/* Base */
:root {
  --bg: #fbfbfb;
  --text: #0f172a;
  --muted: #64748b;
  --primary: #0f172a;
  --card: #fbfbfb;
  --border: #e5e7eb;
  --shadow: 0 10px 30px rgba(2, 6, 23, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: 'Inter', ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, 'Apple Color Emoji', 'Segoe UI Emoji';
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

.container { width: 100%; max-width: 1100px; margin: 0 auto; padding: 0 20px; }
.section { padding: 50px 0; position: relative; overflow: hidden; }
.section h2 { font-size: 32px; margin: 0 0 8px; letter-spacing: -0.02em; }
.section__subtitle { color: var(--muted); margin: 0 0 32px; }
/* Anchor offset for sticky header */
section { scroll-margin-top: 80px; }

.skip-link { position: absolute; left: -9999px; top: auto; width: 1px; height: 1px; overflow: hidden; }
.skip-link:focus { position: static; width: auto; height: auto; padding: 8px 12px; background: #000; color: #fff; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,0.8); backdrop-filter: saturate(180%) blur(12px); border-bottom: 1px solid rgba(0,0,0,0.04); transition: transform .25s ease; }
.site-header.is-hidden { transform: translateY(-100%); }
/* Mobile overlay nav */
.mobile-nav { position: fixed; inset: 0; z-index: 90; pointer-events: none; opacity: 0; visibility: hidden; transition: opacity .35s ease, visibility .35s ease; }
.mobile-nav__backdrop { position: absolute; inset: 0; background: transparent; }
.mobile-nav__panel { position: absolute; top: 64px; left: 0; right: 0; background: #ffffff; border-top: 1px solid var(--border); box-shadow: 0 12px 30px rgba(2,6,23,0.18); opacity: 0; transition: opacity .35s ease; display: flex; flex-direction: column; }
.mobile-nav__panel a { padding: 16px 20px; border-bottom: 1px solid var(--border); color: var(--text); text-decoration: none; }
.mobile-nav__panel a:last-child { border-bottom: 0; }
.mobile-nav.is-open { pointer-events: auto; opacity: 1; visibility: visible; }
.mobile-nav.is-open .mobile-nav__panel { opacity: 1; }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.nav { margin-left: 0; }
.nav-toggle { margin-left: 0; }
.brand__link { display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; border-radius: 10px; background: transparent; color: inherit; font-weight: 700; text-decoration: none; letter-spacing: 0.02em; }
.brand__logo { width: 36px; height: 36px; object-fit: contain; display: block; }
.brand__ghost { display: inline-block; width: 44px; height: 44px; border-radius: 10px; opacity: 0; }
.brand__text { display: inline-flex; align-items: center; justify-content: center; height: 36px; padding: 0 12px; border-radius: 10px; font-weight: 800; letter-spacing: 0.28em; color: var(--text); text-decoration: none; font-size: 18px; }
.nav-toggle { display: none; appearance: none; border: none; background: transparent; color: var(--text); border-radius: 10px; width: 40px; height: 40px; align-items: center; justify-content: center; padding: 0; cursor: pointer; box-shadow: none; position: relative; }
.nav-toggle .bar { position: absolute; width: 22px; height: 2px; background: currentColor; left: 50%; transform: translateX(-50%); transition: transform .3s ease, opacity .2s ease; }
.nav-toggle .bar:nth-child(1) { top: 12px; }
.nav-toggle .bar:nth-child(2) { top: 19px; }
.nav-toggle .bar:nth-child(3) { top: 26px; }
.nav-toggle[aria-expanded="true"] .bar:nth-child(1) { transform: translateX(-50%) translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .bar:nth-child(3) { transform: translateX(-50%) translateY(-7px) rotate(-45deg); }
.nav a { color: var(--text); text-decoration: none; margin-left: 16px; padding: 8px 10px; border-radius: 8px; transition: color .2s ease, background .2s ease; }
.nav a:hover { background: #f3f4f6; }

/* Hero */
.hero { padding-top: 96px; }
.hero__inner { display: grid; grid-template-columns: 1.2fr 1fr; gap: 80px; align-items: center; }
.hero__title { font-size: 48px; line-height: 1.1; letter-spacing: -0.04em; margin: 0 0 20px; }
.hero__subtitle { color: var(--muted); margin: 0 0 24px; }
.hero__cta { display: flex; gap: 12px; }
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 12px 18px; border-radius: 12px; text-decoration: none; cursor: pointer; transition: transform .2s ease, box-shadow .2s ease, background .2s ease, color .2s ease; border: 1px solid var(--border); }
.btn--primary { background: #111827; color: #fff; border-color: #111827; box-shadow: 0 8px 20px rgba(17,24,39,0.15); }
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(17,24,39,0.18); }

