/* ============================================
   LinQo Design System — main.css
   ============================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Brand Colors (Preserved) */
  --teal-deep: #0a3d4f;
  --teal-dark: #0e8fa3;
  --teal: #00b4d8;
  --teal-light: #48cae4;
  --teal-glow: #00e5ff;
  --cyan-bright: #00f0ff;

  /* Accent Colors — Purple/Violet */
  --purple-dark: #4a1d96;
  --purple: #7c3aed;
  --purple-light: #a78bfa;
  --purple-glow: #c084fc;
  --indigo: #6366f1;

  /* Light Theme Backgrounds */
  --bg-body: #f8fafc; /* Very light slate for base background */
  --bg-section: #ffffff; /* Pure white for alternating sections */
  --bg-card: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.75);
  --bg-glass-strong: rgba(255, 255, 255, 0.92);

  /* Light Theme Text */
  --text-main: #0f172a; /* Slate 900 - nearly black */
  --text-muted: #475569; /* Slate 600 - dark gray */
  --text-light: #94a3b8; /* Slate 400 - light gray */

  /* Light Theme Borders */
  --border-light: #e2e8f0; /* Slate 200 */
  --border-main: #cbd5e1; /* Slate 300 */

  /* Gradients */
  --gradient-main: linear-gradient(135deg, #f8fafc 0%, #e0f2fe 40%, #bae6fd 70%, #00b4d8 100%);
  --gradient-hero: linear-gradient(160deg, #f0f9ff 0%, #e0f2fe 30%, #f8fafc 100%);
  --gradient-card: linear-gradient(145deg, #ffffff 0%, #f8fafc 100%);
  --gradient-card-hover: linear-gradient(145deg, #ffffff 0%, #f0f9ff 100%);
  --gradient-teal: linear-gradient(135deg, #00b4d8, #00e5ff);
  --gradient-accent: linear-gradient(135deg, #00b4d8, #7c3aed);
  --gradient-nav: linear-gradient(90deg, rgba(255, 255, 255, 0.95) 0%, rgba(240, 249, 255, 0.85) 100%);

  /* Shadows (Soft Neumorphic for Light Theme) */
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 4px 16px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 10px 30px rgba(15, 23, 42, 0.08);
  --shadow-elevated: 0 20px 40px rgba(15, 23, 42, 0.12);
  --shadow-glow: 0 0 20px rgba(0, 180, 216, 0.2);
  --shadow-glow-strong: 0 0 35px rgba(0, 229, 255, 0.3);
  --shadow-glow-dual: 0 10px 30px rgba(0, 180, 216, 0.15), 0 10px 30px rgba(124, 58, 237, 0.1);

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --fs-hero: clamp(2.5rem, 5vw, 4.5rem);
  --fs-h1: clamp(2rem, 4vw, 3.5rem);
  --fs-h2: clamp(1.5rem, 3vw, 2.5rem);
  --fs-h3: clamp(1.2rem, 2vw, 1.75rem);
  --fs-h4: 1.25rem;
  --fs-body: 1.0625rem;
  --fs-small: 0.9375rem;
  --fs-xs: 0.8125rem;
  --lh-tight: 1.2;
  --lh-normal: 1.6;
  --lh-relaxed: 1.8;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;
  --space-3xl: 8rem;

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 800px;
  --nav-height: 120px;
  --border-radius: 12px;
  --border-radius-lg: 20px;
  --border-radius-pill: 50px;

  /* Transitions */
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-fast: 0.2s;
  --duration-normal: 0.3s;
  --duration-slow: 0.5s;
  --duration-slower: 0.8s;
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-size: var(--fs-body);
  line-height: var(--lh-normal);
  color: var(--text-muted);
  background: var(--bg-body);
  overflow-x: hidden;
}

/* Selection */
::selection {
  background: rgba(0, 180, 216, 0.2);
  color: var(--text-main);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-body);
}

::-webkit-scrollbar-thumb {
  background: var(--border-main);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-light);
}

