:root {
  --portfolio-bg: #f3f8ff;
  --portfolio-surface: rgba(255, 255, 255, 0.76);
  --portfolio-surface-strong: #ffffff;
  --portfolio-border: rgba(18, 87, 162, 0.12);
  --portfolio-border-strong: rgba(18, 87, 162, 0.2);
  --portfolio-text: #0f2747;
  --portfolio-muted: #536d8d;
  --portfolio-soft: #6f88a7;
  --portfolio-blue: #1565d8;
  --portfolio-blue-deep: #0d3f8f;
  --portfolio-blue-soft: #dfeeff;
  --portfolio-sky: #7bb8ff;
  --portfolio-shadow: 0 16px 48px rgba(13, 63, 143, 0.12);
  --portfolio-shadow-soft: 0 10px 28px rgba(13, 63, 143, 0.08);
  --portfolio-radius: 24px;
  --portfolio-radius-md: 18px;
  --portfolio-radius-sm: 14px;
  --portfolio-transition: 220ms cubic-bezier(0.4, 0, 0.2, 1);
  --portfolio-container: 1180px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Manrope", system-ui, sans-serif;
  color: var(--portfolio-text);
  background:
    radial-gradient(circle at top left, rgba(123, 184, 255, 0.45), transparent 34%),
    radial-gradient(circle at top right, rgba(21, 101, 216, 0.12), transparent 28%),
    linear-gradient(180deg, #f8fbff 0%, #eef5ff 100%);
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.container {
  width: min(calc(100% - 32px), var(--portfolio-container));
  margin: 0 auto;
}

.portfolio-shell {
  overflow: clip;
}

.portfolio-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(20px);
  background: rgba(248, 251, 255, 0.78);
  border-bottom: 1px solid rgba(21, 101, 216, 0.08);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 78px;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--portfolio-blue), #4aa4ff);
  color: #fff;
  font-family: "Space Grotesk", sans-serif;
  font-weight: 700;
  box-shadow: 0 8px 20px rgba(21, 101, 216, 0.24);
}

.brand-copy {
  display: grid;
  gap: 2px;
}

.brand-copy strong {
  font-size: 0.98rem;
}

.brand-copy span {
  color: var(--portfolio-muted);
  font-size: 0.84rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--portfolio-muted);
  font-weight: 600;
  font-size: 0.93rem;
  transition: color var(--portfolio-transition);
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--portfolio-blue);
}

.hero {
  padding: 72px 0 28px;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(320px, 0.9fr);
  gap: 28px;
  align-items: start;
}

.hero-copy,
.hero-panel,
.proof-card,
.case-card,
.other-card,
.process-card,
.skill-card,
.contact-card,
.tab-shell {
  background: var(--portfolio-surface);
  border: 1px solid var(--portfolio-border);
  box-shadow: var(--portfolio-shadow-soft);
  backdrop-filter: blur(14px);
}

.hero-copy,
.hero-panel,
.tab-shell,
.contact-card {
  border-radius: calc(var(--portfolio-radius) + 4px);
}

.hero-copy {
  padding: 34px;
  position: relative;
  overflow: hidden;
}

.hero-copy::after {
  content: "";
  position: absolute;
  inset: auto -60px -90px auto;
  width: 240px;
  height: 240px;
  background: radial-gradient(circle, rgba(21, 101, 216, 0.18), transparent 66%);
  pointer-events: none;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--portfolio-blue);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.75rem;
  font-weight: 800;
}

.hero h1,
.section-head h2,
.contact-card h2 {
  margin: 0;
  font-family: "Space Grotesk", sans-serif;
  letter-spacing: -0.04em;
  line-height: 1.02;
}

.hero h1 {
  font-size: clamp(2.6rem, 6vw, 4.9rem);
  max-width: 11ch;
}

.hero-lead {
  margin: 22px 0 0;
  max-width: 62ch;
  color: var(--portfolio-muted);
  font-size: 1.03rem;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 26px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 20px;
  border-radius: 999px;
  font-weight: 700;
  transition: transform var(--portfolio-transition), box-shadow var(--portfolio-transition), background var(--portfolio-transition), color var(--portfolio-transition), border-color var(--portfolio-transition);
}

.btn:hover,
.btn:focus-visible {
  transform: translateY(-1px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--portfolio-blue), #3f90ff);
  color: #fff;
  box-shadow: 0 14px 28px rgba(21, 101, 216, 0.24);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  box-shadow: 0 18px 34px rgba(21, 101, 216, 0.28);
}

.btn-secondary {
  border: 1px solid var(--portfolio-border-strong);
  background: rgba(255, 255, 255, 0.82);
  color: var(--portfolio-blue-deep);
}

