/* ============================================================
   Arghya.online — Design System
   Glassmorphism x Soft Neumorphism · Dark/Light · No dependencies
   ============================================================ */

/* ---------- Tokens ---------- */
:root {
  --font-sans: "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Cascadia Code", "JetBrains Mono", ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --rad-lg: 24px; --rad-md: 17px; --rad-sm: 12px;
  --nav-h: 66px;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #060a13; --bg-2: #0a1120;
  --surface: rgba(15, 22, 40, 0.55); --surface-flat: #0d1526;
  --border: rgba(120, 160, 255, 0.14); --border-hover: rgba(96, 205, 255, 0.45);
  --text-1: #f2f6ff; --text-2: #b9c4dd; --text-3: #8291ad;
  --accent: #22d3ee; --accent-2: #818cf8; --accent-text: #67e3f9;
  --grad: linear-gradient(135deg, #22d3ee, #818cf8);
  --chip-bg: rgba(34, 211, 238, 0.08);
  --neu: 12px 12px 28px rgba(0, 0, 0, 0.5), -8px -8px 22px rgba(80, 110, 180, 0.05);
  --neu-in: inset 5px 5px 12px rgba(0, 0, 0, 0.45), inset -4px -4px 10px rgba(90, 120, 190, 0.07);
  --glow: 0 0 24px rgba(34, 211, 238, 0.18);
  --nav-bg: rgba(7, 11, 20, 0.72);
  --term-bg: #0b1322; --term-head: #0f1930;
  --cell-0: rgba(120,160,255,.07); --cell-1: rgba(34,211,238,.22); --cell-2: rgba(34,211,238,.45); --cell-3: rgba(34,211,238,.8);
}

[data-theme="light"] {
  color-scheme: light;
  --bg: #e7ebf3; --bg-2: #eef1f8;
  --surface: rgba(255, 255, 255, 0.62); --surface-flat: #e9edf5;
  --border: rgba(70, 100, 160, 0.16); --border-hover: rgba(8, 145, 178, 0.5);
  --text-1: #14203c; --text-2: #3d4c6b; --text-3: #61708f;
  --accent: #0891b2; --accent-2: #4f46e5; --accent-text: #0e7490;
  --grad: linear-gradient(135deg, #0891b2, #4f46e5);
  --chip-bg: rgba(8, 145, 178, 0.09);
  --neu: 12px 12px 26px #c9d2e3, -10px -10px 24px #ffffff;
  --neu-in: inset 4px 4px 10px #c9d2e3, inset -4px -4px 10px #ffffff;
  --glow: 0 0 22px rgba(8, 145, 178, 0.16);
  --nav-bg: rgba(238, 241, 248, 0.8);
  --term-bg: #101b30; --term-head: #16233d;
  --cell-0: rgba(70,100,160,.12); --cell-1: rgba(8,145,178,.28); --cell-2: rgba(8,145,178,.55); --cell-3: rgba(8,145,178,.85);
}

/* ---------- Reset / Base ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--bg); color: var(--text-1);
  line-height: 1.65; font-size: 16px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  transition: background 0.45s var(--ease), color 0.45s var(--ease);
}
img { max-width: 100%; display: block; }
a { color: var(--accent-text); text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
section { scroll-margin-top: calc(var(--nav-h) + 26px); }
::selection { background: rgba(34, 211, 238, 0.28); }

/* ---------- Accessibility ---------- */
.skip-link {
  position: fixed; top: -60px; left: 16px; z-index: 300;
  padding: 10px 18px; border-radius: 10px; background: var(--grad); color: #fff;
  font-weight: 700; transition: top 0.3s var(--ease);
}
.skip-link:focus { top: 12px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* ---------- Ambient background ---------- */
.bg-layer {
  position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background:
    radial-gradient(900px 600px at 12% -6%, rgba(34, 211, 238, 0.09), transparent 60%),
    radial-gradient(1000px 700px at 95% 12%, rgba(129, 140, 248, 0.09), transparent 62%),
    radial-gradient(800px 900px at 50% 115%, rgba(34, 211, 238, 0.05), transparent 60%);
}
[data-theme="light"] .bg-layer {
  background:
    radial-gradient(900px 600px at 12% -6%, rgba(8, 145, 178, 0.1), transparent 60%),
    radial-gradient(1000px 700px at 95% 12%, rgba(79, 70, 229, 0.09), transparent 62%);
}
.grid-layer {
  position: fixed; inset: 0; z-index: -1; pointer-events: none; opacity: 0.5;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, black 30%, transparent 75%);
  mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, black 30%, transparent 75%);
}
.code-drift {
  position: absolute; z-index: 0; pointer-events: none; user-select: none;
  font-family: var(--font-mono); font-size: 12px; line-height: 2.1;
  color: var(--accent); opacity: 0.05; white-space: pre;
  animation: drift 60s linear infinite;
}
.code-drift.c2 { animation-duration: 84s; animation-delay: -30s; }
@keyframes drift { from { transform: translateY(0); } to { transform: translateY(-50%); } }