.embed__frame-wrapper { width: 100%; border-radius: 0; overflow: visible; box-shadow: none; background: #fbfbfb; }
.hero__gif { width: 100%; height: auto; display: block; object-fit: contain; }
/* Ensure hero background is pure white and remove decorative layers behind GIF */
.hero { background: #fbfbfb; }
.hero .parallax-layer { display: none; }
/* Slightly nudge GIF upwards and add spacing from title */
.hero__gif { margin-top: -140px; margin-bottom: 12px; }

/* Parallax decorative circles */
.parallax-layer { position: absolute; border-radius: 999px; filter: blur(40px); opacity: 0.6; }
.layer-1 { width: 280px; height: 280px; background: radial-gradient(circle at 30% 30%, #e5e7eb, transparent 60%); top: -40px; left: -60px; }
.layer-2 { width: 220px; height: 220px; background: radial-gradient(circle at 70% 30%, #f1f5f9, transparent 60%); bottom: 10%; right: 10%; }
.layer-3 { width: 180px; height: 180px; background: radial-gradient(circle at 50% 50%, #e2e8f0, transparent 60%); top: 40%; right: -60px; }

/* Projects */
.projects__grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 16px; padding: 20px; box-shadow: 0 0 0 rgba(0,0,0,0); transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease; }
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: #d1d5db; }
.card__title { margin: 0 0 8px; font-size: 18px; letter-spacing: -0.01em; }
.card__desc { margin: 0 0 16px; color: var(--muted); }
.card__links { display: flex; gap: 12px; }
.link { color: var(--primary); text-decoration: none; padding: 6px 8px; border-radius: 8px; transition: background .2s ease; }
.link:hover { background: #f3f4f6; }

/* About */
.about__grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 32px; }
/* Project detail layout */
.project-detail__grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 28px; align-items: start; }
.project-detail__media img { width: 100%; height: auto; display: block; border-radius: 12px; }
.project-detail__media > img + img { margin-top: 0px; }
.project-detail__thumbs { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; align-items: start; }
.project-detail__thumbs img { width: 100%; height: 220px; display: block; border-radius: 12px; object-fit: contain; background: #fff; }
.project-detail__aside { color: var(--muted); line-height: 1.7; }
/* Sketchfab embed */
.project-embed { margin-top: 1px; }
.project-embed iframe { width: 100%; height: 520px; border: 0; border-radius: 12px; }

/* Simple slider */
.slider { position: relative; width: 100%; aspect-ratio: 9/19.5; background: transparent; border-radius: 0; overflow: hidden; border: 0; }
.slider__track { position: absolute; inset: 0; display: flex; transition: transform .6s ease; backface-visibility: hidden; transform: translateZ(0); }
.slider__track { will-change: transform; }
.slider__slide { min-width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; background: transparent; }
.slider__slide img { width: 100%; height: auto; max-height: 100%; object-fit: contain; image-rendering: -webkit-optimize-contrast; }
.slider::after { content: ""; position: absolute; right: 8px; bottom: 8px; width: 6px; height: 6px; border-radius: 999px; background: rgba(255,255,255,0.6); box-shadow: 0 0 0 1px rgba(0,0,0,0.1); }
/* Constrain slider size inside project layout */
.project-detail__media .slider { max-width: 320px; width: 60%; margin-left: 0; margin-right: auto; }
@media (max-width: 820px) { .project-detail__media .slider { max-width: 300px; width: 90%; margin-left: auto; margin-right: auto; } }

/* EMU page: nudge slider and text slightly left */
.project-emu .container { padding-left: 10px; }
@media (max-width: 640px) {
  .project-emu.section { padding: 24px 0; }
  .project-emu .container { padding-left: 20px; padding-right: 20px; }
}

/* Reduce gap between EMU subtitle and slider */
.project-emu .section__subtitle { margin: 0 0 12px; }
@media (max-width: 640px) {
  .project-emu.section + .project-emu.section { padding-top: 4px; }
  .project-emu .section__subtitle { margin: 0 0 4px; }
}

/* Tighter gap between EMU subtitle and slider on mobile */
@media (max-width: 640px) {
  section.project-detail.project-emu:first-of-type { padding-bottom: 4px; }
  section.project-detail.project-emu + section.project-detail.project-emu { padding-top: 4px; }
}

/* Aim card */
.aim__card { border: 1px solid var(--border); border-radius: 12px; background: var(--card); padding: 12px; }

