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

:root {
  --bg: #f0f2f5;
  --bg-card: #ffffff;
  --text: #1a1a2e;
  --text-secondary: #4a4a6a;
  --primary: #1a1a2e;
  --accent: #ffd700;
  --accent-hover: #e6c200;
  --glass: rgba(255, 255, 255, 0.7);
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  --radius: 16px;
  --radius-sm: 12px;
  --gradient: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  --transition-speed: 0.3s;
}

body.dark {
  --bg: #0d0d1a;
  --bg-card: #1a1a2e;
  --text: #e0e0e0;
  --text-secondary: #a0a0c0;
  --glass: rgba(26, 26, 46, 0.85);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background var(--transition-speed), color var(--transition-speed);
  overflow-x: hidden;
}

/* ===== Container ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: 50px;
  background: var(--accent);
  color: var(--primary);
  font-weight: 600;
  text-decoration: none;
  transition: transform var(--transition-speed), box-shadow var(--transition-speed);
  border: none;
  cursor: pointer;
  font-size: 1rem;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(255, 215, 0, 0.3);
}

/* ===== Sections ===== */
.section {
  padding: 80px 0;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 12px;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
}

.section-sub {
  text-align: center;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 48px;
  font-size: 1.1rem;
}

/* ===== Cards ===== */
.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
  transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.15);
}

/* ===== Grids ===== */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 32px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
}

/* ===== Utilities ===== */
.text-center {
  text-align: center;
}

.mt-16 { margin-top: 16px; }
.mt-32 { margin-top: 32px; }
.mb-16 { margin-bottom: 16px; }
.mb-32 { margin-bottom: 32px; }

/* ===== Fade In Animation ===== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Glass Effect ===== */
.glass {
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
}

/* ===== Dark Mode Toggle ===== */
.dark-toggle {
  position: fixed;
  bottom: 30px;
  right: 30px;
  z-index: 1000;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--accent);
  border: none;
  font-size: 24px;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  transition: transform var(--transition-speed);
  display: flex;
  align-items: center;
  justify-content: center;
}

.dark-toggle:hover {
  transform: scale(1.1);
}

/* ===== Back to Top ===== */
.back-top {
  position: fixed;
  bottom: 100px;
  right: 30px;
  z-index: 1000;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--primary);
  border: none;
  font-size: 24px;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  transition: transform var(--transition-speed);
  display: none;
  align-items: center;
  justify-content: center;
}

.back-top.show {
  display: flex;
}

.back-top:hover {
  transform: scale(1.1);
}

/* ===== Navbar ===== */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 999;
  padding: 16px 0;
  transition: background var(--transition-speed), box-shadow var(--transition-speed);
}

.navbar.scrolled {
  background: var(--glass);
  backdrop-filter: blur(16px);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--accent);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition-speed);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition-speed);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-links a:hover {
  color: var(--accent);
}

.mobile-menu {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 28px;
  cursor: pointer;
}

/* ===== Hero Section ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient);
  position: relative;
  overflow: hidden;
  text-align: center;
  color: #fff;
}

.hero::before {
  content: '';
  position: absolute;
  width: 600px;
  height: 600px;
  background: rgba(255, 215, 0, 0.08);
  border-radius: 50%;
  top: -200px;
  right: -200px;
  animation: float 8s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  width: 400px;
  height: 400px;
  background: rgba(255, 215, 0, 0.05);
  border-radius: 50%;
  bottom: -100px;
  left: -100px;
  animation: float 10s ease-in-out infinite reverse;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(30px, -30px); }
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  padding: 20px;
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 20px;
  line-height: 1.2;
}

.hero h1 span {
  color: var(--accent);
}

.hero p {
  font-size: 1.2rem;
  margin-bottom: 32px;
  opacity: 0.9;
}

.hero .btn {
  font-size: 1.1rem;
  padding: 16px 40px;
}

/* ===== Banner Carousel ===== */
.banner {
  position: relative;
  height: 500px;
  overflow: hidden;
  border-radius: var(--radius);
  margin: 40px 0;
}

.banner-slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  color: #fff;
  text-align: center;
  padding: 40px;
  opacity: 0;
  transition: opacity 0.8s ease;
  background: var(--gradient);
}