/* ---------- Reading progress ---------- */
.progress-bar {
  position: fixed; top: 0; left: 0; height: 3px; width: 0;
  background: var(--grad); z-index: 220; border-radius: 0 3px 3px 0;
  box-shadow: 0 0 12px rgba(34, 211, 238, 0.5);
}

/* ---------- Nav ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 200; height: var(--nav-h);
  background: var(--nav-bg);
  -webkit-backdrop-filter: blur(18px); backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
  transition: background 0.45s var(--ease);
}
.nav-inner {
  max-width: 1240px; margin: 0 auto; height: 100%; padding: 0 28px;
  display: flex; align-items: center; justify-content: space-between; gap: 18px;
}
.logo { font-family: var(--font-mono); font-weight: 700; font-size: 1.06rem; color: var(--text-1); letter-spacing: 0.01em; }
.logo span { color: var(--accent-text); }
.nav-links { display: flex; align-items: center; gap: 4px; list-style: none; }
.nav-links a {
  padding: 8px 13px; border-radius: 10px; font-size: 0.9rem; font-weight: 600; color: var(--text-2);
  transition: color 0.3s var(--ease), background 0.3s var(--ease);
}
.nav-links a:hover { color: var(--text-1); background: var(--chip-bg); }
.nav-links a.active { color: var(--accent-text); background: var(--chip-bg); }
.nav-actions { display: flex; align-items: center; gap: 10px; }
.icon-btn {
  width: 40px; height: 40px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--surface); color: var(--text-2);
  display: inline-flex; align-items: center; justify-content: center;
  box-shadow: var(--neu); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.icon-btn:hover { transform: translateY(-2px); border-color: var(--border-hover); color: var(--accent-text); box-shadow: var(--neu), var(--glow); }
.icon-btn svg { width: 19px; height: 19px; }
.kbd-hint {
  display: inline-flex; align-items: center; gap: 7px; height: 40px; padding: 0 13px;
  border-radius: 12px; border: 1px solid var(--border); background: var(--surface);
  color: var(--text-3); font-family: var(--font-mono); font-size: 0.78rem; font-weight: 600;
  box-shadow: var(--neu); transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), color 0.3s var(--ease);
}
.kbd-hint:hover { transform: translateY(-2px); border-color: var(--border-hover); color: var(--accent-text); }
.kbd-hint kbd { font-family: inherit; padding: 1px 6px; border-radius: 6px; background: var(--chip-bg); color: var(--accent-text); }
.burger { display: none; }
.mobile-menu {
  display: none; position: fixed; top: var(--nav-h); left: 0; right: 0; z-index: 190;
  background: var(--nav-bg); -webkit-backdrop-filter: blur(20px); backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border); padding: 14px 24px 22px;
}
.mobile-menu.open { display: block; }
.mobile-menu a {
  display: block; padding: 12px 14px; border-radius: 12px; font-weight: 600; color: var(--text-2);
}
.mobile-menu a:hover, .mobile-menu a.active { color: var(--accent-text); background: var(--chip-bg); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 13px 26px; border-radius: 14px; font-size: 0.94rem; font-weight: 700;
  border: 1px solid transparent; will-change: transform;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease);
}
.btn svg { width: 17px; height: 17px; }
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 10px 26px rgba(34, 211, 238, 0.25); }
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 16px 34px rgba(34, 211, 238, 0.38); }
.btn-ghost {
  background: var(--surface); color: var(--text-1); border-color: var(--border);
  box-shadow: var(--neu); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
}
.btn-ghost:hover { transform: translateY(-3px); border-color: var(--border-hover); color: var(--accent-text); box-shadow: var(--neu), var(--glow); }
.btn-sm { padding: 9px 18px; font-size: 0.85rem; border-radius: 11px; }

