/* ==========================================================================
   Base Styles — SCS Synergy
   ==========================================================================
   Modern CSS reset, typography system, utility classes, grid helpers,
   buttons, and section background variants.  Mobile-first throughout.
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -moz-text-size-adjust: 100%;
}

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  font-weight: var(--weight-regular);
  line-height: var(--leading-normal);
  color: var(--text-dark);
  background-color: var(--bg-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-base);
}

a:hover {
  color: var(--primary);
}

ul,
ol {
  list-style: none;
}

table {
  border-collapse: collapse;
  border-spacing: 0;
}

/* Accessible custom focus style */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* ------------------------------------------------------------------
   2. Typography
   ------------------------------------------------------------------ */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  color: var(--text-dark);
  letter-spacing: var(--tracking-tight);
}

h1 {
  font-size: var(--text-3xl);
  font-weight: var(--weight-extrabold);
}

h2 {
  font-size: var(--text-2xl);
  font-weight: var(--weight-bold);
}

h3 {
  font-size: var(--text-xl);
}

h4 {
  font-size: var(--text-lg);
}

h5 {
  font-size: var(--text-md);
}

h6 {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
}

p {
  margin-bottom: var(--space-4);
  color: var(--text-light);
  line-height: var(--leading-normal);
}

/* "// Subtitle" pattern — accent uppercase label used above section headings */
.subtitle {
  display: inline-block;
  font-family: var(--font-primary);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  color: var(--primary);
  margin-bottom: var(--space-3);
}

.subtitle::before {
  content: '// ';
  color: var(--primary);
}

/* Dark-section heading/text overrides */
.bg-dark .subtitle {
  color: var(--primary);
}

.bg-dark h1,
.bg-dark h2,
.bg-dark h3,
.bg-dark h4,
.bg-dark h5,
.bg-dark h6 {
  color: var(--text-white);
}

.bg-dark p {
  color: rgba(255, 255, 255, 0.7);
}

.bg-dark a:hover {
  color: var(--primary);
}

strong,
b {
  font-weight: var(--weight-semibold);
}

/* ------------------------------------------------------------------
   3. Layout Utilities
   ------------------------------------------------------------------ */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

/* Section spacing */
.section-padding {
  padding-block: var(--space-9);
}

/* ------------------------------------------------------------------
   4. Section Backgrounds
   ------------------------------------------------------------------ */
.bg-dark {
  background-color: var(--bg-dark);
  color: var(--text-white);
}

.bg-light {
  background-color: var(--bg-light);
}

.bg-white {
  background-color: var(--bg-white);
}

/* ------------------------------------------------------------------
   5. Text Utilities
   ------------------------------------------------------------------ */
.text-centre {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

.text-primary {
  color: var(--primary);
}

.text-secondary {
  color: var(--secondary);
}

.text-accent {
  color: var(--primary-light);
}

.text-white {
  color: var(--text-white);
}

/* ------------------------------------------------------------------
   6. Buttons
   ------------------------------------------------------------------ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 14px 32px;
  font-family: var(--font-primary);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  transition:
    background-color var(--transition-base),
    color var(--transition-base),
    border-color var(--transition-base),
    transform var(--transition-fast),
    box-shadow var(--transition-base);
  cursor: pointer;
  white-space: nowrap;
  line-height: 1;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

/* Primary — filled blue button (main CTA) */
.btn-primary {
  background-color: var(--primary);
  color: var(--text-white);
  border-color: var(--primary);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  border-color: var(--primary-hover);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.35);
}

/* Outline — transparent with border */
.btn-outline {
  background-color: transparent;
  color: var(--text-white);
  border-color: var(--text-white);
}

.btn-outline:hover {
  background-color: var(--text-white);
  color: var(--text-dark);
}

/* Dark outline variant for light backgrounds */
.btn-outline-dark {
  background-color: transparent;
  color: var(--text-dark);
  border-color: var(--text-dark);
}

.btn-outline-dark:hover {
  background-color: var(--text-dark);
  color: var(--text-white);
}

/* Blue variant */
.btn-blue {
  background-color: var(--primary);
  color: var(--text-white);
  border-color: var(--primary);
}

.btn-blue:hover {
  background-color: var(--primary-hover);
  border-color: var(--primary-hover);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.35);
}

/* Small variant */
.btn-sm {
  padding: 10px 24px;
  font-size: var(--text-xs);
}

/* Large variant */
.btn-lg {
  padding: 18px 40px;
  font-size: var(--text-base);
}

/* ------------------------------------------------------------------
   7. Grid Helpers
   ------------------------------------------------------------------ */

/* All grids stack on mobile (1 column), breakpoints set in responsive.css */
.grid-2,
.grid-3,
.grid-4 {
  display: grid;
  gap: var(--space-6);
}

/* ------------------------------------------------------------------
   8. Scroll-based Animation Utility
   ------------------------------------------------------------------ */

/* Elements with .fade-in start hidden; JS adds .is-visible on scroll */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

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

/* ------------------------------------------------------------------
   9. Scroll-to-top Button
   ------------------------------------------------------------------ */
.scroll-top-btn {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary);
  color: var(--text-white);
  border: none;
  border-radius: var(--radius-full);
  font-size: var(--text-lg);
  box-shadow: var(--shadow-md);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition:
    opacity var(--transition-base),
    visibility var(--transition-base),
    transform var(--transition-base),
    background-color var(--transition-fast);
  z-index: var(--z-sticky);
}

.scroll-top-btn.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-top-btn:hover {
  background-color: var(--primary-hover);
  transform: translateY(-3px);
}

/* ------------------------------------------------------------------
   10. Miscellaneous Utilities
   ------------------------------------------------------------------ */

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

/* Prevent body scroll when mobile menu is open */
body.menu-open {
  overflow: hidden;
}