/* =========================================================
   Yusuf Ahmed — Portfolio styles
   BEM-ish class names. CSS custom properties for theming.
   ========================================================= */

/* ---------- 1. Tokens / Theme variables ---------- */
:root {
  /* Dark theme (default) */
  --bg:           #0a0e27;
  --bg-elev:      #11173a;
  --bg-elev-2:    #161d4a;
  --text:         #e6e9f5;
  --text-muted:   #98a1c4;
  --border:       rgba(255, 255, 255, 0.08);

  --accent:       #4f8cff;
  --accent-2:     #ffb84f;
  --accent-glow:  rgba(79, 140, 255, 0.35);
  --gradient:     linear-gradient(135deg, #4f8cff 0%, #ffb84f 100%);

  --shadow-card:  0 12px 32px rgba(0, 0, 0, 0.35);
  --shadow-hover: 0 20px 48px rgba(79, 140, 255, 0.25);

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;

  --font-display: 'Space Grotesk', 'Inter', system-ui, sans-serif;
  --font-body:    'Inter', system-ui, -apple-system, sans-serif;

  --max-w:       1200px;
  --section-pad: 7rem;
  --nav-h:       70px;
  --ease:        cubic-bezier(0.22, 1, 0.36, 1);
}

[data-theme="light"] {
  --bg:           #f6f7fb;
  --bg-elev:      #ffffff;
  --bg-elev-2:    #ffffff;
  --text:         #0c1230;
  --text-muted:   #5b6488;
  --border:       rgba(12, 18, 48, 0.10);

  --accent:       #2563eb;
  --accent-2:     #d97706;
  --accent-glow:  rgba(37, 99, 235, 0.20);
  --gradient:     linear-gradient(135deg, #2563eb 0%, #d97706 100%);

  --shadow-card:  0 12px 32px rgba(12, 18, 48, 0.08);
  --shadow-hover: 0 20px 48px rgba(37, 99, 235, 0.18);
}

/* ---------- 2. Reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  transition: background-color 0.3s var(--ease), color 0.3s var(--ease);
}
img, svg { display: block; max-width: 100%; }
a       { color: inherit; text-decoration: none; }
ul, ol  { list-style: none; padding: 0; margin: 0; }
button  { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0;
}

.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;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 3. Scroll progress ---------- */
.scroll-progress {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0;
  background: var(--gradient);
  z-index: 1000;
  transition: width 0.05s linear;
}

/* ---------- 4. Navigation ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--bg) 70%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease), background-color 0.3s var(--ease);
}
.nav--scrolled { border-color: var(--border); }

.nav__container {
  max-width: var(--max-w);
  height: 100%;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-weight: 600;
}
.nav__brand-mark {
  display: inline-grid;
  place-items: center;
  width: 34px; height: 34px;
  border-radius: 10px;
  background: var(--gradient);
  color: #fff;
  font-weight: 700;
}
.nav__brand-name { font-size: 1.05rem; }

.nav__list { display: flex; gap: 2rem; }
.nav__link {
  position: relative;
  font-size: 0.95rem;
  color: var(--text-muted);
  padding: 0.25rem 0;
  transition: color 0.2s var(--ease);
}
.nav__link::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -4px;
  height: 2px;
  background: var(--gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease);
  border-radius: 2px;
}
.nav__link:hover,
.nav__link.is-active            { color: var(--text); }
.nav__link:hover::after,
.nav__link.is-active::after     { transform: scaleX(1); }

.nav__actions { display: flex; align-items: center; gap: 0.5rem; }

.theme-toggle {
  width: 38px; height: 38px;
  border-radius: 10px;
  border: 1px solid var(--border);
  display: grid; place-items: center;
  color: var(--text);
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease), background 0.2s var(--ease);
}
.theme-toggle:hover { border-color: var(--accent); transform: translateY(-1px); }
[data-theme="dark"]  .theme-toggle .icon-sun  { display: none; }
[data-theme="dark"]  .theme-toggle .icon-moon { display: block; }
[data-theme="light"] .theme-toggle .icon-sun  { display: block; }
[data-theme="light"] .theme-toggle .icon-moon { display: none; }

