/* ==========================================================================
   AQUADROP PURIFIER - CORE DESIGN SYSTEM & THEME TOKENS
   Modern, Ultra-Premium Hydration Technology & RO Services
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800;900&display=swap');

:root {
  /* Default Theme: LIGHT GLACIER PURE LUXURY */
  --bg-body: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-surface-subtle: #f0f7fc;
  --bg-card: rgba(255, 255, 255, 0.92);
  --bg-card-hover: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.88);
  --bg-input: #ffffff;

  /* Borders & Highlights */
  --border-glass: rgba(14, 165, 233, 0.16);
  --border-glass-hover: rgba(2, 132, 199, 0.45);
  --border-subtle: rgba(15, 23, 42, 0.07);

  /* Accents & Brand Gradients */
  --accent-cyan: #0284c7;
  --accent-cyan-light: #0ea5e9;
  --accent-cyan-bright: #00b4d8;
  --accent-blue: #0369a1;
  --accent-blue-deep: #075985;
  --accent-emerald: #059669;
  --accent-emerald-glow: rgba(5, 150, 105, 0.18);
  --accent-amber: #d97706;
  --accent-rose: #e11d48;

  --accent-glow: rgba(2, 132, 199, 0.15);
  --accent-glow-strong: rgba(2, 132, 199, 0.28);

  --gradient-brand: linear-gradient(135deg, #0284c7 0%, #0369a1 50%, #075985 100%);
  --gradient-brand-subtle: linear-gradient(135deg, rgba(2, 132, 199, 0.08) 0%, rgba(14, 165, 233, 0.03) 100%);
  --gradient-card: linear-gradient(180deg, #ffffff 0%, #f4f9fd 100%);
  --gradient-glow: radial-gradient(circle, rgba(2, 132, 199, 0.08) 0%, rgba(248, 250, 252, 0) 70%);

  /* Typography Colors */
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverted: #ffffff;

  /* Shadows */
  --shadow-sm: 0 2px 6px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 10px 25px -4px rgba(15, 23, 42, 0.06), 0 4px 12px -2px rgba(2, 132, 199, 0.04);
  --shadow-lg: 0 20px 35px -6px rgba(15, 23, 42, 0.09), 0 8px 20px -4px rgba(2, 132, 199, 0.06);
  --shadow-glow: 0 0 25px rgba(2, 132, 199, 0.15);
  --shadow-glow-lg: 0 0 45px rgba(2, 132, 199, 0.25);

  /* Fonts */
  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  /* Layout Spacing */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;
  --container-max: 1220px;
  --header-height: 76px;

  /* Transitions */
  --transition-fast: 0.18s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: 0.45s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* Optional Dark Theme (Obsidian Mode) */
[data-theme="dark"] {
  --bg-body: #030712;
  --bg-surface: #0a1120;
  --bg-surface-elevated: #0f1c30;
  --bg-surface-subtle: #091322;
  --bg-card: rgba(15, 28, 50, 0.72);
  --bg-card-hover: rgba(22, 42, 75, 0.9);
  --bg-glass: rgba(10, 20, 38, 0.8);
  --bg-input: rgba(15, 28, 50, 0.85);

  --border-glass: rgba(56, 189, 248, 0.16);
  --border-glass-hover: rgba(0, 240, 255, 0.45);
  --border-subtle: rgba(255, 255, 255, 0.08);

  --accent-cyan: #00f0ff;
  --accent-cyan-light: #70f8ff;
  --accent-cyan-bright: #00f0ff;
  --accent-blue: #0284c7;
  --accent-blue-deep: #0369a1;
  --accent-emerald: #10b981;
  --accent-emerald-glow: rgba(16, 185, 129, 0.3);

  --accent-glow: rgba(0, 240, 255, 0.28);
  --accent-glow-strong: rgba(0, 240, 255, 0.55);

