/* ============================================================
   Siam Hossain — portfolio
   Clean, professional, light theme. Optimised for a fast HR scan.
   ============================================================ */

/* ---------- tokens ---------- */
:root{
  --paper:      #FBFAF7;   /* warm off-white page */
  --surface:    #FFFFFF;   /* cards / raised */
  --surface-2:  #F4F2EC;   /* subtle fills (chips, thumbs) */
  --ink:        #18191C;   /* near-black — headings / primary text */
  --ink-2:      #45474D;   /* secondary body text */
  --ink-3:      #6B6E76;   /* muted labels / metadata */
  --rule:       #E7E4DD;   /* hairline borders */
  --rule-2:     #D9D6CD;   /* slightly stronger borders */
  --accent:     #1F44E0;   /* cobalt — links / primary action */
  --accent-deep:#13245C;   /* navy — hovers / strong accents */
  --accent-soft:#ECF0FF;   /* tinted background */
  --ok:         #1A8F4C;   /* status “open” */

  --serif: "Fraunces", "Times New Roman", serif;
  --sans:  "Hanken Grotesk", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono:  "JetBrains Mono", ui-monospace, Menlo, monospace;
  --ease:  cubic-bezier(.2,.7,.1,1);

  --maxw: 1180px;
  --pad:  clamp(20px, 5vw, 64px);
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:16px;
  line-height:1.6;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
img{display:block;max-width:100%}
::selection{background:var(--accent);color:#fff}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:2px}

section{scroll-margin-top:84px}

/* ---------- layout helpers ---------- */
main{max-width:var(--maxw);margin:0 auto;padding:0 var(--pad)}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:.5em;
  font-family:var(--sans);font-weight:600;font-size:14px;letter-spacing:.01em;
  padding:11px 18px;border-radius:9px;border:1px solid transparent;
  white-space:nowrap;cursor:pointer;
  transition:background .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease),transform .2s var(--ease),box-shadow .2s var(--ease);
}
.btn-primary{background:var(--accent);color:#fff;box-shadow:0 1px 2px rgba(19,36,92,.18)}
.btn-primary:hover{background:var(--accent-deep);transform:translateY(-1px);box-shadow:0 6px 18px rgba(19,36,92,.22)}
.btn-ghost{background:var(--surface);color:var(--ink);border-color:var(--rule-2)}
.btn-ghost:hover{border-color:var(--ink);transform:translateY(-1px)}

/* ============================================================
   TOP BAR
   ============================================================ */
.topbar{
  position:sticky;top:0;z-index:50;
  display:flex;align-items:center;gap:24px;
  padding:14px var(--pad);
  background:rgba(251,250,247,.82);
  -webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);
  border-bottom:1px solid var(--rule);
}
.topbar .brand{
  font-family:var(--serif);font-style:italic;font-size:20px;font-weight:500;
  color:var(--ink);letter-spacing:-.01em;flex-shrink:0;
}
.topbar nav{display:flex;gap:26px;margin-left:8px}
.topbar nav a{
  font-size:14px;font-weight:500;color:var(--ink-2);position:relative;padding:2px 0;
  transition:color .2s var(--ease);
}
.topbar nav a::after{content:"";position:absolute;left:0;right:100%;bottom:-2px;height:2px;background:var(--accent);transition:right .3s var(--ease)}
.topbar nav a:hover,
.topbar nav a[aria-current="true"]{color:var(--ink)}
.topbar nav a:hover::after,
.topbar nav a[aria-current="true"]::after{right:0}
.topbar-cta{display:flex;align-items:center;gap:16px;margin-left:auto}

/* skip link (a11y) */
.skip-link{position:absolute;left:-9999px;top:8px;z-index:100;background:var(--accent);color:#fff;padding:10px 16px;border-radius:8px;font-size:14px;font-weight:600}
.skip-link:focus{left:12px}

