/* =============================================================
   KONGREAL — Premium Utilitarian Minimalism
   Protocol: Warm Monochrome + Editorial Serif
   Stack: Vanilla CSS | No Tailwind | No Glassmorphism
   Design Variance: 8 | Motion Intensity: 6 | Visual Density: 4
   ============================================================= */

/* ── Google Fonts ─────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Newsreader:ital,opsz,wght@0,6..72,300;0,6..72,400;0,6..72,500;1,6..72,300;1,6..72,400&family=Outfit:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ── Design Tokens — Light Mode ───────────────────────────── */
:root {
  /* Canvas */
  --canvas:        #F7F6F3;
  --canvas-warm:   #EFEFEC;
  --surface:       #FFFFFF;
  --surface-2:     #F4F3F0;

  /* Borders — increased contrast */
  --border:        #D8D8D5;
  --border-muted:  rgba(0,0,0,0.09);

  /* Text — stronger contrast */
  --text-primary:   #0D0D0D;
  --text-secondary: #5A5956;
  --text-tertiary:  #9A9997;

  /* Muted Pastel Accents */
  --accent-red-bg:    #FDEBEC;
  --accent-red-text:  #9F2F2D;
  --accent-blue-bg:   #E1F3FE;
  --accent-blue-text: #1F6C9F;
  --accent-green-bg:  #EDF3EC;
  --accent-green-text:#346538;
  --accent-yellow-bg: #FBF3DB;
  --accent-yellow-text:#956400;

  /* Typography */
  --font-sans:  'Outfit', 'Helvetica Neue', system-ui, sans-serif;
  --font-serif: 'Newsreader', 'Georgia', serif;
  --font-mono:  'JetBrains Mono', 'SF Mono', monospace;

  /* Spacing scale */
  --space-xs:  8px;
  --space-sm:  16px;
  --space-md:  24px;
  --space-lg:  40px;
  --space-xl:  80px;
  --space-2xl: 128px;

  /* Z-index scale */
  --z-ambient: -1;
  --z-base:     0;
  --z-card:     1;
  --z-sticky:  10;
  --z-overlay: 20;
  --z-modal:   30;

  /* Animation */
  --ease-spring: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-out:    cubic-bezier(0.33, 1, 0.68, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --duration-fast:   180ms;
  --duration-medium: 400ms;
  --duration-slow:   600ms;
}

/* ── Design Tokens — Dark Mode ────────────────────────────── */
[data-theme="dark"] {
  --canvas:        #111110;
  --canvas-warm:   #1A1917;
  --surface:       #1E1D1B;
  --surface-2:     #252422;

  --border:        #2E2D2B;
  --border-muted:  rgba(255,255,255,0.07);

  --text-primary:   #F0EFEC;
  --text-secondary: #938F8A;
  --text-tertiary:  #5E5B57;

  /* Pastels adjust for dark bg */
  --accent-red-bg:    rgba(159,47,45,0.18);
  --accent-red-text:  #F4908E;
  --accent-blue-bg:   rgba(31,108,159,0.18);
  --accent-blue-text: #7EC4EF;
  --accent-green-bg:  rgba(52,101,56,0.18);
  --accent-green-text:#8FCF8E;
  --accent-yellow-bg: rgba(149,100,0,0.2);
  --accent-yellow-text:#E8BF6A;
}

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

html {
  scroll-behavior: smooth;
  /* Offset anchor scrolls by sticky nav height + breathing room */
  scroll-padding-top: 84px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* Each anchored section clears the sticky nav on scroll-to */
section[id],
div[id="education"] {
  scroll-margin-top: 84px;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--canvas);
  overflow-x: hidden;
}

/* ── Ambient Background Layer (fixed, non-scrolling) ──────── */
.ambient-bg {
  position: fixed;
  inset: 0;
  z-index: var(--z-ambient);
  pointer-events: none;
  background:
    radial-gradient(ellipse 900px 700px at 15% 20%, rgba(251, 243, 219, 0.18) 0%, transparent 60%),
    radial-gradient(ellipse 600px 500px at 85% 80%, rgba(237, 243, 236, 0.12) 0%, transparent 55%);
  animation: ambientDrift 28s ease-in-out infinite alternate;
  will-change: transform;
}

