:root {
  --bg: #181a20;
  --card-bg: #232633;
  --primary: #1f6feb;
  --accent: #e2e8f0;
  --text: #e2e8f0;
  --btn-bg: #222;
  --btn-hover: #333;
}

/* Enable smooth scrolling for anchor targets and JS scrolls */
html {
  scroll-behavior: smooth;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', Arial, sans-serif;
  line-height: 1.5;
  min-height: 100vh;
}

/* Side Panel Trigger Button - Perfectly Centered Hamburger */
#side-panel-trigger {
  position: fixed;
  top: 1.25em;
  left: 1.25em;
  z-index: 1100;
  width: 48px;
  height: 48px;
  background: var(--card-bg);
  border: none;
  border-radius: 50%;
  box-shadow: 0 2px 12px rgba(0,0,0,0.3);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
}
#side-panel-trigger .hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 26px;
  height: 22px;
  gap: 5px;
}
#side-panel-trigger .hamburger span {
  display: block;
  width: 22px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

/* Side Panel Drawer */
#side-panel {
  position: fixed;
  top: 0; left: 0;
  width: 260px;
  height: 100vh;
  background: var(--card-bg);
  box-shadow: 2px 0 18px rgba(0,0,0,0.4);
  z-index: 1200;
  transform: translateX(-100%);
  transition: transform 0.3s cubic-bezier(.68,-0.55,.27,1.55);
  display: flex;
  flex-direction: column;
  padding: 1.25em 1em;
}

#side-panel.open {
  transform: translateX(0);
}

#side-panel-close {
  background: none;
  border: none;
  font-size: 2em;
  color: var(--accent);
  align-self: flex-end;
  cursor: pointer;
  margin-bottom: 1.5em;
}

#side-panel-overlay {
  position: fixed;
  top: 0; left: 0;
  width: 100vw; height: 100vh;
  background: rgba(24,26,32,0.8);
  z-index: 1199;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
}

#side-panel-overlay.visible {
  opacity: 1;
  pointer-events: all;
}

.side-nav {
  display: flex;
  flex-direction: column;
  gap: 0.6em;
}

.side-nav h3, .side-nav h4 {
  color: var(--primary);
  margin-bottom: 0.5em;
}

.side-nav-btn {
  background: var(--btn-bg);
  color: var(--accent);
  border: none;
  padding: 0.7em 1.2em;
  margin: 0.2em 0;
  font-size: 1em;
  border-radius: 1.5em;
  cursor: pointer;
  transition: all 0.22s cubic-bezier(.68,-0.55,.27,1.55);
  text-align: left;
  outline: none;
}

.side-nav-btn:hover, .side-nav-btn:focus {
  background: var(--primary);
  color: #fff;
  transform: scale(1.08);
}

a.side-nav-btn.external {
  text-decoration: none;
  display: block;
}

/* Header */
header {
  padding: 2rem 1rem 1rem 1rem;
  text-align: center;
  background: var(--card-bg);
  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
  position: relative;
  z-index: 100;
}

h1 {
  margin-bottom: 1rem;
}

/* Top Nav Buttons Group Spacing */
header nav {
  margin-top: 1rem;
  margin-bottom: 2rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75em;
}

/* Individual nav buttons */
.nav-btn {
  background: var(--btn-bg);
  color: var(--accent);
  border: none;
  padding: 0.75em 2em;
  margin: 0;
  font-size: 1em;
  border-radius: 2em;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(.68,-0.55,.27,1.55);
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
  outline: none;
}

.nav-btn:hover, .nav-btn:focus {
  background: var(--primary);
  color: #fff;
  transform: scale(1.15);
  box-shadow: 0 4px 16px rgba(31,111,235,0.3);
}

main {
  max-width: 800px;
  margin: 2rem auto;
  padding: 0 1rem;
}

/* Sections */
.feature-section, .downloads-section {
  margin-bottom: 3rem;
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s, transform 0.8s;
}

/* Fade-in effect for sections */
.section--visible {
  opacity: 1 !important;
  transform: translateY(0) !important;
}

/* Cards */
.card {
  background: var(--card-bg);
  border-radius: 1em;
  box-shadow: 0 2px 16px rgba(0,0,0,0.18);
  padding: 1.5rem;
  margin: 1rem 0;
  position: relative;
}

/* Fix for card buttons spacing */
.card .nav-btn {
  margin-top: 1em;
  display: inline-block;
}
.card .nav-btn + .nav-btn {
  margin-left: 0.5em;
}

/* Footer */
footer {
  text-align: center;
  padding: 1.5rem;
  background: var(--card-bg);
  color: var(--accent);
  margin-top: 2rem;
  font-size: 1em;
}

/* Responsive: Stack header nav buttons vertically on small screens */
@media (max-width: 600px) {
  #side-panel {
    width: 85vw;
    padding: 1em 0.5em;
  }
  main {
    padding: 0 0.5em;
  }
  header nav {
    flex-direction: column;
    align-items: center;
    gap: 0.75em;
    margin-bottom: 1.5em;
  }
  .nav-btn {
    width: 90%;
    padding: 0.7em 0;
    font-size: 1.05em;
  }
  .card {
    padding: 1em;
  }
}