:root {
  --primary-color: #017439; /* Màu chủ đạo */
  --primary-dark: #005c2e;
  --primary-light: #e8f5e9;
  --accent-color: #FFFFFF;
  --register-color: #C30808;
  --login-color: #C30808;
  --button-text-color: #FFFF00;
  --text-dark: #212121;
  --text-light: #FFFFFF;
  --header-offset: 122px; /* Chiều cao header với header-top 68px + main-nav 52px + 2px */
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
}

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

body {
  font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--accent-color);
  padding-top: var(--header-offset);
  overflow-x: hidden;
}

/* ===== HEADER ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
  min-height: auto;
}

/* Header Top */
.header-top {
  background-color: var(--primary-dark);
  width: 100%;
  padding: 10px 0;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-left: 20px;
  padding-right: 20px;
}

.logo {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: #FFFF00;
  text-decoration: none;
  letter-spacing: 1px;
  line-height: 1.4;
}

.logo:hover {
  color: #FFFF00;
}

/* Desktop Buttons */
.desktop-nav-buttons {
  display: flex;
  gap: 10px;
  align-items: center;
}

.btn {
  display: inline-block;
  padding: 8px 22px;
  font-size: 14px;
  font-weight: 700;
  border-radius: 4px;
  text-decoration: none !important;
  text-align: center;
  transition: all 0.3s ease;
  line-height: 1.5;
  cursor: pointer;
  border: none;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.btn-login {
  background-color: var(--login-color);
  color: var(--button-text-color);
}

.btn-login:hover {
  background-color: #a30707;
  color: var(--button-text-color);
}

.btn-register {
  background-color: var(--register-color);
  color: var(--button-text-color);
}

.btn-register:hover {
  background-color: #a30707;
  color: var(--button-text-color);
}

/* Main Nav */
.main-nav {
  background-color: var(--primary-color);
  width: 100%;
  display: flex;
  flex-direction: row;
  position: static;
  align-items: center;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  padding: 4px 20px;
  width: 100%;
}

.nav-link {
  display: block;
  color: var(--text-light);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 4px;
  transition: background-color 0.2s;
  white-space: nowrap;
}

.nav-link:hover {
  background-color: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

/* Mobile elements hidden on desktop */
.hamburger-menu,
.mobile-menu-overlay,
.mobile-nav-buttons {
  display: none;
}

/* ===== FOOTER ===== */
.site-footer {
  background-color: #1a1a1a;
  color: #cccccc;
  margin-top: 60px;
  font-size: 14px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 40px;
  padding: 40px 20px;
}

.footer-brand {
  text-align: left;
}

.footer-logo {
  font-size: 26px;
  font-weight: 800;
  color: #FFFF00;
  text-decoration: none;
  display: inline-block;
  margin-bottom: 12px;
}

.footer-logo:hover {
  color: #FFFF00;
}

.footer-description {
  margin: 12px 0;
  color: #999999;
  line-height: 1.6;
}

.footer-buttons {
  display: flex;
  gap: 10px;
  margin-top: 15px;
}

.footer-buttons .btn {
  padding: 6px 16px;
  font-size: 13px;
}

.footer-title {
  color: #ffffff;
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 18px;
  position: relative;
  padding-bottom: 10px;
}

.footer-title::after {
  content: '';
  display: block;
  width: 40px;
  height: 2px;
  background-color: var(--register-color);
  margin-top: 8px;
}

.footer-nav {
  display: flex;
  flex-direction: column;
}

.footer-nav a {
  color: #999999;
  text-decoration: none;
  margin-bottom: 10px;
  transition: color 0.3s, padding-left 0.3s;
}

.footer-nav a:hover {
  color: #ffffff;
  padding-left: 5px;
}

.footer-bottom {
  background-color: #111111;
  padding: 18px 20px;
  text-align: center;
  border-top: 1px solid #333333;
}

.copyright {
  color: #888888;
  margin: 0;
  font-size: 13px;
}

.footer-license {
  color: #555555;
  font-size: 12px;
  margin: 6px 0 0;
}

/* ===== Mobile Menu ===== */
@media (max-width: 768px) {
  :root {
    --header-offset: 110px; /* 60px header-top + 48px mobile-nav-buttons + 2px */
  }

  body {
    overflow-x: hidden !important;
  }

  .site-header {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  }

  .header-top {
    padding: 6px 0;
    min-height: 60px;
  }

  .header-container {
    width: 100%;
    max-width: none;
    padding-left: 15px;
    padding-right: 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
  }