@keyframes ambientDrift {
  0%   { transform: translate(0, 0) scale(1); }
  50%  { transform: translate(18px, -12px) scale(1.015); }
  100% { transform: translate(-10px, 14px) scale(0.988); }
}

/* Noise grain overlay */
.ambient-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='1'/%3E%3C/svg%3E");
  background-size: 200px 200px;
  pointer-events: none;
}

/* ── Container ────────────────────────────────────────────── */
.container {
  max-width: 1100px;
  margin-inline: auto;
  padding-inline: clamp(20px, 5vw, 48px);
}

/* ── Skip Link ────────────────────────────────────────────── */
.skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-sm);
  background: var(--text-primary);
  color: var(--surface);
  padding: 8px 16px;
  border-radius: 4px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  z-index: 100;
  transition: top var(--duration-fast);
}
.skip-link:focus {
  top: var(--space-sm);
}

/* ── Navigation ───────────────────────────────────────────── */
.glass-nav {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background: rgba(247, 246, 243, 0.90);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  transition: background var(--duration-medium) var(--ease-out),
              border-color var(--duration-medium) var(--ease-out);
}

[data-theme="dark"] .glass-nav {
  background: rgba(17, 17, 16, 0.90);
}

.glass-nav.scrolled {
  border-bottom-color: var(--border);
  box-shadow: 0 1px 0 var(--border);
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  gap: var(--space-md);
}

.logo {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 400;
  font-style: italic;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  text-decoration: none;
  transition: opacity var(--duration-fast);
}
.logo:hover { opacity: 0.65; }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.nav-link {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 400;
  color: var(--text-secondary);
  text-decoration: none;
  letter-spacing: 0.01em;
  transition: color var(--duration-fast);
  position: relative;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--text-primary);
  transition: width var(--duration-medium) var(--ease-spring);
}
.nav-link:hover,
.nav-link.nav-active {
  color: var(--text-primary);
}
.nav-link:hover::after,
.nav-link.nav-active::after {
  width: 100%;
}

.btn-nav {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  background: var(--text-primary);
  color: var(--surface);
  text-decoration: none;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.02em;
  border-radius: 5px;
  border: none;
  cursor: pointer;
  transition:
    background var(--duration-fast),
    transform var(--duration-fast);
}
.btn-nav:hover { background: #2a2a2a; }
.btn-nav:active { transform: scale(0.97); }

/* ── Theme Toggle Button ────────────────────────────────── */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 13px;
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 5px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition:
    background var(--duration-fast),
    color var(--duration-fast),
    border-color var(--duration-fast),
    transform var(--duration-fast);
  user-select: none;
  flex-shrink: 0;
}
.theme-toggle:hover {
  color: var(--text-primary);
  border-color: var(--text-primary);
  background: var(--canvas-warm);
}
.theme-toggle:active { transform: scale(0.97); }
.theme-toggle svg { flex-shrink: 0; }

/* Dark mode icon swaps */
[data-theme="dark"] .icon-sun  { display: none; }
[data-theme="light"] .icon-moon { display: none; }
.icon-moon { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

/* ── Scroll Reveal System ─────────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition:
    opacity var(--duration-slow) var(--ease-spring),
    transform var(--duration-slow) var(--ease-spring);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}
.reveal[style*="--index"] {
  transition-delay: calc(var(--index, 0) * 80ms);
}

/* ── Main Layout ──────────────────────────────────────────── */
.main-content {
  padding-block: var(--space-xl);
}

section + section {
  margin-top: var(--space-2xl);
}

/* ── Section Titles ───────────────────────────────────────── */
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: var(--space-sm);
}
.section-label::before {
  content: '';
  display: block;
  width: 20px;
  height: 1px;
  background: var(--text-secondary);
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 400;
  letter-spacing: -0.025em;
  line-height: 1.15;
  color: var(--text-primary);
  margin-bottom: var(--space-lg);
}
.section-title.text-center {
  text-align: center;
}

