/* ---------- Reset & basis ---------- */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f5f7fa;
  --color-text: #1c2530;
  --color-text-muted: #5a6472;
  --color-primary: #1e3a5f;
  --color-primary-light: #2e5a8f;
  --color-accent: #3fa9f5;
  --color-border: #e1e5ea;
  --max-width: 1100px;
  --radius: 8px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", system-ui, -apple-system, Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

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

a {
  color: var(--color-primary-light);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

ul {
  list-style: none;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

section {
  padding: 4rem 0;
}

h1, h2, h3 {
  line-height: 1.25;
  color: var(--color-primary);
}

h2 {
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
}

.section-intro {
  color: var(--color-text-muted);
  max-width: 640px;
  margin-bottom: 2.5rem;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.logo span {
  color: var(--color-accent);
}

.logo:hover {
  text-decoration: none;
}

.main-nav ul {
  display: flex;
  gap: 2rem;
}

.main-nav a {
  color: var(--color-text);
  font-weight: 500;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--color-primary-light);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--color-primary);
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(135deg, var(--color-bg-alt), #eef3f8);
  padding: 5rem 0;
}

.hero .container {
  max-width: 720px;
}

.hero h1 {
  font-size: 2.4rem;
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  border: 2px solid transparent;
}

.btn:hover {
  text-decoration: none;
}

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

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

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-primary);
  color: #fff;
}

/* ---------- Cards / grid ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.75rem;
}

.card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.6rem;
}

.card p {
  color: var(--color-text-muted);
}

.card .tags {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.tag {
  background: #e6f0fa;
  color: var(--color-primary-light);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.6rem;
  border-radius: 999px;
}

.section-alt {
  background: var(--color-bg-alt);
}

/* ---------- Contact ---------- */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.contact-details dl {
  margin-top: 1rem;
}

.contact-details dt {
  font-weight: 600;
  color: var(--color-primary);
  margin-top: 1rem;
}

.contact-details dd {
  color: var(--color-text-muted);
}

form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

label {
  font-weight: 600;
  font-size: 0.9rem;
}

input,
textarea {
  width: 100%;
  padding: 0.7rem 0.9rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 1rem;
}

input:focus,
textarea:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 1px;
}

textarea {
  resize: vertical;
  min-height: 140px;
}

.form-note {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
  margin-top: 2rem;
}

.site-footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.site-footer a {
  color: var(--color-text-muted);
}

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    display: none;
  }

  .main-nav.open {
    display: block;
  }

  .main-nav ul {
    flex-direction: column;
    padding: 1rem 1.5rem 1.5rem;
    gap: 1rem;
  }

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

  .hero h1 {
    font-size: 1.9rem;
  }
}