.hero-points {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.hero-points li {
  display: flex;
  gap: 12px;
  align-items: start;
  color: var(--portfolio-muted);
  line-height: 1.6;
}

.hero-points li::before {
  content: "";
  width: 9px;
  height: 9px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--portfolio-blue), var(--portfolio-sky));
  margin-top: 0.45rem;
  flex: none;
}

.hero-panel {
  padding: 22px;
  display: grid;
  gap: 16px;
}

.stat-card {
  border-radius: var(--portfolio-radius-md);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(230, 241, 255, 0.94));
  border: 1px solid rgba(21, 101, 216, 0.09);
  padding: 18px 18px 20px;
}

.stat-label,
.stat-foot,
.signal-grid div > span:first-child,
.proof-kicker,
.panel-badge,
.case-type,
.case-year,
.other-label {
  display: block;
}

.stat-label,
.proof-kicker,
.panel-badge,
.case-type,
.other-label {
  color: var(--portfolio-blue);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.stat-card strong {
  display: block;
  margin-top: 10px;
  font-size: 1.75rem;
  line-height: 1;
}

.stat-foot {
  margin-top: 8px;
  color: var(--portfolio-muted);
  line-height: 1.55;
  font-size: 0.92rem;
}

.signal-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.signal-grid div {
  padding: 16px;
  border-radius: var(--portfolio-radius-sm);
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid rgba(21, 101, 216, 0.09);
}

.signal-grid div > span:first-child {
  color: var(--portfolio-soft);
  font-size: 0.77rem;
  margin-bottom: 6px;
}

.signal-grid strong {
  font-size: 0.98rem;
  line-height: 1.3;
}

.proof-band,
.process,
.skills,
.contact {
  padding: 28px 0;
}

.proof-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.proof-card,
.process-card,
.skill-card {
  border-radius: var(--portfolio-radius-md);
  padding: 24px;
}

.proof-card h2 {
  margin: 10px 0 10px;
  font-size: 1.3rem;
  line-height: 1.15;
}

.proof-card p,
.section-head p,
.panel-intro p,
.case-summary,
.case-list,
.other-card p,
.process-card p,
.skill-card p,
.contact-card p {
  color: var(--portfolio-muted);
}

.showcase,
.other-work {
  padding: 34px 0 28px;
}

.section-head {
  max-width: 760px;
  margin-bottom: 24px;
}

.section-head h2 {
  font-size: clamp(2rem, 4.6vw, 3.25rem);
}

.section-head p {
  margin: 14px 0 0;
  line-height: 1.72;
}

.tab-shell {
  padding: 18px;
}

.tab-list {
  display: inline-flex;
  gap: 10px;
  padding: 8px;
  border-radius: 999px;
  background: rgba(217, 234, 255, 0.7);
  border: 1px solid rgba(21, 101, 216, 0.09);
}

.tab-button {
  border: 0;
  background: transparent;
  color: var(--portfolio-blue-deep);
  border-radius: 999px;
  min-height: 46px;
  padding: 0 22px;
  cursor: pointer;
  font-weight: 800;
  transition: background var(--portfolio-transition), color var(--portfolio-transition), box-shadow var(--portfolio-transition);
}

.tab-button.is-active {
  background: #fff;
  box-shadow: 0 8px 22px rgba(21, 101, 216, 0.13);
}

.tab-button:focus-visible {
  outline: 3px solid rgba(21, 101, 216, 0.22);
  outline-offset: 2px;
}

/* ── Tab Panel Transitions ────────────────────────────────── */
.tab-panel {
  transition: opacity 400ms cubic-bezier(0.4, 0, 0.2, 1),
    transform 400ms cubic-bezier(0.4, 0, 0.2, 1);
  will-change: opacity, transform;
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  max-height: 0;
  overflow: hidden;
  visibility: hidden;
}

.tab-panel.is-active {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
  max-height: 5000px;
  overflow: visible;
  visibility: visible;
  padding-top: 24px;
}

.panel-intro {
  margin-bottom: 16px;
}

.panel-intro h3 {
  margin: 10px 0 8px;
  font-size: 1.7rem;
  font-family: "Space Grotesk", sans-serif;
  letter-spacing: -0.03em;
}

.panel-badge {
  margin-bottom: 6px;
}

.case-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.case-card {
  border-radius: var(--portfolio-radius-md);
  padding: 22px;
  position: relative;
  overflow: hidden;
}

.case-card::after {
  content: "";
  position: absolute;
  inset: auto auto -80px -40px;
  width: 160px;
  height: 160px;
  border-radius: 999px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.8), transparent 68%);
  pointer-events: none;
}