/* ── Tags / Badges ────────────────────────────────────────── */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 10px;
  border-radius: 9999px;
  font-family: var(--font-sans);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  line-height: 1.5;
}
.tag--red    { background: var(--accent-red-bg);    color: var(--accent-red-text); }
.tag--blue   { background: var(--accent-blue-bg);   color: var(--accent-blue-text); }
.tag--green  { background: var(--accent-green-bg);  color: var(--accent-green-text); }
.tag--yellow { background: var(--accent-yellow-bg); color: var(--accent-yellow-text); }

.tag-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.7;
}

/* ── kbd Elements ─────────────────────────────────────────── */
kbd {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 7px;
  background: var(--canvas-warm);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-secondary);
  vertical-align: baseline;
  white-space: nowrap;
}

/* ── Base Card ────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  transition:
    box-shadow var(--duration-medium) var(--ease-out),
    transform var(--duration-medium) var(--ease-out);
}
.card:hover {
  box-shadow: 0 2px 10px rgba(0,0,0,0.04), 0 0 0 1px rgba(0,0,0,0.02);
}

/* ── ── ── HERO SECTION ── ── ── ──────────────────────────── */
.hero-section {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: clamp(32px, 5vw, 64px);
  align-items: center;
  min-height: calc(100dvh - 60px);
  padding-block: var(--space-xl);
}

/* Hello badge */
.hello-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px 6px 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 9999px;
  margin-bottom: var(--space-md);
  transition: opacity 0.3s;
}

.hello-flag {
  border-radius: 2px;
  object-fit: cover;
  transition: opacity 0.3s var(--ease-out), transform 0.3s var(--ease-out);
}

.hello-text {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 400;
  color: var(--text-secondary);
  transition: opacity 0.3s var(--ease-out);
}

/* Hero heading — editorial serif */
.hero-headline {
  font-family: var(--font-serif);
  font-size: clamp(44px, 7vw, 88px);
  font-weight: 300;
  letter-spacing: -0.04em;
  line-height: 1.0;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
  text-wrap: balance;
}
.hero-headline em {
  font-style: italic;
  font-weight: 300;
  color: var(--text-secondary);
}

/* Hero subtitle with typewriter */
.hero-subtitle {
  font-family: var(--font-sans);
  font-size: clamp(16px, 2.2vw, 21px);
  font-weight: 400;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  line-height: 1.5;
}
.name-highlight {
  color: var(--text-primary);
  font-weight: 600;
}
.typed-text {
  color: var(--text-primary);
  font-weight: 400;
}
.typed-cursor {
  color: var(--text-secondary);
  opacity: 1;
  animation: blink 1.1s step-end infinite;
}
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0} }

/* Hero description */
.hero-desc {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-secondary);
  max-width: 62ch;
  margin-bottom: var(--space-lg);
}
.hero-desc strong {
  color: var(--text-primary);
  font-weight: 500;
}

/* Info grid */
.info-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: var(--space-lg);
}

.info-item {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-secondary);
  padding: 6px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
}
.info-item img,
.info-item svg.svg-icon {
  flex-shrink: 0;
  color: var(--text-secondary);
}

/* Hero CTA row */
.hero-cta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  background: var(--text-primary);
  color: var(--surface);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
  text-decoration: none;
  border-radius: 5px;
  border: none;
  cursor: pointer;
  transition:
    background var(--duration-fast),
    transform var(--duration-fast);
}
.btn-primary:hover { background: #2a2a2a; }
.btn-primary:active { transform: scale(0.97); }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  background: transparent;
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 400;
  letter-spacing: 0.01em;
  text-decoration: none;
  border-radius: 5px;
  border: 1px solid var(--border);
  cursor: pointer;
  transition:
    border-color var(--duration-fast),
    background var(--duration-fast),
    transform var(--duration-fast);
}
.btn-secondary:hover {
  background: var(--surface);
  border-color: #ccc;
}
.btn-secondary:active { transform: scale(0.97); }

