/* =========================================================
   MD. Tahmid Ahnaf — Portfolio
   Design concept: a personal sketchbook, flipped through.
   Tokens
   ========================================================= */
:root{
  --paper:        #eeeae0;
  --paper-deep:   #e4dfd0;
  --ink:          #1b1b1a;
  --ink-soft:     #504b42;
  --ink-faint:    #8a8578;
  --line:         #d4cebb;
  --accent:       #2f4b8c;   /* notebook-blue ink */
  --accent-soft:  #2f4b8c22;
  --red:          #a83f30;   /* red-pen annotation, used sparingly */
  --paper-dark:   #23211c;   /* ink section background */
  --paper-dark-2: #2c2a23;
  --cream-on-dark:#efe9d8;

  --font-display: 'Fraunces', Georgia, serif;
  --font-body:    'Inter', -apple-system, Segoe UI, sans-serif;
  --font-hand:    'Caveat', cursive;

  --container: 1120px;
  --gutter: clamp(1.25rem, 5vw, 4rem);
  --radius: 3px;

  --ease: cubic-bezier(.22,.7,.2,1);
}

*, *::before, *::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior: auto; }
  *{ animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

body{
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img{ max-width: 100%; display: block; }
a{ color: inherit; }
code{ font-family: 'SFMono-Regular', Menlo, monospace; background: #00000010; padding: .1em .35em; border-radius: 3px; font-size: .9em; }

::selection{ background: var(--accent); color: var(--cream-on-dark); }

/* focus visibility */
a:focus-visible, button:focus-visible{
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.skip-link{
  position: absolute; left: -999px; top: 0; z-index: 999;
  background: var(--ink); color: var(--paper); padding: .75em 1.25em;
}
.skip-link:focus{ left: 1rem; top: 1rem; }

/* paper grain, one lightweight fixed layer */
.grain{
  position: fixed; inset: 0; z-index: 2000; pointer-events: none;
  opacity: .05; mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* the notebook margin rule running the full page height, left edge */
.page-rule{
  position: absolute; top: 0; bottom: 0; left: clamp(14px, 4vw, 56px);
  width: 1px; z-index: 1;
  background: linear-gradient(var(--red), var(--red)) left/1px 100% no-repeat;
  opacity: .35;
  pointer-events: none;
}
@media (max-width: 720px){ .page-rule{ display:none; } }

/* =========================================================
   Nav
   ========================================================= */
.nav{
  position: fixed; top: 0; left: 0; right: 0; z-index: 500;
  display: flex; align-items: center; justify-content: space-between;
  padding: 1.35rem clamp(1.25rem, 5vw, 3rem);
  mix-blend-mode: normal;
}
.nav-mark{
  font-family: var(--font-display); font-weight: 600; font-size: 1.05rem;
  text-decoration: none; letter-spacing: .04em;
  border: 1px solid var(--ink); border-radius: 50%;
  width: 2.4rem; height: 2.4rem; display: flex; align-items: center; justify-content: center;
  background: var(--paper);
  position: relative; z-index: 502;
}
.nav-links{ display: flex; gap: 2rem; }
.nav-links a{
  text-decoration: none; font-size: .82rem; letter-spacing: .06em; text-transform: uppercase;
  color: var(--ink-soft); position: relative; padding-bottom: 2px;
}
.nav-links a::after{
  content: ""; position: absolute; left: 0; right: 100%; bottom: -2px; height: 1px; background: var(--accent);
  transition: right .25s var(--ease);
}
.nav-links a:hover::after, .nav-links a:focus-visible::after{ right: 0; }

.nav-toggle{ display: none; background: none; border: none; cursor: pointer; padding: .5rem; }
.nav-toggle span{ display: block; width: 22px; height: 1.5px; background: var(--ink); margin: 5px 0; transition: transform .25s var(--ease), opacity .25s var(--ease); }
.nav-toggle[aria-expanded="true"] span:first-child{ transform: translateY(6.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:last-child{ transform: translateY(-6.5px) rotate(-45deg); }

@media (max-width: 720px){
  .nav-links{
    position: fixed; inset: 0 0 auto 0; top: 0; padding: 6rem 2rem 2rem;
    flex-direction: column; gap: 1.5rem; background: var(--paper);
    transform: translateY(-100%); transition: transform .35s var(--ease);
    height: 100vh;
  }
  .nav-links.is-open{ transform: translateY(0); }
  .nav-links a{ font-size: 1.1rem; }
  .nav-toggle{ display: block; z-index: 501; }
}

