/* ==========================================================================
   PRIVEI - DESIGN SYSTEM & STYLESHEET
   Cyber-Privacy Aesthetic | Ultra Responsive | Modern Dark Mode
   ========================================================================== */

:root {
  --color-bg: #0B0F19;
  --color-surface: #151D2A;
  --color-surface-hover: #1E293B;
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-glow: rgba(37, 211, 102, 0.25);

  --color-primary: #25D366;
  --color-primary-glow: rgba(37, 211, 102, 0.15);
  --color-secondary: #00A3DA;
  --color-accent-grad: linear-gradient(135deg, #25D366 0%, #00A3DA 100%);

  --color-text-main: #F8FAFC;
  --color-text-muted: #94A3B8;
  --color-text-dim: #64748B;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "Fira Code", "Courier New", monospace;

  --shadow-card: 0 10px 30px -5px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 25px rgba(37, 211, 102, 0.2);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text-main);
  font-family: var(--font-sans);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* --- Container & Grids --- */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text-main);
}

h1 { font-size: 3.2rem; line-height: 1.15; }
h2 { font-size: 2.2rem; line-height: 1.25; }
h3 { font-size: 1.5rem; }

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

p {
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--color-secondary);
}

/* --- Header & Navigation --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(11, 15, 25, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  padding: 16px 0;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-text-main);
}

.brand-icon {
  width: 38px;
  height: 38px;
  background: var(--color-accent-grad);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: var(--shadow-glow);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-link {
  color: var(--color-text-muted);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-link:hover, .nav-link.active {
  color: var(--color-text-main);
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* --- Buttons & Badges --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 28px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  border: none;
  transition: var(--transition);
}

.btn-primary {
  background: var(--color-accent-grad);
  color: #000;
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 35px rgba(37, 211, 102, 0.4);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text-main);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  background: var(--color-surface-hover);
  border-color: rgba(255, 255, 255, 0.2);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  background: var(--color-primary-glow);
  color: var(--color-primary);
  border: 1px solid var(--color-border-glow);
  margin-bottom: 20px;
}

/* --- Hero Section --- */
.hero {
  padding: 160px 0 100px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 60px;
  align-items: center;
}

.hero-sub {
  font-size: 1.2rem;
  margin: 24px 0 36px;
  max-width: 580px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-mockup {
  position: relative;
  display: flex;
  justify-content: center;
}

.phone-frame {
  width: 300px;
  height: 600px;
  background: var(--color-surface);
  border-radius: 40px;
  border: 8px solid #1E293B;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.8), var(--shadow-glow);
  overflow: hidden;
  position: relative;
  display: flex;
  flex-direction: column;
}

.phone-header {
  background: #0B0F19;
  padding: 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--color-border);
}

.phone-avatar {
  width: 36px;
  height: 36px;
  background: var(--color-accent-grad);
  border-radius: 50%;
}

.phone-body {
  flex: 1;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: #0B0F19;
}

.chat-bubble {
  max-width: 80%;
  padding: 10px 14px;
  border-radius: 16px;
  font-size: 0.85rem;
}

.chat-incoming {
  background: #1E293B;
  color: #FFF;
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}

.chat-outgoing {
  background: #005C4B;
  color: #FFF;
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}

/* --- Features & Cards --- */
.features {
  padding: 100px 0;
  background: rgba(15, 23, 42, 0.5);
}

.section-title {
  text-align: center;
  max-width: 650px;
  margin: 0 auto 60px;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 30px;
}

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-5px);
  border-color: var(--color-border-glow);
  box-shadow: var(--shadow-card);
}

.card-icon {
  width: 54px;
  height: 54px;
  border-radius: var(--radius-md);
  background: var(--color-primary-glow);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 24px;
}

.feature-card h3 {
  margin-bottom: 12px;
}

/* --- FAQ Accordion --- */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  padding: 20px 24px;
  background: none;
  border: none;
  color: var(--color-text-main);
  font-size: 1.1rem;
  font-weight: 600;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}

.faq-answer {
  padding: 0 24px 20px;
  display: none;
  color: var(--color-text-muted);
}

.faq-item.active .faq-answer {
  display: block;
}

/* --- Form Styles --- */
.form-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 40px;
  max-width: 600px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  font-size: 0.95rem;
}

.form-control {
  width: 100%;
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  background: #0B0F19;
  border: 1px solid var(--color-border);
  color: var(--color-text-main);
  font-size: 1rem;
  outline: none;
  transition: var(--transition);
}

.form-control:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 10px rgba(37, 211, 102, 0.2);
}

textarea.form-control {
  min-height: 130px;
  resize: vertical;
}

/* --- Footer --- */
.footer {
  background: #070A12;
  border-top: 1px solid var(--color-border);
  padding: 80px 0 40px;
  margin-top: 100px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 60px;
}

.footer-brand p {
  margin-top: 16px;
  max-width: 300px;
}

.footer-col h4 {
  font-size: 1rem;
  margin-bottom: 20px;
  color: var(--color-text-main);
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col a {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

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

.footer-bottom {
  text-align: center;
  padding-top: 40px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-dim);
  font-size: 0.9rem;
}

/* --- Responsive Breakpoints --- */
@media (max-width: 992px) {
  h1 { font-size: 2.5rem; }
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero-sub { margin: 20px auto 30px; }
  .hero-actions { justify-content: center; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--color-surface);
    flex-direction: column;
    padding: 30px;
    border-bottom: 1px solid var(--color-border);
    display: none;
  }
  .nav-menu.active { display: flex; }
  .mobile-toggle { display: block; }
  .footer-grid { grid-template-columns: 1fr; }
}