/* ==============================================================================
   THỊNH THIÊN HUY — PREMIUM INDUSTRIAL B2B DESIGN SYSTEM
   Standard Color Palette:
   --color-forest:       #183D32 (Chủ đạo, vững chắc, uy tín công nghiệp)
   --color-forest-hover: #122E25
   --color-deep:         #102B24 (Nền tối, footer, thanh tạo tương phản)
   --color-ivory:        #F7F5EF (Nền sáng trắng kem chủ đạo 65-75%)
   --color-ivory-light:  #FCFBF8
   --color-wood:         #B8895B (Điểm nhấn gỗ tự nhiên ấm áp)
   --color-wood-hover:   #9E7044
   --color-wood-light:   #F3EBE1
   --color-charcoal:     #252B28 (Màu chữ chính, độ tương phản cao WCAG AA)
   --color-muted:        #52605A (Chữ phụ, mô tả)
   --color-muted-light:  #7A8882
   --color-sage:         #DDE6DD (Nền phụ dịu nhẹ, thanh lịch)
   --color-sage-light:   #EEF3EE
   --color-white:        #FFFFFF (Card, bề mặt sáng tương phản)
   ============================================================================== */

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

:root {
  --font-sans: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  
  --color-forest: #183D32;
  --color-forest-hover: #122E25;
  --color-deep: #102B24;
  --color-ivory: #F7F5EF;
  --color-ivory-light: #FCFBF8;
  --color-wood: #B8895B;
  --color-wood-hover: #9E7044;
  --color-wood-light: #F3EBE1;
  --color-charcoal: #252B28;
  --color-muted: #52605A;
  --color-muted-light: #7A8882;
  --color-sage: #DDE6DD;
  --color-sage-light: #EEF3EE;
  --color-white: #FFFFFF;

  --color-border: rgba(37, 43, 40, 0.11);
  --color-border-subtle: rgba(37, 43, 40, 0.06);
  --color-border-dark: rgba(255, 255, 255, 0.12);

  --max-w-content: 1200px;
  --header-height: 72px;
  --radius-xs: 3px;
  --radius-sm: 5px;
  --radius-md: 8px;
  --radius-lg: 12px;
  
  --shadow-subtle: 0 2px 8px rgba(16, 43, 36, 0.04);
  --shadow-card: 0 4px 16px rgba(16, 43, 36, 0.05);
  --shadow-card-hover: 0 12px 32px rgba(16, 43, 36, 0.09);
  --shadow-dropdown: 0 16px 36px rgba(16, 43, 36, 0.12);

  --transition-fast: all 0.15s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: all 0.22s cubic-bezier(0.16, 1, 0.3, 1);
}

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

button, input, select, textarea {
  font-family: inherit;
}

html {
  font-family: var(--font-sans);
  background-color: var(--color-ivory);
  color: var(--color-charcoal);
  font-size: 16px;
  line-height: 1.6;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--color-ivory);
  color: var(--color-charcoal);
  overflow-x: hidden;
}

/* Headings with deliberate scale & balanced wrapping */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-forest);
  font-weight: 700;
  line-height: 1.25;
  text-wrap: balance;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2.25rem, 4vw, 3.25rem);
  line-height: 1.18;
}

h2 {
  font-size: clamp(1.75rem, 2.75vw, 2.35rem);
  line-height: 1.24;
}

h3 {
  font-size: clamp(1.2rem, 1.8vw, 1.45rem);
}

h4 {
  font-size: 1.1rem;
}

p {
  color: var(--color-muted);
  max-width: 72ch;
  line-height: 1.68;
}

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

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

/* Layout Utilities */
.container {
  width: 100%;
  max-width: var(--max-w-content);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.section {
  padding-top: 5.25rem;
  padding-bottom: 5.25rem;
  position: relative;
}

.section-sm {
  padding-top: 3.25rem;
  padding-bottom: 3.25rem;
}

.section-header {
  margin-bottom: 3rem;
}

.section-header.text-center {
  text-align: center;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}

.section-kicker {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-wood);
  margin-bottom: 0.625rem;
}

.section-desc {
  font-size: 1.0625rem;
  color: var(--color-muted);
  margin-top: 0.875rem;
  line-height: 1.65;
}

/* ==============================================================================
   HEADER & TOP BAR (TOP BAR CONTRACT)
   Zone 1: Logo Wordmark (Single element)
   Zone 2: Clean text links (Single line, subtle indicator)
   Zone 3: Hotline & Primary Action
   ============================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background-color: rgba(247, 245, 239, 0.96);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  transition: var(--transition-normal);
}

.site-header.scrolled {
  background-color: rgba(255, 255, 255, 0.98);
  box-shadow: 0 4px 20px rgba(16, 43, 36, 0.06);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: 2rem;
}