/* =========================================================
   Layout helpers
   ========================================================= */
.section{ position: relative; padding: clamp(4.5rem, 10vh, 7rem) 0; }
.section-inner{
  max-width: var(--container); margin: 0 auto;
  padding: 0 var(--gutter);
  padding-left: max(var(--gutter), 90px);
}
@media (max-width: 720px){
  .section-inner{ padding-left: var(--gutter); }
}

.section-tint{ background: var(--paper-deep); }
.section-dark{ background: var(--paper-dark); color: var(--cream-on-dark); }
.section-dark .ink-soft, .section-dark p{ color: #cfc9b8; }

.eyebrow{
  font-family: var(--font-hand); font-size: 1.3rem; color: var(--accent);
  margin: 0 0 .5rem;
}

.margin-tab{
  position: absolute; left: max(calc(var(--gutter) - 4px), 14px); top: 2.75rem;
  font-family: var(--font-hand); font-size: 1.15rem; color: var(--accent);
  transform: rotate(-3deg);
}
.margin-tab span{ position: relative; white-space: nowrap; }
.margin-tab span::after{
  content: ""; position: absolute; left: -6px; right: -8px; bottom: 2px; height: 8px;
  background: var(--accent-soft); z-index: -1; border-radius: 2px;
}
.margin-tab-light{ color: #e7d9b8; }
.margin-tab-light span::after{ background: #e7d9b833; }
@media (max-width: 720px){ .margin-tab{ position: static; margin-bottom: 1.25rem; transform: none; } }

.section-title{
  font-family: var(--font-display); font-weight: 500; font-size: clamp(1.9rem, 4vw, 3rem);
  line-height: 1.1; margin: 0 0 1.25rem; letter-spacing: -.01em;
}
.section-title.light{ color: var(--cream-on-dark); }
.section-title .dot{ color: var(--red); }
.section-lede{ max-width: 42em; color: var(--ink-soft); font-size: 1.05rem; margin-bottom: 2.5rem; }

.btn{
  display: inline-flex; align-items: center; gap: .5rem;
  font-size: .85rem; letter-spacing: .04em; text-transform: uppercase;
  text-decoration: none; padding: .9rem 1.6rem; border-radius: 999px;
  border: 1px solid var(--ink); transition: transform .2s var(--ease), background .2s var(--ease), color .2s var(--ease);
}
.btn-primary{ background: var(--ink); color: var(--paper); }
.btn-primary:hover{ transform: translateY(-2px); }
.btn-ghost{ background: transparent; color: var(--ink); }
.section-dark .btn-ghost{ border-color: var(--cream-on-dark); color: var(--cream-on-dark); }
.section-dark .btn-primary{ background: var(--cream-on-dark); color: var(--paper-dark); border-color: var(--cream-on-dark); }
.btn-ghost:hover{ background: var(--ink); color: var(--paper); }
.section-dark .btn-ghost:hover{ background: var(--cream-on-dark); color: var(--paper-dark); }
.hero-cta{ display: flex; flex-wrap: wrap; gap: 1rem; margin-top: 2rem; }

/* =========================================================
   Hero
   ========================================================= */
.hero{
  position: relative; min-height: 100svh; display: flex; align-items: center;
  overflow: hidden; padding: 7rem var(--gutter) 4rem;
}
.hero-layer{ position: absolute; inset: 0; will-change: transform; }
.hero-bg{ z-index: 0; }
.hero-mid{ z-index: 1; }
.hero-content{ position: relative; z-index: 3; max-width: 640px; padding-left: 56px; }
@media (max-width: 720px){ .hero-content{ padding-left: 0; } }

.hero-title{
  font-family: var(--font-display); font-weight: 500;
  font-size: clamp(2.6rem, 8vw, 5.4rem); line-height: 0.98; margin: .3rem 0 1.25rem;
  letter-spacing: -.01em;
}
.hero-title span{ display: block; }
.hero-title-em{ font-style: italic; color: var(--accent); font-weight: 500; }

.hero-role{ font-size: clamp(1.1rem, 2vw, 1.35rem); max-width: 30em; margin: 0 0 .5rem; }
.hero-tag{ color: var(--ink-soft); max-width: 32em; margin: 0; }

.scribble{ position: absolute; width: 130%; height: 130%; left: -15%; top: -10%; fill: none; stroke: var(--ink); opacity: .08; }
.scribble path{ stroke-width: 2.5; stroke-linecap: round; }
.scribble-b{ opacity: .06; stroke: var(--accent); }

.ink-ring{
  position: absolute; border: 1.5px solid var(--red); border-radius: 50%; opacity: .18;
}
.ring-1{ width: 340px; height: 340px; right: 6%; top: 18%; }
.ring-2{ width: 140px; height: 140px; right: 20%; top: 55%; border-color: var(--accent); }
@media (max-width: 720px){ .ink-ring{ display: none; } }