/* mobile nav toggle (hidden on desktop) */
.nav-toggle{display:none;flex-direction:column;justify-content:center;gap:5px;width:42px;height:38px;padding:0 9px;background:var(--surface);border:1px solid var(--rule-2);border-radius:9px;cursor:pointer;flex-shrink:0}
.nav-toggle-bar{display:block;height:2px;width:100%;background:var(--ink);border-radius:2px;transition:transform .25s var(--ease),opacity .2s var(--ease)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.status-pill{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--mono);font-size:11px;letter-spacing:.04em;color:var(--ink-2);
  padding:6px 12px;border:1px solid var(--rule-2);border-radius:999px;background:var(--surface);
}
.status-pill .dot{width:7px;height:7px;border-radius:999px;background:var(--ok);box-shadow:0 0 0 3px rgba(26,143,76,.15);animation:pulse 2s ease-in-out infinite}
@keyframes pulse{50%{opacity:.5}}

/* ============================================================
   HERO — résumé-header summary card
   ============================================================ */
.hero{padding:clamp(36px,6vw,72px) 0 clamp(48px,7vw,88px)}
.summary-card{
  display:grid;grid-template-columns:1.65fr .85fr;gap:clamp(24px,4vw,56px);
  background:var(--surface);
  border:1px solid var(--rule);border-radius:20px;
  padding:clamp(28px,4vw,52px);
  box-shadow:0 1px 2px rgba(24,25,28,.04), 0 18px 50px -28px rgba(24,25,28,.18);
  animation:cardin .55s var(--ease) both;
}
@keyframes cardin{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}

.sc-name{
  font-family:var(--mono);font-size:12px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--ink-3);margin-bottom:14px;
}
.sc-role{
  font-family:var(--sans);font-weight:800;letter-spacing:-.025em;line-height:1;
  font-size:clamp(40px,6.4vw,76px);color:var(--ink);
}
.sc-role-sub{
  display:block;margin-top:10px;
  font-weight:600;font-size:clamp(15px,1.8vw,20px);letter-spacing:.02em;color:var(--accent);
}
.sc-summary{
  margin-top:22px;max-width:48ch;
  font-size:clamp(16px,1.7vw,19px);line-height:1.55;color:var(--ink-2);
}
.sc-now{
  margin-top:22px;display:flex;flex-wrap:wrap;align-items:center;gap:8px 12px;
  font-size:15px;color:var(--ink-2);
}
.sc-now .sc-now-label{
  font-family:var(--mono);font-size:10px;letter-spacing:.16em;text-transform:uppercase;
  color:var(--ink-3);border:1px solid var(--rule-2);border-radius:6px;padding:3px 8px;
}
.sc-now b{color:var(--ink);font-weight:700}
.sc-now .sc-sep{color:var(--ink-3)}

.sc-skills{display:flex;flex-wrap:wrap;gap:8px;margin-top:24px}
.sc-skills li{
  font-family:var(--mono);font-size:12px;letter-spacing:.02em;color:var(--accent-deep);
  background:var(--accent-soft);border:1px solid #d9e1ff;border-radius:7px;padding:6px 11px;
}
.sc-cta{display:flex;flex-wrap:wrap;gap:12px;margin-top:30px}

/* facts column */
.sc-facts{
  display:grid;grid-template-columns:1fr 1fr;gap:1px;align-self:start;
  background:var(--rule);border:1px solid var(--rule);border-radius:14px;overflow:hidden;
}
.sc-facts .fact{background:var(--surface);padding:20px 18px;display:flex;flex-direction:column;gap:6px}
.sc-facts .fact-num{font-family:var(--serif);font-style:italic;font-size:clamp(26px,3vw,38px);line-height:1;color:var(--ink)}
.sc-facts .fact-label{font-family:var(--mono);font-size:10px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3)}

/* ============================================================
   SECTION CHROME
   ============================================================ */
section{padding:clamp(56px,8vw,104px) 0;border-top:1px solid var(--rule)}
.hero{border-top:0}
.sec-head{
  display:grid;grid-template-columns:200px 1fr;gap:32px;align-items:baseline;
  margin-bottom:clamp(32px,4vw,52px);
}
.sec-head .num{font-family:var(--mono);font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-3);padding-top:8px}
.sec-head .num b{color:var(--accent);font-weight:600;margin-right:6px}
.sec-head h2{font-family:var(--serif);font-style:italic;font-weight:400;font-size:clamp(32px,4.4vw,56px);line-height:1.04;letter-spacing:-.01em;color:var(--ink)}