/* ---------- Chips ---------- */
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 13px; border-radius: 999px;
  font-family: var(--font-mono); font-size: 0.78rem; font-weight: 600;
  background: var(--chip-bg); color: var(--accent-text);
  border: 1px solid var(--border);
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}
.chip:hover { border-color: var(--border-hover); transform: translateY(-2px); }

/* ---------- Section shells ---------- */
.wrap { max-width: 1240px; margin: 0 auto; padding: 0 28px; }
.section { padding: 108px 0; position: relative; }
.sec-kicker {
  font-family: var(--font-mono); font-size: 0.8rem; font-weight: 700; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--accent-text); margin-bottom: 14px;
}
.sec-title { font-size: clamp(1.9rem, 3.6vw, 2.7rem); font-weight: 800; letter-spacing: -0.02em; line-height: 1.15; }
.sec-title em { font-style: normal; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sec-lede { margin-top: 16px; color: var(--text-2); max-width: 640px; font-size: 1.02rem; }
.sec-head-row { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; flex-wrap: wrap; }

/* ---------- Glass card primitive ---------- */
.glass {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--rad-lg);
  -webkit-backdrop-filter: blur(20px); backdrop-filter: blur(20px);
  box-shadow: var(--neu);
  transition: transform 0.4s var(--ease), border-color 0.4s var(--ease), box-shadow 0.4s var(--ease);
}
.glass-hover:hover { transform: translateY(-5px); border-color: var(--border-hover); box-shadow: var(--neu), var(--glow); }
.well {
  border-radius: var(--rad-sm); background: var(--surface-flat); box-shadow: var(--neu-in);
  display: inline-flex; align-items: center; justify-content: center; color: var(--accent-text);
}

/* ---------- Reveal ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.8s var(--ease), transform 0.8s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
.reveal-d1 { transition-delay: 0.08s; } .reveal-d2 { transition-delay: 0.16s; } .reveal-d3 { transition-delay: 0.24s; }

/* ---------- Hero ---------- */
.hero { position: relative; padding: calc(var(--nav-h) + 76px) 0 96px; overflow: hidden; }
.hero-inner { position: relative; z-index: 1; display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 60px; align-items: center; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 9px; padding: 8px 18px; border-radius: 999px;
  font-family: var(--font-mono); font-size: 0.8rem; font-weight: 600; color: var(--accent-text);
  background: var(--chip-bg); border: 1px solid var(--border);
  -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 10px var(--accent); animation: pulse 2.4s var(--ease) infinite; }
@keyframes pulse { 0%, 100% { transform: scale(1); opacity: 1; } 50% { transform: scale(0.72); opacity: 0.6; } }
.hero-id { display: flex; align-items: center; gap: 22px; margin-top: 26px; }
.avatar {
  width: 92px; height: 92px; border-radius: 26px; flex-shrink: 0; position: relative;
  background: var(--grad); padding: 3px; box-shadow: var(--neu), var(--glow);
}
.avatar img, .avatar .monogram {
  width: 100%; height: 100%; border-radius: 23px; object-fit: cover;
}
.avatar .monogram {
  display: flex; align-items: center; justify-content: center;
  background: var(--surface-flat); color: var(--accent-text);
  font-family: var(--font-mono); font-weight: 700; font-size: 1.5rem; letter-spacing: 0.04em;
}
.hero h1 { font-size: clamp(2.3rem, 5vw, 3.6rem); font-weight: 800; letter-spacing: -0.03em; line-height: 1.08; }
.hero h1 em { font-style: normal; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-role { margin-top: 6px; font-weight: 700; color: var(--text-2); font-size: 1.05rem; }
.type-line { margin-top: 18px; font-family: var(--font-mono); font-size: 1.02rem; font-weight: 600; color: var(--accent-text); min-height: 1.8em; }
.type-line .caret { display: inline-block; width: 9px; height: 1.15em; vertical-align: text-bottom; background: var(--accent); margin-left: 3px; animation: blink 1.1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }
.hero-tagline { margin-top: 16px; font-size: 1.16rem; font-weight: 650; color: var(--text-1); letter-spacing: -0.01em; }
.hero-copy { margin-top: 12px; color: var(--text-2); max-width: 560px; font-size: 1rem; }
.hero-ctas { margin-top: 30px; display: flex; flex-wrap: wrap; gap: 14px; }
.hero-social { margin-top: 30px; display: flex; gap: 12px; }
.social-btn {
  width: 46px; height: 46px; border-radius: 14px; border: 1px solid var(--border);
  background: var(--surface); box-shadow: var(--neu); color: var(--text-2);
  display: inline-flex; align-items: center; justify-content: center;
  transition: transform 0.35s var(--ease), border-color 0.35s var(--ease), color 0.35s var(--ease), box-shadow 0.35s var(--ease);
}
.social-btn:hover { transform: translateY(-4px) scale(1.05); border-color: var(--border-hover); color: var(--accent-text); box-shadow: var(--neu), var(--glow); }
.social-btn svg { width: 21px; height: 21px; }

