/* Design System & Custom Properties (Blue & Gold Redesign) */
:root {
  --primary-color: HSL(215, 80%, 22%); /* Royal Blue from the skies and seas */
  --primary-light: HSL(215, 60%, 93%);
  --secondary-color: HSL(42, 85%, 55%); /* Metallic Gold from the sun rays and accents */
  --secondary-dark: HSL(42, 85%, 40%);
  --secondary-light: HSL(42, 70%, 94%);
  --text-dark: HSL(215, 40%, 15%);
  --text-muted: HSL(215, 20%, 45%);
  
  /* Gradient themes matching image.png */
  --gradient-gold: linear-gradient(135deg, var(--secondary-color), HSL(35, 90%, 45%));
  --gradient-sky: linear-gradient(180deg, HSL(205, 90%, 93%), HSL(42, 80%, 90%));
  --gradient-blue: linear-gradient(135deg, var(--primary-color), HSL(215, 90%, 12%));
  
  --bg-cream: HSL(38, 50%, 97%); /* Soft golden-cream background */
  --bg-card: rgba(255, 255, 255, 0.85);
  --glass-border: rgba(212, 163, 57, 0.25); /* Gold tinted border */
  --glass-shadow: 0 10px 40px 0 rgba(6, 49, 98, 0.06);
  
  --font-main: 'Outfit', sans-serif;
  --font-serif: 'Playfair Display', serif; /* Classic epic serif font for titles */
  --font-handwritten: 'Patrick Hand', cursive;
  
  --transition-smooth: all 0.45s cubic-bezier(0.165, 0.84, 0.44, 1);
  --border-radius-sm: 8px;
  --border-radius-md: 16px;
  --border-radius-lg: 24px;
}

/* Reset and Base Styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-cream);
  color: var(--text-dark);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

/* Decorative background accents (Bamboo leaves and clouds) */
body::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(212, 163, 57, 0.03) 0%, transparent 40%),
    radial-gradient(circle at 90% 80%, rgba(6, 49, 98, 0.03) 0%, transparent 40%);
  z-index: -2;
  pointer-events: none;
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition-smooth);
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Typography elements */
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.2;
}

.section-title {
  font-size: 2.6rem;
  text-align: center;
  color: var(--primary-color);
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  position: relative;
}

.section-subtitle {
  font-size: 1.15rem;
  text-align: center;
  color: var(--text-muted);
  max-width: 700px;
  margin: 1rem auto 0 auto;
}

/* Decorative Divider matching image.png ❖ */
.title-underline {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 15px;
  margin: 1.5rem auto 0 auto;
  width: 250px;
}

.title-underline::before,
.title-underline::after {
  content: '';
  height: 1.5px;
  background: var(--gradient-gold);
  flex-grow: 1;
}

.title-underline::after {
  background: linear-gradient(to left, var(--secondary-color), transparent);
}
.title-underline::before {
  background: linear-gradient(to right, var(--secondary-color), transparent);
}

.title-underline::before,
.title-underline::after {
  height: 1.5px;
}

.title-underline::before {
  content: '✦';
  color: var(--secondary-color);
  font-size: 1rem;
  background: none;
  flex-grow: 0;
}

.title-underline::after {
  content: '✦';
  color: var(--secondary-color);
  font-size: 1rem;
  background: none;
  flex-grow: 0;
}

.title-underline::before,
.title-underline::after {
  display: inline-block;
}

/* Base structural divider lines */
.title-divider-line {
  width: 120px;
  height: 1.5px;
  background: var(--gradient-gold);
}

.section-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 100px 24px;
}

/* Buttons and Interactivity */
.btn-primary {
  display: inline-block;
  background: var(--gradient-gold);
  color: #fff;
  padding: 14px 34px;
  border-radius: var(--border-radius-lg);
  font-weight: 600;
  font-size: 1rem;
  font-family: var(--font-main);
  box-shadow: 0 4px 15px rgba(212, 163, 57, 0.35);
  border: 1px solid var(--secondary-dark);
  cursor: pointer;
  transition: var(--transition-smooth);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 22px rgba(212, 163, 57, 0.5);
  filter: brightness(1.05);
}

.btn-secondary {
  display: inline-block;
  background: var(--bg-card);
  color: var(--primary-color);
  padding: 14px 34px;
  border-radius: var(--border-radius-lg);
  font-weight: 600;
  font-size: 1rem;
  font-family: var(--font-main);
  border: 1.5px solid var(--primary-color);
  cursor: pointer;
  transition: var(--transition-smooth);
}