/* --- Typography --- */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: var(--lh-tight);
  color: var(--text-main);
}

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

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

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

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

p {
  color: var(--text-muted);
  line-height: var(--lh-relaxed);
}

a {
  color: var(--teal);
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-out);
}

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

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.container--narrow {
  max-width: var(--container-narrow);
}

section {
  padding: var(--space-2xl) 0;
  position: relative;
}

/* --- Components: Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  border: none;
  border-radius: var(--border-radius-pill);
  font-family: var(--font-primary);
  font-size: var(--fs-body);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn--primary {
  background: var(--gradient-teal);
  color: #ffffff;
  box-shadow: var(--shadow-md);
  text-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
  color: #ffffff;
}

.btn--primary::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent, rgba(255, 255, 255, 0.4), transparent);
  transform: translateX(-100%);
  transition: transform 0.6s var(--ease-out);
}

.btn--primary:hover::after {
  transform: translateX(100%);
}

.btn--secondary {
  background: var(--bg-section);
  color: var(--text-main);
  border: 1px solid var(--border-main);
  box-shadow: var(--shadow-sm);
}

.btn--secondary:hover {
  background: var(--bg-body);
  border-color: var(--teal);
  color: var(--teal);
  transform: translateY(-2px);
}

.btn--sm {
  padding: 0.625rem 1.5rem;
  font-size: var(--fs-small);
}

.btn--lg {
  padding: 1rem 2.5rem;
  font-size: 1.125rem;
}

/* --- Components: Cards --- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--border-radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--duration-slow) var(--ease-out);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out);
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-elevated);
  border-color: var(--border-main);
}

.card:hover::before {
  opacity: 1;
}

/* --- Components: Section Header --- */
.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--space-xl);
}

.section-header__label {
  display: inline-block;
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--teal-dark);
  margin-bottom: var(--space-sm);
  position: relative;
}

.section-header__label::before,
.section-header__label::after {
  content: '';
  position: absolute;
  top: 50%;
  width: 30px;
  height: 1px;
  background: var(--border-main);
}

.section-header__label::before {
  right: calc(100% + 12px);
}

.section-header__label::after {
  left: calc(100% + 12px);
}

.section-header__title {
  margin-bottom: var(--space-sm);
}

.section-header__subtitle {
  font-size: 1.125rem;
  color: var(--text-muted);
}

/* --- Components: Badge --- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.875rem;
  border-radius: var(--border-radius-pill);
  font-size: var(--fs-xs);
  font-weight: 600;
  background: rgba(0, 180, 216, 0.1);
  border: 1px solid rgba(0, 180, 216, 0.2);
  color: var(--teal-dark);
}

/* --- Animations: Scroll Reveal --- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--duration-slower) var(--ease-out),
    transform var(--duration-slower) var(--ease-out);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal--delay-1 {
  transition-delay: 0.1s;
}

.reveal--delay-2 {
  transition-delay: 0.2s;
}

.reveal--delay-3 {
  transition-delay: 0.3s;
}

.reveal--delay-4 {
  transition-delay: 0.4s;
}

.reveal--delay-5 {
  transition-delay: 0.5s;
}

/* --- Animations: Keyframes --- */
@keyframes pulse-glow {

  0%,
  100% {
    opacity: 0.6;
  }

  50% {
    opacity: 1;
  }
}

@keyframes float {

  0%,
  100% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-10px);
  }
}

@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }

  100% {
    background-position: 200% 0;
  }
}

@keyframes rotate-slow {
  from {
    transform: rotate(0deg);
  }

  to {
    transform: rotate(360deg);
  }
}

/* --- Utility: Glow dot --- */
.glow-dot {
  width: 8px;
  height: 8px;
  background: var(--teal-glow);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--teal-glow), 0 0 20px rgba(0, 229, 255, 0.3);
  animation: pulse-glow 2s ease-in-out infinite;
}

/* --- Utility: Gradient Text --- */
.gradient-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.gradient-text--teal {
  background: var(--gradient-teal);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* --- Utility: Glass --- */
.glass {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
}