/* ========== CSS Custom Properties ========== */
:root {
  --color-primary: #E97451;       /* màu chủ đạo mới */
  --color-primary-dark: #c85a3a;
  --color-primary-light: #fbe9e4;
  --color-text: #333;
  --color-text-light: #666;
  --color-bg: #fff;
  --color-bg-alt: #f7f7f7;
  --color-border: #e0e0e0;
  --color-focus: #E97451;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;
  --header-height: 64px;
  --max-width: 1280px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
  --radius: 6px;
}

/* Reset & Base */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }
.skip-link { position: absolute; top: -40px; left: 0; background: var(--color-primary); color: #fff; padding: 8px 16px; z-index: 1000; }
.skip-link:focus { top: 0; }

/* Header */
.site-header {
  position: sticky; top: 0; background: var(--color-bg);
  border-bottom: 1px solid var(--color-border); z-index: 100;
  height: var(--header-height); display: flex; align-items: center;
}
.header-container {
  display: flex; justify-content: space-between; align-items: center;
  width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 20px;
}
.logo-link { display: flex; align-items: center; gap: 8px; font-weight: 600; font-size: 1.25rem; color: var(--color-text); text-decoration: none; }
.logo-icon { width: 32px; height: 32px; }
.main-nav { display: flex; align-items: center; }
.nav-menu { list-style: none; display: flex; gap: 4px; }
.nav-link { display: block; padding: 8px 16px; border-radius: var(--radius); color: var(--color-text); position: relative; font-weight: 500; transition: background 0.2s, color 0.2s; }
.nav-link:hover { background: var(--color-primary-light); color: var(--color-primary); text-decoration: none; }
.nav-link.active { color: var(--color-primary); }
.nav-link.active::after {
  content: ''; position: absolute; bottom: -17px; left: 50%; transform: translateX(-50%);
  width: 24px; height: 3px; background: var(--color-primary); border-radius: 2px 2px 0 0;
}
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.hamburger-box { width: 24px; height: 18px; display: block; position: relative; }
.hamburger-inner { display: block; width: 100%; height: 2px; background: var(--color-text); border-radius: 2px; position: absolute; top: 50%; transform: translateY(-50%); transition: background 0.2s; }
.hamburger-inner::before, .hamburger-inner::after { content: ''; width: 100%; height: 2px; background: var(--color-text); border-radius: 2px; position: absolute; left: 0; transition: transform 0.3s; }
.hamburger-inner::before { top: -6px; }
.hamburger-inner::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .hamburger-inner { background: transparent; }
.nav-toggle[aria-expanded="true"] .hamburger-inner::before { transform: rotate(45deg); top: 0; }
.nav-toggle[aria-expanded="true"] .hamburger-inner::after { transform: rotate(-45deg); top: 0; }

/* Main layout */
.site-main {
  max-width: var(--max-width); margin: 40px auto; padding: 0 20px; min-height: 70vh;
}
.loading-indicator { text-align: center; padding: 60px 20px; color: var(--color-text-light); }

/* Grid system */
.page-grid { display: grid; gap: 40px; }
.page-grid.cols-3 { grid-template-columns: 20% 60% 20%; }
.page-grid.cols-2 { grid-template-columns: 30% 1fr; }
.page-grid.cols-1 { grid-template-columns: 1fr; }

/* Hero block (trang chủ) */
.hero-wrapper { display: flex; gap: 40px; align-items: center; }
.hero-text { flex: 0 0 30%; }
.hero-image { flex: 1; text-align: center; }
.hero-image img { max-width: 100%; height: auto; }

/* Buttons */
.btn {
  display: inline-block; padding: 12px 24px; border-radius: var(--radius);
  font-weight: 600; text-align: center; cursor: pointer; border: none;
  transition: background 0.2s, color 0.2s; margin-right: 8px;
}
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); text-decoration: none; }
.btn-secondary { background: var(--color-bg-alt); color: var(--color-text); border: 1px solid var(--color-border); }
.btn-secondary:hover { background: #e0e0e0; text-decoration: none; }

/* Cards, Sections */
.card { background: var(--color-bg); border: 1px solid var(--color-border); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow-sm); }

/* Forms */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; margin-bottom: 4px; font-weight: 500; }
.form-control {
  width: 100%; padding: 10px 12px; border: 1px solid var(--color-border);
  border-radius: var(--radius); font-family: inherit; font-size: 1rem;
}
.form-control:focus { border-color: var(--color-primary); box-shadow: 0 0 0 3px rgba(233,116,81,0.2); outline: none; }
.invalid { border-color: #d32f2f; }
.error-msg { color: #d32f2f; font-size: 0.875rem; }

