/* ===== CSS Variables — MosAIc Brand ===== */
:root {
  --color-bg: #0b0b0f;
  --color-bg-card: #131318;
  --color-bg-card-hover: #1a1a22;
  --color-primary: #00ffc8;
  --color-primary-dim: rgba(0, 255, 200, 0.15);
  --color-primary-glow: rgba(0, 255, 200, 0.25);
  --color-accent: #2dd4a8;
  --color-text: #e8e8ec;
  --color-text-muted: #71717a;
  --color-border: #1e1e26;
  --color-border-hover: #2a2a36;
  --color-warning: #f59e0b;
  --font-main:
    "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ===== Background Effect ===== */
.bg-glow {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  overflow: hidden;
}

.bg-glow::before,
.bg-glow::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(150px);
  opacity: 0.15;
}

.bg-glow::before {
  width: 600px;
  height: 600px;
  background: var(--color-primary);
  top: -250px;
  right: -150px;
  animation: float 12s ease-in-out infinite;
}

.bg-glow::after {
  width: 500px;
  height: 500px;
  background: var(--color-accent);
  bottom: -200px;
  left: -150px;
  animation: float 15s ease-in-out infinite reverse;
}

@keyframes float {
  0%,
  100% {
    transform: translate(0, 0);
  }
  50% {
    transform: translate(20px, -20px);
  }
}

/* ===== Container ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Header ===== */
header {
  padding: 80px 0 40px;
  text-align: center;
}

.logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  font-size: 3rem;
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: 8px;
  letter-spacing: -1px;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  background: var(--color-primary);
  border-radius: 10px;
  font-size: 1.6rem;
  font-weight: 800;
  color: #0b0b0f;
  letter-spacing: 0;
  flex-shrink: 0;
}

.subtitle {
  font-size: 1.3rem;
  color: var(--color-text-muted);
  font-weight: 500;
  margin-bottom: 16px;
  font-style: italic;
}

.tagline {
  font-size: 1rem;
  color: var(--color-text-muted);
  max-width: 650px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ===== Section Title ===== */
.section-title {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--color-primary);
  margin: 48px 0 0;
}

.section-title span {
  color: var(--color-primary);
}

/* ===== Platform Tabs ===== */
.platform-tabs {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin: 48px 0 32px;
  flex-wrap: wrap;
}

.tab-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 26px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 50px;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-main);
}

.tab-btn:hover {
  background: var(--color-bg-card-hover);
  color: var(--color-text);
  border-color: var(--color-border-hover);
}

.tab-btn.active {
  border-color: var(--color-primary);
  background: var(--color-primary-dim);
  color: var(--color-primary);
}

.tab-btn svg {
  width: 20px;
  height: 20px;
}

/* ===== Install Sections ===== */
.install-sections {
  margin-bottom: 80px;
}

.install-section {
  display: none;
  animation: fadeIn 0.4s ease;
}

.install-section.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Cards ===== */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.card:hover {
  border-color: var(--color-border-hover);
  transform: translateY(-2px);
}

.card h3 {
  font-size: 1.4rem;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--color-text);
}

.card h3 .step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background: var(--color-primary);
  color: #0b0b0f;
  border-radius: 50%;
  font-size: 0.95rem;
  font-weight: 700;
  flex-shrink: 0;
}

.card h4 {
  margin-top: 24px;
  margin-bottom: 8px;
  color: var(--color-text);
  font-weight: 600;
}

.card p {
  color: var(--color-text-muted);
}

.card p strong {
  color: var(--color-text);
}

/* ===== Code Blocks ===== */
.code-block {
  background: #08080c;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 20px;
  margin: 16px 0;
  position: relative;
  overflow-x: auto;
}

.code-block code {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-primary);
  white-space: pre-wrap;
  word-break: break-all;
}

.copy-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  padding: 6px 14px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 0.8rem;
  font-family: var(--font-main);
  cursor: pointer;
  transition: var(--transition);
}

.copy-btn:hover {
  background: var(--color-primary);
  color: #0b0b0f;
  border-color: var(--color-primary);
}

/* ===== Lists ===== */
.steps-list {
  list-style: none;
  padding-left: 0;
}

.steps-list li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 12px;
  color: var(--color-text-muted);
}

.steps-list li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: bold;
}

.steps-list li strong {
  color: var(--color-text);
}

/* ===== Download Buttons ===== */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
  margin-top: 20px;
}

.download-btn {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 18px 22px;
  background: var(--color-bg-card-hover);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text);
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
}

.download-btn:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: 0 0 24px rgba(0, 255, 200, 0.1);
}

.download-btn .icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-dim);
  border-radius: 10px;
  flex-shrink: 0;
}

.download-btn .icon svg {
  width: 24px;
  height: 24px;
  fill: var(--color-primary);
}

.download-btn .info {
  flex: 1;
}

.download-btn .info .arch {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  font-weight: 400;
  margin-top: 2px;
}

.download-btn.disabled {
  opacity: 0.4;
  pointer-events: none;
  filter: grayscale(1);
  cursor: not-allowed;
  color: var(--color-text-muted);
  text-decoration: none;
  user-select: none;
}

/* ===== Notice Box ===== */
.notice {
  display: flex;
  gap: 14px;
  padding: 18px 20px;
  background: var(--color-primary-dim);
  border: 1px solid rgba(0, 255, 200, 0.2);
  border-radius: var(--radius-sm);
  margin: 20px 0;
}

.notice.warning {
  background: rgba(245, 158, 11, 0.1);
  border-color: rgba(245, 158, 11, 0.25);
}

.notice-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.notice p {
  color: var(--color-text-muted);
  font-size: 0.92rem;
}

/* ===== Footer ===== */
footer {
  text-align: center;
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
}

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

footer a:hover {
  color: var(--color-accent);
}

/* ===== Specialized Releases Section ===== */
.specialized-releases {
  display: none;
  justify-content: center;
  align-items: center;
  gap: 8px;
  margin: auto 0;
  flex-wrap: wrap;
  animation: fadeIn 0.4s ease;
  font-size: 1rem;
}

.specialized-label {
  color: var(--color-primary);
  font-weight: 600;
}

.specialized-links {
  display: inline;
}

.specialized-link {
  color: var(--color-text);
  text-decoration: underline;
  font-weight: 600;
  transition: var(--transition);
}

.specialized-link:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  header {
    padding: 60px 0 32px;
  }

  .logo {
    font-size: 2.2rem;
    gap: 10px;
  }

  .logo-icon {
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
    border-radius: 8px;
  }

  .tagline {
    font-size: 0.92rem;
  }

  .specialized-releases {
    padding: 0 20px;
  }

  .specialized-select {
    width: 100%;
  }

  .go-btn {
    width: 100%;
  }

  .card {
    padding: 24px;
  }

  .platform-tabs {
    gap: 8px;
  }

  .tab-btn {
    padding: 10px 18px;
    font-size: 0.85rem;
  }

  .download-grid {
    grid-template-columns: 1fr;
  }
}