.hero-portrait{
  position: absolute; inset: auto clamp(-2%, 4vw, 8%) 0 auto; z-index: 2;
  width: min(46vw, 560px); display: flex; align-items: flex-end; justify-content: center;
  pointer-events: none;
}
.portrait-frame{ position: relative; width: 100%; }
.portrait-img{ width: 100%; height: auto; filter: drop-shadow(0 30px 40px rgba(0,0,0,.16)); }
.portrait-underline{ width: 55%; margin: -6px auto 0; overflow: visible; }
.portrait-underline path{
  fill: none; stroke: var(--red); stroke-width: 3; stroke-linecap: round;
  stroke-dasharray: 1; stroke-dashoffset: 1;
  animation: draw-underline 1.4s var(--ease) .9s forwards;
}
@keyframes draw-underline{ to{ stroke-dashoffset: 0; } }

@media (max-width: 900px){
  .hero{ padding-top: 6.5rem; flex-direction: column; align-items: center; }
  .hero-portrait{
    position: relative; inset: auto; width: min(72vw, 340px); margin: 2.5rem 0 0;
    order: 2;
  }
  .hero-content{ max-width: 100%; width: 100%; order: 1; }
}

.scroll-cue{
  position: absolute; left: 50%; bottom: 2rem; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: .4rem;
  background: none; border: none; cursor: pointer; color: var(--ink-soft); z-index: 3;
  font-family: var(--font-hand); font-size: 1rem;
  animation: bob 2.4s ease-in-out infinite;
}
@keyframes bob{ 0%,100%{ transform: translate(-50%,0);} 50%{ transform: translate(-50%,6px);} }
@media (prefers-reduced-motion: reduce){ .scroll-cue{ animation: none; } }
@media (max-width: 640px){ .scroll-cue{ display: none; } }

/* =========================================================
   About
   ========================================================= */
.about-grid{ display: grid; grid-template-columns: 1.5fr .7fr; gap: 3rem; align-items: start; }
.about-copy p{ max-width: 46em; color: var(--ink-soft); font-size: 1.05rem; }
.about-facts{ display: flex; gap: 2.5rem; margin-top: 2.5rem; flex-wrap: wrap; }
.about-facts > div{ display: flex; flex-direction: column; }
.fact-num{ font-family: var(--font-display); font-size: 1.6rem; font-weight: 600; }
.fact-label{ font-size: .8rem; color: var(--ink-faint); text-transform: uppercase; letter-spacing: .04em; margin-top: .2rem; }

.about-aside{ display: flex; justify-content: center; padding-top: 2rem; }
.doodle{ width: 100%; max-width: 190px; fill: none; stroke: var(--ink); stroke-width: 1.6; opacity: .55; }

@media (max-width: 860px){
  .about-grid{ grid-template-columns: 1fr; }
  .about-aside{ display: none; }
}

/* =========================================================
   Skills
   ========================================================= */
.skills-grid{ display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: center; }
.skills-copy p{ max-width: 40em; }
.skill{ margin-bottom: 1.6rem; }
.skill-head{ display: flex; justify-content: space-between; font-size: .9rem; margin-bottom: .5rem; letter-spacing: .02em; }
.skill-pct{ font-family: var(--font-hand); color: #e7d9b8; font-size: 1.05rem; }
.skill-track{ height: 3px; background: #efe9d822; border-radius: 3px; overflow: hidden; }
.skill-fill{
  height: 100%; width: 0; background: linear-gradient(90deg, #e7d9b8, #cfc9b8);
  transition: width 1.1s var(--ease);
}
.skill.is-visible .skill-fill{ width: var(--v); }

@media (max-width: 860px){ .skills-grid{ grid-template-columns: 1fr; gap: 2.5rem; } }

/* =========================================================
   Projects
   ========================================================= */
.project-list{ display: flex; flex-direction: column; }
.project{
  display: grid; grid-template-columns: 70px 1fr; gap: 1.5rem;
  padding: 2.2rem 0; border-top: 1px solid var(--line);
}
.project:last-child{ border-bottom: 1px solid var(--line); }
.project-num{ font-family: var(--font-display); font-style: italic; color: var(--ink-faint); font-size: 1.1rem; }
.project-body h3{ font-family: var(--font-display); font-size: 1.5rem; font-weight: 500; margin: 0 0 .35rem; }
.project-role{ font-size: .82rem; text-transform: uppercase; letter-spacing: .05em; color: var(--accent); margin: 0 0 .8rem; }
.project-body p{ max-width: 56em; color: var(--ink-soft); margin: 0 0 1rem; }
.project-links{ display: flex; gap: 1.5rem; flex-wrap: wrap; }
.tag-link{ font-size: .88rem; text-decoration: none; border-bottom: 1px solid var(--ink); padding-bottom: 1px; }
.tag-link-quiet{ color: var(--ink-soft); border-color: var(--line); }
.tag-link:hover{ color: var(--accent); border-color: var(--accent); }