.nav__toggle {
  display: none;
  width: 38px; height: 38px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  border-radius: 10px;
  border: 1px solid var(--border);
}
.nav__toggle span {
  width: 18px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s var(--ease), opacity 0.25s var(--ease);
}
.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 5. Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: calc(var(--nav-h) + 2rem) 1.5rem 4rem;
  overflow: hidden;
  isolation: isolate;
}

.hero__bg {
  position: absolute; inset: 0;
  z-index: -1;
  overflow: hidden;
}
.hero__blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.55;
  animation: float 18s ease-in-out infinite;
}
.hero__blob--1 {
  width: 520px; height: 520px;
  background: var(--accent);
  top: -120px; left: -120px;
}
.hero__blob--2 {
  width: 480px; height: 480px;
  background: var(--accent-2);
  bottom: -140px; right: -100px;
  animation-delay: -6s;
}
.hero__blob--3 {
  width: 360px; height: 360px;
  background: #a855f7;
  top: 45%; left: 50%;
  transform: translate(-50%, -50%);
  animation-delay: -12s;
  opacity: 0.35;
}
[data-theme="light"] .hero__blob    { opacity: 0.30; }
[data-theme="light"] .hero__blob--3 { opacity: 0.18; }

.hero__grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 75%);
  opacity: 0.5;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33%      { transform: translate(40px, -30px) scale(1.05); }
  66%      { transform: translate(-30px, 30px) scale(0.95); }
}

.hero__inner {
  max-width: 920px;
  text-align: center;
  position: relative;
}
.hero__eyebrow {
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.hero__name {
  font-size: clamp(2.5rem, 7vw, 5.5rem);
  background: var(--gradient);
  -webkit-background-clip: text;
          background-clip: text;
  color: transparent;
  margin-bottom: 1rem;
}
.hero__role {
  font-size: clamp(1rem, 1.6vw, 1.2rem);
  color: var(--text-muted);
  letter-spacing: 0.05em;
  margin: 0 0 2.25rem;
}

.hero__quote {
  margin: 0 auto 2.5rem;
  padding: 1.25rem 1.5rem;
  max-width: 720px;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 1.8vw, 1.4rem);
  font-style: italic;
  color: var(--text);
  border-left: 3px solid var(--accent);
  background: color-mix(in srgb, var(--bg-elev) 60%, transparent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  text-align: left;
  min-height: 3.5em;
  box-shadow: var(--shadow-card);
}
.cursor {
  display: inline-block;
  margin-left: 2px;
  animation: blink 1s steps(1) infinite;
  color: var(--accent);
  font-weight: 300;
}
@keyframes blink { 50% { opacity: 0; } }

.hero__cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1.6rem;
  border-radius: 999px;
  font-weight: 500;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: transform 0.2s var(--ease), box-shadow 0.3s var(--ease), background 0.2s var(--ease), border-color 0.2s var(--ease);
}
.btn--primary {
  background: var(--gradient);
  color: #fff;
  box-shadow: 0 8px 24px var(--accent-glow);
}
.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 36px var(--accent-glow);
}
.btn--ghost {
  color: var(--text);
  border-color: var(--border);
  background: color-mix(in srgb, var(--bg-elev) 50%, transparent);
}
.btn--ghost:hover { border-color: var(--accent); transform: translateY(-2px); }

.hero__scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 40px;
  border-radius: 12px;
  border: 2px solid var(--text-muted);
  display: grid;
  place-items: start center;
  padding-top: 6px;
}
.hero__scroll span {
  display: block;
  width: 3px; height: 7px;
  border-radius: 2px;
  background: var(--text-muted);
  animation: scrollDot 1.8s ease-in-out infinite;
}
@keyframes scrollDot {
  0%   { transform: translateY(0);    opacity: 1; }
  100% { transform: translateY(14px); opacity: 0; }
}