.btn-secondary:hover {
  background: var(--primary-color);
  color: #fff;
  transform: translateY(-3px);
}

/* Glassmorphism utility */
.card-glass {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  border-radius: var(--border-radius-md);
  padding: 35px;
  transition: var(--transition-smooth);
}

.card-glass:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 40px rgba(6, 49, 98, 0.1);
  border-color: var(--secondary-color);
}

/* 1. Header & Navigation */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1.5px solid rgba(212, 163, 57, 0.2);
  box-shadow: 0 2px 20px rgba(6, 49, 98, 0.03);
  transition: var(--transition-smooth);
}

.site-header.scrolled {
  padding: 5px 0;
  background: rgba(255, 255, 255, 0.98);
  box-shadow: 0 4px 25px rgba(6, 49, 98, 0.08);
}

.header-container {
  max-width: 1300px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo-wrapper {
  display: flex;
  align-items: center;
  gap: 15px;
}

.logo-chuoi {
  height: 52px;
  border-radius: 50%;
  border: 1.5px solid var(--secondary-color);
  box-shadow: 0 2px 8px rgba(212, 163, 57, 0.2);
  transition: var(--transition-smooth);
}

.logo-btc-separator {
  width: 1.5px;
  height: 38px;
  background-color: rgba(212, 163, 57, 0.3);
}

.logo-btc-list {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-btc-list img {
  height: 40px;
  object-fit: contain;
  transition: var(--transition-smooth);
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.05));
}

.logo-btc-list img:hover {
  transform: scale(1.1);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 25px;
}

.nav-link-item {
  font-family: var(--font-main);
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--primary-color);
  position: relative;
  padding: 8px 0;
}

.nav-link-item::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2.5px;
  background: var(--gradient-gold);
  transition: var(--transition-smooth);
}

.nav-link-item:hover::after,
.nav-link-item.active::after {
  width: 100%;
}

.nav-link-item:hover,
.nav-link-item.active {
  color: var(--secondary-dark);
}

.cta-header-btn {
  background: var(--gradient-blue);
  color: #fff;
  padding: 10px 24px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.9rem;
  font-family: var(--font-main);
  box-shadow: 0 4px 12px rgba(6, 49, 98, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.cta-header-btn:hover {
  background: var(--gradient-gold);
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(212, 163, 57, 0.3);
}

/* Mobile Toggle Bar */
.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
  z-index: 1100;
}

.hamburger-bar {
  width: 26px;
  height: 3px;
  background-color: var(--primary-color);
  border-radius: 2px;
  transition: var(--transition-smooth);
}

/* Mobile Overlay Menu */
.mobile-menu-overlay {
  position: fixed;
  top: 0;
  right: -100%;
  width: 80%;
  max-width: 400px;
  height: 100vh;
  background-color: var(--bg-cream);
  z-index: 1050;
  box-shadow: -10px 0 35px rgba(6, 49, 98, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-smooth);
}

.mobile-menu-overlay.open {
  right: 0;
}

.mobile-nav-links {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 25px;
  width: 100%;
  padding: 40px;
}

.mobile-nav-item {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary-color);
  font-family: var(--font-serif);
}

.mobile-nav-item:hover {
  color: var(--secondary-dark);
}

.mobile-cta-btn {
  background: var(--gradient-gold);
  color: #fff;
  padding: 12px 30px;
  border-radius: 50px;
  font-weight: 600;
  width: 80%;
  text-align: center;
  box-shadow: 0 4px 12px rgba(212, 163, 57, 0.3);
}

/* 2. Hero Section (Blue & Gold Theme) */
.hero-section {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--gradient-sky); /* Resembles the soft sky background of image.png */
  padding-top: 120px;
  padding-bottom: 100px;
  z-index: 1;
  overflow: hidden;
}

/* Radiant sun rays effect behind hero content */
.hero-section::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 120%;
  height: 120%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.8) 0%, rgba(255, 255, 255, 0) 60%);
  z-index: -1;
  opacity: 0.8;
}

/* Swirling golden clouds overlay at bottom */
.hero-section::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 120px;
  background: linear-gradient(to top, var(--bg-cream) 20%, transparent);
  z-index: 2;
}

.hero-container {
  max-width: 1250px;
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
  width: 100%;
  position: relative;
  z-index: 5;
}

.hero-content {
  color: var(--primary-color);
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.6);
  border: 1px solid rgba(212, 163, 57, 0.4);
  padding: 6px 20px;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 20px;
  color: var(--primary-color);
}

