/* ============================================================
   Nailian — Computer Systems Design
   Light theme · unique palette: cream + deep cobalt blue
   ============================================================ */

:root {
  --bg: #F7F5F0;
  --bg-alt: #EFECE3;
  --card: #FFFFFF;
  --ink: #1A1A1A;
  --ink-soft: #33383F;
  --muted: #5A6070;
  --line: #E4DFD3;
  --accent: #2B5CE6;
  --accent-deep: #16348F;
  --accent-soft: #E8EEFF;
  --hero: #122F8F;
  --hero-2: #1B4BD8;
  --white: #FFFFFF;
  --font-head: "Fraunces", Georgia, "Times New Roman", serif;
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-size: 16px;
  font-family: var(--font-body);
  background-color: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

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

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

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.01em;
}

.container {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Fixed navigation ---------- */

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 120;
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.nav-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 18px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-family: var(--font-head);
  font-size: 1.55rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--white);
  transition: color 0.3s ease;
}

.brand-dot {
  color: var(--accent);
}

.site-nav.scrolled {
  background-color: var(--bg);
  box-shadow: 0 1px 0 var(--line);
}

.site-nav.scrolled .brand {
  color: var(--ink);
}

/* Hamburger button */

.nav-burger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 46px;
  height: 46px;
  padding: 12px;
  background: transparent;
  border: 1px solid var(--white);
  border-radius: 50%;
  cursor: pointer;
  transition: border-color 0.3s ease;
}

.nav-burger span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--white);
  transition: transform 0.3s ease, background 0.3s ease;
}

.site-nav.scrolled .nav-burger {
  border-color: var(--ink);
}

.site-nav.scrolled .nav-burger span {
  background: var(--ink);
}

.nav-burger.open span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.nav-burger.open span:nth-child(2) {
  transform: scaleX(0);
}

.nav-burger.open span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ---------- Fullscreen overlay menu ---------- */

.nav-overlay {
  position: fixed;
  inset: 0;
  z-index: 110;
  background-color: var(--hero);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  transform: translateY(-102%);
  transition: transform 0.4s ease;
  visibility: hidden;
}

.nav-overlay.open {
  transform: translateY(0);
  visibility: visible;
}

.overlay-links {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.overlay-link {
  font-family: var(--font-head);
  font-size: clamp(2rem, 5vw, 3.4rem);
  font-weight: 600;
  color: var(--white);
  padding: 6px 20px;
  transition: color 0.2s ease;
}

.overlay-link:hover,
.overlay-link:focus {
  color: var(--accent-soft);
}

.overlay-foot {
  margin-top: 48px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  color: var(--accent-soft);
  font-size: 0.95rem;
  letter-spacing: 0.02em;
}

/* ---------- Hero (slanted) ---------- */

.hero-section {
  position: relative;
  background: linear-gradient(160deg, var(--hero) 0%, var(--hero-2) 100%);
  color: var(--white);
  padding: 170px 0 160px;
  clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 56px;
  align-items: center;
}

.hero-eyebrow {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent-soft);
  margin-bottom: 22px;
}

.hero-title {
  font-size: clamp(2.4rem, 5vw, 4rem);
  font-weight: 700;
  color: var(--white);
  margin-bottom: 24px;
}

.hero-lede {
  font-size: 1.12rem;
  color: var(--white);
  max-width: 540px;
  margin-bottom: 34px;
}

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

.btn {
  display: inline-block;
  padding: 14px 28px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.98rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-light {
  background-color: var(--white);
  color: var(--hero);
}

.btn-light:hover {
  background-color: var(--accent-soft);
}

.btn-ghost {
  background-color: transparent;
  color: var(--white);
  border-color: var(--white);
}

