* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #f2f2f2;
  --card: #fff;
  --ink: #1a1a1a;
  --sub: #555;
  --mute: #888;
  --faint: #999;
  --line: #e2e2e2;
  --black: #111;
  --shadow: 0 8px 30px rgba(0, 0, 0, .1);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.55;
  overflow-x: hidden;
}

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px;
}

a {
  color: inherit;
}

img {
  max-width: 100%;
  height: auto; /* giữ đúng tỉ lệ gốc khi bị bóp ngang — thiếu dòng này ảnh sẽ biến dạng */
  display: block;
}

/* ===== Nav ===== */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.nav-in {
  max-width: 1080px;
  margin: 0 auto;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  text-decoration: none;
  font-size: 15px;
}

.brand img {
  width: 28px;
  height: 28px;
}

.nav-links {
  display: flex;
  gap: 4px;
  margin-left: auto;
}

.nav-links a {
  text-decoration: none;
  font-size: 14px;
  color: var(--sub);
  padding: 7px 12px;
  border-radius: 999px;
  transition: background .15s, color .15s;
}

.nav-links a:hover {
  background: #f2f2f2;
  color: var(--ink);
}

.nav-cta {
  background: var(--black);
  color: #fff !important;
  font-weight: 600;
}

.nav-cta:hover {
  background: #333 !important;
}

.lang-switch {
  border: 1px solid var(--line);
  font-weight: 600;
}

@media (max-width: 760px) {
  .nav-links a:not(.nav-cta) {
    display: none;
  }

  /* nút chuyển ngữ EN/VI vẫn hiện trên mobile */
  .nav-links a.lang-switch {
    display: inline-block;
  }
}

/* ===== Hero (banner đen) ===== */
.hero {
  background: var(--black);
  color: #fff;
  padding: 176px 0 0; /* chừa chỗ cho nav (49px) + catbar (~51px) cố định */
  position: relative;
  overflow: hidden;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .05) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 90% 80% at 50% 20%, #000 40%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 90% 80% at 50% 20%, #000 40%, transparent 100%);
}

.hero-glow {
  position: absolute;
  width: 560px;
  height: 560px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 255, 255, .14), transparent 65%);
  top: -180px;
  right: -120px;
  pointer-events: none;
}

.hero-in {
  position: relative;
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 40px;
  align-items: center;
  padding-bottom: 90px;
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid rgba(255, 255, 255, .25);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 13px;
  color: rgba(255, 255, 255, .85);
}

.kicker .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #4ade80;
  animation: pulse 2s infinite;
}

@keyframes pulse {

  0%,
  100% {
    box-shadow: 0 0 0 0 rgba(74, 222, 128, .5);
  }

  50% {
    box-shadow: 0 0 0 6px rgba(74, 222, 128, 0);
  }
}

.hero h1 {
  font-size: clamp(40px, 6.5vw, 68px);
  line-height: 1.06;
  letter-spacing: -.02em;
  margin: 18px 0 14px;
  font-weight: 800;
}

.hero h1 .ghost {
  color: transparent;
  -webkit-text-stroke: 1.5px rgba(255, 255, 255, .55);
}

.hero .lead {
  color: rgba(255, 255, 255, .72);
  font-size: 17px;
  max-width: 480px;
}

.hero-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 26px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 12px;
  font-size: 15px;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background .15s, border-color .15s, transform .15s;
}

.btn:active {
  transform: scale(.98);
}

.btn-white {
  background: #fff;
  color: var(--black);
  font-weight: 700;
}

.btn-white:hover {
  background: #e8e8e8;
}

.btn-ghost {
  border-color: rgba(255, 255, 255, .3);
  color: #fff;
}

.btn-ghost:hover {
  border-color: #fff;
}

.btn svg {
  width: 18px;
  height: 18px;
}

/* Portrait 3D card */
.portrait {
  position: relative;
  justify-self: center;
  width: min(340px, 80vw);
  will-change: transform;
  transition: transform .3s ease;
}