/* ============================================================
   ABOUT
   ============================================================ */
.about-grid{display:grid;grid-template-columns:.8fr 1.2fr;gap:clamp(28px,5vw,64px);align-items:start}
.about-portrait{position:relative;border:1px solid var(--rule);border-radius:18px;overflow:hidden;aspect-ratio:4/5;background:var(--surface-2);box-shadow:0 1px 2px rgba(24,25,28,.04), 0 16px 44px -28px rgba(24,25,28,.2)}
.about-portrait img{width:100%;height:100%;object-fit:cover;object-position:center top}
.about-bio{font-size:clamp(16px,1.7vw,18px);line-height:1.7;color:var(--ink-2)}
.about-bio p+p{margin-top:1em}
.about-bio em{font-style:normal;font-weight:600;color:var(--accent-deep)}
.about-facts{margin-top:30px;border-top:1px solid var(--rule);padding-top:24px;display:grid;grid-template-columns:1fr 1fr;gap:18px 28px}
.about-facts li{display:flex;flex-direction:column;gap:4px}
.about-facts li span{font-family:var(--mono);font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-3)}
.about-facts li b{font-size:14px;color:var(--ink);font-weight:600}
@media (max-width:820px){
  .about-grid{grid-template-columns:1fr;gap:28px}
  .about-portrait{max-width:300px;aspect-ratio:1/1}
}
@media (max-width:600px){
  .about-facts{grid-template-columns:1fr}
}

/* ============================================================
   EXPERIENCE TIMELINE
   ============================================================ */
.timeline{display:flex;flex-direction:column}
.tl-item{
  display:grid;grid-template-columns:160px 1fr;gap:clamp(20px,3vw,44px);
  padding:28px 0;border-top:1px solid var(--rule);position:relative;
}
.tl-item:first-child{border-top:0;padding-top:0}
.tl-when{font-family:var(--mono);font-size:12px;letter-spacing:.04em;color:var(--ink-3);padding-top:5px;white-space:nowrap}
.tl-body{position:relative}
.tl-role{font-size:clamp(19px,2.2vw,24px);font-weight:700;color:var(--ink);letter-spacing:-.01em;line-height:1.25}
.tl-role .tl-co{font-weight:600;color:var(--accent)}
.tl-place{font-size:13px;color:var(--ink-3);margin-top:4px}
.tl-points{margin-top:14px;display:flex;flex-direction:column;gap:8px}
.tl-points li{position:relative;padding-left:20px;color:var(--ink-2);font-size:15px;line-height:1.5}
.tl-points li::before{content:"";position:absolute;left:2px;top:9px;width:6px;height:6px;border-radius:999px;background:var(--accent);opacity:.55}
.tl-tags{display:flex;flex-wrap:wrap;gap:7px;margin-top:16px}
.tl-tags li{font-family:var(--mono);font-size:11px;color:var(--ink-2);background:var(--surface-2);border:1px solid var(--rule);border-radius:6px;padding:4px 9px}

/* ============================================================
   SKILLS GRID
   ============================================================ */
.skills-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.skill-group{background:var(--surface);border:1px solid var(--rule);border-radius:14px;padding:22px 22px 24px}
.sg-title{
  font-family:var(--mono);font-size:11px;letter-spacing:.16em;text-transform:uppercase;
  color:var(--accent-deep);margin-bottom:16px;padding-bottom:12px;border-bottom:1px solid var(--rule);
}
.sg-list{display:flex;flex-wrap:wrap;gap:8px}
.sg-list li{font-size:13px;font-weight:500;color:var(--ink);background:var(--surface-2);border:1px solid var(--rule);border-radius:7px;padding:6px 11px}