.btn-ghost:hover {
  background-color: var(--white);
  color: var(--hero);
}

.btn-dark {
  background-color: var(--ink);
  color: var(--white);
}

.btn-dark:hover {
  background-color: var(--accent-deep);
}

/* Hero stat cards */

.hero-side {
  display: grid;
  gap: 18px;
}

.stat-card {
  background-color: var(--white);
  color: var(--ink);
  border-radius: 10px;
  padding: 22px 24px;
  box-shadow: 0 18px 40px #C4CCE6;
}

.stat-card-b {
  transform: translateX(28px);
}

.stat-card-c {
  transform: translateX(-28px);
}

.stat-num {
  display: block;
  font-family: var(--font-head);
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--accent-deep);
  line-height: 1;
}

.stat-label {
  display: block;
  margin-top: 8px;
  font-size: 0.9rem;
  color: var(--muted);
  letter-spacing: 0.02em;
}

/* ---------- Ticker ---------- */

.ticker-section {
  background-color: var(--ink);
  color: var(--white);
  padding: 20px 0;
  overflow: hidden;
  margin-top: -80px;
  position: relative;
  z-index: 2;
}

.ticker-track {
  display: flex;
  gap: 34px;
  white-space: nowrap;
  animation: ticker-scroll 30s linear infinite;
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 500;
}

.ticker-dot {
  color: var(--accent);
}

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

/* ---------- Statement ---------- */

.statement-section {
  padding: 110px 0 100px;
  background-color: var(--bg);
}

.statement-kicker,
.section-kicker {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
}

.statement-title {
  font-size: clamp(1.9rem, 3.6vw, 3rem);
  max-width: 860px;
  margin-bottom: 28px;
}

.statement-body {
  font-size: 1.15rem;
  color: var(--ink-soft);
  max-width: 760px;
}

/* ---------- Section head ---------- */

.section-head {
  margin-bottom: 48px;
}

.section-title {
  font-size: clamp(1.8rem, 3.4vw, 2.7rem);
  max-width: 720px;
}

/* ---------- Services bento ---------- */

.services-section {
  padding: 90px 0 110px;
  background-color: var(--bg-alt);
}

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

.bento-card {
  background-color: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 32px 28px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.bento-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px #DBD6CA;
}

.bento-large {
  grid-column: span 2;
}

.bento-wide {
  grid-column: span 2;
}

.bento-num {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 16px;
}

.bento-card h3 {
  font-size: 1.45rem;
  margin-bottom: 12px;
}

.bento-card p {
  color: var(--muted);
  font-size: 0.98rem;
}

.bento-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
}

.bento-tags li {
  background-color: var(--accent-soft);
  color: var(--accent-deep);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 20px;
}

/* ---------- Approach (numbered list) ---------- */

.approach-section {
  padding: 110px 0;
  background-color: var(--bg);
}

.steps-list {
  list-style: none;
  counter-reset: step;
}

.step {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 28px;
  padding: 34px 0;
  border-top: 1px solid var(--line);
}

.step:last-child {
  border-bottom: 1px solid var(--line);
}

.step-num {
  font-family: var(--font-head);
  font-size: 2.6rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}

.step-body h3 {
  font-size: 1.5rem;
  margin-bottom: 10px;
}

.step-body p {
  color: var(--muted);
  max-width: 680px;
}

/* ---------- Models table ---------- */

.models-section {
  padding: 110px 0;
  background-color: var(--bg-alt);
}

.model-table {
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
  background-color: var(--card);
}

.model-row {
  display: grid;
  grid-template-columns: 1.4fr 1.6fr 1fr 1.6fr;
  border-bottom: 1px solid var(--line);
}

.model-row:last-child {
  border-bottom: none;
}

.model-cell {
  padding: 22px 24px;
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.model-head-row {
  background-color: var(--ink);
}

.model-head-row .model-cell {
  color: var(--white);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.model-cell-name {
  font-weight: 600;
  color: var(--ink);
}

/* ---------- Principles ---------- */

.principles-section {
  padding: 110px 0;
  background-color: var(--bg);
}

.principles-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.principle {
  display: flex;
  gap: 22px;
  align-items: flex-start;
  background-color: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 30px 28px;
}