.hero-tag::before, .hero-tag::after {
  content: '✦';
  color: var(--secondary-color);
}

.hero-main-title {
  font-size: 3.4rem;
  font-weight: 900;
  letter-spacing: -0.5px;
  margin-bottom: 12px;
  line-height: 1.15;
  color: var(--primary-color);
  font-family: var(--font-serif);
  text-shadow: 0 2px 4px rgba(6, 49, 98, 0.05);
}

.hero-sub-title {
  font-family: var(--font-handwritten);
  font-size: 2.2rem;
  color: var(--secondary-dark);
  margin-bottom: 30px;
  transform: rotate(-1deg);
  display: inline-block;
  font-weight: 500;
}

.hero-quotes-box {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-left: 4px solid var(--secondary-color);
  border-radius: 0 var(--border-radius-md) var(--border-radius-md) 0;
  padding: 24px;
  margin-bottom: 35px;
  box-shadow: 0 10px 30px rgba(6, 49, 98, 0.04);
}

.hero-quote-item {
  font-size: 1.1rem;
  font-weight: 500;
  margin-bottom: 12px;
  line-height: 1.6;
  color: var(--text-dark);
}

.hero-quote-item:last-child {
  margin-bottom: 0;
  font-weight: 700;
  color: var(--primary-color);
}

.hero-cta-callout {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 25px;
  color: var(--primary-color);
}

.hero-action-buttons {
  display: flex;
  gap: 20px;
}

/* Redesigned Sidebar with Image Banner from image.png */
.hero-banner-sidebar {
  display: flex;
  flex-direction: column;
  gap: 25px;
}

.hero-banner-card {
  position: relative;
  background: #fff;
  border-radius: var(--border-radius-md);
  padding: 6px;
  border: 2px solid var(--secondary-color);
  box-shadow: 0 20px 50px rgba(6, 49, 98, 0.12);
  transition: var(--transition-smooth);
}

.hero-banner-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 25px 60px rgba(212, 163, 57, 0.25);
  border-color: var(--secondary-dark);
}

.hero-banner-image {
  border-radius: calc(var(--border-radius-md) - 4px);
  width: 100%;
  display: block;
}

/* Badges list below banner */
.info-badges-container {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.info-badge-card {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(212, 163, 57, 0.2);
  border-radius: var(--border-radius-md);
  padding: 16px 20px;
  display: flex;
  gap: 15px;
  align-items: center;
  color: var(--primary-color);
  box-shadow: 0 4px 20px rgba(6, 49, 98, 0.02);
  transition: var(--transition-smooth);
}

.info-badge-card:hover {
  background: #fff;
  transform: translateX(6px);
  border-color: var(--secondary-color);
  box-shadow: 0 6px 25px rgba(212, 163, 57, 0.1);
}

.info-badge-icon {
  font-size: 2rem;
}

.info-badge-text {
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1.4;
}

.hero-wave-divider {
  display: none; /* Hide wave divider to maintain clean cloud fade */
}

/* 3. Thư Ngỏ Section (Book & Luxury Quote Card) */
.thu-ngo-section {
  background-color: var(--bg-cream);
  position: relative;
}

.thu-ngo-layout {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 40px;
  margin-top: 50px;
}

.thu-ngo-paper {
  background-color: #fff;
  border-radius: var(--border-radius-md);
  box-shadow: 0 15px 45px rgba(6, 49, 98, 0.04);
  border: 1.5px solid rgba(212, 163, 57, 0.15);
  padding: 55px 45px;
  position: relative;
}

.thu-ngo-paper::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 5px;
  background: var(--gradient-gold);
  border-radius: var(--border-radius-md) var(--border-radius-md) 0 0;
}

.decor-stamp {
  position: absolute;
  top: 35px;
  right: 45px;
  border: 2px dashed var(--secondary-color);
  color: var(--secondary-color);
  padding: 4px 10px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  transform: rotate(15deg);
  border-radius: 4px;
  opacity: 0.5;
}

.paper-content p,
.paper-content-expanded p {
  font-size: 1.05rem;
  margin-bottom: 22px;
  text-align: justify;
  color: var(--text-dark);
  line-height: 1.7;
}

.paper-content-expanded {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: all 0.65s cubic-bezier(0.165, 0.84, 0.44, 1);
}

.paper-content-expanded.open {
  max-height: 2500px;
  opacity: 1;
  margin-top: 22px;
}