/* Ensure Project Aim text not muted and matches Tools Used */
.project-emu .project-detail__aside .techs__title { color: var(--text); }
.project-emu .project-detail__aside .techs__group { color: var(--text); }
@media (max-width: 640px) {
  .project-emu .project-detail__aside p { color: var(--text); }
}

/* Modules grid */
.modules__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.module { display: grid; grid-template-columns: auto 1fr; align-items: start; gap: 12px; border: 1px solid var(--border); border-radius: 12px; background: var(--card); color: var(--text); padding: 12px; }
.module__num { width: 40px; height: 40px; border-radius: 999px; background: #fff; color: var(--primary); border: 1px solid var(--border); font-weight: 700; display: inline-flex; align-items: center; justify-content: center; }
.module__title { margin: 0 0 8px; font-size: 16px; }
.module ul { margin: 0; padding-left: 18px; }
.module li + li { margin-top: 6px; }

@media (max-width: 820px) {
  .modules__grid { grid-template-columns: 1fr; }
}

/* EMU page typography to match sign-language page */
.project-emu .project-detail__aside h3:not(.techs__title) { font-size: 22px; margin: 0 0 8px; letter-spacing: -0.01em; }
.project-emu .project-detail__aside p { margin: 0 0 12px; color: var(--muted); line-height: 1.7; }
.project-emu .project-detail__aside ul { margin: 0; padding-left: 18px; }
.project-emu .project-detail__aside li + li { margin-top: 6px; }

@media (max-width: 820px) {
  .project-emu .project-detail__aside h3 { font-size: 20px; }
}

/* Uniform media sizing for project page (match GIF ratio, contain) */
.section.project-media .project-detail__media .media-box { position: relative; width: 100%; aspect-ratio: var(--media-ar, auto); background: #ffffff; border-radius: 12px; display: block; }
.section.project-media .project-detail__media .media-box + .media-box { margin-top: 20px; }
.section.project-media .project-detail__media .media-box img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: contain; border-radius: 12px; }

/* Technologies section */
.techs { margin: 24px 0 28px; }
.techs__title { margin: 0 0 12px; font-size: 22px; }
.techs__grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.techs__group { border: 1px solid var(--border); border-radius: 12px; background: var(--card); padding: 12px; }
.techs__group h3 { margin: 0 0 8px; font-size: 16px; }
.techs__group .badges { gap: 8px; }
.techs__group .badge { font-size: 14px; padding: 6px 10px; }

@media (max-width: 820px) {
  .project-detail__grid { grid-template-columns: 1fr; }
  .project-embed iframe { height: 250px; }
  .techs__grid { grid-template-columns: 1fr 1fr; }
}
.about__card { border: 1px solid var(--border); border-radius: 16px; padding: 16px; background: var(--card); }
.list { margin: 10px 0 0; padding-left: 18px; }
/* Reduce space below About section to tighten gap to Skills */
.section.about { padding-bottom: 0px; }
/* Education line logo */
.education-row { display: flex; align-items: center; gap: 12px; margin-top: 50px; }
.edu__logo { height: 52px; width: auto; margin: 0; flex-shrink: 0; }
.education-text { display: inline-flex; flex-direction: column; }
.education-text .abet { margin-top: 4px; font-size: 14px; }

/* Education stats (GPA/CGPA) */
.edu-stats { display: flex; gap: 16px; margin-top: 10px; }
.about__media .edu-stats { justify-content: center; margin-top: 60px; margin-bottom: 36px; }
.edu-stats .stat { display: flex; align-items: baseline; gap: 6px; padding: 6px 10px; border: 1px solid var(--border); border-radius: 10px; background: var(--card); }
.edu-stats .stat__label { font-size: 14px; color: var(--muted); }
.edu-stats .stat__value { font-weight: 700; color: var(--primary); min-width: 44px; text-align: right; }

/* Enlarge GPA on desktop only */
@media (min-width: 821px) {
  .edu-stats .stat { padding: 10px 14px; }
  .edu-stats .stat__label { font-size: 18px; }
  .edu-stats .stat__value { font-size: 32px; min-width: 72px; }
}

/* Skills */
.badges { display: flex; flex-wrap: wrap; gap: 12px; }
.badge { display: inline-flex; align-items: center; padding: 8px 12px; border: 1px solid var(--border); border-radius: 999px; background: var(--card); box-shadow: 0 0 0 rgba(0,0,0,0); transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease; }
.badge:hover { transform: translateY(-2px); box-shadow: var(--shadow); border-color: #d1d5db; }

