  background: var(--bg-card);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.2rem 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  text-decoration: none;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  cursor: pointer;
}

.hub-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-solar);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.1);
}

.hub-card:hover .hub-link-text {
  text-decoration: underline;
}

.hub-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--primary-solar-subtle);
  color: var(--primary-solar);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.hub-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.hub-desc {
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
  margin-bottom: 1.35rem;
}

.hub-link-text {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary-solar);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  text-decoration: none;
}

.hub-link-text::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  z-index: 1;
}

/* ─── Footer Social Links ─── */
.footer-social {
  display: flex;
  align-items: center;
}

.footer-social-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.35rem 0.75rem;
  background: var(--bg-card-subtle, rgba(255, 255, 255, 0.05));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  color: var(--text-main);
  text-decoration: none;
  font-size: 0.825rem;
  font-weight: 600;
  transition: all 0.2s ease;
}

.footer-social-link:hover {
  border-color: #1877F2;
  color: #1877F2;
  transform: translateY(-1px);
}