/* Hero visual — portrait + floating chips */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.portrait-container {
  position: relative;
  width: 280px;
  height: 280px;
}

.avatar-frame {
  width: 220px;
  height: 220px;
  border-radius: 12px;
  border: 1px solid var(--border);
  overflow: hidden;
  background: var(--canvas-warm);
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
.avatar-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  filter: grayscale(8%);
}

/* Floating chip cards */
.float-chip {
  position: absolute;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 13px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  box-shadow: 0 2px 8px rgba(0,0,0,0.03);
  animation: chipFloat linear infinite alternate;
}
.float-chip svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}
.chip-1 { top: 4px;  left: -30px; animation-duration: 5.3s; animation-delay: 0s; }
.chip-2 { top: 60px; right: -24px; animation-duration: 6.1s; animation-delay: -1.2s; }
.chip-3 { bottom: 50px; left: -36px; animation-duration: 5.8s; animation-delay: -2.5s; }
.chip-4 { bottom: 0;  right: -20px; animation-duration: 6.7s; animation-delay: -0.8s; }

/* On desktop the wrapper is invisible to layout */
.chips-row {
  display: contents;
}

@keyframes chipFloat {
  from { transform: translateY(0px); }
  to   { transform: translateY(-7px); }
}

/* ── Marquee ──────────────────────────────────────────────── */
.marquee-wrapper {
  overflow: hidden;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding-block: 14px;
  margin-block: var(--space-xl);
}
.marquee-content {
  display: flex;
  gap: 0;
  width: max-content;
  animation: marqueeScroll 28s linear infinite;
}
.marquee-content:hover { animation-play-state: paused; }

@keyframes marqueeScroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

.marquee-item {
  display: flex;
  align-items: center;
  gap: 24px;
  padding-inline: 24px;
  font-family: var(--font-serif);
  font-size: 15px;
  font-weight: 300;
  font-style: italic;
  color: var(--text-secondary);
  white-space: nowrap;
}

.marquee-sep {
  display: inline-block;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--border);
  flex-shrink: 0;
}

/* ── Education Section ────────────────────────────────────── */
/* Education — Featured FPT card full-width + 3 certs in a row */
.edu-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
}

/* Featured card (FPT University) */
.edu-card-featured {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  padding: var(--space-lg) clamp(24px, 4vw, 48px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition:
    box-shadow var(--duration-medium) var(--ease-out),
    transform var(--duration-medium) var(--ease-out);
}
.edu-card-featured:hover {
  box-shadow: 0 2px 12px rgba(0,0,0,0.05);
  transform: translateY(-1px);
}
.edu-card-featured .edu-icon-large {
  width: 72px;
  height: 72px;
  border-radius: 12px;
  object-fit: contain;
  flex-shrink: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 8px;
}
.edu-card-featured .edu-featured-content {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.edu-card-featured h4 {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  line-height: 1.15;
}
.edu-card-featured .edu-major {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 500;
  color: var(--text-secondary);
}
.edu-card-featured .edu-period {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
  letter-spacing: 0.04em;
}
.edu-card-featured .edu-tag-row {
  display: flex;
  gap: 6px;
  margin-top: 4px;
}

/* 3-column cert grid below the featured card */
.edu-certs-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
}

.edu-card {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md);
}

.edu-icon {
  width: 44px;
  height: 44px;
  border-radius: 8px;
  object-fit: contain;
  flex-shrink: 0;
  background: var(--canvas-warm);
  border: 1px solid var(--border);
  padding: 6px;
}
.edu-icon-svg {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--canvas-warm);
  border: 1px solid var(--border);
  border-radius: 8px;
  flex-shrink: 0;
  color: var(--text-secondary);
}
.edu-icon-svg svg {
  width: 22px;
  height: 22px;
}
.edu-content h4 {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 3px;
}
.edu-desc {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Dark mode card surface */
[data-theme="dark"] .card,
[data-theme="dark"] .edu-card-featured {
  background: var(--surface);
  border-color: var(--border);
}

