/* ==========================================================================
   Style System: Vietnamese Localized Theme (Crimson & Gold)
   Font: Be Vietnam Pro
   ========================================================================== */

:root {
  --color-bg-main: #0d1117;
  --color-bg-card: #161b22;
  --color-bg-card-hover: #21262d;
  --color-bg-nav: #090d12;
  
  --color-primary-red: #d32f2f;
  --color-dark-red: #8b0000;
  --color-bright-red: #e53935;
  
  --color-gold: #ffd700;
  --color-gold-hover: #ffc107;

  --color-text-main: #f0f6fc;
  --color-text-muted: #8b949e;
  --color-border: #30363d;

  --font-main: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, sans-serif;
  --max-width: 1200px;
  --header-height: 70px;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-main);
  background-color: var(--color-bg-main);
  color: var(--color-text-main);
  line-height: 1.7;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding-bottom: 60px;
}

@media (min-width: 768px) {
  body { padding-bottom: 0; }
}

a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.text-gold { color: var(--color-gold); }
.text-red { color: var(--color-bright-red); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: 6px;
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.25s ease;
  border: none;
  text-transform: uppercase;
}

.btn-gold {
  background: linear-gradient(135deg, var(--color-gold) 0%, var(--color-gold-hover) 100%);
  color: #000;
  box-shadow: 0 4px 15px rgba(255, 215, 0, 0.2);
}

.btn-gold:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 215, 0, 0.35);
}

.btn-red {
  background: linear-gradient(135deg, var(--color-bright-red) 0%, var(--color-dark-red) 100%);
  color: #fff;
  border: 1px solid rgba(255, 215, 0, 0.3);
}

.btn-red:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(211, 47, 47, 0.5);
}

.btn-outline {
  background: transparent;
  color: var(--color-gold);
  border: 1px solid var(--color-gold);
}

.btn-outline:hover {
  background: rgba(255, 215, 0, 0.1);
  color: #fff;
}

/* Header & Nav */
.header-main {
  background-color: var(--color-bg-nav);
  border-bottom: 2px solid var(--color-dark-red);
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--header-height);
  display: flex;
  align-items: center;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--color-gold);
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-badge {
  background-color: var(--color-primary-red);
  color: #fff;
  font-size: 0.7rem;
  padding: 2px 6px;
  border-radius: 4px;
}

.nav-desktop { display: none; }
.nav-list { display: flex; gap: 25px; }

.nav-link {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-text-main);
  transition: color 0.2s;
  padding: 5px 0;
  position: relative;
}

.nav-link:hover, .nav-link.active { color: var(--color-gold); }
.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-gold);
}

.header-actions { display: none; gap: 12px; }

.mobile-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
}

.mobile-toggle span {
  width: 24px;
  height: 2px;
  background-color: var(--color-text-main);
}

@media (min-width: 992px) {
  .nav-desktop { display: block; }
  .header-actions { display: flex; }
  .mobile-toggle { display: none; }
}

/* Mobile Drawer */
.mobile-drawer {
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 100%;
  height: calc(100vh - var(--header-height));
  background-color: var(--color-bg-nav);
  padding: 30px 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  transform: translateX(-100%);
  transition: transform 0.3s ease;
  z-index: 999;
  border-top: 1px solid var(--color-border);
}

.mobile-drawer.open { transform: translateX(0); }
.mobile-nav-list { display: flex; flex-direction: column; gap: 15px; }
.mobile-nav-link { font-size: 1.1rem; font-weight: 600; padding: 10px 0; border-bottom: 1px solid var(--color-border); }

/* Mobile Bottom Bar */
.mobile-bottom-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 60px;
  background-color: var(--color-bg-nav);
  border-top: 1px solid var(--color-dark-red);
  display: flex;
  z-index: 1000;
}

.mobile-bottom-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
}

.mobile-bottom-btn.login { color: var(--color-gold); border-right: 1px solid var(--color-border); }
.mobile-bottom-btn.register { background: linear-gradient(135deg, var(--color-bright-red) 0%, var(--color-dark-red) 100%); color: #fff; }