/* Code block */
.code-block {
  background: #2d2d2d;
  color: #f8f8f2;
  border-radius: var(--radius);
  padding: 16px;
  position: relative;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  overflow-x: auto;
  margin: 12px 0;
}
.code-block pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
}
.code-block code {
  font-family: inherit;
}
.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.3);
  color: #fff;
  border-radius: 4px;
  padding: 4px 8px;
  font-size: 0.8rem;
  cursor: pointer;
}
.copy-btn:hover {
  background: rgba(255,255,255,0.25);
}
.doc-content code {
  background: #f0f0f0;
  padding: 2px 6px;
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.9em;
}

/* Modal */
.modal-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 1000; align-items: center; justify-content: center; }
.modal-overlay.open { display: flex; }
.modal-dialog { background: var(--color-bg); border-radius: var(--radius); box-shadow: var(--shadow-md); width: 90%; max-width: 720px; max-height: 85vh; display: flex; flex-direction: column; }
.modal-header { display: flex; justify-content: space-between; align-items: center; padding: 16px 24px; border-bottom: 1px solid var(--color-border); }
.modal-close { background: none; border: none; font-size: 1.8rem; cursor: pointer; color: var(--color-text-light); }
.modal-body { padding: 24px; overflow-y: auto; }

/* Footer */
/* .site-footer { border-top: 1px solid var(--color-border); padding: 24px 0; margin-top: 60px; background: var(--color-bg-alt); } */
/* .footer-container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; display: flex; justify-content: space-between; align-items: center; } */
/* .footer-links { display: flex; gap: 16px; align-items: center; flex-wrap: wrap; } */
/* .link-button { background: none; border: none; color: var(--color-text-light); cursor: pointer; font-size: 0.9rem; text-decoration: underline; } */
/* .link-button:hover { color: var(--color-primary); } */
/* .copyright { color: var(--color-text-light); font-size: 0.9rem; } */


/* ==================== HIGH-PROFESSIONAL OVERHAUL FOOTER ==================== */
.site-footer { 
  border-top: 1px solid var(--color-border); 
  padding: 60px 0 24px 0; 
  background: var(--color-bg-alt); 
  margin-top: 80px; 
}

.footer-container { 
  max-width: var(--max-width); 
  margin: 0 auto; 
  padding: 0 20px; 
}

.footer-grid { 
  display: grid; 
  grid-template-columns: 2fr 1fr 1.5fr; 
  gap: 40px; 
  margin-bottom: 40px; 
}

.footer-col h4 { 
  font-size: 0.95rem; 
  margin-bottom: 20px; 
  color: var(--color-text); 
  font-weight: 600; 
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.footer-logo { 
  display: flex; 
  align-items: center; 
  gap: 10px; 
  font-weight: bold; 
  font-size: 1.2rem; 
  margin-bottom: 16px; 
  color: var(--color-text); 
}

.footer-desc { 
  color: var(--color-text-light); 
  font-size: 0.9rem; 
  line-height: 1.6; 
  max-width: 420px;
}

/* Định dạng danh sách cột */
.footer-col ul { 
  list-style: none !important; 
  padding: 0 !important; 
  margin: 0 !important; 
}

.footer-col ul li { 
  margin-bottom: 12px; 
  line-height: 1.4;
}

/* KHẮC PHỤC: Triệt tiêu hoàn toàn thuộc tính thừa kế từ Header Menu lên .nav-link */
.site-footer .nav-link { 
  display: inline-block !important;
  padding: 0 !important; 
  margin: 0 !important;
  background: transparent !important;
  border: none !important;
  height: auto !important;
  line-height: inherit !important;
  color: var(--color-text-light) !important; 
  font-size: 0.9rem !important; 
  text-decoration: none !important; 
  position: static !important;
  font-weight: normal !important;
  box-shadow: none !important;
}

/* Xóa bỏ đường gạch chân tuyệt đối đổ từ Menu chính xuống */
.site-footer .nav-link::after { 
  display: none !important; 
}

.site-footer .nav-link:hover { 
  color: var(--color-primary) !important; 
  text-decoration: underline !important;
}

/* Kiểu dáng danh sách liên hệ */
.contact-list li { 
  color: var(--color-text-light); 
  font-size: 0.9rem; 
}

.contact-list li strong { 
  color: var(--color-text); 
  font-weight: 500; 
  display: inline-block;
  min-width: 140px; /* Cân bằng đều lề cho các tiêu đề liên hệ */
}

.contact-list li a {
  color: var(--color-text-light);
  text-decoration: none;
  transition: color 0.2s ease;
}