/* ---------- Terminal ---------- */
.terminal {
  border-radius: var(--rad-md); overflow: hidden; border: 1px solid var(--border);
  background: var(--term-bg); box-shadow: var(--neu), 0 24px 60px rgba(0, 0, 0, 0.35);
  font-family: var(--font-mono); font-size: 0.8rem; line-height: 1.75;
}
.term-head { display: flex; align-items: center; gap: 8px; padding: 11px 16px; background: var(--term-head); border-bottom: 1px solid var(--border); }
.term-dot { width: 11px; height: 11px; border-radius: 50%; }
.term-title { margin-left: 8px; color: #8fa0c0; font-size: 0.76rem; }
.term-body { padding: 18px 20px 14px; min-height: 320px; color: #d7e2f5; }
.term-body .tl { display: block; white-space: pre; overflow: hidden; }
.tk-inc { color: #f0a35e; } .tk-kw { color: #7dd3fc; } .tk-type { color: #86efac; }
.tk-fn { color: #c4b5fd; } .tk-cm { color: #64748b; } .tk-str { color: #fbbf24; }
.tk-ok { color: #4ade80; } .tk-prompt { color: #22d3ee; }
.term-input-row { display: flex; align-items: center; gap: 8px; padding: 0 20px 16px; }
.term-input-row .tk-prompt { flex-shrink: 0; }
.term-input {
  flex: 1; background: transparent; border: none; outline: none; color: #d7e2f5;
  font-family: var(--font-mono); font-size: 0.8rem;
}
.term-hint { padding: 0 20px 14px; color: #64748b; font-size: 0.72rem; }

/* ---------- About ---------- */
.about-grid { margin-top: 54px; display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 30px; align-items: start; }
.about-story { padding: 38px 40px; }
.about-story p { color: var(--text-2); margin-bottom: 16px; font-size: 1.01rem; }
.about-story p strong { color: var(--text-1); }
.about-story p:last-child { margin-bottom: 0; }
.about-aside { display: flex; flex-direction: column; gap: 22px; }
.about-card { padding: 24px 26px; display: flex; gap: 18px; align-items: flex-start; }
.about-card .well { width: 52px; height: 52px; flex-shrink: 0; }
.about-card .well svg { width: 24px; height: 24px; }
.about-card h3 { font-size: 1rem; font-weight: 750; }
.about-card p { margin-top: 4px; color: var(--text-2); font-size: 0.9rem; }