/* Zone 1 */
.brand-wordmark {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--color-forest);
  white-space: nowrap;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 0.625rem;
}

.brand-icon {
  width: 28px;
  height: 28px;
  color: var(--color-wood);
}

/* Zone 2 */
.main-nav {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-charcoal);
  white-space: nowrap;
  position: relative;
  padding: 0.375rem 0;
  transition: color 0.15s ease;
}

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

.nav-link.active {
  color: var(--color-forest);
  font-weight: 600;
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-wood);
  border-radius: 2px;
}

/* Zone 3 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 1.125rem;
  flex-shrink: 0;
}

.hotline-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-forest);
  white-space: nowrap;
}

.hotline-link svg {
  width: 16px;
  height: 16px;
  color: var(--color-wood);
  flex-shrink: 0;
}

.hotline-link:hover {
  color: var(--color-wood);
}

/* ==============================================================================
   BUTTON SYSTEM
   ============================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  padding: 0.6875rem 1.35rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  white-space: nowrap;
  border: 1px solid transparent;
  transition: var(--transition-fast);
  text-decoration: none;
  line-height: 1;
}

.btn:active {
  transform: scale(0.985);
}

.btn-primary {
  background-color: var(--color-forest);
  color: var(--color-white);
  border-color: var(--color-forest);
  box-shadow: 0 2px 6px rgba(24, 61, 50, 0.15);
}

.btn-primary:hover {
  background-color: var(--color-forest-hover);
  border-color: var(--color-forest-hover);
  box-shadow: 0 4px 12px rgba(24, 61, 50, 0.22);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-forest);
  border-color: var(--color-forest);
}

.btn-secondary:hover {
  background-color: var(--color-forest);
  color: var(--color-white);
}

.btn-wood {
  background-color: var(--color-wood);
  color: var(--color-white);
  border-color: var(--color-wood);
  box-shadow: 0 2px 6px rgba(184, 137, 91, 0.2);
}

.btn-wood:hover {
  background-color: var(--color-wood-hover);
  border-color: var(--color-wood-hover);
  box-shadow: 0 4px 12px rgba(184, 137, 91, 0.28);
}

.btn-sm {
  padding: 0.45rem 0.95rem;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 0.85rem 1.75rem;
  font-size: 1rem;
}

/* Mobile Toggle */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  color: var(--color-charcoal);
  border-radius: var(--radius-sm);
}

.menu-toggle:focus-visible {
  outline: 2px solid var(--color-forest);
}

.menu-toggle svg {
  width: 26px;
  height: 26px;
}

/* Mobile Drawer */
.mobile-nav-drawer {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 100%;
  background-color: var(--color-ivory);
  border-bottom: 1px solid var(--color-border);
  padding: 1.5rem;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
  z-index: 99;
}

.mobile-nav-drawer.open {
  display: block;
}

.mobile-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.mobile-nav-list .nav-link {
  font-size: 1.0625rem;
  display: block;
  padding: 0.5rem 0;
}

.mobile-drawer-footer {
  margin-top: 1.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

/* ==============================================================================
   HERO SECTION (BALANCED INDUSTRIAL 2-COLUMN SPLIT)
   ============================================================================== */
.hero-section {
  padding-top: 4.75rem;
  padding-bottom: 4.75rem;
  background: linear-gradient(180deg, var(--color-ivory) 0%, #F1EDE4 100%);
  position: relative;
  border-bottom: 1px solid var(--color-border);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 1.35rem;
}

.hero-badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-forest);
}

.hero-badge-tag .dot {
  width: 6px;
  height: 6px;
  background-color: var(--color-wood);
  border-radius: 50%;
}

.hero-title {
  color: var(--color-forest);
  line-height: 1.18;
}

.hero-description {
  font-size: 1.125rem;
  color: var(--color-muted);
  line-height: 1.68;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 0.5rem;
}

.hero-trust-row {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  font-size: 0.875rem;
  color: var(--color-muted);
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--color-border);
}

.hero-trust-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 500;
}

.hero-trust-item svg {
  width: 18px;
  height: 18px;
  color: var(--color-wood);
  flex-shrink: 0;
}

.hero-visual {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: 0 16px 40px rgba(24, 61, 50, 0.1);
  border: 1px solid var(--color-border);
  background-color: var(--color-white);
  aspect-ratio: 16 / 11;
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ==============================================================================
   VALUE & CAPABILITY STRIP (DEEP CONTRAST ROW)
   ============================================================================== */
.value-strip {
  background-color: var(--color-forest);
  color: var(--color-white);
  padding: 3rem 0;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

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

.value-item {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.value-number {
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--color-wood-light);
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.value-label {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-white);
}

.value-desc {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.75);
  line-height: 1.5;
}

