/* ==========================================================================
   PORTFOLIO - ĐÀO NGUYỄN NGỌC QUẾ
   Vị trí: Chăm sóc khách hàng part-time (online) - Trung tâm IELTS
   Bảng màu: Navy #1F2A44 | Nền #FFFFFF | Pastel #E8EEF7, #F1F3F6, #FBF3DC
   Phong cách: Mộc mạc, chỉn chu, có hệ thống, không gradient, không glassmorphism
   ========================================================================== */

:root {
  /* Màu chủ đạo */
  --color-navy: #1F2A44;
  --color-navy-hover: #162035;
  --color-navy-light: #2C3E63;
  --color-white: #FFFFFF;
  
  /* Màu pastel lì (Matte Pastels) */
  --pastel-blue: #E8EEF7;
  --pastel-gray: #F1F3F6;
  --pastel-yellow: #FBF3DC;
  --pastel-green: #E8F5E9;
  
  /* Đường viền & Phân cách */
  --border-light: #E2E8F0;
  --border-subtle: #D8DFEB;
  --border-navy: #1F2A44;
  
  /* Màu chữ */
  --text-main: #1F2A44;
  --text-muted: #53647F;
  --text-soft: #7A89A0;
  --text-white: #FFFFFF;
  
  /* Trạng thái */
  --status-green: #10B981;
  --status-green-bg: #DCFCE7;
  --status-green-border: #86EFAC;
  
  /* Kích thước & Bo góc */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-pill: 9999px;
  
  /* Font chữ */
  --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-display: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  
  /* Khoảng cách */
  --container-max: 1120px;
  --section-padding: 88px;
  --section-padding-mobile: 56px;
  
  /* Hiệu ứng */
  --transition-fast: 0.18s ease;
  --transition-normal: 0.25s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 1.05rem; /* ~16.8px */
  line-height: 1.68;
  color: var(--text-main);
  background-color: var(--color-white);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Headings & Display */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-navy);
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.025em;
}

h1 {
  font-size: clamp(2.4rem, 5.5vw, 4.4rem);
  font-weight: 800;
  letter-spacing: -0.035em;
}

h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 700;
}

h3 {
  font-size: clamp(1.3rem, 2.2vw, 1.7rem);
  font-weight: 700;
}

p {
  color: var(--text-muted);
  margin-bottom: 1rem;
}

p:last-child {
  margin-bottom: 0;
}

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

a:hover {
  color: var(--color-navy-light);
}

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

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

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.container-narrow {
  max-width: 820px;
}

/* ==========================================================================
   NAVIGATION BAR (Fixed, Solid White, Subtle Border)
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: var(--color-white);
  border-bottom: 1px solid var(--border-light);
  z-index: 1000;
  transition: border-color var(--transition-fast);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  color: var(--color-navy);
}

.nav-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: var(--color-navy);
  color: var(--color-white);
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 800;
}

.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 8px;
}

.nav-link {
  display: inline-block;
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-navy);
  background-color: var(--pastel-gray);
}

.nav-link.active {
  color: var(--color-navy);
  background-color: var(--pastel-blue);
  font-weight: 600;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  cursor: pointer;
  color: var(--color-navy);
}

.nav-toggle:focus {
  outline: 2px solid var(--color-navy);
}

/* ==========================================================================
   BUTTONS & BADGES
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
  border: 1px solid transparent;
}

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

.btn-primary:hover {
  background-color: var(--color-navy-hover);
  color: var(--color-white);
  transform: translateY(-2px);
}

.btn-secondary {
  background-color: var(--pastel-gray);
  color: var(--color-navy);
  border-color: var(--border-light);
}

.btn-secondary:hover {
  background-color: #E6EAF0;
  color: var(--color-navy);
  transform: translateY(-2px);
}

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

.btn-outline:hover {
  background-color: var(--color-navy);
  color: var(--color-white);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.88rem;
  border-radius: var(--radius-sm);
}

/* Status Badges */
.badge-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background-color: var(--pastel-green);
  border: 1px solid var(--status-green-border);
  border-radius: var(--radius-pill);
  font-size: 0.85rem;
  font-weight: 600;
  color: #065F46;
}

.status-dot {
  width: 8px;
  height: 8px;
  background-color: var(--status-green);
  border-radius: 50%;
  display: inline-block;
  position: relative;
}

