/* ===================================================================
   Nosia.ai - Apple-Class Dark Theme
   Premium design with glassmorphism, depth, and polished details
   =================================================================== */

/* ===== CSS Custom Properties ===== */
:root {
  /* Apple-Class Color Palette */
  --color-primary: #22c55e;        /* Brand green */
  --color-primary-dark: #16a34a;     /* Green dark */
  --color-primary-glow: rgba(34, 197, 94, 0.15);
  --color-accent: #29caf0;          /* Apple blue */
  --color-accent-glow: rgba(41, 202, 240, 0.15);
  
  /* Background Colors (Apple Dark Mode) */
  --color-bg: #000000;             /* True black */
  --color-surface: #111111;        /* Card backgrounds */
  --color-surface-secondary: rgba(17, 17, 17, 0.4);
  --color-border: #222222;         /* Borders */
  
  /* Text Colors */
  --color-text-primary: #f5f5f7;   /* Apple off-white */
  --color-text-secondary: #a0a0a0;
  --color-text-tertiary: #666666;
  
  /* Glassmorphism */
  --glass-bg: rgba(17, 17, 17, 0.4);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-overlay: rgba(0, 0, 0, 0.2);
  
  /* Typography - Apple San Francisco */
  --font-system: -apple-system, BlinkMacSystemFont, "San Francisco", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "Monaco", "Menlo", monospace;
  
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2rem;
  --text-4xl: 2.5rem;
  --text-5xl: 3rem;
  
  --leading-tight: 1.1;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
  
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  
  /* Spacing - 8px Base Grid */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --spacing-3xl: 6rem;
  
  /* Border Radius - Apple Rounded */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* Shadows - Layered */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --shadow-glow: 0 0 40px rgba(34, 197, 94, 0.15);
  --shadow-glass: 0 8px 32px rgba(0, 0, 0, 0.3);
  
  /* Transitions - Apple Spring Curve */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 600ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Max Width */
  --max-width: 1200px;
}

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

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-system);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  min-height: 100vh;
}

::selection {
  background: rgba(34, 197, 94, 0.3);
  color: var(--color-text-primary);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

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

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-system);
  font-weight: 700;
  line-height: var(--leading-tight);
  letter-spacing: var(--letter-spacing-tight);
  color: var(--color-text-primary);
}

h1 {
  font-size: var(--text-5xl);
  letter-spacing: -0.02em;
}

h2 {
  font-size: var(--text-3xl);
  letter-spacing: -0.01em;
  font-weight: 600;
}

h3 {
  font-size: var(--text-2xl);
  font-weight: 600;
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
}

.subtitle {
  font-size: var(--text-xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  line-height: var(--leading-relaxed);
  font-weight: 400;
}

/* ===================================================================
   LAYOUT
   =================================================================== */

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

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-lg);
}

/* ===================================================================
   HEADER - Glass Navigation
   =================================================================== */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--spacing-md) 0;
  background: rgba(10, 10, 10, 0.8);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border-bottom: 1px solid var(--glass-border);
  transition: all var(--transition-normal);
}

.header.scrolled {
  padding: var(--spacing-sm) 0;
  background: rgba(10, 10, 10, 0.95);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
}

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

.logo {
  display: block;
}

.logo img {
  height: 48px;
  transition: transform var(--transition-normal);
}

.logo:hover img {
  transform: scale(1.05);
}

.nav {
  display: flex;
  gap: var(--spacing-xl);
}

.nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: var(--letter-spacing-wide);
  text-transform: uppercase;
  transition: color var(--transition-fast);
  position: relative;
  padding: var(--spacing-xs) 0;
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: bottom right;
  transition: transform var(--transition-normal);
}

.nav a:hover::after {
  transform: scaleX(1);
  transform-origin: bottom left;
}

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

/* ===================================================================
   HERO SECTION - Premium with Depth
   =================================================================== */

.hero {
  margin-top: var(--spacing-3xl);
  padding: var(--spacing-3xl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, transparent 0%, rgba(0, 0, 0, 0.3) 100%);
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(34, 197, 94, 0.08) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

.hero .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero .logo {
  margin-bottom: var(--spacing-xl);
  position: relative;
}

.hero .logo::after {
  content: '';
  position: absolute;
  top: -30px;
  left: 50%;
  transform: translateX(-50%);
  width: 250px;
  height: 250px;
  background: radial-gradient(circle, rgba(34, 197, 94, 0.12) 0%, transparent 70%);
  z-index: -1;
  pointer-events: none;
}

.hero .logo img {
  margin-bottom: var(--spacing-xl);
  height: 80px;
}

.hero h1 {
  margin-bottom: var(--spacing-lg);
  font-size: var(--text-5xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(180deg, #ffffff 0%, #a0a0a0 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.1;
}

.hero .subtitle {
  margin-bottom: var(--spacing-xl);
}

/* ===================================================================
   CARDS - Glassmorphism
   =================================================================== */

.card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-normal);
  display: block;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.02) 0%, transparent 100%);
  pointer-events: none;
}

