/* ==========================================================================
   WIDELINK VIET NAM - DESIGN SYSTEM
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;500;600;700;800&family=Open+Sans:wght@400;500;600;700&display=swap');

:root {
  /* Colors */
  --primary-blue: #1A73E8; /* Xanh công nghệ rực rỡ */
  --primary-light: #4c96ff;
  --primary-dark: #004ba0;
  
  --accent-orange: #f26522; /* Tương phản cho nút CTA */
  --accent-cyan: #00D4FF; /* Điểm xuyết Xanh Cyan */

  --text-dark: #1e293b;
  --text-body: #475569;
  --text-light: #94a3b8;
  
  --bg-light: #f8fafc;
  --bg-white: #ffffff;
  --bg-dark: #0F172A; /* Khung nền tối Dark Navy */
  
  --glass-bg: rgba(255, 255, 255, 0.85);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);

  /* Typography */
  --font-heading: 'Montserrat', sans-serif;
  --font-body: 'Open Sans', sans-serif;
  
  /* Utilities */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  
  --transition-fast: 0.2s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
  --transition-slow: 0.5s ease;
}

/* ==========================================================================
   RESET & BASE
   ========================================================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-body);
  color: var(--text-body);
  background-color: var(--bg-white);
  line-height: 1.6;
  overflow-x: hidden;
  /* Lưới Grid pattern (Blueprint không gian làm việc) */
  background-image: 
    linear-gradient(rgba(26, 115, 232, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(26, 115, 232, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--text-dark);
  font-weight: 700;
  line-height: 1.2;
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(2rem, 4vw, 3rem); margin-bottom: 1rem; }
h3 { font-size: 1.5rem; margin-bottom: 0.75rem; }

p { margin-bottom: 1rem; }

a {
  text-decoration: none;
  color: var(--primary-blue);
  transition: color var(--transition-fast);
}

ul { list-style: none; }

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

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ==========================================================================
   HEADER & NAVIGATION
   ========================================================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  transition: padding var(--transition-normal);
  padding: 1rem 0;
}

.header.scrolled {
  padding: 0.5rem 0;
}

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

.logo {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--primary-blue);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  letter-spacing: -1px;
}
.logo span {
  color: var(--text-dark);
}

.nav-menu {
  display: flex;
  gap: 2rem;
}

.nav-link {
  color: var(--text-dark);
  font-weight: 500;
  font-size: 1rem;
  position: relative;
  padding: 0.5rem 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--primary-blue);
  transition: width var(--transition-fast);
}

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

.nav-link:hover {
  color: var(--primary-blue);
}

/* Mobile Menu Button */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.hamburger {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-dark);
  position: relative;
  transition: var(--transition-fast);
}

.hamburger::before, .hamburger::after {
  content: '';
  position: absolute;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--text-dark);
  transition: var(--transition-fast);
}

.hamburger::before { top: -6px; }
.hamburger::after { bottom: -6px; }

/* ==========================================================================
   UI COMPONENTS
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  transition: all var(--transition-normal);
  cursor: pointer;
  border: none;
  font-size: 1rem;
}

.btn-primary {
  background: var(--accent-orange); /* Sáng hẳn trên nền tối */
  color: var(--bg-white);
  box-shadow: 0 4px 14px 0 rgba(242, 101, 34, 0.39);
}

.btn-primary:hover {
  background: #d65518;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(242, 101, 34, 0.23);
  color: var(--bg-white);
}

.btn-outline {
  background: transparent;
  color: var(--primary-blue);
  border: 2px solid var(--primary-blue);
}

.btn-outline:hover {
  background: var(--primary-blue);
  color: var(--bg-white);
  transform: translateY(-2px);
}

/* Section Styling */
.section {
  padding: 6rem 0;
  position: relative;
}

.section-bg-dark {
  background: var(--bg-dark);
  color: var(--bg-white);
}

.section-bg-dark h2, .section-bg-dark h3 {
  color: var(--bg-white);
}

.section-header {
  text-align: center;
  max-width: 800px;
  margin: 0 auto 4rem;
}

.section-subtitle {
  color: var(--primary-blue);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
  display: block;
}

/* Cards */
.card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  box-shadow: 0 10px 25px rgba(26, 115, 232, 0.05); /* Bóng đổ màu xanh nhạt cơ bản */
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  border: 1px solid rgba(0,0,0,0.05);
  height: 100%;
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 20px 35px rgba(26, 115, 232, 0.15); /* Bóng đổ màu xanh nhạt khi hover */
}

.card-icon {
  width: 64px;
  height: 64px;
  background: rgba(0, 86, 164, 0.1);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  color: var(--primary-blue);
}

.card-icon svg {
  width: 32px;
  height: 32px;
}

/* Footer */
.footer {
  background: var(--bg-dark);
  color: var(--text-light);
  padding: 4rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-col h4 {
  color: var(--bg-white);
  margin-bottom: 1.5rem;
  font-size: 1.125rem;
}

