/* ==========================================================================
   DESIGN SYSTEM & GLOBAL STYLES - GF Renewable Energy
   ========================================================================== */

/* Imports */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@300;400;500;600;700;800&display=swap');

/* Color Variables and Design Tokens */
:root {
  /* HSL Color System */
  --primary-hue: 170;
  --primary-sat: 75%;
  --primary-light: 16%;
  
  --primary: hsl(var(--primary-hue), var(--primary-sat), var(--primary-light)); /* Eco-Teal: #074b3f */
  --primary-hover: hsl(var(--primary-hue), var(--primary-sat), calc(var(--primary-light) + 8%));
  --primary-light-bg: hsl(var(--primary-hue), var(--primary-sat), 96%);

  --accent-hue: 45;
  --accent-sat: 95%;
  --accent-light: 48%;

  --accent: hsl(var(--accent-hue), var(--accent-sat), var(--accent-light)); /* Solar Gold: #f5b002 */
  --accent-hover: hsl(var(--accent-hue), var(--accent-sat), calc(var(--accent-light) + 8%));
  --accent-light-bg: hsl(var(--accent-hue), var(--accent-sat), 96%);

  /* Neutrals */
  --bg-light: hsl(210, 20%, 98%); /* Base BG: #f8fafc */
  --bg-dark: hsl(220, 25%, 12%);  /* Dark Slate: #161b22 */
  --bg-card: hsl(0, 0%, 100%);
  
  --text-main: hsl(220, 20%, 25%); /* slate-700/800 */
  --text-muted: hsl(220, 15%, 45%);
  --text-light: hsl(210, 20%, 95%);
  
  --border-color: hsl(214, 32%, 91%);
  --border-focus: var(--primary);
  
  /* Layout Dimensions */
  --max-width: 1200px;
  --header-height: 90px;
  --header-shrink-height: 70px;
  --border-radius: 12px;
  --border-radius-sm: 8px;
  --border-radius-lg: 20px;
  
  /* Fonts */
  --font-headers: 'Outfit', 'Inter', sans-serif;
  --font-body: 'Inter', sans-serif;
  
  /* Shadows */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(7, 75, 63, 0.08);
  --shadow-lg: 0 12px 24px rgba(7, 75, 63, 0.12);
  --shadow-hover: 0 16px 32px rgba(7, 75, 63, 0.16);

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==========================================================================
   Resets and Base Styling
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  height: -webkit-fill-available;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  color: var(--text-main);
  background-color: var(--bg-light);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-headers);
  font-weight: 700;
  line-height: 1.25;
  color: var(--bg-dark);
}

p {
  margin-bottom: 1.25rem;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast), border-color var(--transition-fast);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  list-style: none;
}

button, input, textarea, select {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  outline: none;
}

/* ==========================================================================
   Typography and Font Utilities
   ========================================================================== */
.font-display { font-family: var(--font-headers); }
.text-primary { color: var(--primary); }
.text-accent { color: var(--accent); }
.text-light { color: var(--text-light); }
.text-muted { color: var(--text-muted); }

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.fs-h1 { font-size: clamp(2.25rem, 5vw, 3.5rem); font-weight: 800; }
.fs-h2 { font-size: clamp(1.75rem, 4vw, 2.5rem); font-weight: 700; }
.fs-h3 { font-size: clamp(1.25rem, 3vw, 1.75rem); font-weight: 600; }
.fs-body { font-size: 1rem; }
.fs-sm { font-size: 0.875rem; }

/* ==========================================================================
   Grid & Flex Layout Utilities
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.flex {
  display: flex;
}
.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}
.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.flex-column {
  display: flex;
  flex-direction: column;
}

.grid {
  display: grid;
  gap: 1.5rem;
}
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}
.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

/* ==========================================================================
   Section Spacing Utilities
   ========================================================================== */
.section-padding {
  padding-top: clamp(4rem, 8vw, 7rem);
  padding-bottom: clamp(4rem, 8vw, 7rem);
}
.section-padding-sm {
  padding-top: 2rem;
  padding-bottom: 2rem;
}
.mar-bottom-sm { margin-bottom: 1rem; }
.mar-bottom-md { margin-bottom: 2rem; }
.mar-bottom-lg { margin-bottom: 3.5rem; }
.clearfix::after {
  content: "";
  clear: both;
  display: table;
}

/* ==========================================================================
   HEADER & NAVIGATION
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background-color: rgba(248, 250, 252, 0.85); /* base BG semi-transparent */
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(7, 75, 63, 0.06);
  z-index: 1000;
  transition: height var(--transition-normal), background-color var(--transition-normal), box-shadow var(--transition-normal);
}

