@import url("https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Space+Grotesk:wght@500;600;700&display=swap");

:root {
  /* LIGHT (default) — matched to subjects.css :root tokens */
  --bg: oklch(0.995 0.002 250);                 /* subjects --background */
  --bg-translucent: oklch(0.995 0.002 250 / 0.8);
  --bg-glow: radial-gradient(60% 45% at 50% -5%, color-mix(in oklab, var(--primary) 14%, transparent), transparent 70%);

  --surface-solid: oklch(1 0 0);                /* subjects --card */
  --card-grad-1: oklch(1 0 0);                  /* subjects --card */
  --card-grad-2: oklch(0.955 0.02 280);         /* subjects --accent */
  --border: color-mix(in oklab, var(--primary) 20%, transparent); /* subjects eyebrow-primary border tint */
  --border-soft: oklch(0.918 0.008 265);        /* subjects --border */
  --muted-bg: oklch(0.965 0.008 265);           /* subjects --muted */

  --text: oklch(0.19 0.02 265);                 /* subjects --foreground */
  --text-muted: oklch(0.53 0.02 265);           /* subjects --muted-foreground */
  --text-faint: oklch(0.68 0.02 265);           /* lighter step of --muted-foreground */

  --primary: oklch(0.53 0.19 268);              /* subjects --primary 
  --primary-glow: oklch(0.66 0.17 288);         /* subjects --primary-glow */
  --primary-soft: color-mix(in oklab, var(--primary) 10%, transparent);
  --primary-strong: oklch(0.46 0.19 268);       /* darker step of --primary, for hovers */
  --on-primary: oklch(0.99 0.003 250);          /* subjects --primary-foreground */
  --gradient-primary: linear-gradient(135deg, var(--primary), var(--primary-glow)); /* subjects --gradient-primary */

  --youtube: #e11d2e;
  --youtube-soft: rgba(225, 29, 46, 0.08);
  --on-youtube: #c81326;

  --shadow-card: 0 1px 1px oklch(0.2 0.03 265 / 0.04), 0 20px 40px -28px oklch(0.2 0.03 265 / 0.14); /* subjects --shadow-soft */
  --modal-backdrop: oklch(0.2 0.03 265 / 0.5);

  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 10px;

  --font-display: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --font-body: "DM Sans", ui-sans-serif, system-ui, sans-serif;
}

html.dark {
  /* DARK — matched to subjects.css .dark tokens */
  --bg: oklch(0.129 0.042 264.695);             /* subjects --background */
  --bg-translucent: oklch(0.129 0.042 264.695 / 0.8);
  --bg-glow: radial-gradient(60% 45% at 50% -5%, color-mix(in oklab, var(--primary) 20%, transparent), transparent 70%);

  --surface-solid: oklch(0.208 0.042 265.755);  /* subjects --card */
  --card-grad-1: oklch(0.24 0.045 265.755);
  --card-grad-2: oklch(0.185 0.04 265.755);
  --border: oklch(1 0 0 / 10%);                 /* subjects --border */
  --border-soft: oklch(1 0 0 / 7%);
  --muted-bg: oklch(0.279 0.041 260.031);       /* subjects --muted */

  --text: oklch(0.984 0.003 247.858);           /* subjects --foreground */
  --text-muted: oklch(0.704 0.04 256.788);      /* subjects --muted-foreground */
  --text-faint: oklch(0.5 0.03 260);

  --primary: oklch(0.72 0.13 270);              /* purple accent, tuned dark version of subjects hue 268 */
  --primary-glow: oklch(0.8 0.12 290);
  --primary-soft: color-mix(in oklab, var(--primary) 16%, transparent);
  --primary-strong: oklch(0.8 0.11 272);
  --on-primary: oklch(0.16 0.03 265);
  --gradient-primary: linear-gradient(135deg, var(--primary), var(--primary-glow));

  --youtube: #f04446;
  --youtube-soft: rgba(240, 68, 70, 0.12);
  --on-youtube: #ff8a8b;

  --shadow-card: 0 1px 1px oklch(0 0 0 / 0.3), 0 20px 40px -24px oklch(0 0 0 / 0.55); /* subjects --shadow-lift */
  --modal-backdrop: oklch(0.1 0.02 265 / 0.82);
}

* {
  box-sizing: border-box;
}

/* BASE */
html {
  background: var(--bg);
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-body);
  background: var(--bg-glow), var(--bg);
  background-attachment: fixed;
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.2s ease, color 0.2s ease;
}

/* ---------------------------------- NAVBAR ---------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--border-soft);
  background: var(--bg-translucent);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.header-inner {
  max-width: 1120px;
  margin: 0 auto;
  height: 64px;
  padding: 0 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 8px;
  text-decoration: none;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text);
}

.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.brand-tag {
  display: none;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
}
@media (min-width: 640px) {
  .brand-tag { display: inline; }
}

.main-nav {
  display: none;
  align-items: center;
  gap: 28px;
  font-size: 14px;
  color: var(--text-muted);
}
.main-nav a { text-decoration: none; color: inherit; transition: color 0.2s ease; }
.main-nav a:hover,
.main-nav a.active { color: var(--text); }
.main-nav a.active { font-weight: 600; }
@media (min-width: 768px) {
  .main-nav { display: flex; }
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface-solid);
  cursor: pointer;
  transition: background 0.2s ease;
}
.theme-toggle:hover { background: var(--muted-bg); }
.theme-toggle svg {
  width: 16px;
  height: 16px;
  grid-area: 1 / 1;
  color: var(--text);
}
.theme-toggle .icon-sun { display: none; }
.theme-toggle.is-dark .icon-moon { display: none; }
.theme-toggle.is-dark .icon-sun { display: block; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  border-radius: 12px;
  padding: 10px 18px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
}

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

.btn-sm { padding: 8px 14px; }

/* Hamburger — phones only */
.menu-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface-solid);
  color: var(--text);
  font-size: 16px;
  cursor: pointer;
}
@media (min-width: 768px) {
  .menu-toggle { display: none; }
}

/* Get Started: header-actions copy on desktop, dropdown copy on phone */
.cta-mobile { display: none; }

@media (max-width: 767px) {
  .cta-desktop { display: none; }

  .main-nav {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    padding: 14px 30px 18px;
    background: var(--surface-solid);
    border-bottom: 1px solid var(--border-soft);
  }
  .main-nav.show { display: flex; }
  .main-nav a { width: 100%; padding: 8px 0; }
  .main-nav .cta-mobile {
    display: inline-flex;
    width: auto;
    margin-top: 8px;
  }
}