:root {
  --page: #eef2f5;
  --paper: #ffffff;
  --paper-2: #dde5ec;

  --ink: #1f2933;
  --muted: #5f6b76;

  --line: #cfd8e2;

  --accent: #5c7fa3;
  --accent-dark: #3f5f80;
  --accent-soft: #dce7f2;

  --olive: #64748b;

  --shadow: 0 18px 50px rgba(31, 41, 51, 0.10);

  --radius: 22px;
  --max: 1160px;
}

/* --------------------------------------------------
   RESET
-------------------------------------------------- */

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;

  font-family:
    Inter,
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    Arial,
    sans-serif;

  background: var(--page);
  color: var(--ink);

  line-height: 1.65;

  text-rendering: optimizeLegibility;
}

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

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

/* --------------------------------------------------
   LAYOUT
-------------------------------------------------- */

.container {
  width: min(var(--max), calc(100% - 40px));
  margin-inline: auto;
}

.skip-link {
  position: absolute;

  left: -999px;
  top: 10px;

  background: var(--ink);
  color: #fff;

  padding: 0.75rem 1rem;

  border-radius: 999px;

  z-index: 30;
}

.skip-link:focus {
  left: 10px;
}

.sr-only {
  position: absolute;

  width: 1px;
  height: 1px;

  overflow: hidden;

  clip: rect(0, 0, 0, 0);
}

/* --------------------------------------------------
   HEADER
-------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;

  z-index: 20;

  background: rgba(238, 242, 245, 0.88);

  backdrop-filter: blur(18px);

  border-bottom: 1px solid var(--line);
}

.nav {
  width: min(var(--max), calc(100% - 32px));

  margin: auto;

  min-height: 78px;

  display: flex;
  align-items: center;
  justify-content: space-between;

  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
}

.brand img {
  height: 42px;
  width: auto;
}

.nav-menu {
  display: flex;
  align-items: center;

  gap: 6px;
}

.nav-menu a {
  padding: 0.62rem 0.85rem;

  border-radius: 999px;

  color: var(--muted);

  font-weight: 700;
  font-size: 0.94rem;

  transition: 0.2s ease;
}

.nav-menu a:hover,
.nav-menu a:focus {
  background: var(--accent-soft);
  color: var(--accent-dark);
}

.nav-toggle {
  display: none;

  background: transparent;
  border: 0;

  padding: 10px;
}

.nav-toggle span:not(.sr-only) {
  display: block;

  width: 26px;
  height: 2px;

  background: var(--ink);

  margin: 5px 0;

  border-radius: 99px;
}

/* --------------------------------------------------
   SECTIONS
-------------------------------------------------- */

.section {
  padding: 96px 0;
}

/* --------------------------------------------------
   HERO
-------------------------------------------------- */

.hero {
  position: relative;

  min-height: 720px;

  display: grid;
  align-items: center;

  overflow: hidden;

  background:
    linear-gradient(
      135deg,
      #eef2f5 0%,
      #dfe7ee 58%,
      #cfd9e4 100%
    );
}

.hero-bg {
  position: absolute;
  inset: 0;

  background:
    radial-gradient(
      circle at 12% 18%,
      rgba(92, 127, 163, 0.18),
      transparent 32%
    ),
    radial-gradient(
      circle at 85% 16%,
      rgba(100, 116, 139, 0.18),
      transparent 30%
    );
}

.hero-grid {
  position: relative;

  display: grid;

  grid-template-columns:
    minmax(0, 1.15fr)
    minmax(290px, 0.68fr);

  gap: 56px;

  align-items: center;
}

.eyebrow {
  margin: 0 0 14px;

  color: var(--accent-dark);

  text-transform: uppercase;

  letter-spacing: 0.14em;

  font-size: 0.78rem;
  font-weight: 850;
}

.hero h1,
.section h2 {
  line-height: 1.04;

  margin: 0 0 22px;

  letter-spacing: -0.045em;
}

.hero h1 {
  font-size: clamp(2.75rem, 6.2vw, 5.7rem);