.status-dot::after {
  content: '';
  position: absolute;
  top: -2px;
  left: -2px;
  right: -2px;
  bottom: -2px;
  border-radius: 50%;
  background-color: var(--status-green);
  opacity: 0.4;
  animation: pulse-ring 2s infinite ease-out;
}

@keyframes pulse-ring {
  0% { transform: scale(1); opacity: 0.6; }
  70% { transform: scale(2.2); opacity: 0; }
  100% { transform: scale(2.2); opacity: 0; }
}

/* Pill Tags */
.tag-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-navy);
  background-color: var(--pastel-blue);
  border: 1px solid var(--border-subtle);
  transition: transform var(--transition-fast), background-color var(--transition-fast);
}

.tag-pill:hover {
  transform: translateY(-2px);
  background-color: #DDE7F5;
}

.tag-pill-gray {
  background-color: var(--pastel-gray);
  border-color: var(--border-light);
}

.tag-pill-yellow {
  background-color: var(--pastel-yellow);
  border-color: #EFE4BF;
}

/* ==========================================================================
   HERO SECTION (HOME)
   ========================================================================== */
.hero-section {
  padding-top: 140px;
  padding-bottom: 72px;
}

.hero-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.hero-greeting {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

.hero-name {
  margin-bottom: 24px;
  line-height: 1.12;
}

.hero-lead {
  font-size: 1.25rem;
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 780px;
  margin-bottom: 36px;
}

.hero-lead strong {
  color: var(--color-navy);
  font-weight: 600;
}

.scroll-hint {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  margin-top: 16px;
  transition: color var(--transition-fast);
}

.scroll-hint svg {
  animation: bounce-subtle 2s infinite ease-in-out;
}

.scroll-hint:hover {
  color: var(--color-navy);
}

@keyframes bounce-subtle {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(5px); }
}

/* ==========================================================================
   MỤC "MÌNH LÀ AI?" & KỸ NĂNG DẠNG VIÊN THUỐC
   ========================================================================== */
.section-who {
  padding: 64px 0;
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  background-color: #FAFBFD;
}

.who-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.who-content h2 {
  margin-bottom: 16px;
  font-size: 2.1rem;
}

.who-description {
  font-size: 1.15rem;
  line-height: 1.65;
  color: var(--color-navy);
  font-weight: 500;
  margin-bottom: 28px;
}

.pill-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}

.who-action {
  margin-top: 8px;
}

/* ==========================================================================
   CỤM ẢNH ĐỜI THƯỜNG XẾP LỆCH (COLLAGE)
   ========================================================================== */
.collage-section {
  padding: 72px 0 88px;
}

.collage-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 20px;
  align-items: center;
}

.photo-card {
  position: relative;
  background-color: var(--color-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 8px;
  transition: transform var(--transition-normal), border-color var(--transition-fast);
}

.photo-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-navy);
}

.photo-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--radius-md);
  display: block;
}

.photo-badge {
  position: absolute;
  bottom: 18px;
  left: 18px;
  background-color: rgba(31, 42, 68, 0.92);
  color: var(--color-white);
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}

/* Vị trí lệch nhau */
.photo-card.card-1 {
  grid-column: 1 / 5;
  height: 380px;
  transform: rotate(-1.5deg);
}

.photo-card.card-2 {
  grid-column: 5 / 9;
  height: 420px;
  margin-top: -30px;
  transform: rotate(1deg);
}

.photo-card.card-3 {
  grid-column: 9 / 13;
  height: 360px;
  transform: rotate(-1deg);
}

.photo-card.card-1:hover,
.photo-card.card-2:hover,
.photo-card.card-3:hover {
  transform: translateY(-5px) rotate(0deg);
}

/* ==========================================================================
   3 THẺ SỐ LIỆU (STATS CARDS)
   ========================================================================== */
.stats-section {
  padding: 40px 0 88px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.stat-card {
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  border: 1px solid var(--border-light);
  transition: transform var(--transition-normal), border-color var(--transition-fast);
}

.stat-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-navy);
}

.stat-card.blue {
  background-color: var(--pastel-blue);
  border-color: #D4DFEE;
}

.stat-card.gray {
  background-color: var(--pastel-gray);
  border-color: #E2E6EC;
}

.stat-card.yellow {
  background-color: var(--pastel-yellow);
  border-color: #EFE3BC;
}

