/* ============================================================
   cocode.top — Blue-White Minimalist Theme
   Inspired by Apple / Stripe / Vercel design language
   ============================================================ */

:root {
  --color-primary: #2563EB;
  --color-primary-hover: #1D4ED8;
  --color-primary-light: #EFF6FF;
  --color-text: #1E293B;
  --color-text-secondary: #64748B;
  --color-text-tertiary: #94A3B8;
  --color-bg: #FFFFFF;
  --color-bg-subtle: #F8FAFC;
  --color-border: #E2E8F0;
  --color-border-hover: #CBD5E1;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.08);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  --header-height: 64px;
  --max-width: 1100px;
  --transition: 200ms ease;
}

/* Reset */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-hover); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }

/* ---- Header ---- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--header-height);
  background: rgba(255,255,255,0.88);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  display: flex; align-items: center; padding: 0 24px;
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  width: 100%; max-width: var(--max-width); margin: 0 auto;
}
.header-logo {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 18px; color: var(--color-text);
  text-decoration: none; flex-shrink: 0;
}
.header-logo img { width: 32px; height: 32px; border-radius: 8px; }
.header-logo span { color: var(--color-primary); }

.nav-menu { display: flex; align-items: center; gap: 4px; }
.nav-item {
  padding: 8px 16px; font-size: 14px; font-weight: 500;
  color: var(--color-text-secondary); border-radius: var(--radius-sm);
  cursor: pointer; transition: color var(--transition), background var(--transition);
  user-select: none;
}
.nav-item:hover { color: var(--color-text); background: var(--color-bg-subtle); }
.nav-item.active { color: var(--color-primary); background: var(--color-primary-light); }

.menu-toggle {
  display: none; flex-direction: column; justify-content: center; gap: 5px;
  width: 36px; height: 36px; padding: 6px; cursor: pointer;
  border: none; background: none; border-radius: var(--radius-sm);
  transition: background var(--transition);
}
.menu-toggle:hover { background: var(--color-bg-subtle); }
.menu-toggle span {
  display: block; width: 100%; height: 2px; background: var(--color-text);
  border-radius: 1px; transition: transform var(--transition), opacity var(--transition);
}

/* Mobile nav */
.mobile-nav-overlay {
  display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.3);
  z-index: 998; opacity: 0; transition: opacity 300ms ease;
}
.mobile-nav-overlay.show { opacity: 1; }
.mobile-nav {
  display: none; position: fixed; top: 0; right: -280px;
  width: 280px; height: 100%; background: var(--color-bg);
  z-index: 999; padding: 24px; transition: right 300ms ease;
  box-shadow: -4px 0 24px rgba(0,0,0,0.1);
}
.mobile-nav.show { right: 0; }
.mobile-nav-close { display: flex; justify-content: flex-end; margin-bottom: 24px; }
.mobile-nav-close button {
  width: 36px; height: 36px; border: none; background: var(--color-bg-subtle);
  border-radius: var(--radius-sm); font-size: 20px; color: var(--color-text-secondary);
  cursor: pointer; display: flex; align-items: center; justify-content: center;
}
.mobile-nav-item {
  display: block; padding: 12px 16px; font-size: 16px; font-weight: 500;
  color: var(--color-text-secondary); border-radius: var(--radius-sm);
  cursor: pointer; transition: color var(--transition), background var(--transition);
  margin-bottom: 4px;
}
.mobile-nav-item:hover { color: var(--color-text); background: var(--color-bg-subtle); }
.mobile-nav-item.active { color: var(--color-primary); background: var(--color-primary-light); }

/* ---- Main ---- */
.site-main {
  max-width: var(--max-width); margin: 0 auto;
  padding: calc(var(--header-height) + 32px) 24px 48px;
  min-height: calc(100vh - 200px);
}

/* ---- Pages (SPA) ---- */
.page { display: none; }
.page.active { display: block; animation: fadeIn 300ms ease; }
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---- Hero ---- */
.hero { text-align: center; padding: 64px 0 48px; }
.hero-logo {
  width: 80px; height: 80px; border-radius: 20px;
  margin: 0 auto 24px; box-shadow: var(--shadow-md);
}
.hero h1 {
  font-size: 40px; font-weight: 800; color: var(--color-text);
  margin-bottom: 12px; letter-spacing: -0.5px; line-height: 1.2;
}
.hero h1 span { color: var(--color-primary); }
.hero-subtitle {
  font-size: 18px; color: var(--color-text-secondary);
  max-width: 560px; margin: 0 auto 32px; line-height: 1.6;
}
.hero-cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ---- Buttons ---- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 24px; font-size: 14px; font-weight: 600;
  border-radius: var(--radius-sm); border: none; cursor: pointer;
  transition: all var(--transition); text-decoration: none; line-height: 1.5;
}
.btn-primary {
  background: var(--color-primary); color: #FFF;
  box-shadow: 0 1px 3px rgba(37,99,235,0.3);
}
.btn-primary:hover {
  background: var(--color-primary-hover); color: #FFF;
  box-shadow: 0 4px 12px rgba(37,99,235,0.35); transform: translateY(-1px);
}
.btn-secondary {
  background: var(--color-bg); color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-secondary:hover {
  background: var(--color-bg-subtle); border-color: var(--color-border-hover);
  transform: translateY(-1px);
}

