/* ==========================================================================
   Mohammed Thalha — Portfolio
   Design language derived from apple_design.md token system.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;700&display=swap');

:root {
  /* Brand & Accent */
  --color-primary: #0066cc;
  --color-primary-focus: #0071e3;
  --color-primary-on-dark: #2997ff;

  /* Surface */
  --color-canvas: #ffffff;
  --color-canvas-parchment: #f5f5f7;
  --color-surface-pearl: #fafafc;
  --color-surface-tile-1: #272729;
  --color-surface-tile-2: #2a2a2c;
  --color-surface-tile-3: #252527;
  --color-surface-black: #000000;
  --color-surface-chip-translucent: rgba(210, 210, 215, 0.64);

  /* Text */
  --color-ink: #1d1d1f;
  --color-body: #1d1d1f;
  --color-body-on-dark: #ffffff;
  --color-body-muted: #cccccc;
  --color-ink-muted-80: #333333;
  --color-ink-muted-48: #7a7a7a;

  /* Hairlines */
  --color-divider-soft: rgba(0, 0, 0, 0.04);
  --color-hairline: #e0e0e0;

  /* Shadow */
  --shadow-product: rgba(0, 0, 0, 0.22) 3px 5px 30px 0;

  /* Radius */
  --radius-none: 0px;
  --radius-xs: 5px;
  --radius-sm: 8px;
  --radius-md: 11px;
  --radius-lg: 18px;
  --radius-pill: 9999px;

  /* Spacing */
  --space-xxs: 4px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 17px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-xxl: 48px;
  --space-section: 80px;

  /* Fonts — Inter stands in for SF Pro Display/Text per spec's substitution guidance */
  --font-display: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  --font-text: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

@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;
  }
}

body {
  margin: 0;
  font-family: var(--font-text);
  font-feature-settings: "ss03";
  color: var(--color-body);
  background: var(--color-canvas);
  font-size: 17px;
  line-height: 1.47;
  letter-spacing: -0.374px;
}

img, svg { display: block; max-width: 100%; }
a { color: var(--color-primary); text-decoration: none; }
ul { list-style: none; margin: 0; padding: 0; }

/* ---------- Typography scale ---------- */
.type-hero-display {
  font-family: var(--font-display);
  font-size: 56px;
  font-weight: 600;
  line-height: 1.07;
  letter-spacing: -0.29px;
  margin: 0;
}
.type-display-lg {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 600;
  line-height: 1.10;
  letter-spacing: -0.01em;
  margin: 0;
}
.type-display-md {
  font-family: var(--font-text);
  font-size: 34px;
  font-weight: 600;
  line-height: 1.47;
  letter-spacing: -0.384px;
  margin: 0;
}
.type-lead {
  font-size: 28px;
  font-weight: 400;
  line-height: 1.14;
  letter-spacing: 0.196px;
  margin: 0;
}
.type-lead-airy {
  font-size: 24px;
  font-weight: 300;
  line-height: 1.5;
  margin: 0;
}
.type-tagline {
  font-size: 21px;
  font-weight: 600;
  line-height: 1.19;
  letter-spacing: 0.231px;
  margin: 0;
}
.type-body-strong { font-size: 17px; font-weight: 600; line-height: 1.24; letter-spacing: -0.384px; }
.type-dense-link { font-size: 17px; font-weight: 400; line-height: 2.41; }
.type-caption { font-size: 14px; font-weight: 400; line-height: 1.43; letter-spacing: -0.224px; }
.type-caption-strong { font-size: 14px; font-weight: 600; line-height: 1.29; letter-spacing: -0.224px; }
.type-button-large { font-size: 18px; font-weight: 300; line-height: 1; }
.type-button-utility { font-size: 14px; font-weight: 400; line-height: 1.29; letter-spacing: -0.224px; }
.type-fine-print { font-size: 12px; font-weight: 400; line-height: 1; letter-spacing: -0.12px; }
.type-micro-legal { font-size: 10px; font-weight: 400; line-height: 1.3; letter-spacing: -0.08px; }
.type-nav-link { font-size: 12px; font-weight: 400; line-height: 1; letter-spacing: -0.12px; }

/* ==========================================================================
   Global Nav
   ========================================================================== */
.global-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 44px;
  background: var(--color-surface-black);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 22px;
}
.global-nav__brand {
  color: var(--color-body-on-dark);
  font-weight: 600;
  font-size: 14px;
  letter-spacing: -0.12px;
}
.global-nav__links {
  display: flex;
  align-items: center;
  gap: 20px;
}
.global-nav__links a {
  color: var(--color-body-on-dark);
  opacity: 0.88;
}
.global-nav__links a:hover { opacity: 1; }
.global-nav__cta {
  display: inline-flex;
}
.global-nav__hamburger {
  display: none;
  background: none;
  border: none;
  color: var(--color-body-on-dark);
  cursor: pointer;
  padding: 8px;
}
.global-nav__hamburger svg { width: 18px; height: 18px; }

