/* =====================
   RESET / BASE
===================== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: #222;
  background-color: #f9f9f9;
  min-height: 100vh;
}

/* =====================
   TYPOGRAPHY
===================== */
h1, h2, h3, h4, h5, h6 {
  margin-bottom: 0.5em;
  font-weight: 600;
  line-height: 1.2;
  color: #111;
}

h1 { font-size: 2.5rem; margin-top: 1em; }
h2 { font-size: 2rem; margin-top: 1em; }
h3 { font-size: 1.75rem; margin-top: 1em; }

p {
  margin-bottom: 1em;
  color: #444;
}

/* =====================
   LINKS
===================== */
a {
  color: #1e90ff;
  text-decoration: none;
  transition: color 0.2s ease-in-out;
}

a:hover {
  color: #3742fa;
}

/* =====================
   CONTAINERS & LAYOUT
===================== */
.container {
  width: 90%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem 0;
}

header, footer {
  background-color: #fff;
  padding: 1rem 0;
  box-shadow: 0 1px 4px rgba(0,0,0,0.1);
}

main {
  padding: 2rem 0;
}

/* =====================
   LISTS
===================== */
ul, ol {
  margin-bottom: 1em;
  padding-left: 1.5em;
}

li {
  margin-bottom: 0.5em;
}

/* =====================
   IMAGES
===================== */
img {
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: 4px;
}

/* =====================
   BUTTONS
===================== */
button,
input[type="button"],
input[type="submit"] {
  padding: 0.6em 1.2em;
  border: none;
  background-color: #1e90ff;
  color: #fff;
  cursor: pointer;
  border-radius: 6px;
  font-size: 1rem;
  transition: background-color 0.2s ease-in-out;
}

button:hover,
input[type="button"]:hover,
input[type="submit"]:hover {
  background-color: #3742fa;
}

/* =====================
   CARDS / SECTIONS
===================== */
.card {
  background-color: #fff;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
  margin-bottom: 1.5rem;
}

/* =====================
   RESPONSIVENESS
===================== */
@media (max-width: 768px) {
  html { font-size: 15px; }

  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
}