.principle-index {
  flex: 0 0 auto;
  font-family: var(--font-head);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--accent-deep);
  width: 54px;
  height: 54px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--accent-soft);
  border-radius: 50%;
}

.principle-text {
  color: var(--ink-soft);
  font-size: 1.05rem;
}

/* ---------- Outcomes ---------- */

.outcomes-section {
  padding: 110px 0;
  background-color: var(--bg-alt);
}

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

.outcome {
  background-color: var(--card);
  border-radius: 14px;
  padding: 34px 28px;
  border-top: 4px solid var(--accent);
}

.outcome-num {
  display: block;
  font-family: var(--font-head);
  font-size: 2.6rem;
  font-weight: 700;
  color: var(--accent-deep);
  margin-bottom: 14px;
}

.outcome h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.outcome p {
  color: var(--muted);
  font-size: 0.95rem;
}

/* ---------- Contact ---------- */

.contact-section {
  padding: 110px 0;
  background-color: var(--bg);
}

.contact-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.contact-note {
  color: var(--muted);
  margin-bottom: 30px;
  max-width: 460px;
}

.contact-direct {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.contact-direct li {
  display: flex;
  gap: 16px;
  align-items: baseline;
}

.contact-direct span {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  min-width: 70px;
}

.contact-direct a {
  font-weight: 600;
  color: var(--accent-deep);
}

.contact-direct a:hover {
  text-decoration: underline;
}

.contact-form {
  background-color: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 36px 32px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field span {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--ink-soft);
}

.field input,
.field textarea {
  font-family: var(--font-body);
  font-size: 16px;
  padding: 13px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background-color: var(--bg);
  color: var(--ink);
}

.field input:focus,
.field textarea:focus {
  outline: 2px solid var(--accent);
  outline-offset: 0;
  border-color: var(--accent);
}

.form-status {
  font-size: 0.9rem;
  color: var(--accent-deep);
  min-height: 1.2em;
}

/* ---------- Footer ---------- */

.site-footer {
  background-color: var(--ink);
  color: var(--white);
  padding: 80px 0 0;
  overflow: hidden;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 60px;
}

.footer-brand p {
  color: #B9BEC9;
  max-width: 320px;
  margin-top: 18px;
  font-size: 0.95rem;
}

.footer-brand-link {
  color: var(--white);
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col h4 {
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #8A909E;
  margin-bottom: 8px;
}

.footer-col a {
  color: #D4D8DF;
  font-size: 0.95rem;
}

.footer-col a:hover {
  color: var(--white);
  text-decoration: underline;
}

.footer-wordmark {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(4rem, 16vw, 13rem);
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: #2A2F3A;
  text-align: center;
  white-space: nowrap;
  user-select: none;
  margin-top: -10px;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  padding: 28px 24px;
  border-top: 1px solid #2A2F3A;
}

.footer-bottom p {
  color: #8A909E;
  font-size: 0.85rem;
}

/* ---------- Scroll reveal ---------- */

.fade-up {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: none;
}

/* ---------- Responsive ---------- */

@media (max-width: 960px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 44px;
  }

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

  .stat-card-b,
  .stat-card-c {
    transform: none;
  }

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

  .bento-large,
  .bento-wide {
    grid-column: span 2;
  }

  .principles-list {
    grid-template-columns: 1fr;
  }

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

  .contact-inner {
    grid-template-columns: 1fr;
  }

  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .hero-section {
    padding: 140px 0 130px;
  }

  .hero-side {
    grid-template-columns: 1fr;
  }

  .stat-card {
    padding: 18px 20px;
  }

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

  .bento-large,
  .bento-wide {
    grid-column: span 1;
  }

  .model-row {
    grid-template-columns: 1fr 1fr;
  }

  .model-cell {
    padding: 14px 16px;
    font-size: 0.88rem;
  }

  .step {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .footer-top {
    grid-template-columns: 1fr;
  }
}