  .logo {
    display: block;
    font-size: 24px;
    order: 1;
    flex: 1;
    text-align: center;
  }

  /* Hide desktop buttons, show mobile nav buttons */
  .desktop-nav-buttons {
    display: none;
  }

  .mobile-nav-buttons {
    display: flex;
    background-color: var(--primary-dark);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
    justify-content: center;
    gap: 6px;
    padding: 4px 10px;
    z-index: 1000;
    position: relative;
  }

  .mobile-nav-buttons .btn {
    padding: 6px 14px;
    font-size: 13px;
    font-weight: 700;
    border-radius: 4px;
    min-height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex: 1;
    max-width: 170px;
  }

  .mobile-nav-buttons .btn-login,
  .mobile-nav-buttons .btn-register {
    margin: 4px 0;
  }

  /* Hamburger menu - first in DOM order with flex */
  .hamburger-menu {
    display: block;
    cursor: pointer;
    width: 35px;
    height: 30px;
    position: relative;
    z-index: 1100;
    order: 0;
    flex: 0 0 auto;
  }

  .hamburger-menu span {
    display: block;
    position: absolute;
    left: 3px;
    right: 3px;
    height: 3px;
    background-color: #FFFFFF;
    border-radius: 2px;
    transition: all 0.3s ease;
  }

  .hamburger-menu span:nth-child(1) {
    top: 4px;
  }

  .hamburger-menu span:nth-child(2) {
    top: 13px;
  }

  .hamburger-menu span:nth-child(3) {
    top: 22px;
  }

  .hamburger-menu.active span:nth-child(1) {
    transform: rotate(45deg);
    top: 13px;
  }

  .hamburger-menu.active span:nth-child(2) {
    opacity: 0;
  }

  .hamburger-menu.active span:nth-child(3) {
    transform: rotate(-45deg);
    top: 13px;
  }

  /* Main Nav as drawer */
  .main-nav {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    width: 270px;
    height: 100vh;
    height: 100dvh;
    background-color: var(--primary-color);
    padding: 70px 0 20px;
    z-index: 1050;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 2px 0 12px rgba(0, 0, 0, 0.2);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .main-nav.active {
    display: flex;
    transform: translateX(0);
  }

  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    align-items: stretch;
    padding: 10px 12px;
  }

  .nav-link {
    padding: 13px 12px;
    font-size: 15px;
    border-radius: 6px;
    margin-bottom: 4px;
    color: var(--text-light);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  .nav-link:hover {
    background-color: rgba(255, 255, 255, 0.15);
    color: #ffffff;
  }

  /* Overlay */
  .mobile-menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.65);
    z-index: 1040;
    backdrop-filter: blur(2px);
  }

  .mobile-menu-overlay.active {
    display: block;
  }

  /* Footer stack */
  .footer-container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 30px;
    padding: 30px 15px;
  }

  .footer-brand {
    text-align: center;
    order: 1;
  }

  .footer-title {
    margin-bottom: 16px;
  }

  .footer-title::after {
    margin-left: auto;
    margin-right: auto;
  }

  .footer-column {
    order: 2;
  }

  .footer-buttons {
    justify-content: center;
  }

  /* Prevent overflow */
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }

  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
}

/* Landscape phones & small tablets */
@media (max-width: 480px) {
  .header-container {
    min-width: 0;
  }

  .logo {
    display: block;
    font-size: 20px;
  }

  .navbar-spacer,
  .nav-spacer {
    width: 35px;
  }

  .mobile-nav-buttons .btn {
    padding: 6px 8px;
  }
}

/* medium devices and desktop fine-tuning */
@media (min-width: 769px) and (max-width: 940px) {
  .nav-container {
    justify-content: space-between;
    padding-left: 4px;
    padding-right: 4px;
  }
  .nav-link {
    padding: 6px 6px;
    font-size: 12px;
  }
}

body.no-scroll {
  overflow: hidden;
}
/* 移动端内容区防溢出（系统追加，请勿删除） */
@media (max-width: 768px) {
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}
/* 内容保护（系统追加，请勿删除） */
body {
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}
input, textarea, select, [contenteditable="true"] {
  -webkit-user-select: text;
  -moz-user-select: text;
  user-select: text;
}