/* ---- Section title ---- */
.section-title {
  font-size: 28px; font-weight: 700; color: var(--color-text);
  margin: 56px 0 8px; text-align: center; letter-spacing: -0.3px;
}
.section-title:first-child { margin-top: 0; }
.section-desc {
  font-size: 16px; color: var(--color-text-secondary);
  text-align: center; max-width: 600px; margin: 0 auto 40px;
}

/* ---- Card ---- */
.card {
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 32px;
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); border-color: var(--color-border-hover); }

/* ---- Projects ---- */
.projects-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 20px; margin: 0 0 48px;
}
.project-card {
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 28px;
  display: flex; flex-direction: column;
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}
.project-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); border-color: var(--color-border-hover); }
.project-card .card-icon {
  width: 44px; height: 44px; border-radius: 10px;
  background: var(--color-primary-light); color: var(--color-primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; margin-bottom: 16px;
}
.project-card h3 { font-size: 18px; font-weight: 700; color: var(--color-text); margin-bottom: 8px; }
.project-card p { font-size: 14px; color: var(--color-text-secondary); margin-bottom: 8px; line-height: 1.6; }
.project-card .card-meta { font-size: 13px; color: var(--color-text-tertiary); margin-bottom: 4px; }
.project-card .card-footer { margin-top: auto; padding-top: 16px; }

/* ---- About block ---- */
.about-block {
  background: var(--color-bg-subtle); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 40px; text-align: center; margin-bottom: 32px;
}
.about-block p {
  font-size: 16px; color: var(--color-text-secondary);
  max-width: 700px; margin: 0 auto 12px; line-height: 1.8;
}
.about-block .highlight-text { color: var(--color-primary); font-style: italic; margin-top: 16px; }

/* ---- Team ---- */
.team-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px; margin-bottom: 40px;
}
.team-card {
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 32px 24px; text-align: center;
  transition: box-shadow var(--transition), transform var(--transition);
}
.team-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.team-avatar {
  width: 72px; height: 72px; border-radius: 50%;
  background: var(--color-primary-light); color: var(--color-primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 28px; margin: 0 auto 16px;
}
.team-card h4 { font-size: 17px; font-weight: 700; color: var(--color-text); margin-bottom: 8px; }
.team-card p { font-size: 14px; color: var(--color-text-secondary); line-height: 1.6; }
.team-card .team-tag {
  display: inline-block; margin-top: 12px; font-size: 12px; font-weight: 600;
  color: var(--color-primary); background: var(--color-primary-light);
  padding: 4px 12px; border-radius: 20px;
}

/* ---- Callout ---- */
.callout {
  background: var(--color-bg-subtle); border-left: 3px solid var(--color-primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 24px 28px; margin: 32px 0;
}
.callout-title { font-size: 15px; font-weight: 700; color: var(--color-primary); margin-bottom: 6px; }
.callout p { color: var(--color-text-secondary); font-size: 15px; line-height: 1.7; }

/* ---- Tech list ---- */
.tech-list { margin: 20px 0 32px; padding: 0; }
.tech-list li {
  padding: 12px 0; border-bottom: 1px solid var(--color-border);
  font-size: 15px; color: var(--color-text-secondary);
  display: flex; align-items: center; gap: 12px;
}
.tech-list li:last-child { border-bottom: none; }
.tech-list li strong { color: var(--color-text); min-width: 60px; }
.tech-list li::before {
  content: ""; width: 6px; height: 6px; border-radius: 50%;
  background: var(--color-primary); flex-shrink: 0;
}

/* ---- Info grid ---- */
.info-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 16px; margin: 20px 0;
}
.info-item {
  background: var(--color-bg-subtle); border: 1px solid var(--color-border);
  border-radius: var(--radius-sm); padding: 20px;
}
.info-item strong {
  display: block; font-size: 13px; color: var(--color-text-tertiary);
  text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 6px;
}
.info-item span { font-size: 15px; color: var(--color-text); font-weight: 500; }

/* ---- Contact ---- */
.contact-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 20px; margin: 0 0 40px;
}
.contact-card {
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 32px 24px; text-align: center;
  transition: box-shadow var(--transition), transform var(--transition);
}
.contact-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.contact-icon {
  width: 48px; height: 48px; border-radius: 12px;
  background: var(--color-primary-light); color: var(--color-primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; margin: 0 auto 16px;
}
.contact-card h3 { font-size: 16px; font-weight: 700; color: var(--color-text); margin-bottom: 8px; }
.contact-card p { font-size: 14px; color: var(--color-text-secondary); line-height: 1.6; }
.contact-card .contact-note { margin-top: 12px; font-size: 13px; color: var(--color-primary); }

