/* ===========================
   VARIABLES
=========================== */
:root {
  --primary: #1a4e8a;
  --secondary: #2ab27b;
  --light: #f5f7fa;
  --dark: #1c1c1c;
  --gray: #6b7280;
}

/* ===========================
   RESET
=========================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Roboto', sans-serif;
}

html {
  scroll-behavior: smooth;
}

/* ===========================
   BASE STYLES
=========================== */
body {
  line-height: 1.7;
  font-size: 18px;
  color: var(--dark);
  background: var(--light);
  overflow-x: hidden;
  padding-top: 70px;
  font-weight: 400;
}

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.3;
  text-align: center;
}

h2 {
  font-size: 3.2rem;
  margin-bottom: 1rem;
}

h3 {
  font-size: 2.2rem;
  margin-bottom: 1.8rem;
  position: relative;
  display: block;
  padding-bottom: 0.6rem;
}

h3::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 90px;
  height: 3px;
  background: var(--secondary);
  border-radius: 2px;
}

h4 {
  font-size: 1.4rem;
  margin-bottom: 0.6rem;
}

p {
  font-size: 1.15rem;
  line-height: 1.7;
  color: var(--gray);
  text-align: center;
  margin: 0 auto;
  max-width: 900px;
}

/* ===========================
   LAYOUT UTILITIES
=========================== */
.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ===========================
   HEADER & NAVIGATION
=========================== */
.header {
  padding: 18px 20px;
  background: #fff;
  border-bottom: 1px solid #eee;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
}

.logo img {
  height: 34px;
  width: auto;
}

.logo,
.logo:focus,
.logo img,
.logo img:focus {
  outline: none !important;
  box-shadow: none !important;
}

.nav {
  display: flex;
  gap: 28px;
}

.nav a {
  position: relative;
  color: #333;
  font-weight: 500;
  font-size: 1.05rem;
  text-decoration: none;
  letter-spacing: 0.2px;
  transition: color 0.2s ease-in-out;
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--secondary);
  transition: width 0.3s ease;
}

.nav a:hover {
  color: var(--secondary);
}

.nav a:hover::after {
  width: 100%;
}

.hamburger {
  font-size: 26px;
  cursor: pointer;
  display: none;
  background: none;
  border: none;
  color: #333;
}

/* ===========================
   HERO SECTION
=========================== */
.hero {
  background: #000 url('https://picsum.photos/id/1011/1600/900') center/cover no-repeat;
  position: relative;
  color: #fff;
  height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0 20px;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem;
}

.hero h1 {
  font-size: 3.4rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.hero p {
  max-width: 750px;
  margin: 0 auto 1.8rem;
  font-size: 1.25rem;
  color: #f1f1f1;
}

.hero-buttons {
  display: flex;
  justify-content: center;
  gap: 15px;
  flex-wrap: wrap;
}

.hero-buttons .btn {
  white-space: nowrap;
}

/* ===========================
   BUTTONS
=========================== */
.btn {
  background: var(--secondary);
  color: #fff;
  padding: 14px 30px;
  border-radius: 6px;
  text-decoration: none;
  display: inline-block;
  transition: background 0.3s ease;
  font-weight: 600;
  font-size: 1.15rem;
}

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

/* ===========================
   SECTIONS
=========================== */
.section {
  padding: 4.5rem 0;
  scroll-margin-top: 75px;
}

.section.light {
  background: var(--light);
}

.section.colored {
  background: #eef6f2;
}