/* ==============================================================================
   PRODUCT CARDS (PREMIUM B2B)
   ============================================================================== */
.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.product-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-card);
}

.product-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  border-color: rgba(24, 61, 50, 0.3);
}

.product-media {
  position: relative;
  aspect-ratio: 4 / 3;
  background-color: var(--color-sage-light);
  overflow: hidden;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.product-media img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  transition: transform 0.3s ease;
}

.product-card:hover .product-media img {
  transform: scale(1.03);
}

.product-body {
  padding: 1.75rem 1.5rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.product-meta {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-wood);
  margin-bottom: 0.5rem;
}

.product-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-forest);
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.product-desc {
  font-size: 0.9375rem;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.product-specs-list {
  list-style: none;
  font-size: 0.8125rem;
  color: var(--color-charcoal);
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
  padding: 0.875rem 1rem;
  background-color: var(--color-ivory);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border-subtle);
}

.product-specs-list li {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  line-height: 1.45;
}

.product-specs-list li svg {
  width: 14px;
  height: 14px;
  color: var(--color-forest);
  flex-shrink: 0;
  margin-top: 3px;
}

.product-footer {
  margin-top: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border-subtle);
}

/* ==============================================================================
   REASONS / ADVANTAGES BENTO GRID
   ============================================================================== */
.reasons-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.reason-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2.25rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-card);
}

.reason-card:hover {
  border-color: rgba(24, 61, 50, 0.25);
  box-shadow: var(--shadow-card-hover);
}

.reason-icon-wrapper {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  background-color: var(--color-sage-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-forest);
}

.reason-icon-wrapper svg {
  width: 24px;
  height: 24px;
}

.reason-title {
  font-size: 1.1875rem;
  font-weight: 700;
  color: var(--color-forest);
  line-height: 1.35;
}

.reason-desc {
  font-size: 0.9375rem;
  color: var(--color-muted);
  line-height: 1.65;
}

/* ==============================================================================
   PROCESS STEPS SECTION
   ============================================================================== */
.process-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1.5rem;
}

.process-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.75rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-card);
}

.process-card:hover {
  border-color: rgba(24, 61, 50, 0.3);
  transform: translateY(-2px);
}

.process-step-num {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-wood);
  letter-spacing: 0.08em;
}

.process-step-title {
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--color-forest);
  line-height: 1.3;
}

.process-step-desc {
  font-size: 0.8125rem;
  color: var(--color-muted);
  line-height: 1.55;
}

/* ==============================================================================
   GALLERY / PRODUCTION FACILITY
   ============================================================================== */
.gallery-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  grid-template-rows: repeat(2, 230px);
  gap: 1.25rem;
}

.gallery-item {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background-color: var(--color-white);
  box-shadow: var(--shadow-card);
}

.gallery-item.large {
  grid-row: span 2;
}

.gallery-fallback {
  width: 100%;
  height: 100%;
  background-color: #E7E3D8;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 1.5rem;
  position: relative;
}

.gallery-fallback img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.gallery-caption {
  position: relative;
  z-index: 2;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  padding: 0.85rem 1.125rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border-subtle);
}

.gallery-caption-title {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-forest);
}

.gallery-caption-sub {
  font-size: 0.75rem;
  color: var(--color-muted);
  margin-top: 0.15rem;
}

/* ==============================================================================
   INTERACTIVE RFQ & QUOTATION FORM
   ============================================================================== */
.rfq-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2.75rem 2.5rem;
  box-shadow: 0 12px 36px rgba(16, 43, 36, 0.05);
}

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  min-width: 0;
}

.form-group.full-width {
  grid-column: span 2;
}

.form-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-charcoal);
  display: flex;
  justify-content: space-between;
}

.form-label .required {
  color: #C0392B;
}

.form-input,
.form-select,
.form-textarea {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  padding: 0.75rem 0.95rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background-color: var(--color-ivory-light);
  color: var(--color-charcoal);
  width: 100%;
  max-width: 100%;
  min-width: 0;
  box-sizing: border-box;
  transition: var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-forest);
  background-color: var(--color-white);
  box-shadow: 0 0 0 3px rgba(24, 61, 50, 0.1);
}

/* Layout Component Grids */
.about-summary-grid,
.about-main-grid,
.values-sub-grid,
.workflow-grid,
.contact-main-grid {
  min-width: 0;
  max-width: 100%;
}

.about-summary-grid > *,
.about-main-grid > *,
.values-sub-grid > *,
.workflow-grid > *,
.contact-main-grid > * {
  min-width: 0;
  max-width: 100%;
}

.about-summary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3.5rem;
  align-items: center;
}

.about-main-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 4rem;
  align-items: start;
}

.values-sub-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 1.25rem;
}

.workflow-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.contact-main-grid {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: 3.5rem;
  align-items: start;
}