  max-width: 920px;
}

.section h2 {
  font-size: clamp(2rem, 3.6vw, 3.35rem);
}

.hero-text,
.section-head p,
.split p {
  color: var(--muted);

  font-size: 1.1rem;

  max-width: 760px;
}

/* --------------------------------------------------
   BUTTONS
-------------------------------------------------- */

.hero-actions,
.actions-row,
.contact-actions {
  display: flex;

  gap: 14px;

  flex-wrap: wrap;

  margin-top: 30px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;

  min-height: 48px;

  padding: 0.8rem 1.18rem;

  border-radius: 999px;

  font-weight: 850;

  transition:
    transform 0.2s ease,
    background 0.2s ease,
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

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

.btn-primary {
  background: var(--ink);
  color: #fff;

  box-shadow:
    0 10px 28px rgba(31, 41, 51, 0.18);
}

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

.btn-ghost {
  border: 1px solid var(--line);

  background: rgba(255, 255, 255, 0.58);

  color: var(--ink);
}

.btn-ghost:hover {
  background: #fff;

  border-color: #b9c6d3;
}

/* --------------------------------------------------
   CARDS
-------------------------------------------------- */

.hero-card,
.card,
.contact-card,
.project-card {
  border: 1px solid var(--line);

  background: rgba(255, 255, 255, 0.74);

  box-shadow: var(--shadow);

  border-radius: var(--radius);
}

.hero-card {
  padding: 22px;

  display: grid;
  gap: 20px;
}

.profile-image {
  border-radius: 18px;

  aspect-ratio: 4 / 3;

  object-fit: cover;
}

.hero-card h2 {
  margin: 0 0 6px;
}

.hero-card p {
  margin: 0;

  color: var(--muted);
}

/* --------------------------------------------------
   GRID / CARDS
-------------------------------------------------- */

.section-head {
  margin-bottom: 42px;
}

.cards {
  display: grid;

  gap: 20px;
}

.four-columns {
  grid-template-columns: repeat(4, 1fr);
}

.card {
  padding: 26px;

  min-height: 100%;

  transition:
    transform 0.2s ease,
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

.card:hover {
  transform: translateY(-5px);

  border-color: #9db1c5;
}

.card img {
  width: 76px;
  height: 76px;

  object-fit: contain;

  margin-bottom: 24px;
}

.card h3 {
  font-size: 1.22rem;

  margin: 0 0 10px;
}

.card p {
  margin: 0;

  color: var(--muted);
}

/* --------------------------------------------------
   SPLIT SECTION
-------------------------------------------------- */

.split-section,
.muted-section {
  background:
    linear-gradient(
      180deg,
      rgba(255, 255, 255, 0.48),
      rgba(221, 229, 236, 0.58)
    );
}

.split {
  display: grid;

  grid-template-columns: 1fr 1fr;

  gap: 52px;

  align-items: center;
}

.stats {
  display: grid;

  grid-template-columns: repeat(2, 1fr);

  gap: 16px;
}

.stats div {
  padding: 28px;

  border-radius: 24px;

  background: #fff;

  border: 1px solid var(--line);

  box-shadow:
    0 8px 28px rgba(31, 41, 51, 0.07);
}

.stats strong {
  display: block;

  font-size: clamp(2.2rem, 4vw, 4rem);

  line-height: 1;

  color: var(--accent);
}

.stats span {
  display: block;

  color: var(--muted);

  margin-top: 10px;
}

/* --------------------------------------------------
   PROJECTS
-------------------------------------------------- */

.projects-section {
  background: var(--paper);
}

.project-list {
  display: grid;

  gap: 14px;
}

.project-card {
  overflow: hidden;

  box-shadow: none;

  background: #fff;
}

.project-card summary {
  cursor: pointer;

  list-style: none;

  display: grid;

  grid-template-columns: auto 1fr auto;

  align-items: center;

  gap: 16px;

  padding: 20px 22px;

  font-weight: 850;
}

.project-card summary::-webkit-details-marker {
  display: none;
}

.project-card summary::after {
  content: "+";

  font-size: 1.7rem;

