/* ============================================
   ZERO LOGIN VPN — Design System
   Depth-First Layout • Glassmorphism • Cosmic
   ============================================ */

:root {
  /* Base Backgrounds */
  --bg-idle-start: #1A1A2E;
  --bg-idle-end: #16213E;
  --bg-active-start: #003322;
  --bg-active-end: #001100;
  
  /* Primary Accents */
  --cyber-cyan: #00D2FF;
  --neon-green: #00FF88;
  --vivid-rose: #FF416C;
  --vivid-red: #FF4B2B;
  --luxury-gold: #FDC830;
  
  /* Gradients */
  --gradient-idle: linear-gradient(135deg, var(--bg-idle-start) 0%, var(--bg-idle-end) 100%);
  --gradient-active: linear-gradient(135deg, var(--bg-active-start) 0%, var(--bg-active-end) 100%);
  --gradient-connect: linear-gradient(90deg, #0066FF 0%, var(--cyber-cyan) 100%);
  --gradient-disconnect: linear-gradient(90deg, var(--vivid-rose) 0%, var(--vivid-red) 100%);
  
  /* Glass */
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.15);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  
  /* Typography */
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --letter-spacing-wide: 0.15em;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background: var(--gradient-idle);
  min-height: 100vh;
  color: #fff;
  overflow-x: hidden;
}

/* ============================================
   Navigation
   ============================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  background: rgba(26, 26, 46, 0.5);
  backdrop-filter: blur(12px);
}

.nav-brand {
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: 0.08em;
  color: #fff;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: #fff;
}

.nav-toggle-checkbox { display: none; }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: #fff;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  margin: 5px 0;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6rem 2rem 4rem;
  position: relative;
  z-index: 1;
}

.hero-content {
  text-align: center;
  max-width: 480px;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 3.5rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
  color: #fff;
}

.hero-tagline {
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.6;
  margin-bottom: 2rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 1rem 2.5rem;
  font-family: var(--font-main);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-decoration: none;
  border: none;
  border-radius: 24px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn-primary {
  background: #fff;
  color: #1A1A2E;
}

.btn-primary:hover {
  background: rgba(255, 255, 255, 0.9);
}

.btn-hero {
  padding: 0.875rem 2rem;
  font-size: 0.95rem;
  letter-spacing: 0.05em;
}

/* ============================================
   Section Styles
   ============================================ */
section {
  padding: 6rem 2rem;
  position: relative;
  z-index: 1;
}

.section-title {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: var(--letter-spacing-wide);
  text-align: center;
  margin-bottom: 0.5rem;
}

.section-subtitle {
  text-align: center;
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 3rem;
  font-size: 1rem;
}

/* ============================================
   Glass Cards - Features
   ============================================ */
.glass-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  max-width: 1000px;
  margin: 0 auto;
}

.glass-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 2rem;
  backdrop-filter: blur(20px);
  box-shadow: var(--glass-shadow);
  transition: all 0.4s ease;
}

.glass-card:hover {
  transform: translateY(-5px);
  border-color: rgba(0, 210, 255, 0.3);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

.glass-card-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.glass-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
  color: var(--cyber-cyan);
}

.glass-card p {
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.6;
  font-size: 0.95rem;
}

/* ============================================
   Visual Proof - Phone Mockup
   ============================================ */
.visual-proof {
  background: rgba(0, 0, 0, 0.2);
}

.phone-mockup {
  display: flex;
  justify-content: center;
  padding: 2rem 0;
}

.phone-frame {
  width: 280px;
  height: 560px;
  background: #1a1a2e;
  border-radius: 40px;
  padding: 12px;
  box-shadow: 
    0 0 0 3px #333,
    0 0 0 6px #1a1a2e,
    0 30px 60px rgba(0, 0, 0, 0.5),
    inset 0 0 20px rgba(0, 255, 136, 0.1);
  position: relative;
}

.phone-frame::before {
  content: '';
  position: absolute;
  top: 12px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 24px;
  background: #0a0a12;
  border-radius: 0 0 20px 20px;
  z-index: 10;
}

.phone-screen {
  width: 100%;
  height: 100%;
  background: var(--gradient-idle);
  border-radius: 28px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem 1.5rem;
  position: relative;
}

.phone-status-ring {
  position: relative;
  width: 140px;
  height: 140px;
  margin-bottom: 1rem;
}

.phone-ring-arc {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: var(--neon-green);
  border-right-color: var(--neon-green);
  animation: kinetic-ring 3s linear infinite;
}

.phone-pulse {
  position: absolute;
  inset: -15px;
  border-radius: 50%;
  border: 2px solid var(--neon-green);
  opacity: 0;
  animation: pulse-security 2s ease-out infinite;
}

.phone-lock {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
}

.phone-status-text {
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.3em;
  color: var(--neon-green);
  text-shadow: 0 0 20px rgba(0, 255, 136, 0.5);
  margin-bottom: 1.5rem;
}