.banner-slide.active {
  opacity: 1;
}

.banner-slide h2 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 16px;
}

.banner-slide p {
  font-size: 1.1rem;
  max-width: 600px;
  opacity: 0.9;
}

.banner-dots {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 12px;
  z-index: 2;
}

.banner-dots span {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  cursor: pointer;
  transition: background var(--transition-speed);
}

.banner-dots span.active {
  background: var(--accent);
}

/* ===== Stats Grid ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 24px;
  margin: 40px 0;
}

.stat-card {
  text-align: center;
  padding: 32px 16px;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform var(--transition-speed);
}

.stat-card:hover {
  transform: translateY(-4px);
}

.stat-number {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--accent);
  margin-bottom: 4px;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* ===== Article Card ===== */
.article-card {
  padding: 24px;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform var(--transition-speed);
}

.article-card:hover {
  transform: translateY(-4px);
}

.article-card h3 {
  font-size: 1.2rem;
  margin-bottom: 8px;
  color: var(--text);
}

.article-card .date {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.article-card p {
  color: var(--text-secondary);
  margin-bottom: 16px;
  font-size: 0.95rem;
}

/* ===== FAQ Accordion ===== */
.faq-item {
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  padding: 16px 0;
  cursor: pointer;
}

.faq-question {
  font-weight: 600;
  font-size: 1.05rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text);
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  transition: transform var(--transition-speed);
  color: var(--accent);
}

.faq-item.open .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s;
  color: var(--text-secondary);
  padding: 0 16px 0 0;
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding-top: 12px;
}

/* ===== HowTo Steps ===== */
.howto-step {
  display: flex;
  gap: 20px;
  margin-bottom: 24px;
  align-items: flex-start;
}

.howto-step .step-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  flex-shrink: 0;
}

.howto-step h4 {
  font-size: 1.1rem;
  margin-bottom: 4px;
}

.howto-step p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ===== Footer ===== */
.footer {
  background: var(--primary);
  color: #ccc;
  padding: 60px 0 30px;
  margin-top: 80px;
}

.footer .container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
}

.footer h4 {
  color: #fff;
  margin-bottom: 16px;
  font-size: 1.1rem;
}

.footer a {
  color: #aaa;
  text-decoration: none;
  display: block;
  margin-bottom: 8px;
  transition: color var(--transition-speed);
}

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

.footer .copyright {
  text-align: center;
  padding-top: 30px;
  margin-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.9rem;
  grid-column: 1 / -1;
}

/* ===== QR Code Placeholder ===== */
.qr-code {
  width: 120px;
  height: 120px;
  background: var(--accent);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  color: var(--primary);
  text-align: center;
  margin-top: 8px;
}

/* ===== Search Box ===== */
.search-box {
  display: flex;
  gap: 8px;
  max-width: 400px;
  margin: 0 auto 40px;
}

.search-box input {
  flex: 1;
  padding: 12px 20px;
  border-radius: 50px;
  border: 2px solid rgba(255, 215, 0, 0.3);
  background: var(--bg-card);
  color: var(--text);
  outline: none;
  transition: border var(--transition-speed);
}

.search-box input:focus {
  border-color: var(--accent);
}

.search-box button {
  padding: 12px 24px;
  border-radius: 50px;
  background: var(--accent);
  color: var(--primary);
  border: none;
  font-weight: 600;
  cursor: pointer;
}

.search-results {
  margin-top: 20px;
  display: none;
}

.search-results.show {
  display: block;
}

.search-results .result-item {
  padding: 12px 0;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.search-results .result-item h4 {
  margin-bottom: 4px;
}

.search-results .result-item p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* ===== Responsive: Tablet & Mobile ===== */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.2rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.6rem;
  }

  .banner {
    height: 350px;
  }

  .banner-slide h2 {
    font-size: 1.6rem;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    background: var(--glass);
    backdrop-filter: blur(16px);
    flex-direction: column;
    padding: 20px;
    border-radius: 0 0 var(--radius) var(--radius);
  }

  .nav-links.open {
    display: flex;
  }

  .mobile-menu {
    display: block;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer .container {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.8rem;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

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

  .footer .container {
    grid-template-columns: 1fr;
  }
}