/* ============================================================
   SELECTED WORK
   ============================================================ */
.work-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.work-card{
  position:relative;display:flex;flex-direction:column;
  background:var(--surface);border:1px solid var(--rule);border-radius:14px;overflow:hidden;
  transition:border-color .25s var(--ease),transform .25s var(--ease),box-shadow .25s var(--ease);
}
.work-card:hover{border-color:var(--rule-2);transform:translateY(-3px);box-shadow:0 14px 34px -18px rgba(24,25,28,.4)}
.wc-thumb{aspect-ratio:16/10;background:var(--surface-2);overflow:hidden;border-bottom:1px solid var(--rule)}
.wc-thumb img{width:100%;height:100%;object-fit:cover;object-position:top;transition:transform .5s var(--ease)}
.work-card:hover .wc-thumb img{transform:scale(1.04)}
.wc-thumb-code{display:grid;place-items:center}
.wc-thumb-code span{font-family:var(--mono);font-size:34px;color:var(--ink-3);opacity:.7}
.wc-body{padding:18px 20px 20px;display:flex;flex-direction:column;gap:8px;flex:1}
.wc-top{display:flex;align-items:baseline;justify-content:space-between;gap:12px}
.wc-name{font-size:18px;font-weight:700;color:var(--ink);letter-spacing:-.01em}
.wc-yr{font-family:var(--mono);font-size:11px;color:var(--ink-3)}
.wc-desc{font-size:14px;color:var(--ink-2);line-height:1.5;flex:1}
.wc-tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:4px}
.wc-tags li{font-family:var(--mono);font-size:10px;letter-spacing:.04em;color:var(--ink-3);text-transform:uppercase}
.wc-tags li::after{content:"·";margin-left:6px;color:var(--rule-2)}
.wc-tags li:last-child::after{content:""}
.wc-arrow{position:absolute;right:16px;top:14px;color:#fff;background:var(--accent);width:28px;height:28px;border-radius:999px;display:grid;place-items:center;font-size:13px;opacity:0;transform:translateY(-4px);transition:opacity .25s var(--ease),transform .25s var(--ease)}
.work-card:hover .wc-arrow{opacity:1;transform:none}
/* placeholder "in progress" cards */
.work-card-soon{border-style:dashed;background:transparent}
.work-card-soon:hover{transform:none;box-shadow:none;border-color:var(--rule-2)}
.work-card-soon .wc-name{color:var(--ink-2)}
.work-card-soon .wc-arrow{display:none}

/* ============================================================
   PROBLEM SOLVING — live stats
   ============================================================ */
.ps-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.ps-card{
  position:relative;display:flex;flex-direction:column;gap:18px;padding:22px 20px;
  background:var(--surface);border:1px solid var(--rule);border-radius:14px;overflow:hidden;
  transition:border-color .25s var(--ease),transform .25s var(--ease),box-shadow .25s var(--ease);
}
.ps-card::before{content:"";position:absolute;left:0;top:0;bottom:0;width:3px;background:var(--ps-color,var(--rule-2));opacity:.5;transition:opacity .25s var(--ease)}
.ps-card:hover{border-color:var(--ps-color,var(--rule-2));transform:translateY(-3px);box-shadow:0 14px 34px -18px rgba(24,25,28,.35)}
.ps-card:hover::before{opacity:1}
.ps-card[data-platform="leetcode"]{--ps-color:#F89F1B}
.ps-card[data-platform="codeforces"]{--ps-color:#1F8ACB}
.ps-card[data-platform="hackerrank"]{--ps-color:#00A862}
.ps-card[data-platform="codolio"]{--ps-color:var(--accent)}
.ps-logo{width:26px;height:26px;flex-shrink:0}
.ps-logo svg{width:100%;height:100%;fill:var(--ps-color,var(--ink-3))}
.ps-meta{flex:1}
.ps-platform{display:block;font-family:var(--mono);font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-3);margin-bottom:4px}
.ps-handle{display:block;font-size:15px;font-weight:600;color:var(--ink)}
.ps-stat{display:flex;align-items:baseline;gap:7px}
.ps-stat-num{font-family:var(--mono);font-weight:500;font-size:clamp(22px,2.4vw,30px);color:var(--ink);line-height:1;letter-spacing:-.02em;transition:opacity .35s}
.ps-stat-label{font-family:var(--mono);font-size:10px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3)}
.ps-arrow{position:absolute;right:16px;top:16px;color:var(--ink-3);font-size:13px;transition:color .25s,transform .25s var(--ease)}
.ps-card:hover .ps-arrow{color:var(--ps-color,var(--accent));transform:translate(2px,-2px)}

