/* ==========================================================================
   Base Styles & Variables
   ========================================================================== */
@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:wght@400;500;600;700&family=Playfair+Display:wght@400;500;600;700&display=swap');

:root {
  /* Colors */
  --color-navy: #071B2E;
  --color-blue: #0E3854;
  --color-gold: #C9A86A;
  --color-gold-light: #E3D1A8;
  --color-white: #FFFFFF;
  --color-bg: #F5F7F8;
  --color-text-main: #14212B;
  --color-text-muted: #5E6973;

  /* Typography */
  --font-heading: 'Playfair Display', serif;
  --font-body: 'Be Vietnam Pro', sans-serif;

  /* Layout */
  --container-width: 1200px;
  --transition: all 0.3s ease;
  --shadow-sm: 0 2px 8px rgba(7, 27, 46, 0.08);
  --shadow-md: 0 8px 24px rgba(7, 27, 46, 0.12);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
}

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

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

body {
  font-family: var(--font-body);
  color: var(--color-text-main);
  background-color: var(--color-bg);
  line-height: 1.7;
  overflow-x: hidden;
}

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

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

ul {
  list-style: none;
}

/* ==========================================================================
   Typography
   ========================================================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--color-navy);
  line-height: 1.3;
  margin-bottom: 1rem;
}

h1 {
  font-size: clamp(34px, 5vw, 64px);
}

h2 {
  font-size: clamp(28px, 4vw, 46px);
  text-align: center;
  margin-bottom: 3rem;
}

h3 {
  font-size: 1.5rem;
}

.text-center { text-align: center; }
.text-gold { color: var(--color-gold); }

.section-label {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-bottom: 1rem;
}

.section-desc {
  max-width: 800px;
  margin: 0 auto 3rem;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 1.125rem;
}

/* ==========================================================================
   Layout & Utilities
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

section {
  padding: 6rem 0;
}

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

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 2rem;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.btn-primary {
  background-color: var(--color-gold);
  color: var(--color-navy);
}

.btn-primary:hover {
  background-color: var(--color-navy);
  color: var(--color-gold);
  border-color: var(--color-gold);
}

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

.btn-outline:hover {
  background-color: var(--color-gold);
  color: var(--color-navy);
}

.btn-navy {
  background-color: var(--color-navy);
  color: var(--color-white);
}

.btn-navy:hover {
  background-color: var(--color-gold);
  color: var(--color-navy);
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  padding: 1rem 0;
  transition: var(--transition);
  background-color: transparent;
}

header.scrolled {
  background-color: var(--color-white);
  box-shadow: var(--shadow-sm);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.logo-text-wrapper {
  display: flex;
  flex-direction: column;
}

.logo-main {
  font-family: var(--font-heading);
  font-size: clamp(1.2rem, 3vw, 1.5rem);
  font-weight: 700;
  color: var(--color-white);
}

header.scrolled .logo-main {
  color: var(--color-navy);
}

.logo-sub {
  font-size: clamp(0.65rem, 2vw, 0.75rem);
  color: var(--color-gold);
  letter-spacing: 1px;
  text-transform: uppercase;
}

nav ul {
  display: flex;
  gap: 1.25rem;
}

nav a {
  color: var(--color-white);
  font-weight: 500;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

header.scrolled nav a {
  color: var(--color-text-main);
}

nav a:hover {
  color: var(--color-gold);
}

.header-cta .btn {
  padding: 0.5rem 1.5rem;
  font-size: 0.875rem;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-white);
  font-size: 1.5rem;
  cursor: pointer;
}

header.scrolled .menu-toggle {
  color: var(--color-navy);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 8rem;
  padding-bottom: 4rem;
  background-image: linear-gradient(rgba(7, 27, 46, 0.7), rgba(7, 27, 46, 0.7)), url('../images/hero-phu-my-hung.webp');
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  color: var(--color-white);
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 400px;
  gap: 4rem;
  align-items: center;
}