.paper-actions {
  text-align: center;
  margin-top: 30px;
  border-top: 1.5px solid rgba(212, 163, 57, 0.1);
  padding-top: 30px;
}

.btn-expand-paper {
  background: none;
  border: 1.5px solid var(--primary-color);
  color: var(--primary-color);
  padding: 12px 28px;
  border-radius: 50px;
  font-weight: 600;
  font-family: var(--font-main);
  cursor: pointer;
  transition: var(--transition-smooth);
}

.btn-expand-paper:hover {
  background: var(--primary-color);
  color: #fff;
}

/* Quote Sidebar */
.thu-ngo-quote-sidebar {
  display: flex;
  align-items: center;
}

.premium-quote-card {
  background: var(--gradient-blue);
  color: #fff;
  border-radius: var(--border-radius-md);
  padding: 45px 30px;
  position: relative;
  box-shadow: 0 15px 40px rgba(6, 49, 98, 0.15);
  overflow: hidden;
  border: 1.5px solid var(--secondary-color);
}

.premium-quote-card::after {
  content: '';
  position: absolute;
  bottom: -40px;
  right: -40px;
  width: 160px;
  height: 160px;
  border-radius: 50%;
  background: rgba(212, 163, 57, 0.05);
}

.quote-icon {
  font-family: Georgia, serif;
  font-size: 5rem;
  line-height: 1;
  position: absolute;
  top: 10px;
  left: 20px;
  opacity: 0.12;
  color: var(--secondary-color);
}

.quote-text {
  font-family: var(--font-serif);
  font-size: 1.7rem;
  line-height: 1.45;
  margin-bottom: 25px;
  position: relative;
  z-index: 1;
  letter-spacing: 0.5px;
  color: var(--secondary-light);
}

.quote-divider {
  width: 50px;
  height: 2.5px;
  background: var(--gradient-gold);
  margin-bottom: 15px;
}

.quote-author {
  display: block;
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
}

.quote-author-role {
  font-size: 0.85rem;
  opacity: 0.75;
  color: var(--secondary-light);
}

/* 4. Chủ Đề Gợi Ý Section (Dark Theme with Gold Accents) */
.chu-de-section {
  position: relative;
  background-image: url('Images/BG-2.png');
  background-size: cover;
  background-position: center;
  z-index: 1;
  border-top: 2px solid var(--secondary-color);
  border-bottom: 2px solid var(--secondary-color);
}

.chu-de-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(6, 49, 98, 0.95), rgba(28, 19, 10, 0.94));
  z-index: -1;
}

.white-text h2 {
  color: #fff;
  font-family: var(--font-serif);
  font-size: 2.4rem;
}

.white-text p {
  color: var(--secondary-light);
}

.chu-de-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
  margin-top: 50px;
}

.theme-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1.5px solid rgba(212, 163, 57, 0.15);
  border-radius: var(--border-radius-md);
  padding: 35px;
  color: #fff;
  transition: var(--transition-smooth);
}

.theme-card:hover {
  transform: translateY(-8px);
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--secondary-color);
  box-shadow: 0 15px 45px rgba(212, 163, 57, 0.12);
}

.theme-card-header {
  display: flex;
  align-items: center;
  gap: 15px;
  margin-bottom: 25px;
  border-bottom: 1.5px solid rgba(212, 163, 57, 0.2);
  padding-bottom: 15px;
}

.theme-icon {
  font-size: 2rem;
  background: rgba(212, 163, 57, 0.15);
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid var(--secondary-color);
}

.theme-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--secondary-light);
  font-family: var(--font-serif);
}

.theme-prompts {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.prompt-item {
  font-size: 0.95rem;
  line-height: 1.55;
  font-weight: 300;
  position: relative;
  padding-left: 18px;
}

.prompt-item::before {
  content: '✦';
  color: var(--secondary-color);
  position: absolute;
  left: 0;
  top: 1px;
}

.prompt-item strong {
  font-weight: 700;
  color: #fff;
  display: inline;
}

.section-wave-divider {
  display: none; /* Removed wave divider for better styling alignment */
}

/* 5. Thể Lệ Section (Luxury Gold & Glass Design) */
.the-le-section {
  background-color: var(--bg-cream);
}

.the-le-layout {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
  margin-top: 50px;
}

.column-title {
  font-size: 1.4rem;
  color: var(--primary-color);
  margin-bottom: 25px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-serif);
}

.title-number {
  background: var(--gradient-gold);
  color: #fff;
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 0.95rem;
  font-weight: 700;
  font-family: var(--font-main);
  box-shadow: 0 3px 8px rgba(212, 163, 57, 0.2);
}