.contact-list li a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

/* Thanh đáy chân trang */
.footer-bottom { 
  display: flex; 
  justify-content: space-between; 
  align-items: center; 
  padding-top: 24px; 
  border-top: 1px solid var(--color-border); 
  flex-wrap: wrap; 
  gap: 16px; 
}

.footer-legal { 
  display: flex; 
  gap: 24px; 
  align-items: center;
}

/* KHẮC PHỤC: Biến nút EULA & Privacy Policy thành text link thuần túy siêu mịn */
.site-footer .link-button { 
  background: transparent !important; 
  border: none !important; 
  padding: 0 !important;
  margin: 0 !important;
  outline: none !important;
  box-shadow: none !important;
  border-radius: 0 !important;
  color: var(--color-text-light) !important; 
  cursor: pointer; 
  font-size: 0.9rem !important; 
  text-decoration: none !important; 
  font-family: var(--font-sans), sans-serif;
  transition: color 0.2s ease;
}

.site-footer .link-button:hover { 
  color: var(--color-primary) !important; 
  text-decoration: underline !important;
}

.site-footer .copyright { 
  color: var(--color-text-light); 
  font-size: 0.85rem; 
}

/* Responsive mượt mà cho thiết bị di động */
@media (max-width: 768px) {
  .footer-grid { 
    grid-template-columns: 1fr; 
    gap: 32px; 
    text-align: center; 
  }
  .footer-logo { 
    justify-content: center; 
  }
  .footer-desc {
    margin: 0 auto;
  }
  .contact-list li strong {
    display: block;
    margin-bottom: 4px;
  }
  .footer-bottom { 
    flex-direction: column-reverse; 
    text-align: center; 
    padding-top: 20px;
  }
  .footer-legal {
    justify-content: center;
    gap: 20px;
  }
}

/* Download blocks */
.product-block { display: flex; gap: 24px; margin-bottom: 32px; flex-wrap: wrap; }
.version-card { flex: 1; min-width: 260px; padding: 20px; border: 1px solid var(--color-border); border-radius: var(--radius); background: var(--color-bg-alt); }

/* Docs grid (dùng khi docs.json có total=1) */
.docs-grid { display: grid; grid-template-columns: 20% 60% 20%; gap: 30px; }
.doc-nav { position: sticky; top: calc(var(--header-height) + 20px); align-self: start; }
.doc-nav a { display: block; padding: 4px 0; color: var(--color-text); font-size: 0.95rem; }
.doc-nav a:hover, .doc-nav a.active { color: var(--color-primary); }
.doc-content h2 { margin-top: 40px; margin-bottom: 16px; }
.doc-content h3 { margin-top: 32px; margin-bottom: 12px; }
.doc-sidebar { position: sticky; top: calc(var(--header-height) + 20px); align-self: start; font-size: 0.9rem; color: var(--color-text-light); }
.reading-time { margin-bottom: 20px; padding: 8px; background: var(--color-bg-alt); border-radius: var(--radius); }

/* Responsive */
@media (max-width: 1024px) {
  .docs-grid { grid-template-columns: 25% 75%; }
  .doc-sidebar { display: none; }
}
@media (max-width: 768px) {
  .nav-toggle { display: block; }
  .nav-menu {
    display: none; position: absolute; top: var(--header-height); left: 0; right: 0;
    background: var(--color-bg); border-bottom: 1px solid var(--color-border);
    flex-direction: column; padding: 12px 0; box-shadow: var(--shadow-sm);
  }
  .nav-menu.open { display: flex; }
  .nav-link.active::after { bottom: 0; }
  .page-grid.cols-3, .page-grid.cols-2 { grid-template-columns: 1fr; }
  .hero-wrapper { flex-direction: column; }
  .hero-text { flex: 1; }
  .docs-grid { grid-template-columns: 1fr; }
  .doc-nav { position: static; margin-bottom: 20px; }
  .footer-container { flex-direction: column; gap: 12px; text-align: center; }
}

/* Language Switcher */
.lang-switcher {
  margin-left: auto;
  display: flex;
  align-items: center;
}
.lang-select {
  padding: 6px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 0.9rem;
  background: var(--color-bg);
  color: var(--color-text);
  cursor: pointer;
}
.lang-select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(233,116,81,0.2);
  outline: none;
}

/* ========== Progress Bar ========== */
#progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  background: var(--color-primary);
  z-index: 9999;
  transition: width 0.4s ease-out, opacity 0.3s ease;
  opacity: 0;
  pointer-events: none;
}
#progress-bar.active {
  opacity: 1;
}
#progress-bar.completed {
  width: 100%;
  opacity: 0;
  transition: width 0.4s ease-out, opacity 0.6s ease;
}