[data-theme="dark"] kbd {
  background: var(--canvas-warm);
  border-color: var(--border);
  color: var(--text-secondary);
}

[data-theme="dark"] .ambient-bg {
  background:
    radial-gradient(ellipse 900px 700px at 15% 20%, rgba(60,50,20,0.12) 0%, transparent 60%),
    radial-gradient(ellipse 600px 500px at 85% 80%, rgba(20,50,30,0.08) 0%, transparent 55%);
}

[data-theme="dark"] .contact-cta::before {
  background: radial-gradient(ellipse 700px 500px at 50% 110%, rgba(149,100,0,0.08) 0%, transparent 60%);
}

[data-theme="dark"] .lightbox {
  background: rgba(0,0,0,0.92);
}

[data-theme="dark"] ::selection {
  background: rgba(149,100,0,0.35);
  color: var(--accent-yellow-text);
}

/* ── Bento Skills Grid ────────────────────────────────────── */
.bento-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

/* Asymmetric CSS Grid (DESIGN_VARIANCE: 8) */
.bento-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  grid-template-rows: auto auto;
  gap: var(--space-sm);
}

.bento-item {
  padding: var(--space-lg);
}

.bento-item.span-col-2 {
  grid-column: span 2;
}
.bento-item.span-row-2 {
  grid-row: span 2;
}
.bento-item.col-start-1 {
  grid-column-start: 1;
}
.bento-item.full-row {
  grid-column: 1 / -1;
}

/* SEO flagship card */
.seo-card-header {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: var(--space-md);
}
.seo-icon-wrap {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--canvas-warm);
  border: 1px solid var(--border);
  border-radius: 8px;
  flex-shrink: 0;
}
.seo-card-header h4 {
  font-family: var(--font-sans);
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.2;
  margin-bottom: 4px;
}
.seo-card-header p {
  font-size: 13px;
  color: var(--text-secondary);
}

.seo-sub-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border);
}

.seo-sub-item h5 {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.seo-sub-item p {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
}
.seo-sub-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* Skill brand card */
.skill-brand-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
}
.skill-brand-icon {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border-radius: 8px;
  background: var(--canvas-warm);
  padding: 6px;
  border: 1px solid var(--border);
}
.skill-brand-card h4 {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.2;
}
.skill-brand-card p {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Tool tags row */
.tool-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: auto;
  padding-top: 12px;
}

/* ── Stats row ────────────────────────────────────────────── */
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
}

.stat-item {
  text-align: center;
  padding: var(--space-md);
}

.stat-number {
  font-family: var(--font-serif);
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 300;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--text-primary);
  display: block;
  margin-bottom: 6px;
  font-variant-numeric: tabular-nums;
}

.stat-label {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--text-secondary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ── Experience Timeline ──────────────────────────────────── */
.center-timeline {
  position: relative;
  padding-block: var(--space-sm);
}
.center-timeline::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 1px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  width: 46%;
  margin-bottom: var(--space-lg);
}
.timeline-item.left  { margin-right: auto; margin-left: 0; padding-right: clamp(20px, 4vw, 40px); }
.timeline-item.right { margin-left: auto;  margin-right: 0; padding-left: clamp(20px, 4vw, 40px); }

.timeline-dot {
  position: absolute;
  width: 10px;
  height: 10px;
  background: var(--text-primary);
  border: 2px solid var(--canvas);
  border-radius: 50%;
  top: 20px;
  z-index: var(--z-card);
}
.timeline-item.left  .timeline-dot { right: -5px; transform: translateX(50%); }
.timeline-item.right .timeline-dot { left: -5px;  transform: translateX(-50%); }

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

.tl-date {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-tertiary);
  letter-spacing: 0.05em;
  margin-bottom: 10px;
}