.styled-list li {
  font-size: 0.98rem;
  margin-bottom: 18px;
  padding-left: 28px;
  position: relative;
  line-height: 1.55;
}

.styled-list li::before {
  content: '✦';
  color: var(--secondary-color);
  font-weight: 900;
  position: absolute;
  left: 0;
  top: 1px;
}

.the-le-copyright {
  margin-top: 40px;
}

.copyright-list li::before {
  content: '🛡️';
}

/* 6. Ban Giám Khảo Section */
.bgk-section {
  background-color: var(--bg-cream);
  border-top: 1.5px solid rgba(212, 163, 57, 0.15);
}

.bgk-grid {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 30px;
  margin-top: 50px;
}

.bgk-card {
  background: #fff;
  border-radius: var(--border-radius-md);
  padding: 35px 25px;
  text-align: center;
  box-shadow: 0 10px 30px rgba(6, 49, 98, 0.03);
  border: 1.5px solid rgba(212, 163, 57, 0.15);
  transition: var(--transition-smooth);
  width: calc(33.333% - 20px);
  min-width: 280px;
  max-width: 350px;
  box-sizing: border-box;
}

.bgk-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 40px rgba(212, 163, 57, 0.15);
  border-color: var(--secondary-color);
}

.bgk-avatar {
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-light), var(--bg-cream));
  color: var(--primary-color);
  font-size: 2.2rem;
  font-weight: 700;
  font-family: var(--font-serif);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px auto;
  border: 3px solid #fff;
  box-shadow: 0 5px 15px rgba(212, 163, 57, 0.1);
}

.bgk-name {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 5px;
  font-family: var(--font-serif);
}

.bgk-role {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--secondary-dark);
  margin-bottom: 15px;
  letter-spacing: 0.5px;
}

.bgk-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.55;
}

.bgk-avatar-has-img {
  padding: 0;
  overflow: hidden;
  border: 3px solid #fff;
  background: none;
}

.bgk-avatar-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
  display: block;
}

.bgk-card.has-popup {
  cursor: zoom-in;
}

.bgk-card.has-popup:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 45px rgba(212, 163, 57, 0.2);
}

/* Modal Popup BGK */
.bgk-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.bgk-modal.open {
  opacity: 1;
  pointer-events: auto;
}

.bgk-modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(8, 25, 47, 0.85);
  backdrop-filter: blur(8px);
}

.bgk-modal-content-wrap {
  position: relative;
  z-index: 10002;
  max-width: 500px;
  width: 90%;
  background: #fff;
  border-radius: var(--border-radius-md);
  padding: 24px;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.45);
  border: 2px solid var(--secondary-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: bgkModalScaleUp 0.4s cubic-bezier(0.165, 0.84, 0.44, 1) forwards;
}

@keyframes bgkModalScaleUp {
  0% {
    transform: scale(0.85);
    opacity: 0;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

.bgk-modal-close {
  position: absolute;
  top: 12px;
  right: 16px;
  font-size: 2.2rem;
  color: var(--text-muted);
  cursor: pointer;
  line-height: 1;
  transition: var(--transition-smooth);
}

.bgk-modal-close:hover {
  color: var(--secondary-dark);
  transform: rotate(90deg);
}

.bgk-modal-img {
  width: 100%;
  max-height: 60vh;
  object-fit: cover;
  border-radius: var(--border-radius-sm);
  border: 1px solid rgba(212, 163, 57, 0.15);
  margin-bottom: 20px;
}

.bgk-modal-caption {
  text-align: center;
  width: 100%;
}

#bgk-modal-name {
  font-size: 1.5rem;
  color: var(--primary-color);
  margin-bottom: 6px;
  font-family: var(--font-serif);
}

#bgk-modal-role {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--secondary-dark);
  letter-spacing: 1px;
}

/* 7. Cơ Cấu Giải Thưởng Section */
.giai-thuong-section {
  background-color: var(--bg-cream);
  border-top: 1.5px solid rgba(212, 163, 57, 0.15);
}

.giai-thuong-layout {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 40px;
  margin-top: 50px;
}

.prizes-type-title {
  font-size: 1.35rem;
  color: var(--primary-color);
  margin-bottom: 30px;
  border-left: 4px solid var(--secondary-color);
  padding-left: 15px;
  font-family: var(--font-serif);
}