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

.hero-desc {
  font-size: 1.125rem;
  margin-bottom: 2rem;
  opacity: 0.9;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
}

.hero-benefits {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.hero-benefits li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  opacity: 0.8;
}

.hero-benefits li::before {
  content: '✓';
  color: var(--color-gold);
  font-weight: bold;
}

.hero-form-box {
  background: var(--color-white);
  padding: 2.5rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  color: var(--color-text-main);
}

.hero-form-box h3 {
  font-family: var(--font-body);
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
  text-align: center;
}

/* Forms */
.form-group {
  margin-bottom: 1rem;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid #ddd;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.9rem;
  transition: var(--transition);
}

.form-control:focus {
  outline: none;
  border-color: var(--color-gold);
}

.form-check {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: 1rem;
}

/* ==========================================================================
   Trust Bar
   ========================================================================== */
.trust-bar {
  background-color: var(--color-navy);
  padding: 2rem 0;
  color: var(--color-white);
}

.trust-bar ul {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.trust-bar li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1rem;
}

.trust-bar svg {
  fill: var(--color-gold);
  width: 24px;
  height: 24px;
}

/* ==========================================================================
   Needs Selection
   ========================================================================== */
.needs-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.need-card {
  background: var(--color-white);
  padding: 2rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: var(--transition);
  cursor: pointer;
  border-top: 3px solid transparent;
}

.need-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-gold);
}

.need-card h3 {
  margin-bottom: 1rem;
  font-size: 1.25rem;
}

.need-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Projects
   ========================================================================== */
.project-filters {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.filter-btn {
  background: none;
  border: 1px solid #ddd;
  padding: 0.5rem 1.5rem;
  border-radius: 20px;
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-body);
  font-weight: 500;
}

.filter-btn.active, .filter-btn:hover {
  background: var(--color-navy);
  color: var(--color-white);
  border-color: var(--color-navy);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 2.5rem;
}

.project-card {
  background: var(--color-white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.project-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.project-img {
  position: relative;
  aspect-ratio: 4/3;
  overflow: hidden;
}

.project-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.project-card:hover .project-img img {
  transform: scale(1.05);
}

.project-tag {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: var(--color-gold);
  color: var(--color-navy);
  padding: 0.25rem 0.75rem;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 20px;
  text-transform: uppercase;
  z-index: 2;
}

.project-content {
  padding: 2rem;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
}

.project-meta {
  display: flex;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
}

.project-meta span {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.project-content p {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

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

.project-actions .btn {
  flex: 1;
  padding: 0.6rem 1rem;
  font-size: 0.8rem;
}

/* ==========================================================================
   Comparison Table
   ========================================================================== */
.table-responsive {
  overflow-x: auto;
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
}

.comparison-table th, .comparison-table td {
  padding: 1.25rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}

.comparison-table th {
  background: var(--color-navy);
  color: var(--color-white);
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 600;
}

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

/* ==========================================================================
   Story / Features Sections
   ========================================================================== */
.story-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.story-content ul {
  margin-top: 1.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.story-content li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.story-content li::before {
  content: '■';
  color: var(--color-gold);
  font-size: 0.8rem;
}

.story-image img {
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

/* ==========================================================================
   Process (Steps)
   ========================================================================== */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.step-card {
  background: var(--color-white);
  padding: 2.5rem 2rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(7, 27, 46, 0.05);
  border-top: 3px solid transparent;
  position: relative;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  overflow: hidden;
}

.step-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
  border-top-color: var(--color-gold);
}

.step-num {
  font-family: var(--font-heading);
  font-size: 4rem;
  color: var(--color-gold-light);
  line-height: 1;
  opacity: 0.2;
  transition: var(--transition);
  position: absolute;
  top: 1rem;
  right: 1.5rem;
}

.step-card:hover .step-num {
  opacity: 0.6;
  color: var(--color-gold);
  transform: scale(1.1);
}

.step-card h3 {
  margin-top: 2rem;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: var(--color-navy);
}