@media (min-width: 768px) {
  .mobile-bottom-bar { display: none; }
}

/* Content Elements */
.hero-banner {
  background: linear-gradient(180deg, rgba(139, 0, 0, 0.4) 0%, var(--color-bg-main) 100%);
  padding: 60px 0 40px 0;
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.hero-title {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-gold);
  margin-bottom: 15px;
  line-height: 1.3;
}

.hero-subtitle {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  max-width: 1000px;
  margin: 0 auto 25px auto;
}

.hero-cta-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
  justify-content: center;
  max-width: 400px;
  margin: 0 auto;
}

@media (min-width: 576px) {
  .hero-cta-group { flex-direction: row; max-width: 100%; }
}

@media (min-width: 768px) {
  .hero-banner { padding: 80px 0 60px 0; }
  .hero-title { font-size:2.8rem; }
}

.content-section { padding: 50px 0; }
.content-section article img{display: block;margin:20px auto;}

.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-gold);
  margin-bottom: 20px;
  position: relative;
  padding-left: 15px;
}

.section-title::before {
  content: '';
  position: absolute;
  left: 0;
  top: 15%;
  height: 70%;
  width: 4px;
  background-color: var(--color-primary-red);
}

.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 25px;
}

@media (min-width: 768px) { .card-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 992px) { .card-grid { grid-template-columns: repeat(3, 1fr); } }

.feature-card {
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 25px;
  transition: transform 0.25s, border-color 0.25s;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-gold);
}

.feature-icon { font-size: 2.2rem; margin-bottom: 15px; }
.feature-title { font-size: 1.25rem; font-weight: 700; color: #fff; margin-bottom: 10px; }
.feature-desc { color: var(--color-text-muted); font-size: 0.95rem; line-height: 1.6; }

/* Tables */
.custom-table-container {
  overflow-x: auto;
  margin: 25px 0;
  border-radius: 8px;
  border: 1px solid var(--color-border);
}

.custom-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}

.custom-table th {
  background-color: var(--color-bg-nav);
  color: var(--color-gold);
  padding: 14px 18px;
  border-bottom: 2px solid var(--color-dark-red);
  font-weight: 700;
}

.custom-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-muted);
  background-color: var(--color-bg-card);
}

.custom-table tr:last-child td { border-bottom: none; }

/* FAQ Component */
.faq-list { display: flex; flex-direction: column; gap: 12px; margin-top: 20px; }
.faq-item { background-color: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: 6px; overflow: hidden; }

.faq-header {
  width: 100%;
  padding: 18px 20px;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.05rem;
  font-weight: 600;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-family: var(--font-main);
}

.faq-icon { font-size: 1.2rem; color: var(--color-gold); transition: transform 0.3s; }
.faq-item.active .faq-icon { transform: rotate(45deg); }

.faq-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  background-color: rgba(0, 0, 0, 0.2);
}

.faq-item.active .faq-content { max-height: 300px; padding: 0 20px 18px 20px; }
.faq-text { color: var(--color-text-muted); font-size: 0.95rem; line-height: 1.7; }

/* Footer */
.footer-main {
  background-color: #05070a;
  border-top: 1px solid var(--color-border);
  padding: 50px 0 20px 0;
  margin-top: auto;
}

.footer-grid { display: grid; grid-template-columns: 1fr; gap: 30px; margin-bottom: 40px; }
@media (min-width: 768px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }

.footer-brand p { color: var(--color-text-muted); font-size: 0.9rem; margin-top: 12px; max-width: 450px; }
.footer-title { font-size: 1.1rem; font-weight: 700; color: var(--color-gold); margin-bottom: 15px; }
.footer-links { display: flex; flex-direction: column; gap: 10px; }
.footer-links a { color: var(--color-text-muted); font-size: 0.9rem; }
.footer-links a:hover { color: var(--color-gold); }

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--color-text-muted);
  font-size: 0.85rem;
}