.main-prizes-list,
.extra-prizes-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.prize-rank-card {
  background: #fff;
  border-radius: var(--border-radius-md);
  padding: 22px 28px;
  display: flex;
  gap: 20px;
  align-items: center;
  box-shadow: 0 4px 15px rgba(6, 49, 98, 0.02);
  border: 1.5px solid rgba(212, 163, 57, 0.1);
  transition: var(--transition-smooth);
}

.prize-rank-card:hover {
  transform: translateX(8px);
  box-shadow: 0 10px 25px rgba(212, 163, 57, 0.15);
  border-color: var(--secondary-color);
}

/* Top 3 prizes border */
.prize-rank-card.rank-gold {
  border-left: 6px solid #FFD700;
}
.prize-rank-card.rank-silver {
  border-left: 6px solid #C0C0C0;
}
.prize-rank-card.rank-bronze {
  border-left: 6px solid #CD7F32;
}

.prize-medal {
  font-size: 2.8rem;
  min-width: 60px;
}

.prize-detail {
  flex-grow: 1;
}

.prize-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-dark);
  font-family: var(--font-serif);
}

.prize-value {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--secondary-dark);
  margin: 2px 0;
}

.prize-gift {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* Extra Prizes Cards */
.prize-extra-card {
  background: #fff;
  border-radius: var(--border-radius-md);
  padding: 20px 24px;
  border: 1.5px solid rgba(212, 163, 57, 0.1);
  box-shadow: 0 4px 15px rgba(6, 49, 98, 0.02);
  transition: var(--transition-smooth);
}

.prize-extra-card:hover {
  transform: translateX(8px);
  border-color: var(--secondary-color);
  box-shadow: 0 10px 25px rgba(212, 163, 57, 0.15);
}

.prize-extra-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary-color);
  font-family: var(--font-serif);
}

.prize-extra-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin: 5px 0 12px 0;
  line-height: 1.45;
}

.prize-extra-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1.5px solid rgba(212, 163, 57, 0.1);
  padding-top: 10px;
  font-size: 0.9rem;
}

.prize-extra-val {
  font-weight: 700;
  color: var(--secondary-dark);
}

.prize-extra-gift {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* 8. Lộ Trình Timeline Section */
.timeline-section {
  background-color: var(--bg-cream);
  border-top: 1.5px solid rgba(212, 163, 57, 0.15);
}

.timeline-wrapper {
  position: relative;
  max-width: 900px;
  margin: 50px auto 0 auto;
}

.timeline-line {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 100%;
  background: var(--secondary-light);
  border-left: 1px dashed var(--secondary-color);
}

.timeline-steps {
  display: flex;
  flex-direction: column;
  gap: 50px;
}

.timeline-node {
  display: grid;
  grid-template-columns: 1fr 60px 1fr;
  align-items: center;
  width: 100%;
}

.timeline-date-box {
  text-align: right;
  padding: 0 20px;
}

.timeline-date {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--secondary-dark);
  background: var(--secondary-light);
  border: 1.5px solid var(--secondary-color);
  padding: 6px 18px;
  border-radius: 50px;
  display: inline-block;
}

.timeline-node:nth-child(even) .timeline-date-box {
  grid-column: 3;
  text-align: left;
}

.timeline-circle {
  grid-column: 2;
  width: 24px;
  height: 24px;
  background: var(--primary-color);
  border: 4px solid var(--secondary-color);
  border-radius: 50%;
  margin: 0 auto;
  box-shadow: 0 4px 10px rgba(6, 49, 98, 0.15);
  z-index: 2;
}

.timeline-content-box {
  padding: 0 20px;
  grid-column: 3;
}

.timeline-node:nth-child(even) .timeline-content-box {
  grid-column: 1;
  text-align: right;
}

.timeline-step-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 8px;
  font-family: var(--font-serif);
}

.timeline-step-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.55;
}

/* 9. Cổng Nộp Bài Section */
.nop-bai-section {
  position: relative;
  background-color: #fff;
  border-top: 3px solid var(--secondary-color);
}

/* Section badge row */
.section-badge-row {
  display: flex;
  justify-content: center;
  margin-bottom: 24px;
}

.section-badge {
  display: inline-block;
  padding: 8px 24px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
}

.submit-badge {
  background: rgba(212, 163, 57, 0.12);
  color: var(--secondary-dark);
  border: 1.5px solid var(--secondary-color);
}

.contact-badge {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, 0.4);
}

.nop-bai-grid-layout {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 32px;
  margin-top: 40px;
  align-items: stretch;
}

