/* ===== CSS Variables / Theme ===== */
:root {
  --primary: #0a4b7a;
  --primary-light: #1a6bb5;
  --primary-dark: #072f4f;
  --secondary: #00a8b5;
  --secondary-light: #5dd5e0;
  --accent: #f5a623;
  --accent-light: #ffd966;
  --bg-dark: #0b1a2e;
  --bg-light: #f4f7fb;
  --bg-white: #ffffff;
  --text-dark: #1a2332;
  --text-mid: #4a5568;
  --text-light: #718096;
  --text-white: #f0f4ff;
  --shadow: 0 4px 20px rgba(10, 75, 122, 0.10);
  --shadow-lg: 0 12px 40px rgba(10, 75, 122, 0.15);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 1200px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font);
  color: var(--text-dark);
  background: var(--bg-light);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--primary-light); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--secondary); }
img { max-width: 100%; height: auto; display: block; }
ul { list-style: none; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
section { padding: 80px 0; }
.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-dark);
  text-align: center;
  margin-bottom: 12px;
  position: relative;
}
.section-subtitle {
  text-align: center;
  color: var(--text-light);
  font-size: 1.05rem;
  max-width: 640px;
  margin: 0 auto 48px;
  line-height: 1.6;
}
.section-divider {
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 2px;
  margin: 0 auto 16px;
}

/* ===== Help Tooltip ===== */
.help-trigger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--secondary);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  margin-left: 6px;
  position: relative;
  transition: var(--transition);
  border: none;
  vertical-align: middle;
  flex-shrink: 0;
}
.help-trigger:hover, .help-trigger:focus {
  background: var(--primary);
  transform: scale(1.15);
}
.help-popup {
  display: none;
  position: absolute;
  bottom: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-dark);
  color: var(--text-white);
  padding: 14px 18px;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 400;
  line-height: 1.5;
  width: 280px;
  max-width: 90vw;
  z-index: 999;
  box-shadow: 0 8px 30px rgba(0,0,0,0.3);
  pointer-events: none;
  text-align: left;
}
.help-popup::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 8px solid transparent;
  border-top-color: var(--bg-dark);
}
.help-trigger.active .help-popup { display: block; }

/* ===== Header / Nav ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 10px rgba(0,0,0,0.06);
  transition: var(--transition);
}
.site-header.scrolled { background: rgba(255,255,255,0.98); box-shadow: 0 2px 20px rgba(0,0,0,0.10); }
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--primary-dark);
}
.logo-img {
  width: 600px;
  height: auto;
  max-height: 42px;
  object-fit: contain;
  flex-shrink: 0;
}
.nav-links { display: flex; align-items: center; gap: 8px; }
.nav-links a {
  padding: 8px 16px;
  border-radius: 8px;
  color: var(--text-mid);
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition);
}
.nav-links a:hover, .nav-links a.active {
  color: var(--primary);
  background: rgba(10, 75, 122, 0.06);
}
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.menu-toggle span {
  width: 26px;
  height: 2.5px;
  background: var(--text-dark);
  border-radius: 2px;
  transition: var(--transition);
}
.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--bg-dark) 0%, #0d2847 40%, #133a5e 70%, #0a4b7a 100%);
  position: relative;
  overflow: hidden;
  padding: 100px 0 60px;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 20% 50%, rgba(0,168,181,0.12) 0%, transparent 50%),
              radial-gradient(circle at 80% 30%, rgba(245,166,35,0.06) 0%, transparent 40%);
  pointer-events: none;
}
.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}
.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
  padding: 0 24px;
}
.hero-badge {
  display: inline-block;
  padding: 6px 20px;
  border-radius: 20px;
  background: rgba(0,168,181,0.15);
  color: var(--secondary-light);
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 20px;
  border: 1px solid rgba(0,168,181,0.25);
}
.hero h1 {
  font-size: clamp(2.2rem, 6vw, 3.8rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.15;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}
.hero h1 .highlight { background: linear-gradient(135deg, var(--secondary), var(--accent)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero p {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: rgba(255,255,255,0.7);
  max-width: 600px;
  margin: 0 auto 36px;
  line-height: 1.7;
}
.hero-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  font-family: var(--font);
}
.btn-primary {
  background: linear-gradient(135deg, var(--secondary), #007a8a);
  color: #fff;
  box-shadow: 0 4px 15px rgba(0,168,181,0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(0,168,181,0.4); color: #fff; }
.btn-outline {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255,255,255,0.3);
}
.btn-outline:hover { border-color: var(--secondary); color: var(--secondary); transform: translateY(-2px); }
.hero-stats {
  display: flex;
  gap: 40px;
  justify-content: center;
  margin-top: 48px;
  flex-wrap: wrap;
}
.hero-stat { text-align: center; }
.hero-stat .num {
  font-size: 2rem;
  font-weight: 800;
  color: #fff;
  display: block;
}
.hero-stat .label {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.55);
  margin-top: 4px;
}
.scroll-indicator {
  position: absolute;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: rgba(255,255,255,0.4);
  font-size: 0.75rem;
  animation: bounce 2s infinite;
}
.scroll-indicator .arrow { width: 20px; height: 20px; border-right: 2px solid rgba(255,255,255,0.4); border-bottom: 2px solid rgba(255,255,255,0.4); transform: rotate(45deg); }
@keyframes bounce { 0%, 100% { transform: translateX(-50%) translateY(0); } 50% { transform: translateX(-50%) translateY(8px); } }

