* { box-sizing: border-box; }

:root {
  --bg: #f5f7fb;
  --panel: #ffffff;
  --primary: #2c3e50;
  --primary-strong: #1f2d3d;
  --accent: #00a8ff;
  --text: #1f2937;
  --muted: #4b5563;
  --border: #dfe7f1;
  --shadow: 0 12px 30px rgba(15, 23, 42, 0.08);
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

header {
  background: var(--primary);
  color: white;
  padding: 28px 20px 18px;
  text-align: center;
}

header h1 {
  margin: 0 0 8px;
  font-size: clamp(2rem, 3vw, 3rem);
}

header p {
  margin: 0;
  opacity: 0.9;
}

nav {
  background: var(--primary-strong);
  padding: 12px 16px;
  text-align: center;
}

nav a {
  color: white;
  margin: 0 14px;
  text-decoration: none;
  font-weight: 600;
}

nav a:hover {
  text-decoration: underline;
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 36px 20px 52px;
}

section {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 28px 24px;
  margin-bottom: 28px;
}

h2 {
  margin-top: 0;
  color: var(--primary);
  font-size: clamp(1.6rem, 2vw, 2.2rem);
}

p {
  margin: 0 0 14px;
  color: var(--text);
}

.page-intro {
  text-align: center;
  margin-bottom: 30px;
}

.page-intro p {
  max-width: 760px;
  margin: 0 auto;
  color: var(--muted);
}

.portfolio-grid {
  display: grid;
  gap: 24px;
}

.portfolio-item {
  display: grid;
  grid-template-columns: minmax(180px, 260px) 1fr;
  gap: 22px;
  align-items: center;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: linear-gradient(135deg, #f9fbff 0%, #ffffff 100%);
}

.portfolio-item img {
  width: 100%;
  max-width: 230px;
  height: auto;
  display: block;
  margin: 0 auto;
  border-radius: 18px;
  background: #eef7ff;
  padding: 12px;
}

.portfolio-item h3 {
  margin: 0 0 10px;
  color: var(--primary);
  font-size: 1.5rem;
}

.portfolio-item p {
  margin: 0;
  color: var(--muted);
}

.accordion {
  display: grid;
  gap: 16px;
}

.accordion details {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fff;
  overflow: hidden;
}

.accordion summary {
  list-style: none;
  cursor: pointer;
  padding: 18px 20px;
  font-weight: bold;
  font-size: 1.1rem;
  color: var(--primary);
  background: #f4f8ff;
}

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

.accordion-content {
  padding: 20px;
  border-top: 1px solid var(--border);
}

.accordion-content h3 {
  margin-top: 0;
  color: var(--primary);
}

.accordion-content ul {
  margin: 12px 0 0 18px;
  color: var(--muted);
  padding: 0;
}

.footer {
  text-align: center;
  background: var(--primary);
  color: white;
  padding: 18px 16px;
}

@media (max-width: 700px) {
  .portfolio-item {
    grid-template-columns: 1fr;
    text-align: center;
  }

  nav a {
    display: inline-block;
    margin: 6px 10px;
  }
}