/* Certificates */
.certs__grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.cert { display: flex; flex-direction: column; align-items: stretch; gap: 12px; border: 1px solid var(--border); border-radius: 14px; padding: 18px; text-decoration: none; color: var(--text); background: var(--card); transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease; }
.cert:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #d1d5db; }
.cert__badge { width: 80px; height: 80px; border-radius: 0; display: inline-flex; align-items: center; justify-content: center; border: 0; background: transparent; overflow: hidden; align-self: center; }
.cert__badge img { width: 100%; height: 100%; object-fit: contain; display: block; }
.cert__content { display: flex; flex-direction: column; gap: 6px; align-items: flex-start; text-align: left; }
.cert__logo { font-weight: 600; color: var(--muted); }
.cert__title { font-size: 14px; }
/* Center only the logo and title inside the certificate content */
.cert__logo, .cert__title { align-self: center; text-align: center; }
/* Sub-list inside certificate cards */
.cert__sublist {
  margin: 8px 0 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}
.cert__sublist li { margin: 0; }
.cert__sublist li + li { margin-top: 4px; }

/* Certificates total counter */
.certs__total { margin-top: 12px; text-align: center; }
.certs__total #cert-total { font-weight: 700; color: var(--primary); }

/* Contact */
.contact__grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 24px; align-items: center; }
.contact__links { display: flex; flex-direction: column; gap: 36px; justify-content: center; align-items: stretch; align-self: center; justify-self: center; height: 100%; }
.icon-link { display: inline-flex; align-items: center; gap: 10px; padding: 14px 16px; border-radius: 14px; color: var(--text); text-decoration: none; border: 1px solid var(--border); transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease, color .2s ease; min-width: 200px; justify-content: center; font-size: 16px; width: 100%; max-width: 260px; }
.icon-link:hover { transform: translateY(-2px); box-shadow: var(--shadow); border-color: #d1d5db; color: var(--primary); }
.icon-link svg { width: 28px; height: 28px; }
.contact__form { border: 1px solid var(--border); border-radius: 16px; padding: 16px; background: var(--card); }
.form__row { display: flex; flex-direction: column; gap: 8px; margin-bottom: 12px; }
label { font-size: 14px; color: var(--muted); }
input, textarea { font: inherit; padding: 12px; border-radius: 12px; border: 1px solid var(--border); background: #fff; outline: none; transition: border-color .2s ease, box-shadow .2s ease; }
input:focus, textarea:focus { border-color: #cbd5e1; box-shadow: 0 0 0 4px rgba(59,130,246,0.08); }
.form__actions { display: flex; align-items: center; gap: 12px; }
.muted { color: var(--muted); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); }
.site-footer .small {
  font-size: 0.8rem;
  opacity: 0.7;
}
.site-footer p {
  margin: 0;
}
.site-footer p + p {
  margin-top: 0; 
}
.footer-inner { display: flex; flex-direction: column; align-items: center; justify-content: center; height: auto; padding: 12px 0; }

/* Reveal on scroll */
.reveal { opacity: 0; transform: translateY(12px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: translateY(0); }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  .reveal { opacity: 1 !important; transform: none !important; }
  .parallax-layer { display: none !important; }
}

/* Responsive */
@media (max-width: 1024px) {
  .projects__grid { grid-template-columns: repeat(3, 1fr); }
  .certs__grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 820px) {
  .hero__inner { grid-template-columns: 1fr; display: flex; flex-direction: column; }
  .hero__embed { order: -1; }
  .about__grid { grid-template-columns: 1fr; }
  .contact__grid { grid-template-columns: 1fr; }
  .section h2 { font-size: 28px; }
  .section__subtitle { font-size: 15px; }
  /* Place GIF above text and reset offset; add more spacing */
  .hero__gif { margin-top: 0; margin-bottom: 44px; }
  /* Show hamburger on tablets too */
  .nav-toggle { display: inline-flex; }
  /* Ensure overlay menu works at <=820px as well */
  .nav { position: fixed; inset: 64px 0 0 0; background: #ffffff; display: flex; flex-direction: column; padding: 0; gap: 0; transform: translateY(-100%); transition: transform .25s ease, opacity .2s ease; border-top: 1px solid var(--border); opacity: 0; visibility: hidden; pointer-events: none; box-shadow: 0 8px 24px rgba(2,6,23,.12); z-index: 60; max-height: calc(100vh - 64px); overflow-y: auto; }
  .nav[data-open="true"] { transform: translateY(0); opacity: 1; visibility: visible; pointer-events: auto; }
  .nav a { margin: 0; padding: 16px 20px; font-size: 16px; display: block; border-bottom: 1px solid var(--border); border-radius: 0; background: transparent; }
  .nav a:last-child { border-bottom: 0; }
  .contact__links { flex-direction: row; align-self: auto; height: auto; justify-content: center; gap: 24px; }
  .icon-link { max-width: none; width: auto; }
}

