/* =========================================
   PRODUCT HERO
   ========================================= */
.pd-hero {
  margin-top: 80px; /* Tránh header fixed */
}

.pd-hero__grid {
  display: grid;
  grid-template-columns: 5fr 7fr; /* Cột trái nhỏ hơn cột phải một chút */
  min-height: 600px;
}

/* Cột Trái (Nền hình ảnh) */
.pd-hero__left {
  background-size: cover;
  background-position: center;
  position: relative;
  color: var(--color-white);
  padding: 40px;
  display: flex;
  flex-direction: column;
}
/* Phủ màu mờ đen nhẹ để đọc chữ trên nền ảnh */
.pd-hero__left::before {
  content: ''; position: absolute; inset: 0; background: rgba(17, 27, 87, 0.4);
}
.pd-hero__left-content {
  position: relative; z-index: 2; display: flex; flex-direction: column; height: 100%;
}
.pd-hero__left-title {
  font-size: 24px; font-weight: 700; line-height: 1.3; margin-bottom: auto; letter-spacing: 0.5px;
}
.pd-hero__main-img {
  text-align: center; margin: 40px 0;
}
.pd-hero__main-img img {
  max-width: 100%; height: auto; max-height: 450px; object-fit: contain;
  filter: drop-shadow(0 20px 30px rgba(0,0,0,0.3));
}
.pd-hero__slogan {
  font-size: 15px; font-weight: 600; letter-spacing: 1px; line-height: 1.4; margin-top: auto;
}

/* Cột Phải (Thông tin) */
.pd-hero__right {
  padding: 60px 80px;
  background-color: var(--color-white);
  display: flex; flex-direction: column; justify-content: center;
}
.pd-hero__cat {
  font-size: 13px; font-weight: 700; color: #495057; margin-bottom: 12px; display: block;
}
.pd-hero__title {
  font-size: 40px; font-weight: 700; color: var(--color-primary); line-height: 1.1; margin-bottom: 16px;
}
.pd-hero__sub {
  font-size: 18px; color: var(--color-text); margin-bottom: 16px; font-weight: 500;
}
.pd-hero__desc {
  font-size: 15px; color: #555; line-height: 1.6; margin-bottom: 32px;
}

.pd-actions .btn {color: #000;}

/* Icon Tính năng */
.pd-hero__features {
  display: flex; gap: 32px; margin-bottom: 40px; padding-bottom: 32px; border-bottom: 1px solid var(--color-border);
}
.feat-item {
  display: flex; flex-direction: column; align-items: center; text-align: center; gap: 12px;
}
.feat-icon {
  width: 56px; height: 56px; border-radius: 50%; border: 1px solid var(--color-border);
  display: flex; align-items: center; justify-content: center;
}
.feat-icon img { width: 28px; height: 28px; }
.feat-item span { font-size: 13px; font-weight: 600; color: var(--color-primary); line-height: 1.3; }

/* Dung tích */
.pd-capacity { margin-bottom: 40px; }
.pd-capacity__title { font-size: 15px; margin-bottom: 12px; color: var(--color-text); }
.pd-capacity__options { display: flex; gap: 12px; }
.capacity-btn {
  padding: 10px 24px; border: 1px solid var(--color-border); background: var(--color-white);
  font-size: 14px; font-weight: 600; color: var(--color-text); border-radius: 4px; cursor: pointer; transition: 0.2s;
}
.capacity-btn:hover { border-color: var(--color-primary); }
.capacity-btn.is-active { background: var(--color-primary); color: var(--color-white); border-color: var(--color-primary); }

/* Buttons */
.pd-actions { display: flex; gap: 16px; }

/* =========================================
   STICKY NAVIGATION
   ========================================= */
.pd-nav {
  background-color: var(--color-primary);
  position: sticky;
  top: 80px; /* Dính ngay dưới Main Header */
  z-index: 100;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
.pd-nav__list {
  display: flex; list-style: none; padding: 0; margin: 0; overflow-x: auto;
}
.pd-nav__list li { flex-shrink: 0; }
.pd-nav__list a {
  display: block; padding: 20px 24px; color: rgba(255,255,255,0.7); text-decoration: none;
  font-size: 14px; font-weight: 600; transition: 0.2s; border-bottom: 3px solid transparent;
}
.pd-nav__list a:hover { color: var(--color-white); }
.pd-nav__list a.is-active {
  color: var(--color-white); border-bottom-color: var(--color-cta);
}

/* =========================================
   ƯU ĐIỂM NỔI BẬT
   ========================================= */
.pd-section__header { margin-bottom: 48px; }
.pd-section__header .header-left { max-width: 500px; }
.pd-section__header .header-right { max-width: 400px; font-size: 14px; color: #555; }

.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.adv-card__img { position: relative; margin-bottom: 24px; }
.adv-card__img > img { width: 100%; height: 200px; object-fit: cover; border-radius: 8px; }
.adv-card__icon {
  position: absolute; bottom: -20px; left: 20px; width: 48px; height: 48px;
  background: var(--color-white); border-radius: 50%; box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  display: flex; align-items: center; justify-content: center;
}
.adv-card__icon img { width: 24px; height: 24px; }
.adv-card__title { font-size: 16px; font-weight: 700; color: var(--color-primary); margin-bottom: 12px; line-height: 1.4; }
.adv-card__desc { font-size: 14px; color: #555; line-height: 1.5; }