.portrait-card {
  background: linear-gradient(160deg, #1c1c1c, #2a2a2a);
  border: 1px solid rgba(255, 255, 255, .12);
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 30px 60px rgba(0, 0, 0, .45);
}

/* khóa cứng tỉ lệ vuông: lệch bao nhiêu thì CẮT (cover), không bao giờ kéo giãn */
.portrait-card img {
  width: 100%;
  aspect-ratio: 1 / 1;
  height: auto;
  object-fit: cover;
  object-position: center top;
}

.chip {
  position: absolute;
  background: #fff;
  color: var(--black);
  font-size: 13px;
  font-weight: 700;
  padding: 8px 14px;
  border-radius: 999px;
  box-shadow: var(--shadow);
  animation: floaty 5s ease-in-out infinite;
  white-space: nowrap;
}

.chip.c1 {
  top: 8%;
  left: -14%;
  animation-delay: 0s;
}

.chip.c2 {
  top: 42%;
  right: -18%;
  animation-delay: 1.2s;
}

.chip.c3 {
  bottom: 10%;
  left: -10%;
  animation-delay: 2.4s;
}

@keyframes floaty {

  0%,
  100% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-10px);
  }
}

@media (max-width: 860px) {
  .hero-in {
    grid-template-columns: 1fr;
    padding-bottom: 70px;
  }

  .portrait {
    margin-top: 10px;
  }

  .chip.c1 {
    left: -4%;
  }

  .chip.c2 {
    right: -4%;
  }

  .chip.c3 {
    left: -2%;
  }
}

/* Marquee */
.marquee {
  border-top: 1px solid rgba(255, 255, 255, .12);
  background: rgba(255, 255, 255, .03);
  overflow: hidden;
  position: relative;
  padding: 14px 0;
}

.marquee-track {
  display: flex;
  gap: 40px;
  width: max-content;
  animation: scroll 28s linear infinite;
}

.marquee-track span {
  color: rgba(255, 255, 255, .55);
  font-size: 14px;
  letter-spacing: .12em;
  text-transform: uppercase;
  white-space: nowrap;
}

@keyframes scroll {
  from {
    transform: translateX(0);
  }

  to {
    transform: translateX(-50%);
  }
}

/* ===== Sections chung ===== */
section {
  padding: 84px 0;
  /* anchor không bị nav + catbar cố định (~100px) che mất tiêu đề */
  scroll-margin-top: 60px;
}

/* Card dịch vụ có id (đích anchor từ dropdown danh mục) */
.card[id] {
  scroll-margin-top: 128px;
}

.card:target {
  border-color: var(--black);
}

.sec-head {
  max-width: 640px;
  margin-bottom: 40px;
}

.sec-label {
  display: inline-block;
  background: #fff;
  border: 1px solid var(--line);
  color: var(--sub);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 14px;
}

.sec-head h2 {
  font-size: clamp(28px, 4vw, 40px);
  letter-spacing: -.01em;
  line-height: 1.15;
}

.sec-head p {
  color: var(--sub);
  margin-top: 10px;
}

/* Reveal on scroll */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .6s ease, transform .6s ease;
  transition-delay: var(--d, 0s);
}

.reveal.in {
  opacity: 1;
  transform: none;
}

/* ===== Stats ===== */
.stats-band {
  position: relative;
  margin-top: -1px;
  background: var(--black);
  padding: 0 0 70px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.stat {
  background: rgba(255, 255, 255, .05);
  border: 1px solid rgba(255, 255, 255, .12);
  border-radius: 20px;
  padding: 22px 20px;
  color: #fff;
}

.stat b {
  font-size: clamp(30px, 3.8vw, 42px);
  font-weight: 800;
  letter-spacing: -.02em;
  display: block;
  white-space: nowrap;
}

/* chỉ áp cho dòng mô tả (con trực tiếp) — KHÔNG đụng số đếm nằm trong <b> */
.stat>span {
  display: block;
  color: rgba(255, 255, 255, .6);
  font-size: 13.5px;
  margin-top: 6px;
}

.stat b span {
  font-size: inherit;
  color: inherit;
  display: inline;
  margin: 0;
}