@media (max-width: 640px) {
  .section { padding: 20px 0; }
  /* Ensure only hero is visible on initial load on small screens */
  .hero { min-height: 100vh; }
  .hero__title { font-size: 34px; text-align: center; }
  .hero__subtitle { font-size: 15px; text-align: center; }
  .projects__grid { grid-template-columns: 1fr; }
  .certs__grid { grid-template-columns: 1fr; display: flex; flex-direction: column; }
  /* Mobile certificate order: IBM, Stanford, DeepLearning.AI, Duke */
  .certs__grid .cert { order: 5; }
  .certs__grid .cert:has(.cert__badge img[alt="IBM"]) { order: 1; }
  .certs__grid .cert:has(.cert__badge img[alt="Stanford University"]) { order: 2; }
  .certs__grid .cert:has(.cert__badge img[alt="DeepLearning.AI"]) { order: 3; }
  .certs__grid .cert:has(.cert__badge img[alt="Duke University"]) { order: 4; }
  .nav-toggle { display: inline-flex; }
  .nav { position: fixed; inset: 64px 0 0 0; background: #ffffff; display: flex; flex-direction: column; padding: 0; gap: 0; transform: translateY(-100%); transition: transform .25s ease, opacity .2s ease; border-top: 1px solid var(--border); opacity: 0; visibility: hidden; pointer-events: none; box-shadow: 0 8px 24px rgba(2,6,23,.12); z-index: 60; max-height: calc(100vh - 64px); overflow-y: auto; }
  .nav[data-open="true"] { transform: translateY(0); opacity: 1; visibility: visible; pointer-events: auto; }
  .nav a { margin: 0; padding: 16px 20px; font-size: 16px; display: block; border-bottom: 1px solid var(--border); border-radius: 0; background: transparent; }
  .nav a:last-child { border-bottom: 0; }
  .header-inner { gap: 8px; }
  .hero__cta { gap: 10px; }
  .about__card { padding: 14px; }
  .card { padding: 16px; }
  .embed__frame-wrapper iframe { height: 300px; }
  .contact__links { flex-direction: row; justify-content: center; align-items: stretch; gap: 12px; }
  .icon-link { flex: 1 1 50%; width: auto; min-width: 0; font-size: 17px; padding: 16px 18px; }
  /* On small phones, add more spacing between GIF and title */
  .hero__gif { margin-top: 0; margin-bottom: 56px; }
  .hero__cta { justify-content: center; }
  /* Enlarge GPA text on mobile */
  .edu-stats .stat__label { font-size: 18px; }
  .edu-stats .stat__value { font-size: 26px; }
  .techs__grid { grid-template-columns: 1fr; }
  /* Ensure vertical spacing between stacked images */
  .project-detail__media > img + img { margin-top: 20px !important; }
}

/* Mobile-only certificate preview below IBM cert content */
.cert-mobile-preview { display: none; margin: 16px 0 0; }
/* Square, moulded (çıtalı) white frame */
.certificate-frame { padding: 16px; border-radius: 0; background: #ffffff; position: relative; box-shadow: 0 12px 24px rgba(0,0,0,0.12); }
.certificate-frame::before { content: none; }
/* inner slatted mouldings */
.certificate-frame::after { content: ""; position: absolute; inset: 0; border-radius: 0; pointer-events: none; box-shadow: inset 0 0 0 2px #e5e7eb, inset 0 0 0 10px #ffffff, inset 0 0 0 12px #e5e7eb, inset 0 0 0 20px #ffffff, inset 0 0 0 22px #e5e7eb; }
.certificate-frame img { width: 100%; height: auto; display: block; border-radius: 0; cursor: zoom-in; box-shadow: 0 1px 2px rgba(0,0,0,0.12); }

@media (max-width: 640px) {
  .cert-mobile-preview { display: block; }
}

/* Image modal */
.img-modal { position: fixed; inset: 0; z-index: 100; display: none; align-items: center; justify-content: center; }
.img-modal.is-open { display: flex; }
.img-modal__backdrop { position: absolute; inset: 0; background: rgba(0,0,0,0.6); }
.img-modal__content { position: relative; max-width: 92vw; max-height: 92vh; padding: 0; border-radius: 12px; box-shadow: var(--shadow); }
.img-modal__content img { display: block; max-width: 92vw; max-height: 92vh; width: auto; height: auto; border-radius: 12px; }