/* =========================================
   ỨNG DỤNG THỰC TẾ
   ========================================= */
.app-grid { display: grid; grid-template-columns: 4fr 8fr; gap: 60px; align-items: center; }
.app-list { list-style: none; padding: 0; margin-top: 32px; }
.app-list li { display: flex; align-items: center; gap: 16px; margin-bottom: 20px; font-size: 15px; font-weight: 600; color: var(--color-primary); }
.app-list .icon-wrap { width: 40px; height: 40px; border: 1px solid var(--color-border); border-radius: 50%; display: flex; align-items: center; justify-content: center; }
.app-list .icon { width: 20px; height: 20px; }

.app-img-wrap { position: relative; }
.app-img-wrap img { width: 100%; height: auto; border-radius: 12px; }
.app-quote {
  position: absolute; top: 32px; left: -32px; background: var(--color-primary); color: var(--color-white);
  padding: 24px 32px; font-family: 'Playfair Display', serif; font-size: 20px; font-style: italic;
  border-radius: 8px; box-shadow: 0 12px 24px rgba(17, 27, 87, 0.2);
}

/* =========================================
   THÔNG SỐ KỸ THUẬT
   ========================================= */
.specs-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 60px; }
.specs-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.specs-table td { padding: 16px 0; border-bottom: 1px solid var(--color-border); color: #444; }
.specs-table td:first-child { font-weight: 600; width: 35%; color: var(--color-primary); }

.specs-info-list { list-style: none; padding: 0; }
.specs-info-list li { display: flex; gap: 20px; margin-bottom: 32px; }
.specs-info-list .icon-wrap { color: var(--color-primary); }
.specs-info-list .icon { width: 32px; height: 32px; }
.info-text h5 { font-size: 15px; font-weight: 700; color: var(--color-primary); margin-bottom: 4px; }
.info-text p { font-size: 14px; color: #444; line-height: 1.5; }
.info-text span { font-size: 12px; color: #888; }

/* =========================================
   HƯỚNG DẪN THI CÔNG
   ========================================= */
.steps-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 24px; margin-top: 48px; }
.step-num { font-size: 32px; font-weight: 800; color: var(--color-primary); margin-bottom: 8px; font-family: 'Playfair Display', serif; }
.step-title { font-size: 16px; font-weight: 700; margin-bottom: 20px; height: 40px; }
.step-img { width: 100%; aspect-ratio: 4/3; object-fit: cover; border-radius: 8px; margin-bottom: 16px; }
.step-desc { font-size: 13.5px; color: #555; line-height: 1.5; }

/* =========================================
   TÀI LIỆU KỸ THUẬT
   ========================================= */
.docs-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.doc-card {
  display: flex; align-items: center; gap: 16px; padding: 24px; border: 1px solid var(--color-border);
  border-radius: 8px; text-decoration: none; color: var(--color-text); transition: 0.3s;
}
.doc-card:hover { border-color: var(--color-primary); box-shadow: 0 8px 16px rgba(0,0,0,0.05); }
.doc-icon { width: 32px; height: 32px; }
.doc-info { flex: 1; }
.doc-info h4 { font-size: 15px; font-weight: 700; margin-bottom: 4px; color: var(--color-primary); }
.doc-info span { font-size: 12px; color: #888; }
.dl-icon { width: 20px; height: 20px; color: var(--color-primary); }

/* =========================================
   BOTTOM CTA
   ========================================= */
.bottom-cta { padding: 80px 0; background-size: cover; background-position: center; position: relative; color: var(--color-white); }
.bottom-cta::before { content: ''; position: absolute; inset: 0; background: rgb(135 135 135 / 61%); }
.bottom-cta__inner { position: relative; z-index: 2; display: flex; justify-content: space-between; align-items: center; }
.bottom-cta__text h2 { font-size: 28px; font-weight: 700; margin-bottom: 12px; }
.bottom-cta__text p { font-size: 15px; opacity: 0.9; }
.bottom-cta__actions { display: flex; gap: 16px; }

/* =========================================
   RESPONSIVE
   ========================================= */
@media (max-width: 1199px) {
  .pd-hero__right { padding: 40px; }
  .pd-hero__title { font-size: 32px; }
  .pd-hero__features { gap: 16px; flex-wrap: wrap; }
  .adv-grid { grid-template-columns: repeat(2, 1fr); gap: 40px 24px; }
  .steps-grid { grid-template-columns: repeat(3, 1fr); gap: 40px 24px; }
}

@media (max-width: 991px) {
  .pd-hero__grid { grid-template-columns: 1fr; }
  .pd-hero__left { min-height: 400px; padding: 32px; }
  .pd-section__header { flex-direction: column; align-items: flex-start; gap: 16px; }
  .app-grid { grid-template-columns: 1fr; }
  .app-quote { position: relative; top: -30px; left: 20px; display: inline-block; padding: 16px 24px; font-size: 16px; }
  .specs-grid { grid-template-columns: 1fr; gap: 40px; }
  .docs-grid { grid-template-columns: 1fr; }
  .bottom-cta__inner { flex-direction: column; text-align: center; gap: 24px; }
}

@media (max-width: 767px) {
  .pd-hero__features { grid-template-columns: 1fr 1fr; display: grid; }
  .pd-actions { flex-direction: column; }
  .adv-grid { grid-template-columns: 1fr; }
  .steps-grid { grid-template-columns: 1fr; }
  .bottom-cta__actions { flex-direction: column; width: 100%; }
}