@media (max-width: 860px) {
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== Cards chung ===== */
.grid {
  display: grid;
  gap: 16px;
}

.g3 {
  grid-template-columns: repeat(3, 1fr);
}

.g2 {
  grid-template-columns: repeat(2, 1fr);
}

@media (max-width: 960px) {
  .g3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {

  .g3,
  .g2 {
    grid-template-columns: 1fr;
  }
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 24px;
  transition: transform .2s ease, box-shadow .2s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.card h3 {
  font-size: 17px;
  margin: 14px 0 6px;
}

.card p {
  color: var(--sub);
  font-size: 14.5px;
}

.icon-chip {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--black);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-chip svg {
  width: 22px;
  height: 22px;
}

.pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 14px;
}

.pills span {
  background: var(--bg);
  color: #444;
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 999px;
}

/* ===== Terminal mockup ===== */
.term-wrap {
  margin-top: 44px;
}

.terminal {
  background: var(--black);
  border-radius: 20px;
  box-shadow: var(--shadow);
  overflow: hidden;
  max-width: 720px;
  margin: 0 auto;
  will-change: transform;
  transition: transform .3s ease;
}

.term-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: #1d1d1d;
  border-bottom: 1px solid rgba(255, 255, 255, .08);
}

.term-bar i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #3a3a3a;
}

.term-bar i:first-child {
  background: #ff5f57;
}

.term-bar i:nth-child(2) {
  background: #febc2e;
}

.term-bar i:nth-child(3) {
  background: #28c840;
}

.term-bar em {
  font-style: normal;
  color: #777;
  font-size: 12.5px;
  margin-left: 10px;
  font-family: Consolas, "Courier New", monospace;
}

.term-body {
  font-family: Consolas, "Courier New", monospace;
  font-size: 13.5px;
  padding: 18px 20px 24px;
  color: #d4d4d4;
  min-height: 210px;
}

.term-body div {
  opacity: 0;
  transform: translateY(4px);
  transition: opacity .3s, transform .3s;
  margin-top: 6px;
  white-space: pre-wrap;
}

.term-body div.on {
  opacity: 1;
  transform: none;
}

.t-cmd {
  color: #fff;
}

.t-ok {
  color: #4ade80;
}

.t-dim {
  color: #8a8a8a;
}

.cursor {
  display: inline-block;
  width: 8px;
  height: 15px;
  background: #d4d4d4;
  vertical-align: -2px;
  animation: blink 1s steps(1) infinite;
}

@keyframes blink {
  50% {
    opacity: 0;
  }
}

/* ===== Timeline ===== */
.timeline {
  position: relative;
  margin-top: 10px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--line);
}

.t-item {
  position: relative;
  padding: 0 0 26px 36px;
}

.t-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--black);
  border: 4px solid var(--bg);
}

.t-item time {
  font-size: 13px;
  color: var(--mute);
  font-weight: 600;
  letter-spacing: .03em;
}

.t-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 18px 20px;
  margin-top: 8px;
  transition: transform .2s, box-shadow .2s;
}

.t-card:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow);
}

.t-card h3 {
  font-size: 16px;
}

.t-card .role {
  color: var(--mute);
  font-size: 13.5px;
  margin: 2px 0 8px;
}

.t-card p {
  color: var(--sub);
  font-size: 14.5px;
}

/* ===== Laptop mockup (KHÔNG tilt để chữ trong ảnh luôn nét) ===== */
.laptop {
  max-width: 860px;
  margin: 50px auto 0;
}

.laptop .screen {
  background: #0d0d0d;
  border-radius: 18px 18px 0 0;
  padding: 14px 14px 0;
  border: 1px solid #2a2a2a;
  border-bottom: none;
}

.laptop .cam {
  width: 6px;
  height: 6px;
  background: #333;
  border-radius: 50%;
  margin: 0 auto 10px;
}

.laptop .screen img {
  border-radius: 6px 6px 0 0;
  width: 100%;
  height: auto;
}