/* ---------- 6. Sections ---------- */
.section {
  padding: var(--section-pad) 1.5rem;
  position: relative;
}
.section--alt { background: var(--bg-elev); }
.container    { max-width: var(--max-w); margin: 0 auto; }

.section__header { margin-bottom: 3.5rem; text-align: center; }
.section__kicker {
  display: inline-block;
  font-size: 0.8rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
  font-weight: 500;
}
.section__title    { font-size: clamp(2rem, 4vw, 3rem); }
.section__subtitle { color: var(--text-muted); margin-top: 0.75rem; font-size: 1.05rem; }

/* ---------- 7. About ---------- */
.about {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 3rem;
  align-items: center;
}
.about__portrait { position: relative; }
.about__avatar {
  width: 100%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--bg-elev);
  padding: 1rem;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border);
}
.about__chip {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  padding: 0.4rem 0.85rem;
  border-radius: 999px;
  font-size: 0.8rem;
  white-space: nowrap;
  color: var(--text-muted);
  box-shadow: var(--shadow-card);
}
.about__text p          { margin: 0 0 1rem; color: var(--text-muted); font-size: 1.05rem; }
.about__text p strong   { color: var(--text); font-weight: 600; }
.about__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.5rem;
}
.tag {
  padding: 0.35rem 0.9rem;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--accent);
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 500;
  border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
}

/* ---------- 8. Timeline ---------- */
.timeline {
  position: relative;
  padding: 1rem 0;
  margin: 0 auto;
  max-width: 920px;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 0; bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, transparent, var(--border) 10%, var(--border) 90%, transparent);
  transform: translateX(-50%);
}
.timeline__item {
  position: relative;
  width: 50%;
  padding: 1rem 2.5rem;
}
.timeline__item:nth-child(odd)  { left: 0;   text-align: right; }
.timeline__item:nth-child(even) { left: 50%; text-align: left;  }

.timeline__dot {
  position: absolute;
  top: 1.75rem;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 18%, transparent);
}
.timeline__item:nth-child(odd)  .timeline__dot { right: -9px; }
.timeline__item:nth-child(even) .timeline__dot { left:  -9px; }
.timeline__item--current .timeline__dot {
  background: var(--accent);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0  color-mix(in srgb, var(--accent) 50%, transparent); }
  70%  { box-shadow: 0 0 0 14px transparent; }
  100% { box-shadow: 0 0 0 0  transparent; }
}

.timeline__card {
  background: var(--bg-elev-2);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease);
  display: inline-block;
  text-align: left;
}
.timeline__card:hover { transform: translateY(-4px); border-color: var(--accent); }
.timeline__period {
  display: inline-block;
  font-size: 0.78rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 600;
  margin-bottom: 0.5rem;
}
.timeline__title { font-size: 1.2rem; margin-bottom: 0.4rem; }
.timeline__desc  { color: var(--text-muted); margin: 0; font-size: 0.95rem; }

/* ---------- 9. Experience cards ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}
.card {
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  position: relative;
  overflow: hidden;
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--gradient);
  opacity: 0;
  transition: opacity 0.3s var(--ease);
  z-index: 0;
  pointer-events: none;
}
.card > * { position: relative; z-index: 1; }
.card:hover {
  transform: translateY(-6px);
  border-color: color-mix(in srgb, var(--accent) 60%, transparent);
  box-shadow: var(--shadow-hover);
}
.card:hover::before { opacity: 0.06; }

.card__icon {
  width: 48px; height: 48px;
  border-radius: 12px;
  background: var(--gradient);
  color: #fff;
  display: grid; place-items: center;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: 1rem;
  letter-spacing: 0.02em;
}
.card__title { font-size: 1.15rem; margin-bottom: 0.25rem; }
.card__meta  {
  font-size: 0.78rem;
  color: var(--accent);
  margin: 0 0 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 500;
}
.card__desc  { color: var(--text-muted); font-size: 0.95rem; margin: 0; }

