/* ========================================
   SOLAR DESIGN SYSTEM - CSS VARIABLES
   ======================================== */

:root {
  /* ===== PRIMARY COLORS ===== */
  --solar-orange: #FF6B35;
  --solar-orange-light: #FF8A5C;
  --solar-orange-dark: #E65420;

  --solar-yellow: #F7B801;
  --solar-yellow-light: #FFD23F;
  --solar-yellow-dark: #D99F00;

  --energy-green: #2ECC71;
  --energy-green-light: #58D68D;
  --energy-green-dark: #27AE60;

  /* ===== SECONDARY COLORS ===== */
  --sky-blue: #3498DB;
  --sky-blue-light: #5DADE2;
  --sky-blue-dark: #2980B9;

  --deep-blue: #2C3E50;
  --deep-blue-light: #34495E;
  --deep-blue-dark: #1A252F;

  /* ===== NEUTRAL COLORS ===== */
  --white: #FFFFFF;
  --light-gray: #F8F9FA;
  --medium-gray: #6C757D;
  --dark-gray: #343A40;
  --black: #000000;

  --gray-50: #F9FAFB;
  --gray-100: #F3F4F6;
  --gray-200: #E5E7EB;
  --gray-300: #D1D5DB;
  --gray-400: #9CA3AF;
  --gray-500: #6B7280;
  --gray-600: #4B5563;
  --gray-700: #374151;
  --gray-800: #1F2937;
  --gray-900: #111827;

  /* ===== GRADIENTS ===== */
  --gradient-primary: linear-gradient(135deg, #FF6B35 0%, #F7B801 100%);
  --gradient-secondary: linear-gradient(135deg, #3498DB 0%, #2ECC71 100%);
  --gradient-overlay: linear-gradient(135deg, rgba(255, 107, 53, 0.9) 0%, rgba(247, 184, 1, 0.9) 100%);
  --gradient-dark: linear-gradient(135deg, rgba(44, 62, 80, 0.95) 0%, rgba(26, 37, 47, 0.95) 100%);

  /* ===== TYPOGRAPHY ===== */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-secondary: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  /* Font Sizes */
  --fs-xs: 0.75rem;
  /* 12px */
  --fs-sm: 0.875rem;
  /* 14px */
  --fs-base: 1rem;
  /* 16px */
  --fs-lg: 1.125rem;
  /* 18px */
  --fs-xl: 1.25rem;
  /* 20px */
  --fs-2xl: 1.5rem;
  /* 24px */
  --fs-3xl: 1.875rem;
  /* 30px */
  --fs-4xl: 2.25rem;
  /* 36px */
  --fs-5xl: 3rem;
  /* 48px */
  --fs-6xl: 3.75rem;
  /* 60px */
  --fs-7xl: 4.5rem;
  /* 72px */

  /* Font Weights */
  --fw-light: 300;
  --fw-regular: 400;
  --fw-medium: 500;
  --fw-semibold: 600;
  --fw-bold: 700;
  --fw-extrabold: 800;

  /* Line Heights */
  --lh-tight: 1.25;
  --lh-normal: 1.5;
  --lh-relaxed: 1.75;
  --lh-loose: 2;

  /* ===== SPACING ===== */
  --spacing-xs: 0.25rem;
  /* 4px */
  --spacing-sm: 0.5rem;
  /* 8px */
  --spacing-md: 1rem;
  /* 16px */
  --spacing-lg: 1.5rem;
  /* 24px */
  --spacing-xl: 2rem;
  /* 32px */
  --spacing-2xl: 3rem;
  /* 48px */
  --spacing-3xl: 4rem;
  /* 64px */
  --spacing-4xl: 6rem;
  /* 96px */
  --spacing-5xl: 8rem;
  /* 128px */

  /* ===== SHADOWS ===== */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
  --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.25);

  /* ===== BORDER RADIUS ===== */
  --radius-sm: 0.25rem;
  /* 4px */
  --radius-md: 0.5rem;
  /* 8px */
  --radius-lg: 1rem;
  /* 16px */
  --radius-xl: 1.5rem;
  /* 24px */
  --radius-2xl: 2rem;
  /* 32px */
  --radius-full: 9999px;

  /* ===== TRANSITIONS ===== */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;

  /* ===== Z-INDEX ===== */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;

  /* ===== LAYOUT ===== */
  --container-max-width: 1200px;
  --container-padding: 1rem;
  --header-height: 80px;
  --header-top-height: 40px;
}

/* ========================================
   GLOBAL RESET & BASE STYLES
   ======================================== */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-size: var(--fs-base);
  font-weight: var(--fw-regular);
  line-height: var(--lh-normal);
  color: var(--gray-800);
  background-color: var(--white);
  overflow-x: hidden;
}