.nop-bai-left-col, .nop-bai-right-col {
  display: flex;
  flex-direction: column;
}

.nop-bai-action-card, .nop-bai-guide-card {
  height: 100%;
  background: #fff;
  border: 1.5px solid rgba(212, 163, 57, 0.18);
  border-radius: var(--border-radius-md);
  padding: 40px;
  box-shadow: var(--glass-shadow);
  display: flex;
  flex-direction: column;
}

.nop-bai-action-title, .nop-bai-guide-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 20px;
  font-family: var(--font-serif);
  position: relative;
  padding-bottom: 12px;
  border-bottom: 1.5px dashed rgba(212, 163, 57, 0.25);
}

.nop-bai-action-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 30px;
}

.nop-bai-cta-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  margin-bottom: 30px;
}

.btn-nop-bai {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  background: var(--gradient-blue);
  color: #fff;
  padding: 16px 32px;
  border-radius: var(--border-radius-md);
  font-family: var(--font-main);
  text-decoration: none;
  transition: var(--transition-smooth);
  box-shadow: 0 8px 24px rgba(6, 49, 98, 0.2);
  border: none;
  width: 100%;
  justify-content: center;
}

.btn-nop-bai:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 35px rgba(6, 49, 98, 0.3);
  filter: brightness(1.15);
}

.btn-nop-bai-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.btn-nop-bai-action {
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: 0.5px;
}

.btn-nop-bai-arrow {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.nop-bai-note-text {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.nop-bai-quick-note {
  margin-top: auto;
  background: var(--secondary-light);
  border-left: 4px solid var(--secondary-color);
  padding: 16px;
  border-radius: 4px;
  font-size: 0.88rem;
  color: var(--text-dark);
  line-height: 1.5;
}

/* Right column guide styling */
.nop-bai-logo-wrapper {
  display: flex;
  justify-content: center;
  margin-bottom: 24px;
}

.nop-bai-logo-img {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid #fff;
  box-shadow: 0 5px 15px rgba(212, 163, 57, 0.2);
}

.guide-steps-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.guide-steps-list li {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.step-num {
  background: var(--gradient-gold);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 3px 8px rgba(212, 163, 57, 0.2);
  margin-top: 2px;
}

.step-text {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.55;
}

.step-text strong {
  color: var(--text-dark);
}

.step-text code {
  background: rgba(212, 163, 57, 0.1);
  color: var(--secondary-dark);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: monospace;
  font-size: 0.85rem;
  font-weight: 600;
}

/* 10. Liên Hệ / Hỏi Đáp Ban Tổ Chức Section */
.lien-he-section {
  position: relative;
  background: linear-gradient(145deg, HSL(215, 80%, 10%) 0%, HSL(215, 65%, 14%) 100%);
  border-top: 3px solid var(--secondary-color);
}

.lien-he-layout {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 40px;
  margin-top: 40px;
  align-items: stretch;
}

.lien-he-form-card {
  background: rgba(255, 255, 255, 0.05);
  border: 1.5px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius-md);
  padding: 40px;
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
  backdrop-filter: blur(10px);
}

.lien-he-form-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 25px;
  font-family: var(--font-serif);
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

/* Dark-themed form labels */
.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  width: 100%;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--border-radius-sm);
  border: 1.5px solid rgba(255, 255, 255, 0.15);
  font-family: var(--font-main);
  font-size: 0.95rem;
  color: #fff;
  background-color: rgba(255, 255, 255, 0.07);
  transition: var(--transition-smooth);
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: rgba(255, 255, 255, 0.35);
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  background-color: rgba(255, 255, 255, 0.12);
  border-color: var(--secondary-color);
  box-shadow: 0 0 0 3px rgba(212, 163, 57, 0.2);
}

.btn-contact-submit {
  display: block;
  width: 100%;
  padding: 14px;
  background: var(--gradient-gold);
  color: var(--primary-color);
  border: none;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-main);
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: var(--transition-smooth);
  box-shadow: 0 6px 20px rgba(212, 163, 57, 0.3);
}

.btn-contact-submit:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(212, 163, 57, 0.45);
  filter: brightness(1.05);
}

.form-status-msg {
  margin-top: 15px;
  padding: 12px;
  border-radius: var(--border-radius-sm);
  font-size: 0.9rem;
  text-align: center;
}

.success-msg {
  background-color: rgba(11, 41, 23, 0.2);
  color: #a3e635;
  border: 1px solid #a3e635;
}

