/**
 * SGE Works — Base CSS Reset, Typography, Accessibility & Core Layout
 */

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

/* 2. Root & Document Setup */
html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  background-color: var(--color-background);
  color: var(--color-on-surface);
}

body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  font-weight: 400;
  background-color: var(--color-background);
  color: var(--color-on-surface);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11';
}

/* 3. Text Selection */
::selection {
  background-color: var(--color-furnace-orange);
  color: var(--color-text-high-contrast);
}

/* 4. Anchor Scroll Offset (Prevents Sticky Header from obscuring headings) */
[id] {
  scroll-margin-top: var(--scroll-offset);
}

/* 5. Typography Scale */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  color: var(--color-text-high-contrast);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.025em;
}

h1 {
  font-size: clamp(2.25rem, 5vw + 1rem, 4.25rem);
  line-height: 1.05;
  letter-spacing: -0.035em;
  font-weight: 800;
}

h2 {
  font-size: clamp(1.85rem, 3vw + 1rem, 2.75rem);
  line-height: 1.15;
  letter-spacing: -0.025em;
  font-weight: 700;
}

h3 {
  font-size: clamp(1.25rem, 2vw + 0.5rem, 1.75rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
  font-weight: 600;
}

h4 {
  font-size: 1.125rem;
  letter-spacing: -0.01em;
  font-weight: 600;
}

p {
  margin-bottom: 0.85rem;
  color: var(--color-on-surface-variant);
  line-height: 1.65;
}

p:last-child {
  margin-bottom: 0;
}

strong, b {
  font-weight: 600;
  color: var(--color-text-high-contrast);
}

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

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

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

/* 6. Technical Micro Labels */
.font-mono {
  font-family: var(--font-body);
}

.label-mono {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.label-mono-sm {
  font-family: var(--font-body);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.metric-number {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.02em;
}

/* 7. Containers & Structural Layout */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--gutter-desktop);
  padding-right: var(--gutter-desktop);
}

@media (max-width: 768px) {
  .container {
    padding-left: var(--gutter-mobile);
    padding-right: var(--gutter-mobile);
  }
}

@media (max-width: 480px) {
  :root {
    --gutter-mobile: 1rem;
    --nav-height: 68px;
    --scroll-offset: 72px;
  }

  .container {
    padding-left: 1rem;
    padding-right: 1rem;
  }
}

.section-padding {
  padding-top: clamp(2.5rem, 4.5vw, 3.75rem);
  padding-bottom: clamp(2.75rem, 5vw, 4.25rem);
}

@media (max-width: 768px) {
  .section-padding {
    padding-top: 2rem;
    padding-bottom: 2.5rem;
  }
}

/* 8. Editorial Section Headers — Studio Architecture */
.section-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: clamp(1.25rem, 2.5vw, 1.75rem);
  padding-bottom: 0.65rem;
  border-bottom: 1px solid var(--color-hairline);
  position: relative;
}

.section-header-row::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 44px;
  height: 2px;
  background-color: var(--color-furnace-orange);
}

@media (max-width: 768px) {
  .section-header-row {
    margin-bottom: var(--space-md);
  }
}

.section-index {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.section-index-num {
  font-family: var(--font-display);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-furnace-orange);
}

.section-index-title {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-chrome-silver);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section-meta-tag {
  font-family: var(--font-body);
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--color-outline);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

@media (max-width: 640px) {
  .section-meta-tag {
    display: none;
  }
}

.section-desc-wrap {
  max-width: 820px;
  margin-bottom: clamp(1.25rem, 2.5vw, 1.75rem);
}

/* 9. Accessibility Elements */
.skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-md);
  z-index: 9999;
  padding: var(--space-sm) var(--space-md);
  background-color: var(--color-furnace-orange-deep);
  color: #ffffff;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-md);
  outline: 2px solid #ffffff;
  outline-offset: 2px;
}

.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;
}

:focus-visible {
  outline: 2px solid var(--color-furnace-orange);
  outline-offset: 3px;
}

/* 10. Scroll Reveals & Motion */
.reveal-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 600ms cubic-bezier(0.16, 1, 0.3, 1), transform 600ms cubic-bezier(0.16, 1, 0.3, 1);
  will-change: opacity, transform;
}

.reveal-on-scroll.is-revealed {
  opacity: 1;
  transform: translateY(0);
}

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

  .reveal-on-scroll {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}