/* ---------- Timeline ---------- */
.timeline { margin-top: 60px; position: relative; max-width: 760px; margin-left: auto; margin-right: auto; }
.timeline-rail { position: absolute; left: 26px; top: 8px; bottom: 8px; width: 3px; border-radius: 3px; background: var(--surface-flat); box-shadow: var(--neu-in); }
.timeline-fill { position: absolute; left: 0; top: 0; width: 100%; height: 0; border-radius: 3px; background: var(--grad); box-shadow: 0 0 12px rgba(34, 211, 238, 0.4); transition: height 0.2s linear; }
.tl-item { position: relative; padding: 0 0 44px 76px; }
.tl-item:last-child { padding-bottom: 0; }
.tl-node {
  position: absolute; left: 13px; top: 4px; width: 29px; height: 29px; border-radius: 50%;
  background: var(--surface-flat); box-shadow: var(--neu); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
}
.tl-node::after { content: ""; width: 11px; height: 11px; border-radius: 50%; background: var(--grad); box-shadow: 0 0 10px var(--accent); }
.tl-card { padding: 22px 26px; }
.tl-year { font-family: var(--font-mono); font-size: 0.8rem; font-weight: 700; color: var(--accent-text); }
.tl-card h3 { margin-top: 4px; font-size: 1.08rem; font-weight: 750; }
.tl-card p { margin-top: 6px; color: var(--text-2); font-size: 0.93rem; }

/* ---------- Achievements ---------- */
.ach-grid { margin-top: 54px; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 26px; }
.ach-card { padding: 30px; position: relative; overflow: hidden; }
.ach-card .well { width: 56px; height: 56px; border-radius: 16px; }
.ach-card .well svg { width: 26px; height: 26px; }
.ach-metric { margin-top: 20px; font-family: var(--font-mono); font-size: 1.9rem; font-weight: 700; letter-spacing: -0.02em; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.ach-card h3 { margin-top: 6px; font-size: 1.05rem; font-weight: 750; }
.ach-card p { margin-top: 8px; color: var(--text-2); font-size: 0.9rem; }
.ach-tag { position: absolute; top: 20px; right: 20px; }

/* ---------- Projects ---------- */
.filter-bar { margin-top: 44px; display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.filter-chip {
  padding: 9px 20px; border-radius: 999px; font-family: var(--font-mono); font-size: 0.82rem; font-weight: 600;
  color: var(--text-2); background: var(--surface); border: 1px solid var(--border); box-shadow: var(--neu);
  transition: all 0.35s var(--ease);
}
.filter-chip:hover { color: var(--accent-text); border-color: var(--border-hover); transform: translateY(-2px); }
.filter-chip.active { background: var(--grad); color: #fff; border-color: transparent; box-shadow: 0 8px 22px rgba(34, 211, 238, 0.3); }
.search-box {
  display: flex; align-items: center; gap: 10px; padding: 0 16px; height: 42px; min-width: 240px;
  border-radius: 999px; background: var(--surface-flat); box-shadow: var(--neu-in); border: 1px solid var(--border);
}
.search-box svg { width: 16px; height: 16px; color: var(--text-3); flex-shrink: 0; }
.search-box input { flex: 1; border: none; outline: none; background: transparent; color: var(--text-1); font-size: 0.9rem; font-family: inherit; }
.search-box input::placeholder { color: var(--text-3); }
.projects-grid { margin-top: 36px; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 30px; }
.project-card { display: flex; flex-direction: column; overflow: hidden; opacity: 1; transform: none; transition: transform 0.4s var(--ease), border-color 0.4s var(--ease), box-shadow 0.4s var(--ease), opacity 0.4s var(--ease); }
.project-card.filtered-out { display: none; }
.project-thumb {
  height: 190px; position: relative; display: flex; align-items: center; justify-content: center;
  background:
    linear-gradient(160deg, rgba(34, 211, 238, 0.12), rgba(129, 140, 248, 0.12)),
    var(--surface-flat);
  border-bottom: 1px solid var(--border);
}
.project-thumb img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.project-thumb .well { width: 72px; height: 72px; border-radius: 20px; }
.project-thumb .well svg { width: 33px; height: 33px; }
.proj-flags { position: absolute; top: 16px; right: 16px; display: flex; gap: 8px; }
.status-chip { background: rgba(74, 222, 128, 0.12); color: #4ade80; border-color: rgba(74, 222, 128, 0.25); }
[data-theme="light"] .status-chip { background: rgba(22, 163, 74, 0.1); color: #15803d; border-color: rgba(22, 163, 74, 0.3); }
.project-body { padding: 26px 28px 28px; display: flex; flex-direction: column; flex: 1; }
.project-title-row { display: flex; align-items: baseline; justify-content: space-between; gap: 14px; }
.project-title-row h3 { font-size: 1.22rem; font-weight: 750; letter-spacing: -0.01em; }
.project-date { font-family: var(--font-mono); font-size: 0.82rem; color: var(--text-3); flex-shrink: 0; }
.project-desc { margin-top: 12px; color: var(--text-2); font-size: 0.95rem; }
.project-tags { margin-top: 16px; display: flex; flex-wrap: wrap; gap: 8px; }
.case-study { margin-top: 18px; border-top: 1px solid var(--border); }
.case-study summary {
  list-style: none; display: flex; align-items: center; gap: 8px; padding: 14px 2px 4px;
  font-weight: 700; font-size: 0.88rem; color: var(--accent-text); cursor: pointer; user-select: none;
}
.case-study summary::-webkit-details-marker { display: none; }
.case-study summary svg { width: 15px; height: 15px; transition: transform 0.35s var(--ease); }
.case-study[open] summary svg { transform: rotate(90deg); }
.case-rows { padding: 10px 2px 4px; display: flex; flex-direction: column; gap: 12px; }
.case-row h4 { font-family: var(--font-mono); font-size: 0.72rem; font-weight: 700; letter-spacing: 0.14em; text-transform: uppercase; color: var(--text-3); }
.case-row p { margin-top: 3px; color: var(--text-2); font-size: 0.9rem; }
.project-foot { margin-top: 20px; display: flex; flex-wrap: wrap; gap: 10px; }
.no-results { display: none; margin-top: 36px; padding: 40px; text-align: center; color: var(--text-3); }
.no-results.show { display: block; }