/* ===== TYPOGRAPHY ===== */

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-secondary);
  font-weight: var(--fw-bold);
  line-height: var(--lh-tight);
  color: var(--deep-blue);
  margin-bottom: 1rem;
}

h1 {
  font-size: var(--fs-5xl);
}

h2 {
  font-size: var(--fs-4xl);
}

h3 {
  font-size: var(--fs-3xl);
}

h4 {
  font-size: var(--fs-2xl);
}

h5 {
  font-size: var(--fs-xl);
}

h6 {
  font-size: var(--fs-lg);
}

p {
  margin-bottom: 1rem;
  line-height: var(--lh-relaxed);
}

a {
  color: var(--solar-orange);
  text-decoration: none;
  transition: color var(--transition-base);
}

a:hover {
  color: var(--solar-orange-dark);
}

a:focus {
  outline: 2px solid var(--solar-orange);
  outline-offset: 2px;
}

ul,
ol {
  list-style: none;
}

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

/* ===== CONTAINER ===== */

.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* ===== SECTIONS ===== */

.section-padding {
  padding: var(--spacing-4xl) 0;
}

.section-header {
  margin-bottom: var(--spacing-3xl);
}

.section-title {
  font-size: var(--fs-4xl);
  font-weight: var(--fw-bold);
  color: var(--deep-blue);
  margin-bottom: var(--spacing-md);
}

.section-subtitle {
  font-size: var(--fs-lg);
  color: var(--gray-600);
  /* max-width: 600px; */
}

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

.text-center .section-subtitle {
  margin: 0 auto;
}

/* ===== BACKGROUNDS ===== */

.bg-light {
  background-color: var(--gray-50);
}

.bg-gradient {
  background: var(--gradient-primary);
  color: var(--white);
}

.bg-gradient .section-title,
.bg-gradient h1,
.bg-gradient h2,
.bg-gradient h3 {
  color: var(--white);
}

.bg-gradient .section-subtitle,
.bg-gradient p {
  color: rgba(255, 255, 255, 0.9);
}

/* ===== BUTTONS ===== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-secondary);
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  text-align: center;
  text-decoration: none;
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  white-space: nowrap;
}

.btn:focus {
  outline: 2px solid var(--solar-orange);
  outline-offset: 2px;
}

.btn-primary {
  background: var(--gradient-primary);
  color: var(--white);
  border-color: transparent;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: var(--white);
}

.btn-secondary {
  background-color: var(--white);
  color: var(--solar-orange);
  border-color: var(--white);
}

.btn-secondary:hover {
  background-color: var(--gray-50);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background-color: transparent;
  color: var(--solar-orange);
  border-color: var(--solar-orange);
}

.btn-outline:hover {
  background-color: var(--solar-orange);
  color: var(--white);
}

.btn-outline-white {
  background-color: transparent;
  color: var(--white);
  border-color: var(--white);
}

.btn-outline-white:hover {
  background-color: var(--white);
  color: var(--solar-orange);
}

.btn-white {
  background-color: var(--white);
  color: var(--solar-orange);
  border-color: var(--white);
}

.btn-white:hover {
  background-color: var(--gray-50);
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: var(--fs-lg);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: var(--fs-sm);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  pointer-events: none;
}

/* ===== UTILITIES ===== */

.highlight {
  color: var(--solar-orange);
  position: relative;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--solar-orange);
  color: var(--white);
  padding: 8px 16px;
  text-decoration: none;
  z-index: 100;
  border-radius: var(--radius-md);
}

.skip-link:focus {
  top: 0;
}

/* Back to Top functionality is now handled by Vue (BackToTop.vue) */

/* ===== RESPONSIVE TYPOGRAPHY ===== */

@media (max-width: 768px) {
  :root {
    --fs-5xl: 2.5rem;
    /* 40px */
    --fs-4xl: 2rem;
    /* 32px */
    --fs-3xl: 1.5rem;
    /* 24px */
    --fs-2xl: 1.25rem;
    /* 20px */
  }

  h1 {
    font-size: var(--fs-4xl);
  }

  h2 {
    font-size: var(--fs-3xl);
  }

  h3 {
    font-size: var(--fs-2xl);
  }

  .section-padding {
    padding: var(--spacing-3xl) 0;
  }

  .section-title {
    font-size: var(--fs-3xl);
  }
}

@media (max-width: 480px) {
  :root {
    --container-padding: 1rem;
  }

  .section-padding {
    padding: var(--spacing-2xl) 0;
  }
}