.footer-link {
  color: var(--text-light);
  display: block;
  margin-bottom: 0.75rem;
}

.footer-link:hover {
  color: var(--primary-light);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 2rem;
  text-align: center;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* ==========================================================================
   SPECIFIC SECTIONS
   ========================================================================== */

/* Hero */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 80px;
  position: relative;
  background: var(--bg-dark); /* Màu nền tối Dark Navy */
  color: var(--text-light);
  overflow: hidden;
}

/* Hiệu ứng mờ ảo góc (Glow/Blur khổng lồ) */
.hero::before {
  content: '';
  position: absolute;
  top: -20%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(0,212,255,0.4) 0%, rgba(255,255,255,0) 70%); /* Cyan rực rỡ */
  border-radius: 50%;
  filter: blur(80px); /* Làm mờ mạnh tạo glow */
  z-index: 0;
  animation: pulse 8s infinite alternate;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -20%;
  left: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(26,115,232,0.4) 0%, rgba(255,255,255,0) 70%); /* Xanh Primary Blue rực rỡ */
  border-radius: 50%;
  filter: blur(80px); /* Làm mờ mạnh tạo glow */
  z-index: 0;
  animation: pulse 6s infinite alternate-reverse;
}

.hero-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content h1 {
  margin-bottom: 1.5rem;
  color: var(--bg-white);
}

.hero-content p {
  font-size: 1.125rem;
  margin-bottom: 2.5rem;
  color: var(--text-light); /* Khắc phục độ tương phản chữ Body trên nền Dark Navy */
}

.hero-actions {
  display: flex;
  gap: 1rem;
}

.hero-image {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
}

/* Trust Indicators Slider */
.partners {
  padding: 2rem 0; /* Tăng nhẹ padding để logo thoáng */
  margin-top: 8px;
  background: #ffffff; /* Đổi sang nền trắng để logo hiển thị rõ nhất */
  border-top: 1px solid rgba(0,0,0,0.05);
  border-bottom: 1px solid rgba(0,0,0,0.05);
  overflow: hidden;
  position: relative;
}

.partners-slider {
  display: flex;
  width: max-content; /* Tự động theo nội dung */
  animation: scroll 40s linear infinite; /* Chậm lại một chút để dễ nhìn */
}

.partners-slide {
  flex: 0 0 250px; /* Tăng độ rộng mỗi slide để logo không bị sít */
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 0 1rem;
  transition: var(--transition-normal);
}

.partners-slide img {
  height: 45px; /* Kích thước đồng nhất */
  width: auto;
  max-width: 180px;
  object-fit: contain;
  filter: grayscale(0.2) opacity(0.8); /* Hiệu ứng chuyên nghiệp */
  transition: all var(--transition-normal);
}

.partners-slide:hover img {
  filter: grayscale(0) opacity(1);
  transform: scale(1.1);
}


/* Grid Layouts */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 4rem;
  align-items: center;
}

/* Features Block */
.feature-list {
  margin-top: 2rem;
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.feature-item svg {
  color: var(--primary-blue);
  flex-shrink: 0;
  margin-top: 0.25rem;
}

/* Page Headers */
.page-header {
  padding: 180px 0 80px;
  background: linear-gradient(45deg, #0A192F 0%, #1A73E8 50%, #00D4FF 100%); /* Flow of Data Gradient */
  text-align: center;
  color: var(--bg-white);
  position: relative;
  overflow: hidden;
}

.page-header h1 {
  color: var(--bg-white);
  position: relative;
  z-index: 2;
}

/* Contact Form */
.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: var(--text-dark);
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid #cbd5e1;
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: 1rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-blue);
  box-shadow: 0 0 0 3px rgba(0, 86, 164, 0.1);
}

/* Animations */
@keyframes scroll {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

@keyframes pulse {
  0% { transform: scale(1); opacity: 0.8; }
  100% { transform: scale(1.1); opacity: 1; }
}

.animate-fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

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

/* ==========================================================================
   RESPONSIVE DESIGN
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-container { grid-template-columns: 1fr; text-align: center; }
  .hero-actions { justify-content: center; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    height: 100vh;
    background: var(--bg-white);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transition: var(--transition-normal);
    box-shadow: -10px 0 30px rgba(0,0,0,0.1);
  }
  
  .nav-menu.active {
    right: 0;
  }
  
  .menu-toggle { display: block; z-index: 1001; position: relative; }
  
  /* Hamburger Animation */
  .menu-toggle.active .hamburger { background: transparent; }
  .menu-toggle.active .hamburger::before { transform: rotate(45deg); top: 0; }
  .menu-toggle.active .hamburger::after { transform: rotate(-45deg); bottom: 0; }
  
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 1rem; }
  
  .page-header { padding: 140px 0 60px; }
}