.site-header.sticky {
  height: var(--header-shrink-height);
  background-color: rgba(248, 250, 252, 0.95);
  box-shadow: var(--shadow-sm);
}

.header-container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-block {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-block img {
  height: 50px;
  width: 50px;
  border-radius: var(--border-radius-sm);
  transition: transform var(--transition-normal);
}

.site-header.sticky .logo-block img {
  height: 40px;
  width: 40px;
}

.logo-block:hover img {
  transform: rotate(5deg) scale(1.05);
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-family: var(--font-headers);
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--primary);
  line-height: 1.1;
}

.brand-subtitle {
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
}

/* Nav Menu */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  font-family: var(--font-headers);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  position: relative;
  padding: 0.5rem 0;
}

/* Fix active line overlaying CTA button */
.nav-link:not(.nav-cta)::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--accent);
  transition: width var(--transition-fast) ease-in-out;
}

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

.nav-link:not(.nav-cta):hover::after,
.nav-link:not(.nav-cta).active::after {
  width: 100%;
}

.nav-link.active {
  color: var(--primary);
}

/* Header Contact CTA in Navbar */
.nav-cta {
  background-color: var(--primary);
  color: white !important;
  padding: 0.6rem 1.25rem;
  border-radius: 50px;
  font-weight: 600;
  box-shadow: var(--shadow-sm);
  transition: background var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.nav-cta::after {
  display: none !important;
}

.nav-cta:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Hamburger menu button */
.mobile-nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 24px;
  height: 18px;
  cursor: pointer;
  z-index: 1100;
}

.mobile-nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--primary);
  border-radius: 2px;
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

/* Hamburger transform when menu open */
.mobile-nav-toggle.open span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.mobile-nav-toggle.open span:nth-child(2) {
  opacity: 0;
}

.mobile-nav-toggle.open span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* Responsive navigation styles */
@media (max-width: 900px) {
  .mobile-nav-toggle {
    display: flex;
  }
  
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 300px;
    height: 100vh;
    background-color: var(--bg-card);
    box-shadow: -10px 0 30px rgba(0, 0, 0, 0.1);
    flex-direction: column;
    justify-content: center;
    gap: 2.5rem;
    z-index: 1050;
    transition: right var(--transition-normal);
  }
  
  .nav-menu.open {
    right: 0;
  }
  
  .nav-link {
    font-size: 1.25rem;
  }
  
  .nav-cta {
    width: 80%;
    text-align: center;
  }
}

/* ==========================================================================
   HERO SLIDER
   ========================================================================== */
.hero-slider {
  position: relative;
  height: clamp(450px, 70vh, 600px);
  width: 100%;
  overflow: hidden;
  background-color: var(--bg-dark);
}

.slides-container {
  position: relative;
  width: 100%;
  height: 100%;
}

.slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  z-index: 1;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  display: flex;
  align-items: center;
  transition: opacity var(--transition-slow) ease-in-out;
}

.slide.active {
  opacity: 1;
  z-index: 2;
}

.slide-content {
  color: white;
  text-align: left;
  max-width: 800px;
  transform: translateY(20px);
  opacity: 0;
  transition: transform var(--transition-slow) ease-out, opacity var(--transition-slow) ease-out;
  transition-delay: 0.2s;
}

.slide.active .slide-content {
  transform: translateY(0);
  opacity: 1;
}

.slide-tag {
  background-color: var(--accent);
  color: var(--bg-dark);
  padding: 0.4rem 1rem;
  border-radius: 50px;
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
  display: inline-block;
}

.slide-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 2rem;
}

.btn-filled {
  background-color: var(--primary);
  color: white !important;
  border: 2px solid var(--primary);
  padding: 0.8rem 1.75rem;
  border-radius: 50px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  transition: all var(--transition-fast);
}

.btn-filled:hover {
  background-color: var(--primary-hover);
  border-color: var(--primary-hover);
  transform: translateY(-2px);
}

.btn-outline {
  border: 2px solid white;
  color: white !important;
  padding: 0.8rem 1.75rem;
  border-radius: 50px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  transition: all var(--transition-fast);
}

.btn-outline:hover {
  background-color: white;
  color: var(--primary) !important;
  transform: translateY(-2px);
}

/* Slider arrows */
.slide-prev, .slide-next {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.1);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.2);
  cursor: pointer;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

.slide-prev:hover, .slide-next:hover {
  background-color: var(--accent);
  color: var(--bg-dark);
  border-color: var(--accent);
}