.stat-number {
  font-size: clamp(1.8rem, 2.8vw, 2.3rem);
  font-weight: 800;
  color: var(--color-navy);
  line-height: 1.2;
  margin-bottom: 12px;
}

.stat-desc {
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin: 0;
}

/* ==========================================================================
   MỤC "VÀI THỨ MÌNH ĐÃ LÀM" (CASE STUDIES TRANG CHỦ)
   ========================================================================== */
.section-work {
  padding: 88px 0;
  border-top: 1px solid var(--border-light);
}

.section-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

.section-subtitle {
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-soft);
  margin-bottom: 6px;
}

.section-title {
  font-size: clamp(1.9rem, 3.2vw, 2.5rem);
  font-weight: 800;
  color: var(--color-navy);
}

.section-link {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-navy);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border-bottom: 2px solid var(--color-navy);
  padding-bottom: 3px;
  transition: all var(--transition-fast);
}

.section-link:hover {
  opacity: 0.8;
  gap: 10px;
}

/* Case Study Cards List */
.case-cards-list {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.case-card-large {
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 36px;
  align-items: center;
  background-color: var(--color-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: transform var(--transition-normal), border-color var(--transition-fast);
}

.case-card-large:hover {
  transform: translateY(-3px);
  border-color: var(--border-navy);
}

.case-card-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}

.case-index {
  font-size: 0.95rem;
  font-weight: 800;
  color: var(--color-navy);
  padding: 4px 10px;
  background-color: var(--pastel-gray);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
}

.case-date {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-soft);
}

.case-card-title {
  font-size: clamp(1.35rem, 2vw, 1.7rem);
  margin-bottom: 14px;
  line-height: 1.35;
}

.case-card-title a {
  color: var(--color-navy);
}

.case-card-title a:hover {
  text-decoration: underline;
}

.case-card-desc {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
}

.case-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.case-card-image {
  background-color: var(--pastel-gray);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-light);
  aspect-ratio: 16 / 10;
  display: flex;
  align-items: center;
  justify-content: center;
}

.case-card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-normal);
}

.case-card-large:hover .case-card-image img {
  transform: scale(1.02);
}

/* ==========================================================================
   CHÂN TRANG (FOOTER & CTA)
   ========================================================================== */
.site-footer {
  background-color: #FAFBFD;
  border-top: 1px solid var(--border-light);
  padding: 88px 0 40px;
}

.footer-cta {
  background-color: var(--color-navy);
  color: var(--color-white);
  border-radius: var(--radius-lg);
  padding: 56px 48px;
  margin-bottom: 64px;
}

.footer-cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
}

.footer-cta-title {
  color: var(--color-white);
  font-size: clamp(2rem, 3.8vw, 2.9rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.footer-cta-msg {
  color: #D1DCE8;
  font-size: 1.15rem;
  max-width: 580px;
  margin-bottom: 0;
  line-height: 1.6;
}

.footer-cta-action {
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: flex-start;
}

.footer-cta-action .btn-primary {
  background-color: var(--color-white);
  color: var(--color-navy);
}

.footer-cta-action .btn-primary:hover {
  background-color: #F1F3F6;
  color: var(--color-navy);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: 1px solid var(--border-light);
  font-size: 0.92rem;
  color: var(--text-soft);
}

.footer-links {
  display: flex;
  gap: 20px;
  list-style: none;
}

.footer-links a {
  color: var(--text-muted);
}

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

/* ==========================================================================
   PAGE: ABOUT
   ========================================================================== */
.about-header {
  padding-top: 140px;
  padding-bottom: 48px;
}

.about-intro-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 48px;
  align-items: start;
  margin-bottom: 72px;
}

.about-text-lead {
  font-size: 1.2rem;
  line-height: 1.7;
  color: var(--color-navy);
  font-weight: 500;
  margin-bottom: 20px;
}

.about-text-p {
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.about-portrait-card {
  position: sticky;
  top: 100px;
  background-color: var(--color-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 12px;
}

.about-portrait-img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-radius: var(--radius-md);
  margin-bottom: 14px;
}

.about-portrait-caption {
  font-size: 0.92rem;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.5;
}

/* Education Box */
.section-edu {
  padding: 48px 0;
  border-top: 1px solid var(--border-light);
}