  --gradient-brand: linear-gradient(135deg, #00f0ff 0%, #0284c7 50%, #38bdf8 100%);
  --gradient-brand-subtle: linear-gradient(135deg, rgba(0, 240, 255, 0.12) 0%, rgba(2, 132, 199, 0.05) 100%);
  --gradient-card: linear-gradient(180deg, rgba(18, 35, 64, 0.75) 0%, rgba(10, 18, 34, 0.92) 100%);
  --gradient-glow: radial-gradient(circle, rgba(0, 240, 255, 0.15) 0%, rgba(3, 7, 18, 0) 70%);

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverted: #030712;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px -4px rgba(0, 0, 0, 0.5), 0 4px 12px -2px rgba(0, 240, 255, 0.05);
  --shadow-lg: 0 16px 36px -6px rgba(0, 0, 0, 0.6), 0 8px 20px -4px rgba(0, 240, 255, 0.12);
  --shadow-glow: 0 0 30px rgba(0, 240, 255, 0.25);
  --shadow-glow-lg: 0 0 50px rgba(0, 240, 255, 0.4);
}

/* ==========================================================================
   GLOBAL RESETS & BASE STYLES
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Ambient Canvas */
#ambient-water-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  opacity: 0.35;
  transition: opacity var(--transition-normal);
}

[data-theme="dark"] #ambient-water-canvas {
  opacity: 0.65;
}

/* Subtle Decorative Background Orbs */
.ambient-glow-orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
  z-index: 0;
  opacity: 0.25;
}

.orb-1 {
  top: 5%;
  right: -5%;
  width: 550px;
  height: 550px;
  background: radial-gradient(circle, rgba(14, 165, 233, 0.25) 0%, rgba(248, 250, 252, 0) 70%);
}

.orb-2 {
  top: 45%;
  left: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(2, 132, 199, 0.18) 0%, rgba(248, 250, 252, 0) 70%);
}

.orb-3 {
  bottom: 5%;
  right: 10%;
  width: 480px;
  height: 480px;
  background: radial-gradient(circle, rgba(16, 185, 129, 0.16) 0%, rgba(248, 250, 252, 0) 70%);
}

/* Page Content Wrapper */
.page-wrapper {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

/* Typography Hierarchy */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2.35rem, 4.5vw + 0.5rem, 3.85rem);
  font-weight: 800;
  line-height: 1.12;
}

h2 {
  font-size: clamp(1.85rem, 3vw + 0.5rem, 2.6rem);
  font-weight: 700;
}

h3 {
  font-size: clamp(1.3rem, 1.8vw + 0.4rem, 1.65rem);
}

h4 {
  font-size: 1.2rem;
}

p {
  color: var(--text-secondary);
  font-size: 1.025rem;
  line-height: 1.68;
}

a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: all var(--transition-fast);
}

a:hover {
  color: var(--accent-cyan-light);
}

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

ul, ol {
  list-style: none;
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  border: none;
  outline: none;
}

/* Gradient Text Effect */
.text-gradient {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

/* Section Common Styles */
section {
  padding: 5.5rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 3.75rem auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.95rem;
  background: var(--gradient-brand-subtle);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-full);
  color: var(--accent-cyan);
  font-family: var(--font-heading);
  font-size: 0.825rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.section-tag svg {
  width: 15px;
  height: 15px;
  fill: currentColor;
}

.section-title {
  margin-bottom: 1.15rem;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
}

/* Glassmorphism Card Base */
.glass-panel {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.glass-panel:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-glass-hover);
  box-shadow: var(--shadow-lg);
}

/* Accessible Focus States */
:focus-visible {
  outline: 2px solid var(--accent-cyan);
  outline-offset: 3px;
}

/* Responsive Layout */
@media (max-width: 1024px) {
  section {
    padding: 4.5rem 0;
  }
  .section-header {
    margin-bottom: 3rem;
  }
}

@media (max-width: 768px) {
  section {
    padding: 3.5rem 0;
  }
  .container {
    padding-left: 1.25rem;
    padding-right: 1.25rem;
  }
  p {
    font-size: 0.975rem;
  }
}