  line-height: 1;

  color: var(--accent);

  font-weight: 500;
}

.project-card[open] summary::after {
  content: "–";
}

.project-number {
  font-size: 0.78rem;

  letter-spacing: 0.12em;

  color: var(--accent-dark);

  background: var(--accent-soft);

  border-radius: 999px;

  padding: 0.3rem 0.55rem;
}

.project-title {
  font-size: 1.08rem;
}

.project-body {
  border-top: 1px solid var(--line);

  padding: 20px 22px 24px;

  color: var(--muted);

  background: #f6f9fb;
}

.project-body p {
  margin: 0;
}

.project-body b {
  color: var(--ink);
}

.project-body br {
  line-height: 1.9;
}

/* --------------------------------------------------
   CERTIFICATES
-------------------------------------------------- */

.cert-grid {
  display: grid;

  grid-template-columns: repeat(6, 1fr);

  gap: 16px;

  align-items: center;
}

.cert-grid img {
  width: 100%;

  aspect-ratio: 1 / 1;

  object-fit: contain;

  border-radius: 18px;

  background: #fff;

  padding: 16px;

  border: 1px solid var(--line);

  box-shadow:
    0 8px 28px rgba(31, 41, 51, 0.07);
}

/* --------------------------------------------------
   CONTACT
-------------------------------------------------- */

.contact-card {
  padding: 42px;

  display: flex;
  justify-content: space-between;
  align-items: center;

  gap: 30px;

  background:
    linear-gradient(
      135deg,
      #25313d,
      #46586b
    );

  color: #fff;
}

.contact-card .eyebrow {
  color: #c8d7e6;
}

.contact-card p {
  color: rgba(255, 255, 255, 0.76);
}

.contact-card .btn-ghost {
  color: #fff;

  background: rgba(255, 255, 255, 0.08);

  border-color: rgba(255, 255, 255, 0.22);
}

/* --------------------------------------------------
   FOOTER
-------------------------------------------------- */

.footer {
  padding: 38px 0;

  background: #1f2933;

  border-top: 1px solid rgba(255, 255, 255, 0.08);

  color: #cbd5df;
}

.footer-grid {
  display: grid;

  grid-template-columns: 1fr 1fr 1fr;

  gap: 28px;
}

.footer strong {
  color: #fff;
}

.footer a {
  color: #c8d7e6;
}

/* --------------------------------------------------
   ANIMATIONS
-------------------------------------------------- */

.reveal {
  opacity: 0;

  transform: translateY(16px);

  transition:
    opacity 0.65s ease,
    transform 0.65s ease;
}

.reveal.is-visible {
  opacity: 1;

  transform: none;
}

/* --------------------------------------------------
   RESPONSIVE
-------------------------------------------------- */

@media (max-width: 1000px) {

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

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

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

@media (max-width: 760px) {

  .nav-toggle {
    display: block;
  }

  .nav-menu {
    position: fixed;

    top: 76px;
    left: 16px;
    right: 16px;

    display: none;
    flex-direction: column;
    align-items: stretch;

    padding: 14px;

    background: rgba(238, 242, 245, 0.98);

    border: 1px solid var(--line);

    border-radius: 20px;

    box-shadow: var(--shadow);
  }

  .nav-menu.is-open {
    display: flex;
  }

  .nav-menu a {
    padding: 1rem;
  }

  .section {
    padding: 72px 0;
  }

  .hero {
    min-height: 680px;
  }

  .four-columns,
  .stats,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .contact-card {
    display: block;
  }

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

  .container {
    width: min(var(--max), calc(100% - 28px));
  }

  .project-card summary {
    grid-template-columns: auto 1fr;

    gap: 10px;
  }

  .project-card summary::after {
    grid-column: 2;

    justify-self: start;
  }

  .hero h1 {
    font-size: clamp(2.35rem, 11vw, 3.4rem);
  }
}

@media (prefers-reduced-motion: reduce) {

  html {
    scroll-behavior: auto;
  }

  .reveal,
  .btn,
  .card {
    transition: none;
  }
}