:root {
  --navy-900: #071633;
  --navy-800: #0b2149;
  --navy-700: #123067;
  --navy-600: #1c4180;
  --navy-100: #e8edf6;
  --accent: #2f6fe0;
  --accent-2: #8b5cf6;
  --bg: #f5f7fb;
  --surface: #ffffff;
  --text: #101a2e;
  --text-muted: #5c6b85;
  --border: #e2e7f0;
  --badge-bg: var(--navy-100);
  --badge-text: var(--navy-700);
  --radius: 14px;
  --shadow: 0 10px 30px rgba(7, 22, 51, 0.08);
  --shadow-hover: 0 20px 45px rgba(47, 111, 224, 0.22);
  --transition: 220ms ease;
  --theme-transition: background-color 400ms ease, color 400ms ease, border-color 400ms ease;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --accent: #7db8ff;
  --accent-2: #a78bfa;
  --bg: #060b16;
  --surface: #101a2e;
  --text: #e9edf7;
  --text-muted: #93a0bf;
  --border: rgba(255, 255, 255, 0.1);
  --badge-bg: rgba(125, 184, 255, 0.14);
  --badge-text: #9cc9ff;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  --shadow-hover: 0 22px 50px rgba(125, 184, 255, 0.25);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  font-family: "Vazirmatn", "Segoe UI", Tahoma, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  opacity: 0;
  animation: page-fade 500ms ease forwards;
  transition: var(--theme-transition);
}

@keyframes page-fade {
  to { opacity: 1; }
}

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

.container {
  max-width: 1120px;
  margin-inline: auto;
  padding-inline: 24px;
}

#scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  z-index: 100;
  transition: width 120ms linear;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--navy-900);
  color: #fff;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.15);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: 14px;
  gap: 16px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.05rem;
}

.brand img {
  height: 42px;
  width: 42px;
  object-fit: contain;
  animation: logo-float 4s ease-in-out infinite;
}

@keyframes logo-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.main-nav a {
  position: relative;
  font-size: 0.95rem;
  opacity: 0.9;
  padding-block: 4px;
}

.main-nav a::after {
  content: "";
  position: absolute;
  inset-inline-start: 0;
  bottom: -2px;
  height: 2px;
  width: 0;
  background: var(--accent);
  transition: width var(--transition);
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.lang-toggle {
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: transparent;
  color: #fff;
  border-radius: 999px;
  padding: 6px 16px;
  font-family: inherit;
  font-size: 0.85rem;
  cursor: pointer;
  transition: transform var(--transition), background var(--transition);
}

.lang-toggle:hover { background: rgba(255, 255, 255, 0.12); }
.lang-toggle:active { transform: scale(0.94); }

.theme-toggle {
  position: relative;
  width: 38px;
  height: 38px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  transition: transform var(--transition), background var(--transition);
}

.theme-toggle:hover { background: rgba(255, 255, 255, 0.12); }
.theme-toggle:active { transform: scale(0.9); }

.theme-toggle svg {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  margin: auto;
  width: 18px;
  height: 18px;
  color: #fff;
  transition: transform 420ms ease, opacity 420ms ease;
}

.theme-toggle .icon-sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.theme-toggle .icon-moon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.5);
}

:root[data-theme="dark"] .theme-toggle .icon-sun {
  opacity: 0;
  transform: rotate(90deg) scale(0.5);
}

:root[data-theme="dark"] .theme-toggle .icon-moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.hero {
  position: relative;
  background: linear-gradient(135deg, var(--navy-900), var(--navy-700));
  color: #fff;
  padding-block: 80px;
  text-align: center;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.35;
  pointer-events: none;
}

.hero-glow-a {
  background: var(--accent);
  top: -140px;
  inset-inline-start: -100px;
  animation: drift-a 16s ease-in-out infinite alternate;
}

.hero-glow-b {
  background: var(--accent-2);
  bottom: -160px;
  inset-inline-end: -120px;
  animation: drift-b 20s ease-in-out infinite alternate;
}

@keyframes drift-a {
  from { transform: translate(0, 0); }
  to { transform: translate(60px, 40px); }
}

@keyframes drift-b {
  from { transform: translate(0, 0); }
  to { transform: translate(-50px, -30px); }
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero img.hero-logo {
  height: 110px;
  margin-bottom: 24px;
  animation: hero-in 700ms ease both, logo-float 5s ease-in-out 700ms infinite;
}

.hero h1 {
  font-size: clamp(1.6rem, 3vw, 2.6rem);
  margin: 0 0 12px;
  animation: hero-in 700ms ease 150ms both;
}

.hero p {
  color: rgba(255, 255, 255, 0.8);
  max-width: 620px;
  margin-inline: auto;
  font-size: 1.05rem;
  animation: hero-in 700ms ease 300ms both;
}

@keyframes hero-in {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: translateY(0); }
}

.section {
  padding-block: 56px;
}

.section h2 {
  font-size: 1.5rem;
  margin-bottom: 28px;
  color: var(--navy-800);
}

:root[data-theme="dark"] .section h2 {
  color: var(--text);
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms ease, transform 600ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.course-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition), var(--theme-transition);
  display: block;
}

.course-card:hover {
  transform: translateY(-6px) scale(1.01);
  box-shadow: var(--shadow-hover);
}

.course-card .badge {
  display: inline-block;
  background: var(--badge-bg);
  color: var(--badge-text);
  font-size: 0.75rem;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 14px;
  transition: var(--theme-transition);
}

.course-card h3 {
  margin: 0 0 8px;
  color: var(--navy-900);
}

:root[data-theme="dark"] .course-card h3 {
  color: var(--text);
}

.course-card p {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin: 0;
}

.term-group + .term-group {
  margin-top: 40px;
}

.term-heading {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-muted);
  margin: 0 0 16px;
}

.site-footer {
  background: var(--navy-900);
  color: rgba(255, 255, 255, 0.75);
  text-align: center;
  padding-block: 28px;
  margin-top: 64px;
  font-size: 0.85rem;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}