.tl-header-with-logo {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: var(--space-sm);
}

.tl-company-logo {
  width: 36px;
  height: 36px;
  border-radius: 6px;
  object-fit: contain;
  background: var(--canvas-warm);
  border: 1px solid var(--border);
  padding: 4px;
  flex-shrink: 0;
}

.tl-logo-placeholder {
  width: 36px;
  height: 36px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--canvas-warm);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 16px;
  flex-shrink: 0;
}

.tl-header-with-logo h4 {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 3px;
}

.tl-role {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 400;
  color: var(--text-secondary);
}

.timeline-card p {
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-secondary);
  margin-bottom: 10px;
}
.timeline-card p strong {
  color: var(--text-primary);
  font-weight: 600;
}

.tl-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin-top: 10px;
}

.portfolio-link {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 15px;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: opacity var(--duration-fast);
}
.portfolio-link:hover { opacity: 0.6; }

.tl-checklist {
  list-style: none;
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.tl-checklist li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.4;
}
.tl-checklist svg.check-icon {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--accent-green-text);
}

/* ── Gallery / Projects ───────────────────────────────────── */
.gallery-section {
  overflow: hidden;
}

.slide-track-wrapper {
  overflow: hidden;
  border-radius: 12px;
  border: 1px solid var(--border);
  cursor: grab;
  user-select: none;
}
.slide-track-wrapper:active { cursor: grabbing; }

.slide-track {
  display: flex;
  gap: var(--space-sm);
  padding: var(--space-sm);
  animation: slideAuto 30s linear infinite;
  width: max-content;
}
.slide-track:hover { animation-play-state: paused; }

@keyframes slideAuto {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

.slide-item {
  position: relative;
  width: 280px;
  aspect-ratio: 16/10;
  border-radius: 8px;
  overflow: hidden;
  flex-shrink: 0;
  border: 1px solid var(--border);
  cursor: pointer;
}
.slide-item:hover .gallery-overlay { opacity: 1; }

.gallery-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  filter: grayscale(5%);
  transition: transform var(--duration-slow) var(--ease-out);
}
.slide-item:hover .gallery-img {
  transform: scale(1.02);
}

.gallery-overlay {
  position: absolute;
  inset: 0;
  background: rgba(17, 17, 17, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--duration-medium) var(--ease-out);
}
.gallery-label {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: rgba(255,255,255,0.9);
  letter-spacing: 0.04em;
}

/* ── Contact CTA Section ──────────────────────────────────── */
.contact-cta {
  position: relative;
  padding: clamp(48px, 8vw, 96px) clamp(32px, 6vw, 80px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  text-align: center;
}

.contact-cta::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 700px 500px at 50% 110%, rgba(251,243,219,0.22) 0%, transparent 60%);
  pointer-events: none;
}

.cta-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: var(--space-sm);
}

.cta-title {
  font-family: var(--font-serif);
  font-size: clamp(36px, 6vw, 68px);
  font-weight: 300;
  letter-spacing: -0.04em;
  line-height: 1.05;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
  text-wrap: balance;
}

.cta-sub {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  max-width: 52ch;
  margin-inline: auto;
}

.cta-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 22px;
  border-radius: 7px;
  text-decoration: none;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  transition:
    background var(--duration-fast),
    border-color var(--duration-fast),
    transform var(--duration-fast);
}
.cta-btn:active { transform: scale(0.97); }

.cta-btn--email {
  background: var(--text-primary);
  color: var(--surface);
  border: 1px solid var(--text-primary);
}
.cta-btn--email:hover { background: #2a2a2a; border-color: #2a2a2a; }

.cta-btn--zalo {
  background: var(--surface);
  color: var(--text-primary);
  border: 1px solid var(--border);
}
.cta-btn--zalo:hover { border-color: #ccc; background: var(--canvas-warm); }