/* Sub-nav (frosted) — shows the current section context while scrolling */
.sub-nav {
  position: sticky;
  top: 44px;
  z-index: 90;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 22px;
  background: rgba(245, 245, 247, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  opacity: 0;
  transform: translateY(-6px);
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
}
.sub-nav.is-visible { opacity: 1; transform: translateY(0); pointer-events: auto; }
.sub-nav__section { color: var(--color-ink); }
.sub-nav__links { display: flex; align-items: center; gap: 18px; }
.sub-nav__links a { color: var(--color-ink); }

@media (max-width: 833px) {
  .global-nav__links { display: none; }
  .global-nav__hamburger { display: inline-flex; }
  .sub-nav__links a:not(.button-primary-inline) { display: none; }
}

/* Mobile menu tray */
.mobile-tray {
  position: fixed;
  inset: 44px 0 0 0;
  background: var(--color-surface-black);
  z-index: 99;
  display: none;
  flex-direction: column;
  padding: var(--space-xl) 24px;
  gap: var(--space-lg);
}
.mobile-tray.is-open { display: flex; }
.mobile-tray a {
  color: var(--color-body-on-dark);
  font-size: 21px;
  font-weight: 600;
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.button-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: #ffffff;
  font-size: 17px;
  font-weight: 400;
  border: none;
  border-radius: var(--radius-pill);
  padding: 11px 22px;
  cursor: pointer;
  transition: transform 0.12s ease;
  min-height: 44px;
}
.button-primary:active { transform: scale(0.95); }
.button-primary:focus-visible { outline: 2px solid var(--color-primary-focus); outline-offset: 2px; }

.button-secondary-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  color: var(--color-primary);
  font-size: 17px;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-pill);
  padding: 11px 22px;
  cursor: pointer;
  transition: transform 0.12s ease;
  min-height: 44px;
}
.button-secondary-pill:active { transform: scale(0.95); }
.button-secondary-pill:focus-visible { outline: 2px solid var(--color-primary-focus); outline-offset: 2px; }

.on-dark .button-secondary-pill {
  color: var(--color-primary-on-dark);
  border-color: var(--color-primary-on-dark);
}

.button-dark-utility {
  display: inline-flex;
  align-items: center;
  background: var(--color-ink);
  color: #ffffff;
  font-size: 14px;
  letter-spacing: -0.224px;
  border: none;
  border-radius: var(--radius-sm);
  padding: 8px 15px;
  cursor: pointer;
  transition: transform 0.12s ease;
}
.button-dark-utility:active { transform: scale(0.95); }

.text-link { color: var(--color-primary); }
.on-dark .text-link, .text-link-on-dark { color: var(--color-primary-on-dark); }

/* ==========================================================================
   Tiles (full-bleed sections)
   ========================================================================== */
.tile {
  padding: var(--space-section) 24px;
  border-radius: var(--radius-none);
}
.tile-light { background: var(--color-canvas); color: var(--color-ink); }
.tile-parchment { background: var(--color-canvas-parchment); color: var(--color-ink); }
.tile-dark-1 { background: var(--color-surface-tile-1); color: #ffffff; }
.tile-dark-2 { background: var(--color-surface-tile-2); color: #ffffff; }
.tile-dark-3 { background: var(--color-surface-tile-3); color: #ffffff; }

.tile-inner {
  max-width: 1024px;
  margin: 0 auto;
}
.tile-inner--wide { max-width: 1200px; }

.tile-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--space-xxl);
}
.tile-eyebrow {
  display: inline-block;
  color: var(--color-primary);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.224px;
  margin-bottom: var(--space-sm);
}
.on-dark .tile-eyebrow { color: var(--color-primary-on-dark); }
.tile-header p { color: var(--color-ink-muted-80); margin-top: var(--space-sm); }
.on-dark .tile-header p { color: var(--color-body-muted); }

/* ---------- Hero ---------- */
.hero {
  min-height: calc(100vh - 44px);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}
.hero-stack { max-width: 760px; margin: 0 auto; }
.hero-eyebrow {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: -0.224px;
  margin-bottom: var(--space-lg);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.hero-eyebrow .dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: #34c759;
  display: inline-block;
}
.hero h1 { margin-bottom: var(--space-lg); }
.hero .type-lead { color: var(--color-ink-muted-80); margin-bottom: var(--space-xl); }
.hero-ctas { display: flex; gap: var(--space-md); justify-content: center; flex-wrap: wrap; }
.hero-scroll-cue {
  margin-top: 64px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--color-ink-muted-48);
}
.hero-scroll-cue svg { width: 16px; height: 16px; animation: bob 2s ease-in-out infinite; }
@keyframes bob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(6px); }
}