.card:hover {
  transform: translateY(-6px);
  border-color: rgba(34, 197, 94, 0.3);
  box-shadow: 
    0 20px 40px rgba(0, 0, 0, 0.3),
    0 0 0 1px rgba(255, 255, 255, 0.1);
}

.card .icon {
  font-size: var(--text-3xl);
  display: block;
  margin-bottom: var(--spacing-md);
  line-height: 1;
}

.card h3 {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-primary);
  font-weight: 600;
  font-size: var(--text-xl);
  letter-spacing: var(--letter-spacing-tight);
}

.card p {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  font-weight: 400;
}

.features .card:hover {
  box-shadow: 
    0 20px 40px rgba(0, 0, 0, 0.3),
    0 0 60px rgba(34, 197, 94, 0.15);
}

/* Reveal animation class - applied by JavaScript */
.card.reveal,
section.reveal {
  opacity: 1;
  transform: translateY(0);
}

/* Initial hidden state for reveal animation */
.card.hidden,
section.hidden {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

/* ===================================================================
   BUTTONS - Premium Pill Style
   =================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md) var(--spacing-2xl);
  font-size: var(--text-lg);
  font-weight: 600;
  letter-spacing: var(--letter-spacing-wide);
  border-radius: var(--radius-full);
  border: none;
  cursor: pointer;
  transition: all var(--transition-normal);
  text-transform: uppercase;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(180deg, var(--color-primary) 0%, #16a34a 100%);
  color: white;
  box-shadow: 0 4px 14px rgba(34, 197, 94, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(180deg, #2af06a 0%, #1db954 100%);
  box-shadow: 
    0 6px 20px rgba(34, 197, 94, 0.4),
    0 0 0 1px rgba(34, 197, 94, 0.3);
  transform: translateY(-2px);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: 0 2px 10px rgba(34, 197, 94, 0.3);
}

/* ===================================================================
   CODE BLOCKS - Refined
   =================================================================== */

.code-block {
  background: rgba(17, 17, 17, 0.5);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  overflow-x: auto;
  margin-bottom: var(--spacing-md);
  backdrop-filter: blur(10px);
  font-size: var(--text-sm);
}

.code-block code {
  font-family: var(--font-mono);
  color: var(--color-text-primary);
  background: none;
  padding: 0;
  line-height: var(--leading-relaxed);
  white-space: pre-wrap;
  word-break: break-all;
}

/* ===================================================================
   FOOTER - Elevated
   =================================================================== */

.footer {
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
  border-top: 1px solid var(--glass-border);
  background: linear-gradient(180deg, transparent 0%, rgba(0, 0, 0, 0.2) 100%);
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(34, 197, 94, 0.3), transparent);
  pointer-events: none;
}

.footer .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-lg);
}

.footer p {
  color: var(--color-text-tertiary);
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
}

.footer .links {
  display: flex;
  gap: var(--spacing-xl);
  flex-wrap: wrap;
  justify-content: center;
}

.footer .links a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--text-sm);
  letter-spacing: var(--letter-spacing-wide);
  transition: color var(--transition-fast);
}

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

/* ===================================================================
   BACK TO TOP BUTTON - Refined
   =================================================================== */

.back-to-top {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  background: rgba(17, 17, 17, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  cursor: pointer;
  transition: all var(--transition-normal);
  z-index: 1000;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  transform: translateY(20px);
  opacity: 0;
}

.back-to-top:hover {
  background: rgba(34, 197, 94, 0.15);
  border-color: rgba(34, 197, 94, 0.3);
  box-shadow: 0 15px 50px rgba(34, 197, 94, 0.2);
  color: var(--color-primary);
}

.back-to-top.visible {
  transform: translateY(0);
  opacity: 1;
}

/* ===================================================================
   RESPONSIVE DESIGN
   =================================================================== */

@media (max-width: 768px) {
  html {
    font-size: 15px;
  }
  
  .nav {
    display: none;
  }
  
  h1 {
    font-size: var(--text-4xl);
  }
  
  h2 {
    font-size: var(--text-2xl);
  }
  
  h3 {
    font-size: var(--text-xl);
  }
  
  .hero {
    padding: var(--spacing-2xl) 0;
  }
  
  .hero::before {
    display: none;
  }
  
  .subtitle {
    font-size: var(--text-lg);
    max-width: 100%;
  }
  
  .grid {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
  }
  
  .card {
    padding: var(--spacing-lg);
  }
  
  .card.hidden {
    opacity: 0;
    transform: translateY(20px);
  }
  
  .btn {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--text-base);
  }
  
  .footer {
    padding: var(--spacing-2xl) 0 var(--spacing-xl);
  }
  
  .footer .links {
    gap: var(--spacing-lg);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes glow {
  0%, 100% {
    box-shadow: 0 0 20px rgba(34, 197, 94, 0.3);
  }
  50% {
    box-shadow: 0 0 40px rgba(34, 197, 94, 0.5);
  }
}