.cta-btn-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}
.cta-btn-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  line-height: 1.2;
}
.cta-btn-label {
  font-size: 11px;
  opacity: 0.65;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.cta-btn-value {
  font-size: 14px;
  font-weight: 500;
}

/* ── Lightbox ─────────────────────────────────────────────── */
.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(17, 17, 17, 0.88);
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-medium) var(--ease-out);
  backdrop-filter: blur(4px);
}
.lightbox.active {
  opacity: 1;
  pointer-events: auto;
}
.lightbox img {
  max-width: 88vw;
  max-height: 85vh;
  border-radius: 8px;
  object-fit: contain;
  border: 1px solid rgba(255,255,255,0.08);
  transform: scale(0.96);
  transition: transform var(--duration-medium) var(--ease-spring);
}
.lightbox.active img { transform: scale(1); }
.lightbox-close {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.7);
  font-size: 20px;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--duration-fast);
  line-height: 1;
  font-family: var(--font-sans);
}
.lightbox-close:hover { background: rgba(255,255,255,0.14); }

/* ── Footer ───────────────────────────────────────────────── */
.site-footer {
  margin-top: var(--space-2xl);
  border-top: 1px solid var(--border);
  padding-block: var(--space-xl);
}
.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-lg);
  text-align: center;
}

.footer-quote-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 8px;
}

.footer-quote {
  font-family: var(--font-serif);
  font-size: clamp(22px, 4vw, 36px);
  font-weight: 300;
  font-style: italic;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--text-primary);
  max-width: 680px;
}

.footer-quote span {
  color: var(--text-secondary);
}

.social-links {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-secondary);
  text-decoration: none;
  transition:
    border-color var(--duration-fast),
    color var(--duration-fast),
    background var(--duration-fast);
}
.social-link svg {
  width: 16px;
  height: 16px;
}
.social-link:hover {
  border-color: var(--text-primary);
  color: var(--text-primary);
  background: var(--canvas-warm);
}

.footer-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
  justify-content: center;
}
.copyright {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--text-tertiary);
}
.footer-legal-links {
  display: flex;
  gap: var(--space-sm);
}
.footer-legal-links a {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color var(--duration-fast);
}
.footer-legal-links a:hover { color: var(--text-secondary); }

/* ── Focus Styles (Accessibility) ────────────────────────── */
:focus-visible {
  outline: 2px solid var(--text-primary);
  outline-offset: 3px;
  border-radius: 3px;
}

/* ── Selection ────────────────────────────────────────────── */
::selection {
  background: var(--accent-yellow-bg);
  color: var(--accent-yellow-text);
}

/* ── Scrollbar ────────────────────────────────────────────── */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 9999px; }
::-webkit-scrollbar-thumb:hover { background: #ccc; }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 900px) {
  .bento-grid {
    grid-template-columns: 1fr 1fr;
  }
  .bento-item.span-col-2 {
    grid-column: 1 / -1;
  }
  .edu-certs-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  section + section {
    margin-top: var(--space-xl);
  }

  /* Hero stacks vertically on mobile */
  .hero-section {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-block: var(--space-lg);
    gap: var(--space-lg);
  }
  .hero-visual {
    order: -1;
  }
  .portrait-container {
    width: 180px;
    height: 180px;
  }
  .avatar-frame {
    width: 160px;
    height: 160px;
  }
  .float-chip { display: none; }

  /* Nav */
  .nav-links { gap: var(--space-xs); }
  .btn-nav { padding: 7px 12px; font-size: 12px; }
  .theme-toggle { display: none; } /* hide on small nav */
  .nav-link { font-size: 13px; }

  /* Education */
  .edu-card-featured {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-md);
    padding: var(--space-md);
  }
  .edu-certs-grid {
    grid-template-columns: 1fr;
  }

  /* Bento collapse */
  .bento-grid {
    grid-template-columns: 1fr;
  }
  .bento-item.span-col-2,
  .bento-item.span-row-2,
  .bento-item.full-row {
    grid-column: auto;
    grid-row: auto;
  }

