/* =========================
   RESET (Task 3.1)
========================= */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-size: 18px;
  font-weight: 600;
}

/* =========================
   VARIABLES (Task 3.3 + 3.4)
========================= */
:root {
  /* Typography */
  --font-xs: 0.75rem;
  --font-sm: 0.875rem;
  --font-base: 1rem;
  --font-lg: 1.125rem;
  --font-xl: 1.25rem;
  --font-2xl: 1.5rem;
  --font-3xl: 1.875rem;
  --font-4xl: 2.25rem;

  /* Colors */
  --color-primary: #1d4ed8;
  --color-primary-light: #60a5fa;
  --color-primary-dark: #3352a7;
  --color-secondary: #f59e0b;
  --color-background: #f8fafc;
  --color-surface: rgba(255,255,255,0.85);
  --color-text: #111827;
  --color-muted: #475569;
  --color-border: #94a3b8;
  --color-danger: #dc2626;

  --radius: 10px;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.1);
  --shadow-md: 0 10px 20px rgba(0,0,0,0.12);
}

/* =========================
   BASE (Task 3.1)
========================= */
body {
  font-family: 'Roboto', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
}
@keyframes gradientShift {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}
body.projects-page,
body.contact-page {
    background: linear-gradient(
    270deg,
    #469df5,
    #58faef,
    #e7e7e7
  );
  background-size: 400% 400%;
  animation: gradientShift 15s ease infinite;
}
body.home-page {
    background: linear-gradient(
    270deg,
    #469df5,
    #58faef,
    #e7e7e7
  );
  background-size: 400% 400%;
  animation: gradientShift 15s ease infinite;
}
body.about-page {
    background: linear-gradient(
    270deg,
    #469df5,
    #58faef,
    #e7e7e7
  );
  background-size: 400% 400%;
  animation: gradientShift 15s ease infinite;
}
/* =========================
   TYPOGRAPHY (Task 3.3)
========================= */
h1 { font-size: var(--font-4xl); }
h2 { font-size: var(--font-3xl); margin-top: 30px; }
h3 { font-size: var(--font-2xl); }
p { margin-bottom: 1rem; }

h1, h2, h3 {
  color: var(--color-primary-dark);
  font-family: 'Poppins', sans-serif;
}

/* =========================
   LAYOUT
========================= */
.container {
  width: min(1000px, 90%);
  margin: 0 auto;
}

/* =========================
   NAV (Task 4.1 Flexbox)
========================= */
nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  padding: 20px 0;
}

.logo {
  font-weight: 700;
  font-size: var(--font-xl);
  color: var(--color-primary-dark);
  text-decoration: none;
  padding: 0;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 12px;
}

/* LINKS */
nav a {
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--color-text);
  background: rgba(255,255,255,0.4);
  transition: all 0.3s ease;
}

nav a:hover {
  transform: translateY(-2px);
  background: rgba(255,255,255,0.6);
}

/* =========================
   HAMBURGER
========================= */
.menu-toggle {
  display: none;
  font-size: 1.8rem;
  cursor: pointer;
}

#menu-checkbox {
  display: none;
}

/* MOBILE NAV */
@media (max-width: 700px) {
  .menu-toggle { display: block; }

  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 60px;
    right: 0;
    background: white;
    padding: 20px;
    width: 200px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
  }

  #menu-checkbox:checked ~ .nav-links {
    display: flex;
  }
}

/* DESKTOP NAV */
@media (min-width: 701px) {
  .nav-links { display: flex; }
}

/* =========================
   BUTTONS (Task 4.4)
========================= */
.btn {
 display: inline-block;
  background-color: var(--color-primary);
  color: white;
  padding: 15px 30px;
  font-size: 1.2em;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font: inherit;
  text-decoration: none;
  transition: all 0.3s ease;
  
}

.btn:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
}

/* =========================
   CARDS (Task 3.2 + 4.1)
========================= */
.card {
  background: var(--color-surface);
  padding: 20px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

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

/* Card Row (Flexbox requirement) */
.card-row {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.card-row .card {
  flex: 1 1 300px;
}

/* =========================
   GRID (Task 4.2)
========================= */
.gallery {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.projects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
.gallery img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.magazine-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.mag-header,
.mag-sidebar,
.mag-main,
.mag-footer {
  padding: 20px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.75);
}
img {
  max-width: 100%;
  height: auto;
}
/* =========================
   FOOTER (Task 4.1)
========================= */
footer {
  margin-top: 40px;
  padding: 30px 20px;
}

.footer-grid {
  display: grid;
  gap: 20px;
}

.footer-bottom {
  text-align: center;
  margin-top: 20px;
}

/* =========================
   FORMS (Polish)
========================= */
form {
  background: var(--color-surface);
  padding: 20px;
  border-radius: var(--radius);
}

input, textarea, select {
  width: 100%;
  padding: 10px;
  border: 1px solid var(--color-border);
  border-radius: 6px;
}

input:focus, textarea:focus {
  border-color: var(--color-primary);
  outline: none;
}

input:invalid, textarea:invalid {
  border-color: var(--color-danger);
}

/* =========================
   RESPONSIVE (Task 4.3)
========================= */

  /* Tablet */
  @media (min-width: 768px) {
  .row {
    grid-template-columns: 1fr 1fr;
  }

  .projects-grid,
  .grid,
  .skills-grid,
  .gallery,
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .contact-layout {
    grid-template-columns: 2fr 1fr;
  }
}

/* Desktop */
@media (min-width: 1024px) {
  .projects-grid,
  .gallery {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .magazine-layout {
    grid-template-columns: 250px 1fr;
    grid-template-areas:
      "header header"
      "sidebar main"
      "footer footer";
  }

  .mag-header { grid-area: header; }
  .mag-sidebar { grid-area: sidebar; }
  .mag-main { grid-area: main; }
  .mag-footer { grid-area: footer; }
}

/* Large Desktop */
@media (min-width: 1280px) {
  .container {
    width: min(1200px, 92%);
  }
}

/* Smaller screens only */
@media (max-width: 700px) {
  nav {
    flex-direction: column;
    align-items: flex-start;
  }

  nav ul {
    flex-direction: column;
    align-items: flex-start;
  }
}
section {
  margin-bottom: 40px;
}
.row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-bottom: 16px;
}
form {
  background: var(--color-surface);
  padding: 20px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

fieldset {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px;
  margin: 20px;
}

legend {
  font-weight: 600;
  padding: 0 8px;
}