.card--more {
  background: transparent;
  border-style: dashed;
}

/* ---------- 10. Hobbies ---------- */
.hobbies {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}
.hobby {
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 2rem 1.75rem;
  text-align: center;
  transition: transform 0.4s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.hobby:hover {
  transform: translateY(-8px) rotate(-1deg);
  border-color: var(--accent);
  box-shadow: var(--shadow-hover);
}
.hobby__emoji {
  font-size: 3rem;
  line-height: 1;
  margin-bottom: 1rem;
  display: inline-block;
  transition: transform 0.4s var(--ease);
}
.hobby:hover .hobby__emoji { transform: scale(1.15) rotate(-8deg); }
.hobby__title { font-size: 1.2rem; margin-bottom: 0.5rem; }
.hobby__desc  { color: var(--text-muted); margin: 0; font-size: 0.95rem; }

/* ---------- 11. Socials ---------- */
.socials {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  max-width: 880px;
  margin: 0 auto;
}
.social {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.social:hover {
  transform: translateY(-3px);
  border-color: var(--accent);
  box-shadow: var(--shadow-hover);
}
.social__icon {
  width: 44px; height: 44px;
  border-radius: 12px;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--accent);
  display: grid; place-items: center;
  flex-shrink: 0;
}
.social__text   { display: flex; flex-direction: column; min-width: 0; }
.social__label  { font-weight: 500; }
.social__handle { color: var(--text-muted); font-size: 0.85rem; }

/* ---------- 12. Footer ---------- */
.footer {
  border-top: 1px solid var(--border);
  padding: 2.5rem 1.5rem;
  background: var(--bg-elev);
}
.footer__inner { text-align: center; }
.footer__name  { margin: 0 0 0.4rem; font-weight: 500; }
.footer__quote { margin: 0; color: var(--text-muted); font-size: 0.9rem; font-style: italic; }

/* ---------- 13. Back-to-top ---------- */
.back-to-top {
  position: fixed;
  bottom: 2rem; right: 2rem;
  width: 48px; height: 48px;
  border-radius: 50%;
  background: var(--gradient);
  color: #fff;
  display: grid; place-items: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease), visibility 0.3s;
  box-shadow: 0 10px 28px var(--accent-glow);
  z-index: 90;
}
.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-to-top:hover { transform: translateY(-3px); }

/* ---------- 14. Reveal-on-scroll ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 15. Responsive ---------- */
@media (max-width: 1024px) {
  :root { --section-pad: 5rem; }
  .about { grid-template-columns: 220px 1fr; gap: 2rem; }
}

@media (max-width: 768px) {
  .nav__list {
    position: fixed;
    inset: var(--nav-h) 0 auto 0;
    flex-direction: column;
    gap: 0;
    background: var(--bg-elev);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.5rem 2rem;
    transform: translateY(-150%);
    transition: transform 0.35s var(--ease);
  }
  .nav__list.is-open { transform: translateY(0); }
  .nav__list li      { width: 100%; }
  .nav__link {
    display: block;
    padding: 0.9rem 0;
    border-bottom: 1px solid var(--border);
  }
  .nav__link::after  { display: none; }
  .nav__toggle       { display: flex; }

  /* Single-column timeline on mobile */
  .timeline::before { left: 16px; }
  .timeline__item,
  .timeline__item:nth-child(odd),
  .timeline__item:nth-child(even) {
    width: 100%;
    left: 0;
    text-align: left;
    padding: 0.5rem 0 0.5rem 2.5rem;
  }
  .timeline__item:nth-child(odd)  .timeline__dot,
  .timeline__item:nth-child(even) .timeline__dot { left: 7px; right: auto; }

  .about {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .about__portrait { max-width: 220px; margin: 0 auto; }
  .about__tags     { justify-content: center; }
}

@media (max-width: 640px) {
  :root { --section-pad: 4rem; }
  .hero__quote { padding: 1rem 1.1rem; }
  .back-to-top { bottom: 1.25rem; right: 1.25rem; }
  .hero__cta   { gap: 0.6rem; }
  .btn         { padding: 0.75rem 1.25rem; font-size: 0.9rem; }
}

/* ---------- 16. Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}