.laptop .base {
  height: 16px;
  background: linear-gradient(#d8d8d8, #b5b5b5);
  border-radius: 0 0 16px 16px;
  position: relative;
}

.laptop .base::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  transform: translateX(-50%);
  width: 110px;
  height: 6px;
  background: #a3a3a3;
  border-radius: 0 0 8px 8px;
}

.laptop-cap {
  text-align: center;
  color: var(--mute);
  font-size: 13.5px;
  margin-top: 14px;
}

/* ===== Browser mockups (website — mô phỏng code editor) ===== */
.site {
  display: block;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  overflow: hidden;
  transition: box-shadow .25s ease;
  will-change: transform;
}

.site:hover {
  box-shadow: var(--shadow);
}

.site-bar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  background: #fafafa;
}

.site-bar i {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #ddd;
}

.site-bar .url {
  margin-left: 8px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 12px;
  color: var(--sub);
  padding: 3px 12px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.site-body {
  position: relative;
  height: 148px;
  overflow: hidden;
  background: #141414;
  padding: 14px 16px;
}

.site-body .big {
  position: absolute;
  right: -4px;
  bottom: -30px;
  font-size: 104px;
  font-weight: 800;
  color: rgba(255, 255, 255, .05);
  line-height: 1;
  letter-spacing: -.04em;
  user-select: none;
}

.code-line {
  display: flex;
  align-items: center;
  gap: 7px;
  margin-bottom: 9px;
}

.code-line .ln {
  font-family: Consolas, "Courier New", monospace;
  font-size: 10px;
  color: #4a4a4a;
  width: 14px;
  flex: none;
  text-align: right;
}

.code-line i {
  height: 8px;
  border-radius: 4px;
  display: block;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .5s ease;
}

.site.in .code-line i {
  transform: scaleX(1);
}

.code-cursor {
  display: inline-block;
  width: 7px;
  height: 12px;
  background: #d4d4d4;
  margin-left: 21px;
  animation: blink 1s steps(1) infinite;
}

.site-name {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  font-weight: 600;
}

.site-name small {
  color: var(--mute);
  font-weight: 400;
}

/* ===== Kết quả / case study ===== */
.kq {
  border-left: 4px solid var(--black);
}

.kq b {
  font-size: 22px;
  letter-spacing: -.01em;
}

/* ===== Contact ===== */
.contact {
  background: var(--black);
  color: #fff;
}

.contact .sec-label {
  background: transparent;
  border-color: rgba(255, 255, 255, .25);
  color: rgba(255, 255, 255, .7);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

@media (max-width: 760px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

.contact h2 {
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.15;
}

.contact .sub {
  color: rgba(255, 255, 255, .65);
  margin-top: 12px;
}

.c-btns {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.c-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 18px;
  border: 1px solid rgba(255, 255, 255, .2);
  border-radius: 12px;
  text-decoration: none;
  color: #fff;
  font-size: 15px;
  transition: background .15s, border-color .15s;
}

.c-btn:hover {
  background: rgba(255, 255, 255, .08);
  border-color: rgba(255, 255, 255, .45);
}

.c-btn svg {
  width: 20px;
  height: 20px;
  flex: none;
}

.c-btn small {
  margin-left: auto;
  color: rgba(255, 255, 255, .5);
  font-size: 13px;
}

.c-btn.solid {
  background: #fff;
  color: var(--black);
  font-weight: 700;
  justify-content: center;
  border-color: #fff;
}

.c-btn.solid:hover {
  background: #e8e8e8;
}

footer {
  background: var(--black);
  color: var(--faint);
  text-align: center;
  font-size: 12.5px;
  padding: 22px 0 26px;
  border-top: 1px solid rgba(255, 255, 255, .1);
}

footer a {
  color: inherit;
}

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

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .chip,
  .marquee-track,
  .kicker .dot,
  .cursor,
  .code-cursor {
    animation: none !important;
  }

  .term-body div {
    opacity: 1;
    transform: none;
  }

  .code-line i,
  .site.in .code-line i {
    transform: scaleX(1);
    transition: none;
  }
}