.case-card-erp {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(225, 239, 255, 0.9));
}

.case-card-ecom {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.95), rgba(235, 246, 255, 0.92));
}

.case-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.case-year {
  color: var(--portfolio-soft);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: none;
}

.case-card h4,
.other-card h3,
.process-card h3,
.skill-card h3 {
  margin: 12px 0 10px;
  font-size: 1.28rem;
  line-height: 1.15;
}

.case-summary {
  margin: 0 0 16px;
  line-height: 1.7;
}

.case-list {
  margin: 0;
  padding-left: 18px;
  line-height: 1.68;
}

.other-card {
  border-radius: var(--portfolio-radius-md);
  padding: 24px;
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
}

.process-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.3fr);
  gap: 24px;
  align-items: start;
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.process-card > span:first-child {
  display: inline-flex;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  align-items: center;
  justify-content: center;
  background: var(--portfolio-blue-soft);
  color: var(--portfolio-blue);
  font-weight: 800;
}

.skill-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.contact-card {
  padding: 30px;
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.8fr);
  gap: 20px;
  align-items: center;
}

.contact-card h2 {
  font-size: clamp(1.9rem, 4vw, 3rem);
}

.contact-card p {
  margin: 14px 0 0;
  line-height: 1.72;
}

.contact-actions {
  display: grid;
  gap: 12px;
}

.portfolio-footer {
  padding: 30px 0 40px;
}

.footer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  color: var(--portfolio-soft);
  font-size: 0.92rem;
}

.footer-links {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--portfolio-blue);
}

/* ── Scroll Reveal ────────────────────────────────────────── */
.reveal {
  opacity: 0;
  transition: opacity 560ms cubic-bezier(0.4, 0, 0.2, 1),
    transform 560ms cubic-bezier(0.4, 0, 0.2, 1);
  will-change: opacity, transform;
}

.reveal[data-reveal="up"],
.reveal:not([data-reveal]) {
  transform: translateY(24px);
}

.reveal[data-reveal="down"] {
  transform: translateY(-24px);
}

.reveal[data-reveal="left"] {
  transform: translateX(-30px);
}

.reveal[data-reveal="right"] {
  transform: translateX(30px);
}

.reveal[data-reveal="scale"] {
  transform: scale(0.92);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0) translateX(0) scale(1);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal,
  .tab-panel {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .reveal[data-reveal="scale"] {
    transform: none;
  }

  .tab-panel.is-active {
    max-height: none;
    overflow: visible;
    visibility: visible;
  }

  .btn,
  .tab-button,
  .nav-links a {
    transition: none;
  }
}

@media (max-width: 1080px) {

  .hero-grid,
  .process-grid,
  .contact-card,
  .proof-grid,
  .skill-grid {
    grid-template-columns: 1fr;
  }

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

  .hero h1 {
    max-width: none;
  }
}

@media (max-width: 760px) {

  .nav-inner,
  .footer-row,
  .other-card {
    grid-template-columns: 1fr;
    display: grid;
  }

  .nav-links,
  .footer-links {
    gap: 14px;
  }

  .nav-inner {
    padding: 14px 0;
  }

  .hero {
    padding-top: 38px;
  }

  .hero-copy,
  .hero-panel,
  .proof-card,
  .case-card,
  .process-card,
  .skill-card,
  .contact-card,
  .other-card,
  .tab-shell {
    padding-left: 18px;
    padding-right: 18px;
  }

  .hero-copy {
    padding-top: 24px;
    padding-bottom: 24px;
  }

  .tab-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    width: 100%;
  }

  .tab-button {
    min-height: 48px;
    width: 100%;
  }

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

/* ── Bilingual System ─────────────────────────────────────── */
html[lang="en"] .lang-vi { display: none !important; }
html[lang="vi"] .lang-en { display: none !important; }

.lang-switch {
  display: inline-flex;
  align-items: center;
  background: rgba(217, 234, 255, 0.4);
  border: 1px solid rgba(21, 101, 216, 0.1);
  border-radius: 999px;
  padding: 4px;
  margin-left: 12px;
}

.lang-btn {
  border: none;
  background: transparent;
  padding: 6px 12px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.8rem;
  color: var(--portfolio-muted);
  cursor: pointer;
  transition: all var(--portfolio-transition);
}

.lang-btn.is-active {
  background: #fff;
  color: var(--portfolio-blue-deep);
  box-shadow: 0 4px 12px rgba(21, 101, 216, 0.1);
}

.lang-btn:hover:not(.is-active) {
  color: var(--portfolio-blue);
}