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

/* ==========================================================================
   Profile Section
   ========================================================================== */
.profile-section .story-grid {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  gap: 0;
}

.profile-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
}

.profile-content {
  padding: 4rem;
}

.profile-content h2 {
  text-align: left;
  margin-bottom: 1.5rem;
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--color-white);
  margin-bottom: 1rem;
  border-radius: var(--radius-sm);
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.faq-q {
  width: 100%;
  text-align: left;
  padding: 1.5rem;
  background: none;
  border: none;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--color-navy);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-q::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--color-gold);
  transition: var(--transition);
}

.faq-item.active .faq-q::after {
  content: '−';
}

.faq-a {
  padding: 0 1.5rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq-item.active .faq-a {
  padding-bottom: 1.5rem;
  max-height: 500px; /* arbitrary max height for transition */
}

/* ==========================================================================
   Footer
   ========================================================================== */
footer {
  background-color: var(--color-navy);
  color: var(--color-white);
  padding: 4rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 4rem;
  margin-bottom: 3rem;
}

.footer-col h4 {
  color: var(--color-gold);
  font-family: var(--font-body);
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
}

.footer-col p {
  color: #a0aec0;
  margin-bottom: 0.5rem;
}

.footer-links {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}

.footer-links a {
  color: #a0aec0;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 2rem;
  text-align: center;
  font-size: 0.85rem;
  color: #718096;
}

.disclaimer {
  font-size: 0.8rem;
  line-height: 1.6;
  opacity: 0.7;
  max-width: 900px;
  margin: 0 auto 1.5rem;
}

/* ==========================================================================
   Mobile Fixed CTA
   ========================================================================== */
.mobile-cta-bar {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  background: var(--color-white);
  box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
  z-index: 999;
  padding: 0.5rem;
}

.mobile-cta-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
}

.mobile-cta-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 0.5rem;
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--color-navy);
  text-transform: uppercase;
  border-radius: 4px;
}

.mobile-cta-btn.call { background: var(--color-gold); color: var(--color-navy); }
.mobile-cta-btn.zalo { background: #0068FF; color: var(--color-white); }
.mobile-cta-btn.form { background: var(--color-navy); color: var(--color-white); }

/* ==========================================================================
   Popup Modal
   ========================================================================== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(7, 27, 46, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background: var(--color-white);
  padding: 3rem;
  border-radius: var(--radius-md);
  width: 90%;
  max-width: 500px;
  position: relative;
  transform: translateY(20px);
  transition: var(--transition);
}

.modal-overlay.active .modal-content {
  transform: translateY(0);
}

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1024px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-actions, .hero-benefits {
    justify-content: center;
    align-items: center;
  }
  .needs-grid { grid-template-columns: repeat(2, 1fr); }
  .story-grid { grid-template-columns: 1fr; }
  .profile-section .story-grid { grid-template-columns: 1fr; }
  .profile-content { padding: 3rem; }
}

@media (max-width: 1024px) {
  header nav {
    position: fixed;
    top: 70px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 70px);
    background: var(--color-navy);
    flex-direction: column;
    padding: 2rem;
    transition: var(--transition);
  }
  header nav.active { left: 0; }
  .menu-toggle { display: block; }
  .header-cta { display: none; }
}

@media (max-width: 768px) {
  .projects-grid { grid-template-columns: 1fr; }
  .steps-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  
  .trust-bar ul { flex-direction: column; align-items: flex-start; }
  
  .mobile-cta-bar { display: block; }
  body { padding-bottom: 60px; }
}

@media (max-width: 480px) {
  .needs-grid { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; }
  .project-actions { flex-direction: column; }
}

/* Form Loading Spinner */
.loading-spinner {
  display: inline-block;
  width: 1rem;
  height: 1rem;
  border: 2px solid rgba(255,255,255,0.3);
  border-radius: 50%;
  border-top-color: var(--color-white);
  animation: spin 1s ease-in-out infinite;
  margin-left: 0.5rem;
  vertical-align: middle;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}