/* ===== About Section ===== */
.about-section { background: var(--bg-white); }
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.about-text h3 { font-size: 1.6rem; color: var(--primary-dark); margin-bottom: 16px; }
.about-text p { color: var(--text-mid); margin-bottom: 16px; font-size: 1rem; line-height: 1.8; }
.about-text ul { display: flex; flex-direction: column; gap: 10px; margin-top: 20px; }
.about-text ul li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  color: var(--text-mid);
  font-size: 0.95rem;
}
.about-text ul li .check { color: var(--secondary); font-weight: 700; flex-shrink: 0; }
.about-visual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.about-card {
  background: var(--bg-light);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  transition: var(--transition);
}
.about-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.about-card .icon { font-size: 2rem; margin-bottom: 10px; }
.about-card h4 { font-size: 1rem; color: var(--primary-dark); margin-bottom: 6px; }
.about-card p { font-size: 0.85rem; color: var(--text-light); line-height: 1.5; }

/* ===== Business Layout ===== */
.biz-section { background: var(--bg-light); }
.biz-intro {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 48px;
  color: var(--text-mid);
  font-size: 1.05rem;
  line-height: 1.7;
}
.biz-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.biz-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}
.biz-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.biz-card-header {
  padding: 32px 28px 20px;
  position: relative;
}
.biz-card-header .biz-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 14px;
}
.biz-card-header h3 { font-size: 1.35rem; color: var(--primary-dark); margin-bottom: 8px; }
.biz-card-header p { color: var(--text-light); font-size: 0.9rem; line-height: 1.6; }
.biz-card-body { padding: 0 28px 24px; flex: 1; }
.biz-card-body ul { display: flex; flex-direction: column; gap: 8px; }
.biz-card-body ul li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  color: var(--text-mid);
  font-size: 0.9rem;
}
.biz-card-body ul li .dot { color: var(--secondary); font-weight: 700; flex-shrink: 0; }
.biz-card-footer { padding: 16px 28px; border-top: 1px solid #eef2f7; }
.biz-card-footer a {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary-light);
  display: flex;
  align-items: center;
  gap: 6px;
}

/* ===== Subsidiary Detail Sections ===== */
.sub-section { background: var(--bg-white); }
.sub-section:nth-child(even) { background: var(--bg-light); }
.sub-header {
  text-align: center;
  margin-bottom: 48px;
}
.sub-header .sub-icon {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 12px;
}
.sub-header h2 { font-size: 1.8rem; color: var(--primary-dark); margin-bottom: 8px; }
.sub-header p { color: var(--text-light); max-width: 600px; margin: 0 auto; }

/* Tabs */
.tabs { display: flex; gap: 4px; margin-bottom: 32px; flex-wrap: wrap; border-bottom: 2px solid #e8ecf1; padding-bottom: 0; }
.tab-btn {
  padding: 10px 22px;
  border: none;
  background: transparent;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-light);
  cursor: pointer;
  transition: var(--transition);
  border-radius: 8px 8px 0 0;
  font-family: var(--font);
  position: relative;
}
.tab-btn:hover { color: var(--primary); background: rgba(10,75,122,0.04); }
.tab-btn.active { color: var(--primary); background: rgba(10,75,122,0.06); }
.tab-btn.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--primary);
  border-radius: 2px 2px 0 0;
}
.tab-content { display: none; }
.tab-content.active { display: block; animation: fadeIn 0.4s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

/* Feature Grid */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }
.feature-card {
  background: var(--bg-light);
  border-radius: var(--radius);
  padding: 24px;
  transition: var(--transition);
  position: relative;
}
.feature-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.feature-card .fc-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  margin-bottom: 12px;
}
.feature-card h4 { font-size: 1.05rem; color: var(--primary-dark); margin-bottom: 6px; }
.feature-card p { font-size: 0.88rem; color: var(--text-light); line-height: 1.6; }

/* Case Study Cards */
.case-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.case-card {
  background: var(--bg-white);
  border: 1px solid #eef2f7;
  border-radius: var(--radius);
  padding: 28px;
  transition: var(--transition);
}
.case-card:hover { border-color: var(--secondary); box-shadow: var(--shadow); }
.case-card .case-tag {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 10px;
}
.case-card h4 { font-size: 1.1rem; color: var(--primary-dark); margin-bottom: 6px; }
.case-card .case-client { font-size: 0.85rem; color: var(--text-light); margin-bottom: 12px; }
.case-card .case-desc { font-size: 0.88rem; color: var(--text-mid); line-height: 1.7; }