  /* Timeline mobile (single column) */
  .center-timeline::before {
    left: 12px;
  }
  .timeline-item {
    width: 100%;
    padding-left: 36px;
    padding-right: 0;
    margin: 0 0 var(--space-md) 0;
  }
  .timeline-item.left  .timeline-dot,
  .timeline-item.right .timeline-dot {
    left: 7px;
    right: auto;
    transform: none;
  }
  .timeline-item.right {
    padding-left: 36px;
  }

  /* Stats */
  .stats-row {
    grid-template-columns: 1fr;
  }
  .stat-item {
    text-align: left;
    border-bottom: 1px solid var(--border);
    border-radius: 0;
  }

  /* CTA */
  .contact-cta {
    padding: 40px 24px;
  }
  .cta-buttons {
    flex-direction: column;
    align-items: stretch;
  }
  .cta-btn {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .hero-headline { font-size: clamp(36px, 11vw, 52px); }
  .edu-grid { grid-template-columns: 1fr; }
  .info-grid { gap: 8px; }
  .nav-links .nav-link:not(:last-child) { display: none; }
}

/* ── Utility ──────────────────────────────────────────────── */
.text-center { text-align: center; }
.mt-auto { margin-top: auto; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border-width: 0;
}

/* ── Tools & Products Section ─────────────────────────────── */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
}

.tool-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  padding: var(--space-lg);
}

/* Header row: badge left, ext-link right */
.tool-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 28px;
}

/* Name */
.tool-name {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  line-height: 1.15;
}

/* Description */
.tool-desc {
  font-family: var(--font-sans);
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-secondary);
  flex-grow: 1;
}

/* Tags row */
.tool-tags-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
  margin-top: auto;
}

/* Status badges */
.tool-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border-radius: 9999px;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.tool-badge--live {
  background: var(--accent-green-bg);
  color: var(--accent-green-text);
}

.tool-badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-green-text);
  animation: pulseGreen 2s ease-in-out infinite;
}

@keyframes pulseGreen {
  0%, 100% { opacity: 1;   transform: scale(1); }
  50%       { opacity: 0.4; transform: scale(0.75); }
}

.tool-badge--soon {
  background: var(--accent-yellow-bg);
  color: var(--accent-yellow-text);
}

/* External link icon button */
.tool-ext-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-tertiary);
  text-decoration: none;
  transition:
    color var(--duration-fast),
    border-color var(--duration-fast),
    background var(--duration-fast);
}
.tool-ext-link:hover {
  color: var(--text-primary);
  border-color: var(--text-primary);
  background: var(--canvas-warm);
}

/* Progress bar */
.tool-progress {
  margin-top: var(--space-xs);
}

.tool-progress-track {
  height: 3px;
  background: var(--border);
  border-radius: 9999px;
  overflow: hidden;
  margin-bottom: 6px;
}

.tool-progress-fill {
  height: 100%;
  width: var(--pct, 0%);
  background: var(--text-primary);
  border-radius: 9999px;
  transition: width 1s var(--ease-spring);
}

.tool-progress-label {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-tertiary);
  letter-spacing: 0.05em;
}

/* Empty slot card */
.tool-card--empty {
  border-style: dashed;
  background: transparent;
}

[data-theme="dark"] .tool-card--empty {
  border-color: var(--border);
}

.tool-empty-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 10px;
  height: 100%;
  min-height: 160px;
}

.tool-empty-icon {
  width: 48px;
  height: 48px;
  border: 1px solid var(--border);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-tertiary);
}

.tool-empty-label {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
}

.tool-empty-sub {
  font-family: var(--font-serif);
  font-size: 12px;
  font-style: italic;
  color: var(--text-tertiary);
}

/* Responsive */
@media (max-width: 900px) {
  .tools-grid { grid-template-columns: 1fr 1fr; }
  .tool-card--empty { display: none; }
}
@media (max-width: 600px) {
  .tools-grid { grid-template-columns: 1fr; }
  .tool-card--empty { display: none; }
}