@media (max-width: 640px){
  .project{ grid-template-columns: 1fr; gap: .5rem; }
}

.project-detail{ margin-top: 1rem; }
.project-detail-inner{
  background: var(--paper-deep); border-radius: var(--radius);
  padding: clamp(1.5rem, 4vw, 2.75rem); border-left: 3px solid var(--red);
}
.project-detail-inner p{ max-width: 60em; color: var(--ink-soft); }
.project-detail-inner p:last-child{ margin-bottom: 0; }

/* =========================================================
   Hobbies
   ========================================================= */
.hobby-grid{ display: grid; grid-template-columns: repeat(2, 1fr); gap: 2.5rem 3rem; }
.hobby h3{ font-family: var(--font-display); font-size: 1.3rem; font-weight: 500; margin: 0 0 .6rem; position: relative; display: inline-block; }
.hobby p{ color: var(--ink-soft); margin: 0; max-width: 34em; }
@media (max-width: 720px){ .hobby-grid{ grid-template-columns: 1fr; } }

/* =========================================================
   Achievements timeline
   ========================================================= */
.timeline{ list-style: none; margin: 0; padding: 0; max-width: 62em; }
.timeline li{
  display: grid; grid-template-columns: 90px 1fr; gap: 1.5rem;
  padding: 1.5rem 0; border-top: 1px solid var(--line);
}
.timeline li:last-child{ border-bottom: 1px solid var(--line); }
.timeline-year{ font-family: var(--font-hand); font-size: 1.4rem; color: var(--red); }
.timeline-body h3{ font-size: 1.05rem; font-weight: 600; margin: 0 0 .3rem; }
.timeline-body p{ margin: 0; color: var(--ink-soft); font-size: .95rem; }
.timeline-quote{
  font-family: var(--font-display); font-style: italic; font-size: 1.3rem;
  max-width: 34em; margin: 2.5rem 0 0; color: var(--ink-soft);
}
@media (max-width: 560px){ .timeline li{ grid-template-columns: 60px 1fr; } }

/* =========================================================
   Blog
   ========================================================= */
.blog-list{ display: grid; grid-template-columns: repeat(2, 1fr); gap: 2.5rem 3rem; }
.blog-post h3{ font-family: var(--font-display); font-size: 1.25rem; font-weight: 500; margin: 0 0 .6rem; }
.blog-post p{ color: #cfc9b8; margin: 0; font-size: .96rem; }
@media (max-width: 720px){ .blog-list{ grid-template-columns: 1fr; } }

/* =========================================================
   Resume / contact
   ========================================================= */
.resume-grid{ display: grid; grid-template-columns: 1.4fr .7fr; gap: 3rem; align-items: start; }
.resume-copy p{ max-width: 42em; color: var(--ink-soft); }
.resume-facts{ display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.75rem; margin: 2.25rem 0; }
.resume-facts h4{ font-size: .78rem; text-transform: uppercase; letter-spacing: .06em; color: var(--accent); margin: 0 0 .4rem; }
.resume-facts p{ font-size: .92rem; margin: 0; }
.resume-aside{ display: flex; justify-content: center; }

@media (max-width: 860px){
  .resume-grid{ grid-template-columns: 1fr; }
  .resume-facts{ grid-template-columns: 1fr; }
  .resume-aside{ display: none; }
}

/* =========================================================
   Footer
   ========================================================= */
.site-footer{ background: var(--paper-dark); color: var(--cream-on-dark); padding: 2.5rem 0; }
.footer-inner{ display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; padding-left: var(--gutter) !important; }
.footer-links{ display: flex; gap: 1.5rem; }
.footer-links a{ text-decoration: none; font-size: .85rem; color: #cfc9b8; }
.footer-links a:hover{ color: var(--cream-on-dark); }
.footer-copy{ margin: 0; font-size: .8rem; color: var(--ink-faint); }

/* =========================================================
   Scroll reveal
   ========================================================= */
.reveal{
  opacity: 0; transform: translateY(22px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
  transition-delay: calc(var(--d, 0) * 90ms);
}
.reveal.is-visible{ opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce){
  .reveal{ opacity: 1; transform: none; transition: none; }
}