.slide-prev { left: 20px; }
.slide-next { right: 20px; }

/* Dot navigation */
.slider-dots {
  position: absolute;
  bottom: 25px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 0.75rem;
  z-index: 10;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.3);
  cursor: pointer;
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.dot.active {
  background-color: var(--accent);
  transform: scale(1.2);
}

@media (max-width: 768px) {
  .slide-prev, .slide-next {
    display: none;
  }
}

/* ==========================================================================
   FOOTER SECTION
   ========================================================================== */
.site-footer {
  background-color: var(--bg-dark);
  color: var(--text-light);
  border-top: 5px solid var(--accent);
  padding-top: 4.5rem;
  padding-bottom: 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3.5rem;
  margin-bottom: 4rem;
}

@media (max-width: 800px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
}

.footer-col h3 {
  color: white;
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.footer-col h3::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 2px;
  background-color: var(--accent);
}

.footer-about {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.footer-logo img {
  height: 50px;
  width: 50px;
  border-radius: var(--border-radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-logo .brand-title {
  color: white;
}

.footer-col p {
  color: var(--text-light);
  opacity: 0.85;
  font-size: 0.95rem;
}

/* Contact lists in footer */
.footer-contact-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-contact-item {
  display: flex;
  gap: 0.75rem;
  font-size: 0.95rem;
}

.footer-contact-item i {
  color: var(--accent);
  font-size: 1.1rem;
  margin-top: 0.25rem;
}

.footer-contact-item span,
.footer-contact-item a {
  color: var(--text-light);
  opacity: 0.85;
}

.footer-contact-item a:hover {
  color: var(--accent);
  opacity: 1;
}

/* Navigation lists in footer */
.footer-links-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-link-item a {
  color: var(--text-light);
  opacity: 0.8;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-link-item a::before {
  content: '→';
  color: var(--accent);
  transition: transform var(--transition-fast);
}

.footer-link-item a:hover {
  color: white;
  opacity: 1;
  transform: translateX(4px);
}

.footer-link-item a:hover::before {
  transform: scale(1.2);
}

/* Footer Bottom */
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.875rem;
}

.footer-bottom p {
  margin-bottom: 0;
  opacity: 0.7;
}

.footer-bottom a {
  color: white;
  opacity: 0.85;
}

.footer-bottom a:hover {
  color: var(--accent);
}

.designer-credit {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.designer-credit img {
  height: 14px;
}

/* ==========================================================================
   FORM INPUT STYLES
   ========================================================================== */
.form-group {
  margin-bottom: 1.25rem;
  text-align: left;
}

.form-label {
  display: block;
  font-family: var(--font-headers);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.form-input {
  width: 100%;
  padding: 0.75rem 1rem;
  border-radius: var(--border-radius-sm);
  border: 1px solid var(--border-color);
  background-color: white;
  color: var(--text-main);
  font-family: var(--font-body);
  font-size: 0.95rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(7, 75, 63, 0.15);
  background-color: white;
}

textarea.form-input {
  resize: vertical;
}

/* ==========================================================================
   SCROLL UP COMPONENT
   ========================================================================== */
.scroll-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background-color: var(--accent);
  color: var(--bg-dark);
  font-size: 1.25rem;
  font-weight: bold;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal), background var(--transition-fast), transform var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.scroll-top.show {
  opacity: 1;
  visibility: visible;
}

.scroll-top:hover {
  background-color: var(--accent-hover);
  transform: translateY(-3px) scale(1.05);
  box-shadow: var(--shadow-lg);
}

/* Helper to adjust section top margins due to sticky header */
.header-spacing {
  margin-top: var(--header-height);
}

/* Scroll Offset for Anchor Navigation due to Sticky Header */
#site, #system, #proposal, #installation {
  scroll-margin-top: 110px; /* var(--header-shrink-height) 70px + 40px padding spacing */
}

/* ==========================================================================
   SCROLL TRIGGERED MICRO-ANIMATIONS
   ========================================================================== */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1), transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  will-change: opacity, transform;
}

.animate-on-scroll.appear {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger delays for grid children */
.delay-100 { transition-delay: 100ms; }
.delay-200 { transition-delay: 200ms; }
.delay-300 { transition-delay: 300ms; }
.delay-400 { transition-delay: 400ms; }

/* Micro-interaction zoom scales */
.hover-zoom {
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}
.hover-zoom:hover {
  transform: translateY(-5px) scale(1.02);
  box-shadow: var(--shadow-hover);
}