/*
 * Dubble - Main Stylesheet
 * Modern CSS with Grid/Flexbox, Mobile-First
 */

/* ================================
   Custom Properties
   ================================ */
:root {
  --color-bg: #000;
  --color-text: #333;
  --color-text-light: #999;
  --color-heading: #000;
  --color-link: #000;
  --color-link-visited: #000;
  --color-accent: #66ccff;
  --color-white: #fff;

  --font-body: Verdana, system-ui, -apple-system, sans-serif;
  --font-heading: 'Trebuchet MS', Trebuchet, Arial, sans-serif;

  --line-height: 1.6;
  --border-radius: 7px;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
}

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

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-body);
  font-size: clamp(0.78rem, 2.19vw, 0.875rem);
  line-height: var(--line-height);
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image: url(../imgs/background.jpg);
  background-repeat: repeat-y;
  background-position: top center;
  background-size: 100% auto;
}

img {
  max-width: 100%;
  height: auto;
  border: 0;
}

ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

p {
  margin: 0 0 var(--space-sm) 0;
}

/* ================================
   Typography
   ================================ */
h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3.75vw, 2rem);
  font-weight: bold;
  color: var(--color-heading);
  margin: 0 0 var(--space-xs) 0;
}

h2 {
  font-family: var(--font-heading);
  font-size: clamp(0.875rem, 2.19vw, 1.0625rem);
  font-weight: bold;
  color: var(--color-heading);
  margin: 0 0 var(--space-xs) 0;
}

h3 {
  font-family: var(--font-heading);
  font-size: clamp(0.78rem, 1.75vw, 0.875rem);
  font-weight: bold;
  color: var(--color-heading);
  margin: 0 0 var(--space-xs) 0;
}

/* ================================
   Links
   ================================ */
a {
  color: var(--color-link);
  text-decoration: none;
  transition: color 0.2s ease, background-color 0.2s ease;
}

a:visited {
  color: var(--color-link-visited);
  text-decoration: line-through;
}

a:hover,
a:focus {
  color: var(--color-white);
  background-color: var(--color-accent);
  outline: none;
}

a:active {
  color: var(--color-link);
}

/* ================================
   Layout
   ================================ */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: var(--space-md);
}

/* ================================
   Header / Logo
   ================================ */
.logo {
  margin-bottom: var(--space-lg);
}

.logo img {
  display: block;
  max-width: 30%;
  height: auto;
}

/* ================================
   Sections
   ================================ */
section {
  background-image: url(../imgs/transparent.png);
  border-radius: var(--border-radius);
  padding: var(--space-sm);
  margin-bottom: var(--space-md);
}

/* ================================
   About
   ================================ */
.about ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  margin-top: var(--space-xs);
  list-style: disc inside;
}

/* ================================
   Hero
   ================================ */
.hero-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-sm);
}

.hero-header h1 {
  margin: 0;
}

.hero-logo {
  display: block;
  height: auto;
  max-width: 100%;
}

.app-icon {
  width: 80px;
  height: 80px;
  border-radius: 18px;
  flex-shrink: 0;
}

.hero .tagline {
  font-family: var(--font-heading);
  font-size: clamp(0.9375rem, 2.25vw, 1.125rem);
  color: var(--color-heading);
  margin-bottom: var(--space-sm);
}

.hero p {
  margin-bottom: var(--space-xs);
}

.hero .platforms {
  color: var(--color-text-light);
  margin-top: var(--space-sm);
}

.hero-screenshot {
  margin-top: var(--space-md);
}

.hero-screenshot img {
  display: block;
  width: 90%;
  margin: 0 auto;
  border-radius: var(--border-radius);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

/* ================================
   Features Grid
   ================================ */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  margin-top: var(--space-sm);
}

.features-column p {
  margin-bottom: 0;
}

.features-column ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.features-column li {
  margin: 0;
}

/* ================================
   Specs Grid
   ================================ */
.specs-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-sm);
  margin-top: var(--space-sm);
}

.specs-item p {
  margin-bottom: 0;
}

/* ================================
   Privacy Callout
   ================================ */
.privacy-callout h2 {
  font-size: clamp(0.875rem, 2.19vw, 1.0625rem);
}

.privacy-callout p {
  margin-bottom: 0;
}

/* ================================
   Download CTA
   ================================ */
.cta {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  background-color: var(--color-heading);
  color: var(--color-white);
  border-radius: var(--border-radius);
  font-family: var(--font-heading);
  font-size: clamp(0.78rem, 1.75vw, 0.875rem);
  margin-top: var(--space-sm);
}

.cta:visited {
  color: var(--color-white);
  text-decoration: none;
}

.cta:hover,
.cta:focus {
  background-color: var(--color-accent);
  color: var(--color-white);
}

/* ================================
   Privacy Policy Page
   ================================ */
.policy h3 {
  margin-top: var(--space-md);
}

.policy-meta {
  color: var(--color-text-light);
}

/* ================================
   Footer
   ================================ */
footer {
  background-image: url(../imgs/transparent.png);
  border-radius: var(--border-radius);
  padding: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

.footer-column p {
  margin-bottom: var(--space-xs);
}

.footer-column p:last-child {
  margin-bottom: 0;
}

.copyright {
  color: var(--color-text-light);
}

/* ================================
   Media Queries - Tablet (600px+)
   ================================ */
@media (min-width: 600px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .specs-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .footer-content {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ================================
   Media Queries - Desktop (900px+)
   ================================ */
@media (min-width: 900px) {
  .container {
    padding: var(--space-lg);
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .app-icon {
    width: 100px;
    height: 100px;
    border-radius: 22px;
  }
}

/* ================================
   Accessibility
   ================================ */
@media (prefers-reduced-motion: reduce) {
  a {
    transition: none;
  }
}

/* Focus visible for keyboard navigation */
a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}