/* ---- Collab list ---- */
.collab-list { padding: 0; margin: 20px auto; max-width: 400px; }
.collab-list li {
  padding: 10px 0; font-size: 15px; color: var(--color-text-secondary);
  border-bottom: 1px solid var(--color-border);
  display: flex; align-items: center; gap: 10px;
}
.collab-list li:last-child { border-bottom: none; }
.collab-list li::before {
  content: ""; width: 8px; height: 8px; border-radius: 50%;
  background: var(--color-primary); flex-shrink: 0;
}

/* ---- Download ---- */
.download-hero { text-align: center; padding: 40px 0 32px; }
.download-hero .download-icon { font-size: 64px; color: var(--color-primary); margin-bottom: 20px; }
.download-hero h2 {
  font-size: 28px; font-weight: 700; color: var(--color-text);
  margin-bottom: 8px; text-align: center;
}
.download-hero p { color: var(--color-text-secondary); font-size: 16px; margin-bottom: 24px; }
.download-buttons { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-bottom: 24px; }

/* ---- Features ---- */
.features-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 20px; margin: 0 0 40px;
}
.feature-card {
  background: var(--color-bg-subtle); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 28px; text-align: center;
  transition: box-shadow var(--transition), transform var(--transition);
}
.feature-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.feature-card i { font-size: 28px; color: var(--color-primary); margin-bottom: 12px; display: block; }
.feature-card h3 { font-size: 16px; font-weight: 700; color: var(--color-text); margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--color-text-secondary); }

/* ---- Steps ---- */
.steps-list { counter-reset: step; padding: 0; margin: 20px 0; }
.steps-list li {
  counter-increment: step; padding: 14px 0 14px 48px;
  border-bottom: 1px solid var(--color-border);
  font-size: 15px; color: var(--color-text-secondary); position: relative;
}
.steps-list li:last-child { border-bottom: none; }
.steps-list li::before {
  content: counter(step); position: absolute; left: 0; top: 14px;
  width: 28px; height: 28px; border-radius: 50%;
  background: var(--color-primary); color: #fff;
  font-size: 13px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}

/* ---- Plan list ---- */
.plan-list { padding: 0; margin: 20px 0; }
.plan-list li {
  padding: 10px 0 10px 24px; font-size: 15px;
  color: var(--color-text-secondary); position: relative;
}
.plan-list li::before {
  content: "\f00c"; font-family: "Font Awesome 6 Free"; font-weight: 900;
  position: absolute; left: 0; color: var(--color-primary); font-size: 12px;
}

/* ---- Content block ---- */
.content-block { margin-bottom: 40px; }
.content-block h2 { font-size: 22px; font-weight: 700; color: var(--color-text); margin-bottom: 12px; }
.content-block p { font-size: 15px; color: var(--color-text-secondary); line-height: 1.8; margin-bottom: 8px; }

/* ---- Footer ---- */
.site-footer {
  background: var(--color-bg-subtle); border-top: 1px solid var(--color-border);
  padding: 40px 24px; margin-top: 48px;
}
.footer-inner {
  max-width: var(--max-width); margin: 0 auto;
  display: flex; justify-content: space-between;
  align-items: flex-start; gap: 40px; flex-wrap: wrap;
}
.footer-brand { max-width: 300px; }
.footer-brand h3 { font-size: 16px; font-weight: 700; color: var(--color-text); margin-bottom: 8px; }
.footer-brand p { font-size: 13px; color: var(--color-text-tertiary); line-height: 1.6; }
.footer-links h4 {
  font-size: 13px; font-weight: 700; color: var(--color-text);
  text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 12px;
}
.footer-links a {
  display: block; font-size: 14px; color: var(--color-text-secondary);
  padding: 4px 0; transition: color var(--transition);
}
.footer-links a:hover { color: var(--color-primary); }
.footer-bottom {
  max-width: var(--max-width); margin: 24px auto 0;
  padding: 20px 24px 0; border-top: 1px solid var(--color-border);
  text-align: center; font-size: 13px; color: var(--color-text-tertiary);
}

/* ---- Responsive ---- */
@media (max-width: 900px) {
  .projects-grid { grid-template-columns: 1fr; }
  .team-grid { grid-template-columns: 1fr; max-width: 400px; margin-left: auto; margin-right: auto; }
  .contact-grid { grid-template-columns: 1fr; max-width: 400px; margin-left: auto; margin-right: auto; }
  .info-grid { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr; max-width: 400px; margin-left: auto; margin-right: auto; }
  .footer-inner { flex-direction: column; gap: 24px; }
}

@media (max-width: 768px) {
  .nav-menu { display: none; }
  .menu-toggle { display: flex; }
  .mobile-nav, .mobile-nav-overlay { display: block; }
  .hero h1 { font-size: 30px; }
  .hero-subtitle { font-size: 16px; }
  .section-title { font-size: 24px; }
  .site-main { padding-left: 16px; padding-right: 16px; }
  .about-block { padding: 28px 20px; }
  .card, .project-card { padding: 24px 20px; }
  .download-buttons .btn { width: 100%; justify-content: center; }
}

@media (max-width: 480px) {
  .hero { padding: 40px 0 32px; }
  .hero h1 { font-size: 26px; }
  .hero-cta { flex-direction: column; align-items: center; }
  .hero-cta .btn { width: 100%; justify-content: center; }
}