.edu-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 28px;
}

.edu-card {
  background-color: var(--pastel-gray);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 30px;
}

.edu-card.highlight {
  background-color: var(--pastel-blue);
  border-color: #D4DFEE;
}

.edu-school {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-navy);
  margin-bottom: 8px;
}

.edu-major {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.edu-scores {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.score-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background-color: var(--color-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-pill);
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--color-navy);
}

/* Timeline */
.section-timeline {
  padding: 64px 0;
  border-top: 1px solid var(--border-light);
}

.timeline-list {
  display: flex;
  flex-direction: column;
  gap: 28px;
  margin-top: 32px;
  position: relative;
}

.timeline-list::before {
  content: '';
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 19px;
  width: 2px;
  background-color: var(--border-light);
}

.timeline-item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 24px;
  position: relative;
}

.timeline-marker {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--pastel-blue);
  border: 2px solid var(--color-navy);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.85rem;
  color: var(--color-navy);
  z-index: 1;
}

.timeline-card {
  background-color: var(--color-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  transition: border-color var(--transition-fast);
}

.timeline-card:hover {
  border-color: var(--border-navy);
}

.timeline-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}

.timeline-role {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-navy);
}

.timeline-period {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-soft);
  background-color: var(--pastel-gray);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
}

.timeline-body ul {
  padding-left: 20px;
  margin-top: 8px;
}

.timeline-body li {
  color: var(--text-muted);
  font-size: 0.98rem;
  margin-bottom: 6px;
  line-height: 1.6;
}

/* Reference & Availability Boxes */
.info-callout-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin: 48px 0;
}

.info-callout {
  border-radius: var(--radius-lg);
  padding: 30px;
  border: 1px solid var(--border-light);
}

.info-callout.yellow {
  background-color: var(--pastel-yellow);
  border-color: #EFE4BF;
}

.info-callout.blue {
  background-color: var(--pastel-blue);
  border-color: #D4DFEE;
}

.info-callout-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-navy);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.info-callout-text {
  font-size: 0.98rem;
  line-height: 1.6;
  color: var(--text-main);
  margin: 0;
}

/* ==========================================================================
   PAGE: CASE STUDY DETAIL TEMPLATE (Khung 5 bước)
   ========================================================================== */
.cs-header {
  padding-top: 130px;
  padding-bottom: 40px;
}

.cs-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-soft);
  margin-bottom: 18px;
}

.cs-breadcrumb a {
  color: var(--text-muted);
}

.cs-breadcrumb a:hover {
  color: var(--color-navy);
}

.cs-title {
  font-size: clamp(2rem, 3.8vw, 3rem);
  line-height: 1.25;
  margin-bottom: 20px;
}

.cs-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  padding: 16px 20px;
  background-color: var(--pastel-gray);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  margin-bottom: 36px;
  font-size: 0.92rem;
}

.cs-meta-item strong {
  color: var(--color-navy);
}

.cs-cover-wrapper {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
  background-color: var(--pastel-gray);
  margin-bottom: 56px;
}

.cs-cover-img {
  width: 100%;
  max-height: 520px;
  object-fit: contain;
  background-color: #F8FAFC;
}

/* 5-Step Framework */
.cs-step {
  margin-bottom: 56px;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--border-light);
}

.cs-step:last-of-type {
  border-bottom: none;
  padding-bottom: 0;
}

.cs-step-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}

.cs-step-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 4px 12px;
  background-color: var(--color-navy);
  color: var(--color-white);
  border-radius: var(--radius-pill);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.cs-step-title {
  font-size: clamp(1.4rem, 2.2vw, 1.85rem);
}

.cs-text {
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.cs-text strong {
  color: var(--color-navy);
}

/* Image Showcase inside Case Study */
.cs-image-box {
  background-color: var(--pastel-gray);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 16px;
  margin: 28px 0;
}

.cs-image-box img {
  border-radius: var(--radius-md);
  width: 100%;
  border: 1px solid var(--border-light);
  background-color: var(--color-white);
}

.cs-image-caption {
  margin-top: 10px;
  font-size: 0.9rem;
  color: var(--text-soft);
  text-align: center;
  font-weight: 500;
}

/* Formula & Code Box */
.formula-block {
  background-color: #F8FAFC;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  margin: 24px 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.92rem;
  color: var(--color-navy);
  line-height: 1.6;
  overflow-x: auto;
}