/* ============================================================
   CONTACT
   ============================================================ */
.contact-lead{font-size:clamp(18px,2.2vw,24px);line-height:1.5;color:var(--ink-2);max-width:46ch}
.contact-cta{display:flex;flex-wrap:wrap;gap:12px;margin-top:26px}
.socials{
  margin-top:40px;display:grid;grid-template-columns:repeat(4,1fr);gap:14px;
  border-top:1px solid var(--rule);padding-top:28px;
}
.social{
  display:flex;flex-direction:column;gap:5px;padding:16px 18px;
  background:var(--surface);border:1px solid var(--rule);border-radius:12px;
  transition:border-color .2s var(--ease),transform .2s var(--ease)}
.social:hover{border-color:var(--ink);transform:translateY(-2px)}
.social-label{font-family:var(--mono);font-size:10px;letter-spacing:.16em;text-transform:uppercase;color:var(--ink-3)}
.social-handle{font-size:15px;font-weight:600;color:var(--ink);word-break:break-word}
.foot{
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;
  margin-top:48px;padding-top:24px;border-top:1px solid var(--rule);
  font-family:var(--mono);font-size:11px;letter-spacing:.04em;color:var(--ink-3);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 920px){
  .summary-card{grid-template-columns:1fr;gap:28px}
  .sc-facts{grid-template-columns:repeat(4,1fr)}
  .skills-grid{grid-template-columns:repeat(2,1fr)}
  .work-grid{grid-template-columns:repeat(2,1fr)}
  .ps-cards{grid-template-columns:repeat(2,1fr)}
  .sec-head{grid-template-columns:1fr;gap:10px;margin-bottom:32px}
  .sec-head .num{padding-top:0}

  .nav-toggle{display:flex}
  .topbar{flex-wrap:wrap}
  .topbar nav{
    flex-direction:column;gap:0;margin-left:0;
    position:absolute;top:100%;left:0;right:0;
    background:rgba(251,250,247,.97);
    -webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);
    border-bottom:1px solid var(--rule);
    padding:0 var(--pad);
    max-height:0;overflow:hidden;
    transition:max-height .3s var(--ease);
  }
  .topbar nav[data-open="true"]{max-height:60vh;padding:6px var(--pad) 14px}
  .topbar nav a{padding:13px 0;font-size:16px;color:var(--ink);border-top:1px solid var(--rule)}
  .topbar nav a:first-child{border-top:0}
  .topbar nav a::after{display:none}
}

@media (max-width: 600px){
  body{font-size:16px}
  .topbar{gap:12px;padding:12px 18px}
  .topbar .brand{font-size:18px}
  .status-pill{display:none}
  .topbar-cta{margin-left:auto}
  .btn{padding:10px 15px;font-size:13.5px}

  .hero{padding:24px 0 36px}
  .summary-card{padding:24px 20px;border-radius:16px}
  .sc-role{font-size:clamp(34px,11vw,46px)}
  .sc-summary{font-size:16px;margin-top:18px}
  .sc-cta .btn{flex:1;justify-content:center}
  .sc-facts{grid-template-columns:1fr 1fr}
  .sc-now .sc-sep{display:none}
  .sc-now{gap:6px 10px}

  .tl-item{grid-template-columns:1fr;gap:6px;padding:24px 0}
  .tl-when{padding-top:0}

  .skills-grid{grid-template-columns:1fr}
  .work-grid{grid-template-columns:1fr}
  .socials{grid-template-columns:1fr 1fr}
  .foot{font-size:10px}
}

@media (max-width: 380px){
  .ps-cards{grid-template-columns:1fr 1fr;gap:10px}
  .ps-card{padding:16px 14px;gap:12px}
  .socials{grid-template-columns:1fr}
}

@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important}
  html{scroll-behavior:auto}
}