.error-msg {
  background-color: rgba(212, 102, 38, 0.2);
  color: #f97316;
  border: 1px solid #f97316;
}

/* Info card sidebar in lien-he */
.lien-he-info-card {
  background: rgba(212, 163, 57, 0.05);
  border: 1.5px solid rgba(212, 163, 57, 0.2);
  border-radius: var(--border-radius-md);
  padding: 40px;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.lien-he-info-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--secondary-color);
  margin-bottom: 25px;
  font-family: var(--font-serif);
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(212, 163, 57, 0.15);
}

.contact-detail-items {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact-detail-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.contact-detail-icon {
  font-size: 1.3rem;
  background: rgba(255, 255, 255, 0.08);
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.12);
  flex-shrink: 0;
  color: var(--secondary-color);
}

.contact-detail-text h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 6px;
  font-family: var(--font-main);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.contact-detail-text p {
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.5;
}

.email-link {
  color: var(--secondary-color) !important;
  font-weight: 700;
  border-bottom: 1.5px solid var(--secondary-color);
}

.email-link:hover {
  color: var(--secondary-light) !important;
}

.hotline-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.hotline-list li {
  font-weight: 700;
  color: rgba(255, 255, 255, 0.85);
}

.fanpages-container {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 6px;
}

.fanpage-item-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  color: var(--secondary-color) !important;
  border-bottom: 1.5px solid var(--secondary-color);
  width: fit-content;
  font-size: 0.92rem;
}

.fanpage-item-link:hover {
  color: var(--secondary-light) !important;
}

.lien-he-divider {
  height: 1px;
  background: rgba(255, 255, 255, 0.1);
  margin: 30px 0;
}

.contact-support-note {
  margin-top: auto;
  background: rgba(255, 255, 255, 0.03);
  border-left: 4px solid var(--secondary-color);
  padding: 16px;
  border-radius: 4px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.5;
}

/* 10. Footer Section */
.site-footer {
  background-color: HSL(215, 80%, 8%);
  color: rgba(255, 255, 255, 0.85);
  padding: 60px 24px;
  border-top: 2px solid var(--secondary-color);
}

.footer-container {
  max-width: 1100px;
  margin: 0 auto;
  text-align: center;
}

.footer-slogan {
  font-size: 1.7rem;
  color: var(--secondary-color);
  margin-bottom: 15px;
  font-family: var(--font-serif);
}

.footer-quote {
  font-family: var(--font-handwritten);
  font-size: 1.7rem;
  color: rgba(255, 255, 255, 0.7);
  max-width: 700px;
  margin: 0 auto 30px auto;
  line-height: 1.4;
  font-weight: 500;
}

.footer-bottom {
  border-top: 1px solid rgba(212, 163, 57, 0.15);
  padding-top: 25px;
}

.footer-copyright {
  font-size: 0.85rem;
  opacity: 0.6;
}

/* Responsive Breakpoints */
@media (max-width: 992px) {
  html {
    font-size: 15px;
  }
  
  .hero-container {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }
  
  .hero-sub-title {
    font-size: 2rem;
  }
  
  .hero-action-buttons {
    justify-content: center;
  }
  
  .thu-ngo-layout {
    grid-template-columns: 1fr;
  }
  
  .thu-ngo-quote-sidebar {
    justify-content: center;
  }
  
  .chu-de-grid {
    grid-template-columns: 1fr;
  }
  
  .bgk-card {
    width: calc(50% - 15px);
  }
  
  .nop-bai-grid-layout {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .nop-bai-action-card, .nop-bai-guide-card,
  .lien-he-form-card, .lien-he-info-card {
    padding: 30px 24px;
  }
  
  .lien-he-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .logo-btc-separator {
    display: none;
  }
  
  .logo-btc-list {
    display: none;
  }
  
  .nav-links {
    display: none;
  }
  
  .mobile-menu-toggle {
    display: flex;
  }
  
  .mobile-menu-toggle.open .hamburger-bar:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
  }
  
  .mobile-menu-toggle.open .hamburger-bar:nth-child(2) {
    opacity: 0;
  }
  
  .mobile-menu-toggle.open .hamburger-bar:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }
  
  .bgk-card {
    width: 100%;
    max-width: 350px;
  }
  
  .the-le-layout {
    grid-template-columns: 1fr;
  }
  
  .thu-ngo-paper {
    padding: 45px 25px;
  }
  
  .decor-stamp {
    top: 20px;
    right: 25px;
  }
  
  .section-title {
    font-size: 2.1rem;
  }
}