/* ============================================
   base.css — Reset, Variables, Typography,
   Navigation, Layout, Mobile Menu
   ============================================ */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Syne:wght@700;800&family=DM+Sans:wght@300;400;500&display=swap');

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

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

button {
  background: none;
  border: none;
  cursor: pointer;
  font: inherit;
}

/* ---- CSS Variables ---- */
:root {
  --bg: #0a0a0f;
  --bg-surface: #141419;
  --text: #e0e0e0;
  --text-muted: #555;
  --accent: #e8734a;
  --border: rgba(255, 255, 255, 0.06);
  --radius: 10px;
  --max-width: 900px;
  --font-heading: 'Syne', sans-serif;
  --font-body: 'DM Sans', sans-serif;
  --nav-height: 64px;
  --transition: 0.25s ease;
}

/* ---- Typography ---- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text);
}

h1 { font-size: clamp(2rem, 5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2rem); }
h3 { font-size: clamp(1.1rem, 2.5vw, 1.35rem); }
h4 { font-size: 1.1rem; }

p {
  font-weight: 300;
  color: var(--text-muted);
  max-width: 65ch;
}

strong {
  font-weight: 500;
  color: var(--text);
}

/* ---- Layout ---- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

@media (min-width: 768px) {
  .container {
    padding: 0 48px;
  }
}

/* ---- Navigation ---- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(10, 10, 15, 0.75);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

@media (min-width: 768px) {
  .nav-inner {
    padding: 0 48px;
  }
}

/* Logo */
.nav-logo {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.4rem;
  color: var(--text);
  letter-spacing: -0.5px;
}

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

/* Desktop links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--text-muted);
  position: relative;
  transition: color var(--transition);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--accent);
  transition: width var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* Hamburger button */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 36px;
  height: 36px;
  gap: 5px;
  z-index: 110;
}

.nav-hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--text);
  transition: transform var(--transition), opacity var(--transition);
  transform-origin: center;
}

/* Hamburger open state */
.nav-hamburger.open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

.nav-hamburger.open span:nth-child(2) {
  opacity: 0;
}

.nav-hamburger.open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* Mobile overlay */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 105;
  opacity: 0;
  transition: opacity var(--transition);
}

.nav-overlay.visible {
  opacity: 1;
}

/* Mobile panel */
.nav-mobile {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 260px;
  background: var(--bg-surface);
  z-index: 106;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  display: flex;
  flex-direction: column;
  padding: calc(var(--nav-height) + 32px) 32px 48px;
  gap: 28px;
  border-left: 1px solid var(--border);
}

.nav-mobile.open {
  transform: translateX(0);
}

.nav-mobile a {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: color var(--transition);
}

.nav-mobile a:hover,
.nav-mobile a.active {
  color: var(--accent);
}

/* Responsive: show hamburger, hide desktop links */
@media (max-width: 767px) {
  .nav-links {
    display: none;
  }

  .nav-hamburger {
    display: flex;
  }

  .nav-overlay {
    display: block;
  }
}