/* Tech Platform Cards */
.platform-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 20px; }
.platform-card {
  background: var(--bg-white);
  border: 1px solid #eef2f7;
  border-radius: var(--radius);
  padding: 22px;
  text-align: center;
  transition: var(--transition);
}
.platform-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--secondary); }
.platform-card .pc-icon { font-size: 2rem; margin-bottom: 10px; }
.platform-card h4 { font-size: 1rem; color: var(--primary-dark); margin-bottom: 6px; }
.platform-card p { font-size: 0.85rem; color: var(--text-mid); line-height: 1.6; }

/* ===== Tech Advantages ===== */
.advantage-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 20px; }
.advantage-card {
  background: var(--bg-white);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: var(--transition);
  position: relative;
}
.advantage-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.advantage-card .av-icon { font-size: 1.8rem; margin-bottom: 10px; }
.advantage-card h4 { font-size: 0.95rem; color: var(--primary-dark); margin-bottom: 4px; }
.advantage-card p { font-size: 0.82rem; color: var(--text-light); }

/* ===== Partners ===== */
.partners-section { background: var(--bg-white); }
.partner-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}
.partner-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
  border-radius: var(--radius);
  border: 1px solid #eef2f7;
  transition: var(--transition);
}
.partner-card:hover { border-color: var(--secondary); background: rgba(0,168,181,0.03); }
.partner-card .pc-avatar {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}
.partner-card .pc-info h4 { font-size: 0.95rem; color: var(--primary-dark); }
.partner-card .pc-info p { font-size: 0.8rem; color: var(--text-light); }

/* ===== Contact ===== */
.contact-section { background: var(--bg-dark); color: var(--text-white); }
.contact-section .section-title { color: #fff; }
.contact-section .section-subtitle { color: rgba(255,255,255,0.6); }
.contact-section .section-divider { background: linear-gradient(90deg, var(--secondary), var(--accent)); }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.contact-info { display: flex; flex-direction: column; gap: 20px; }
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}
.contact-item .ci-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.contact-item h4 { font-size: 0.95rem; color: #fff; margin-bottom: 2px; }
.contact-item p { font-size: 0.88rem; color: rgba(255,255,255,0.6); }
.contact-form { display: flex; flex-direction: column; gap: 16px; }
.contact-form input, .contact-form textarea {
  padding: 14px 18px;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,0.12);
  background: rgba(255,255,255,0.06);
  color: #fff;
  font-size: 0.95rem;
  font-family: var(--font);
  transition: var(--transition);
}
.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; border-color: var(--secondary); background: rgba(255,255,255,0.1); }
.contact-form textarea { min-height: 120px; resize: vertical; }
.contact-form .btn { align-self: flex-start; }

/* ===== Footer ===== */
.site-footer {
  background: #060f1a;
  color: rgba(255,255,255,0.5);
  text-align: center;
  padding: 32px 24px;
  font-size: 0.85rem;
}
.site-footer a { color: rgba(255,255,255,0.6); }
.site-footer a:hover { color: var(--secondary); }

/* ===== Back to Top ===== */
.back-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: 0 4px 15px rgba(10,75,122,0.3);
  opacity: 0;
  transform: translateY(20px);
  transition: var(--transition);
  z-index: 999;
}
.back-top.visible { opacity: 1; transform: translateY(0); }
.back-top:hover { background: var(--primary-light); transform: translateY(-3px); }

/* ===== Lightbox / Modal ===== */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(6px);
  z-index: 2000;
  justify-content: center;
  align-items: center;
  padding: 24px;
}
.modal-overlay.active { display: flex; }
.modal-content {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  max-width: 560px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  padding: 36px;
  position: relative;
  animation: fadeIn 0.3s ease;
}
.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: none;
  background: var(--bg-light);
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}
.modal-close:hover { background: #e8ecf1; }
.modal-content h3 { font-size: 1.4rem; color: var(--primary-dark); margin-bottom: 16px; }
.modal-content p { color: var(--text-mid); line-height: 1.7; margin-bottom: 12px; }
.modal-content ul { display: flex; flex-direction: column; gap: 8px; margin: 12px 0; }
.modal-content ul li { display: flex; gap: 8px; color: var(--text-mid); font-size: 0.9rem; }
.modal-content ul li .mdot { color: var(--secondary); flex-shrink: 0; }

/* ===== Responsive ===== */
@media (max-width: 968px) {
  .about-grid { grid-template-columns: 1fr; }
  .biz-cards { grid-template-columns: 1fr; }
  .case-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  section { padding: 60px 0; }
  .section-title { font-size: 1.6rem; }
}
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 16px 24px;
    border-bottom: 1px solid #eef2f7;
    box-shadow: 0 8px 20px rgba(0,0,0,0.06);
  }
  .nav-links.open { display: flex; }
  .menu-toggle { display: flex; }
  .hero-stats { gap: 24px; }
  .hero-stat .num { font-size: 1.5rem; }
  .about-visual { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .partner-list { grid-template-columns: 1fr; }
  .advantage-grid { grid-template-columns: repeat(2, 1fr); }
  .hero h1 { font-size: 2rem; }
  .hero-buttons { flex-direction: column; align-items: center; }
  .btn { width: 100%; justify-content: center; }
}
@media (max-width: 480px) {
  .advantage-grid { grid-template-columns: 1fr; }
  .modal-content { padding: 24px; }
}