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

html {
  -moz-text-size-adjust: none;
  -webkit-text-size-adjust: none;
  text-size-adjust: none;
  /* Linear uses subpixel where available, then grayscale */
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-feature-settings: "cv01", "ss03";  /* Inter Variable optical features */
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-20);
}

body {
  min-height: 100dvh;
  line-height: 1.65;
  font-family: var(--font-body, 'Inter', sans-serif);
  font-size: var(--text-base);
  font-weight: 400;
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color 0.3s ease, color 0.3s ease;
}

img, picture, video, canvas, svg { display: block; max-width: 100%; height: auto; }
ul[role="list"], ol[role="list"] { list-style: none; }
input, button, textarea, select { font: inherit; color: inherit; }

/* Headings — Inter with weight 590 (bold) + aggressive tracking */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display, 'Inter', sans-serif);
  font-feature-settings: "cv01", "ss03";
  text-wrap: balance;
  line-height: 1.1;
  color: var(--color-text);
  font-weight: 590;
  letter-spacing: var(--ls-heading);
}

h1 { letter-spacing: var(--ls-hero); }
h2 { letter-spacing: var(--ls-display); }

p, li, figcaption { text-wrap: pretty; }

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--color-primary-hover); }

/* Linear selection color — indigo tint */
::selection {
  background: rgba(94, 106, 210, 0.25);
  color: var(--color-text);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

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

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

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border-width: 0;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-6), 5vw, var(--space-16));
}
.container--narrow  { max-width: var(--content-narrow); }
.container--default { max-width: var(--content-default); }

/* Section Spacing */
section {
  padding-block: clamp(var(--space-16), 8vw, var(--space-32));
}

/* Utility classes */
.text-center  { text-align: center; }
.text-muted   { color: var(--color-text-muted); }
.text-primary { color: var(--color-primary); }
.font-display { font-family: var(--font-display); }

/* Gradient text — Linear indigo-to-violet */
.gradient-text {
  background: linear-gradient(135deg, #5e6ad2 0%, #7170ff 50%, #828fff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── Badge ── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  border: 1px solid rgba(94,106,210,0.25);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 590;
  letter-spacing: var(--ls-label);
  text-transform: uppercase;
  font-feature-settings: "cv01", "ss03";
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 510;
  letter-spacing: 0.005em;
  font-feature-settings: "cv01", "ss03";
  transition: all var(--transition-interactive);
  cursor: pointer;
  border: none;
  text-decoration: none;
  white-space: nowrap;
}

/* Primary — Linear indigo */
.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 1px 0 rgba(0,0,0,0.2), 0 0 0 1px rgba(94,106,210,0.5);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: 0 1px 0 rgba(0,0,0,0.25), 0 4px 16px rgba(94,106,210,0.35);
  transform: translateY(-1px);
  color: #fff;
}
.btn-primary:active { transform: translateY(0); }

/* Outline */
.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-highlight);
}

/* Ghost — Linear frosted glass */
.btn-ghost {
  background: rgba(255,255,255,0.02);
  color: #fff;
  border: 1px solid rgba(255,255,255,0.08);
  backdrop-filter: blur(8px);
}
.btn-ghost:hover {
  background: rgba(255,255,255,0.06);
  border-color: rgba(255,255,255,0.14);
  color: #fff;
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
  border-radius: var(--radius-lg);
}

/* ── Cards ── */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-sm);
  transition:
    box-shadow var(--transition-interactive),
    transform  var(--transition-interactive),
    border-color var(--transition-fast);
}
.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: rgba(255,255,255,0.12);
}

/* ── Fade-in animations ── */
.fade-up {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity   0.6s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* No-JS / scripting:none fallback */
@media (scripting: none) {
  .fade-up { opacity: 1; transform: none; }
}
.fade-up.delay-1 { transition-delay: 0.1s; }
.fade-up.delay-2 { transition-delay: 0.2s; }
.fade-up.delay-3 { transition-delay: 0.3s; }
.fade-up.delay-4 { transition-delay: 0.4s; }
.fade-up.delay-5 { transition-delay: 0.5s; }