.formula-tag {
  display: inline-block;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  background-color: var(--pastel-blue);
  color: var(--color-navy);
  font-weight: 700;
  font-size: 0.85rem;
  margin-right: 6px;
  margin-bottom: 6px;
  border: 1px solid var(--border-subtle);
}

/* Message Template Box (Case Study 2) */
.message-template-card {
  background-color: #FFFFFF;
  border: 2px solid var(--pastel-blue);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin: 28px 0;
  box-shadow: none;
}

.message-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-light);
}

.message-card-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-navy);
}

.message-text {
  font-size: 0.98rem;
  line-height: 1.7;
  color: var(--color-navy);
  background-color: var(--pastel-gray);
  padding: 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  white-space: pre-line;
}

/* Results Highlight Box */
.results-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin: 28px 0;
}

.result-item {
  background-color: var(--pastel-blue);
  border: 1px solid #D4DFEE;
  border-radius: var(--radius-md);
  padding: 24px;
}

.result-val {
  font-size: 1.7rem;
  font-weight: 800;
  color: var(--color-navy);
  margin-bottom: 8px;
}

.result-label {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin: 0;
}

/* Placeholder callout badge */
.badge-placeholder {
  display: inline-block;
  padding: 2px 6px;
  background-color: #FEF3C7;
  color: #92400E;
  border: 1px dashed #F59E0B;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 700;
}

/* ==========================================================================
   PAGE: CONTACT & CV
   ========================================================================== */
.contact-header {
  padding-top: 140px;
  padding-bottom: 40px;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 56px;
  margin-bottom: 72px;
}

.contact-info-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin: 32px 0;
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact-info-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background-color: var(--pastel-blue);
  border: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-navy);
  flex-shrink: 0;
}

.contact-info-label {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-soft);
  margin-bottom: 4px;
}

.contact-info-value {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-navy);
}

.contact-form-card {
  background-color: var(--color-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 36px;
}

.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--color-navy);
  margin-bottom: 8px;
}

.form-input, .form-textarea {
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  background-color: var(--pastel-gray);
  color: var(--color-navy);
  font-size: 0.98rem;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.form-input:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--color-navy);
  background-color: var(--color-white);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

/* Image fallback placeholder styling */
.img-placeholder-box {
  width: 100%;
  aspect-ratio: 16 / 9;
  background-color: var(--pastel-gray);
  border: 2px dashed var(--border-subtle);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px;
  text-align: center;
  color: var(--text-muted);
}

.img-placeholder-box .file-name {
  font-family: monospace;
  font-weight: 700;
  color: var(--color-navy);
  font-size: 1rem;
  margin-bottom: 6px;
}

.img-placeholder-box .file-ratio {
  font-size: 0.88rem;
  color: var(--text-soft);
}

/* ==========================================================================
   RESPONSIVE DESIGN (Mobile First & Breakpoints)
   ========================================================================== */
@media (max-width: 992px) {
  .who-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }
  
  .collage-grid {
    grid-template-columns: 1fr;
  }
  
  .photo-card.card-1,
  .photo-card.card-2,
  .photo-card.card-3 {
    grid-column: auto;
    height: 320px;
    transform: none !important;
    margin-top: 0;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .case-card-large {
    grid-template-columns: 1fr;
  }
  
  .about-intro-grid {
    grid-template-columns: 1fr;
  }
  
  .about-portrait-card {
    position: static;
    max-width: 400px;
    margin: 0 auto 36px;
  }
  
  .edu-grid {
    grid-template-columns: 1fr;
  }
  
  .contact-grid {
    grid-template-columns: 1fr;
  }
  
  .results-grid {
    grid-template-columns: 1fr;
  }
  
  .info-callout-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .hero-section {
    padding-top: 108px;
    padding-bottom: 48px;
  }
  
  .nav-menu {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--border-light);
    flex-direction: column;
    padding: 16px 24px;
    gap: 8px;
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.05);
  }
  
  .nav-menu.open {
    display: flex;
  }
  
  .nav-link {
    width: 100%;
    padding: 12px 16px;
  }
  
  .nav-toggle {
    display: block;
  }
  
  .footer-cta {
    padding: 36px 24px;
  }
  
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* ==========================================================================
   ACCESSIBILITY: PREFERS REDUCED MOTION
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}