.phone-stats {
  display: flex;
  gap: 1.5rem;
}

.phone-stat {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 0.5rem 1rem;
  border-radius: 12px;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.9);
}

/* ============================================
   Simplicity Section
   ============================================ */
.simplicity-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  max-width: 900px;
  margin: 0 auto;
}

.simplicity-item {
  text-align: center;
  padding: 2rem;
}

.simplicity-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--luxury-gold), #f7971e);
  border-radius: 50%;
  font-weight: 800;
  font-size: 1.2rem;
  color: #000;
  margin-bottom: 1rem;
}

.simplicity-item h3 {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
  color: #fff;
}

.simplicity-item p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* ============================================
   Download Section
   ============================================ */
.download {
  padding: 6rem 2rem;
}

.download-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  justify-content: center;
  align-items: center;
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 2rem;
  min-width: 220px;
  border-radius: 24px;
  text-decoration: none;
  transition: all 0.3s ease;
}

.btn-android {
  background: var(--gradient-connect);
  color: #fff;
  box-shadow: 0 4px 30px rgba(0, 210, 255, 0.4);
}

.btn-android:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 40px rgba(0, 210, 255, 0.5);
}

.btn-ios {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: rgba(255, 255, 255, 0.7);
}

.btn-disabled {
  cursor: not-allowed;
  opacity: 0.7;
  pointer-events: none;
}

.btn-disabled:hover {
  transform: none;
}

.download-icon {
  font-size: 2rem;
}

.download-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-align: left;
}

.download-text small {
  font-size: 0.7rem;
  opacity: 0.9;
}

.download-text strong {
  font-size: 1.1rem;
  letter-spacing: 0.05em;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  padding: 3rem 2rem;
  text-align: center;
  border-top: 1px solid var(--glass-border);
  background: rgba(0, 0, 0, 0.2);
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 1rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.3s;
}

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

.footer-copy {
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.85rem;
}

/* ============================================
   Page Layouts (FAQ, Privacy, Terms, Contact)
   ============================================ */
.page {
  min-height: 100vh;
  padding: 8rem 2rem 4rem;
  position: relative;
  z-index: 1;
}

.page-header {
  max-width: 800px;
  margin: 0 auto 3rem;
}

.page-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: var(--letter-spacing-wide);
  margin-bottom: 0.5rem;
}

.page-subtitle {
  color: rgba(255, 255, 255, 0.6);
  font-size: 1rem;
}

.page-content {
  max-width: 800px;
  margin: 0 auto;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 2.5rem;
  backdrop-filter: blur(20px);
}

.page-content h2 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--cyber-cyan);
  margin: 2rem 0 0.75rem;
  letter-spacing: 0.1em;
}

.page-content h2:first-child {
  margin-top: 0;
}

.page-content p, .page-content li {
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.8;
  margin-bottom: 1rem;
}

.page-content ul {
  margin-left: 1.5rem;
  margin-bottom: 1rem;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--cyber-cyan);
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 2rem;
  transition: opacity 0.3s;
}

.back-link:hover {
  opacity: 0.8;
}

/* FAQ (details/summary) */
.faq-list {
  margin: 0;
  padding: 0;
}

.faq-item {
  border-bottom: 1px solid var(--glass-border);
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-question {
  padding: 1.25rem 0;
  color: #fff;
  font-family: var(--font-main);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  transition: color 0.3s;
}

.faq-question::-webkit-details-marker { display: none; }

.faq-question::after {
  content: '+';
  float: right;
  font-size: 1.5rem;
  color: var(--cyber-cyan);
}

.faq-item[open] .faq-question::after {
  content: '−';
}

.faq-question:hover {
  color: var(--cyber-cyan);
}

.faq-answer-inner {
  padding: 0 0 1.25rem;
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.7;
}

/* Contact Form */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.contact-form label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: rgba(255, 255, 255, 0.9);
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  color: #fff;
  font-family: var(--font-main);
  font-size: 1rem;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: rgba(255, 255, 255, 0.4);
}

.contact-form textarea {
  min-height: 150px;
  resize: vertical;
}

.contact-form .btn {
  align-self: flex-start;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .nav-toggle {
    display: block;
  }

  .nav-toggle-checkbox:checked ~ .nav-links {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(26, 26, 46, 0.95);
    padding: 1rem;
  }

  .hero {
    padding: 6rem 1.5rem 3rem;
  }

  .status-ring-container {
    width: 160px;
    height: 160px;
  }

  .status-core {
    inset: 40px;
  }

  .lock-icon {
    width: 36px;
    height: 36px;
  }

  .phone-frame {
    width: 240px;
    height: 480px;
  }

  .download-buttons {
    flex-direction: column;
  }

  .btn-download {
    width: 100%;
    max-width: 280px;
  }
}