/* ---------- About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: var(--space-xxl);
  align-items: center;
}
.about-copy p { margin: 0 0 var(--space-lg); color: var(--color-body-muted); }
.about-copy p:last-child { margin-bottom: 0; }
.about-copy strong { color: #ffffff; font-weight: 600; }
.about-mark {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-product);
  overflow: hidden;
}

/* ---------- Experience ---------- */
.exp-list { display: flex; flex-direction: column; gap: var(--space-xl); }
.exp-card {
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}
.exp-card__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: var(--space-sm);
}
.exp-card__role { font-size: 21px; font-weight: 600; letter-spacing: 0.231px; }
.exp-card__period { color: var(--color-ink-muted-48); font-size: 14px; }
.exp-card__org { color: var(--color-primary); font-weight: 600; margin-bottom: var(--space-md); }
.exp-card ul { display: flex; flex-direction: column; gap: 10px; }
.exp-card li {
  position: relative;
  padding-left: 18px;
  color: var(--color-ink-muted-80);
}
.exp-card li::before {
  content: "";
  position: absolute;
  left: 0; top: 9px;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--color-primary);
}

/* ---------- Projects ---------- */
.project-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}
.project-card {
  background: var(--color-surface-tile-3);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}
.project-card__glyph {
  width: 48px; height: 48px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-product);
}
.project-card h3 { font-size: 21px; font-weight: 600; letter-spacing: 0.231px; }
.project-card p { color: var(--color-body-muted); margin: 0; flex-grow: 1; }
.chip-row { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  display: inline-flex;
  align-items: center;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.14);
  color: #ffffff;
  font-size: 12px;
  letter-spacing: -0.12px;
  padding: 6px 12px;
  border-radius: var(--radius-pill);
}
.tile-light .chip, .tile-parchment .chip {
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline);
  color: var(--color-ink);
}

/* ---------- Skills ---------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}
.skill-card {
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}
.skill-card h3 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.374px;
  margin-bottom: var(--space-md);
}
.skill-card .chip-row { gap: 8px; }

/* ---------- Education ---------- */
.edu-card {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
}
.edu-card h3 { margin-bottom: 6px; }
.edu-card .org { color: var(--color-primary); font-weight: 600; margin-bottom: 4px; }
.edu-card .period { color: var(--color-ink-muted-48); font-size: 14px; margin-bottom: var(--space-lg); }
.edu-card p.note { color: var(--color-ink-muted-80); }

/* ---------- Kyra Labs ---------- */
.kyra-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: var(--space-xxl);
  align-items: center;
}
.kyra-mark {
  background: var(--color-surface-pearl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-product);
  padding: var(--space-xxl) var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: center;
}
.kyra-mark img { width: 100%; height: auto; }

@media (max-width: 833px) {
  .kyra-grid { grid-template-columns: 1fr; }
  .kyra-copy { text-align: center; }
  .kyra-copy .button-primary { display: inline-flex; }
}

/* ---------- Contact / CTA ---------- */
.contact-tile { text-align: center; }
.contact-links {
  display: flex;
  gap: var(--space-lg);
  justify-content: center;
  flex-wrap: wrap;
  margin-top: var(--space-xl);
}
.contact-links a { color: var(--color-primary-on-dark); }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-canvas-parchment);
  color: var(--color-ink-muted-80);
  padding: 64px 24px 32px;
}
.footer-grid {
  max-width: 1024px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: var(--space-xxl);
}
.footer-col h4 {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.224px;
  margin: 0 0 var(--space-sm);
}
.footer-col a, .footer-col p {
  display: block;
  font-size: 17px;
  line-height: 2.41;
  color: var(--color-ink-muted-80);
}
.footer-legal {
  max-width: 1024px;
  margin: var(--space-xxl) auto 0;
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-hairline);
  font-size: 12px;
  letter-spacing: -0.12px;
  color: var(--color-ink-muted-48);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

/* ==========================================================================
   Reveal-on-scroll (subtle, respects reduced motion)
   ========================================================================== */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1068px) {
  .type-hero-display { font-size: 40px; }
  .project-grid { grid-template-columns: repeat(2, 1fr); }
  .skills-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 833px) {
  .about-grid { grid-template-columns: 1fr; }
  .about-mark { max-width: 320px; margin: 0 auto; }
}

@media (max-width: 640px) {
  .type-hero-display { font-size: 34px; }
  .type-display-lg { font-size: 28px; }
  .tile { padding: 48px 20px; }
  .project-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: var(--space-xl); }
  .exp-card__head { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 419px) {
  .type-hero-display { font-size: 28px; }
  .hero-ctas { flex-direction: column; width: 100%; }
  .hero-ctas .button-primary, .hero-ctas .button-secondary-pill { width: 100%; }
}