/* =====================================================
   HND Group — Presentation Website
   Style: Professional, minimal, Apple-review ready
   ===================================================== */

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

:root {
  --color-bg: #FAFAFA;
  --color-surface: #FFFFFF;
  --color-text: #111827;
  --color-text-secondary: #6B7280;
  --color-accent: #111827;
  --color-border: #E5E7EB;
  --color-border-light: #F3F4F6;

  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --radius-card: 16px;
  --radius-sm: 8px;

  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 48px;
  --space-xl: 80px;
  --space-2xl: 120px;

  --max-width: 1024px;
  --container-padding: 24px;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

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

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

/* --- Typography --- */
h1 {
  font-size: clamp(36px, 6vw, 56px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--color-text);
}

h2 {
  font-size: clamp(20px, 3vw, 24px);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--color-text);
}

h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

p {
  color: var(--color-text-secondary);
  font-size: 16px;
  line-height: 1.7;
}

.label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

/* --- Divider --- */
.divider {
  height: 1px;
  background-color: var(--color-border);
  border: none;
  margin: 0;
}

/* =====================================================
   HEADER
   ===================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(250, 250, 250, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  font-size: 18px;
  font-weight: 800;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.header-contact {
  font-size: 14px;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.header-contact:hover {
  color: var(--color-text);
}

/* =====================================================
   HERO
   ===================================================== */
.hero {
  padding: var(--space-2xl) 0 var(--space-xl);
}

.hero-content {
  max-width: 720px;
}

.hero-tagline {
  margin-bottom: var(--space-md);
}

.hero-description {
  font-size: 18px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  max-width: 580px;
  margin-bottom: var(--space-xl);
}

/* =====================================================
   SECTION — Common
   ===================================================== */
.section {
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--color-border);
}

.section-label {
  margin-bottom: var(--space-lg);
}

/* =====================================================
   FLAGSHIP PRODUCT
   ===================================================== */
.product-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 40px;
  max-width: 640px;
  transition: box-shadow 0.2s ease;
}

.product-card:hover {
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
}

.product-name {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-sm);
}

.product-description {
  font-size: 16px;
  margin-bottom: var(--space-md);
  line-height: 1.7;
}

.product-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-border-light);
}

.meta-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.meta-label {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

.meta-value {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text);
}

.meta-value a {
  color: var(--color-text);
  text-decoration: none;
  border-bottom: 1px solid var(--color-border);
  transition: border-color 0.2s ease;
}

.meta-value a:hover {
  border-color: var(--color-text);
}

/* =====================================================
   CORE ACTIVITIES
   ===================================================== */
.activities-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.activity-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: var(--space-md) var(--space-md) 28px;
  transition: box-shadow 0.2s ease;
}

.activity-card:hover {
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
}

.activity-icon {
  width: 40px;
  height: 40px;
  margin-bottom: var(--space-sm);
  color: var(--color-text);
}

.activity-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--color-text);
}

.activity-text {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* =====================================================
   ABOUT / COMPANY
   ===================================================== */
.company-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: start;
}

.company-info-block {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.info-row {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border-light);
}

.info-row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.info-key {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

.info-value {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
}

.info-value a {
  color: var(--color-text);
  text-decoration: none;
  border-bottom: 1px solid var(--color-border);
  transition: border-color 0.2s ease;
}

.info-value a:hover {
  border-color: var(--color-text);
}

.company-mission {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.company-mission p {
  font-size: 16px;
  line-height: 1.75;
}

/* =====================================================
   FOOTER
   ===================================================== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-lg) 0;
  text-align: center;
}

.footer-text {
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-bottom: 4px;
}

/* =====================================================
   RESPONSIVE — Tablet
   ===================================================== */
@media (max-width: 768px) {
  :root {
    --container-padding: 20px;
    --space-xl: 56px;
    --space-2xl: 72px;
  }

  .activities-grid {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
  }

  .company-grid {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }
}

/* =====================================================
   RESPONSIVE — Mobile
   ===================================================== */
@media (max-width: 480px) {
  :root {
    --container-padding: 16px;
    --space-xl: 48px;
    --space-2xl: 56px;
  }

  .product-card {
    padding: var(--space-md);
  }

  .product-meta {
    flex-direction: column;
    gap: var(--space-sm);
  }

  .header-contact {
    font-size: 12px;
  }
}