.form-textarea {
  resize: vertical;
  min-height: 100px;
}

.form-error {
  font-size: 0.75rem;
  color: #C0392B;
  display: none;
  margin-top: 0.2rem;
}

.form-error.visible {
  display: block;
}

/* Dimension Builder Sub-Card */
.dimension-box {
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 1.35rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.dimension-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.spec-calc-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  padding-top: 0.85rem;
  border-top: 1px dashed var(--color-border);
  font-size: 0.8125rem;
  color: var(--color-muted);
}

.spec-calc-strip strong {
  color: var(--color-forest);
  font-variant-numeric: tabular-nums;
}

.form-actions {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.75rem;
}

.form-notice {
  font-size: 0.8125rem;
  color: var(--color-muted);
  line-height: 1.5;
}

.form-alert {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  display: none;
  margin-bottom: 1.5rem;
}

.form-alert.visible {
  display: block;
}

.form-alert-info {
  background-color: var(--color-sage-light);
  border: 1px solid rgba(24, 61, 50, 0.2);
  color: var(--color-forest);
}

.form-alert-success {
  background-color: #E8F5E9;
  border: 1px solid #A5D6A7;
  color: #1B5E20;
}

.form-alert-error {
  background-color: #FFEBEE;
  border: 1px solid #FFCDD2;
  color: #B71C1C;
}

/* ==============================================================================
   ARTICLE CARDS (KIẾN THỨC)
   ============================================================================== */
.article-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.article-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2.25rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-card);
}

.article-card:hover {
  border-color: rgba(24, 61, 50, 0.3);
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-2px);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--color-wood);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 700;
}

.article-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-forest);
  line-height: 1.35;
}

.article-excerpt {
  font-size: 0.9375rem;
  color: var(--color-muted);
  line-height: 1.65;
}

.article-link {
  margin-top: auto;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-wood);
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
}

.article-link:hover {
  color: var(--color-wood-hover);
  text-decoration: underline;
}

/* ==============================================================================
   FOOTER (DEEP GREEN SOLID B2B FOUNDATION)
   ============================================================================== */
.site-footer {
  background-color: var(--color-deep);
  color: rgba(255, 255, 255, 0.85);
  padding-top: 4.75rem;
  padding-bottom: 2.75rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 3rem;
  margin-bottom: 3.5rem;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-brand {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: -0.01em;
}

.footer-tagline {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.65);
  line-height: 1.6;
  max-width: 32ch;
}

.footer-heading {
  font-size: 0.8125rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-wood);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.footer-links a {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.72);
}

.footer-links a:hover {
  color: var(--color-white);
  padding-left: 2px;
}

.footer-contact-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
  font-size: 0.875rem;
}

.footer-contact-list li {
  display: flex;
  gap: 0.625rem;
  color: rgba(255, 255, 255, 0.75);
  line-height: 1.5;
}

.footer-contact-list svg {
  width: 18px;
  height: 18px;
  color: var(--color-wood);
  flex-shrink: 0;
  margin-top: 3px;
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.5);
}

/* ==============================================================================
   RESPONSIVE MEDIA QUERIES
   ============================================================================== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.75rem;
  }

  .about-summary-grid,
  .about-main-grid,
  .contact-main-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .value-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.75rem;
  }

  .product-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .process-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .gallery-grid {
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto;
  }

  .gallery-item.large {
    grid-row: auto;
    grid-column: span 2;
    height: 280px;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .container {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .header-container {
    gap: 0.75rem;
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .brand-wordmark {
    font-size: 1.0625rem;
  }

  .brand-icon {
    width: 24px;
    height: 24px;
  }

  .header-actions .btn-sm {
    display: none;
  }

  .section {
    padding-top: 3.5rem;
    padding-bottom: 3.5rem;
  }

  .main-nav,
  .hotline-link {
    display: none;
  }

  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .hero-section {
    padding-top: 2.5rem;
    padding-bottom: 2.5rem;
  }

  .about-summary-grid,
  .about-main-grid,
  .contact-main-grid,
  .workflow-grid,
  .values-sub-grid,
  .product-grid,
  .reasons-grid,
  .article-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .process-grid {
    grid-template-columns: 1fr;
  }

  .value-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }

  .rfq-card {
    padding: 1.5rem 1rem;
  }

  .dimension-box {
    padding: 1rem 0.75rem;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  .form-group.full-width {
    grid-column: span 1;
  }

  .dimension-row {
    grid-template-columns: 1fr;
    gap: 0.875rem;
  }

  .spec-calc-strip {
    gap: 0.75rem;
    font-size: 0.75rem;
  }

  .gallery-grid {
    grid-template-columns: 1fr;
  }

  .gallery-item.large {
    grid-column: span 1;
    height: 220px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}