/* ---------- Presentations ---------- */
.talks-list { margin-top: 48px; display: flex; flex-direction: column; gap: 24px; }
.talk-row { display: grid; grid-template-columns: 56px 62px 1fr auto; gap: 22px; align-items: center; padding: 30px 34px; }
.talk-index { font-family: var(--font-mono); font-size: 1.5rem; font-weight: 700; color: var(--accent-text); opacity: 0.85; }
.talk-icon { width: 62px; height: 62px; border-radius: 17px; display: flex; align-items: center; justify-content: center; background: var(--surface-flat); box-shadow: var(--neu-in); color: var(--accent-text); }
.talk-icon svg { width: 28px; height: 28px; }
.talk-body h3 { font-size: 1.14rem; font-weight: 750; letter-spacing: -0.01em; }
.talk-meta { display: flex; align-items: center; gap: 12px; margin-bottom: 7px; }
.talk-date { font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-3); display: inline-flex; align-items: center; gap: 6px; }
.talk-date svg { width: 13px; height: 13px; }
.talk-body p { margin-top: 8px; color: var(--text-2); font-size: 0.93rem; max-width: 560px; }
.talk-tags { margin-top: 12px; display: flex; flex-wrap: wrap; gap: 8px; }
.talk-action { justify-self: end; }

/* ---------- Research ---------- */
.research-grid { margin-top: 54px; display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 30px; align-items: start; }
.research-card { padding: 36px 38px; }
.research-card h3 { font-size: 1.3rem; font-weight: 780; letter-spacing: -0.01em; }
.research-rows { margin-top: 22px; display: flex; flex-direction: column; gap: 16px; }
.research-row { display: grid; grid-template-columns: 130px 1fr; gap: 16px; }
.research-row h4 { font-family: var(--font-mono); font-size: 0.74rem; font-weight: 700; letter-spacing: 0.14em; text-transform: uppercase; color: var(--text-3); padding-top: 3px; }
.research-row p { color: var(--text-2); font-size: 0.93rem; }
.research-side { display: flex; flex-direction: column; gap: 22px; }
.research-interests { padding: 28px 30px; }
.research-interests h3 { font-size: 1.02rem; font-weight: 750; }
.interest-chips { margin-top: 16px; display: flex; flex-wrap: wrap; gap: 9px; }

/* ---------- Skills ---------- */
.skills-grid { margin-top: 54px; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 26px; }
.skill-card { padding: 30px; }
.skill-head { display: flex; align-items: center; gap: 16px; }
.skill-head .well { width: 52px; height: 52px; }
.skill-head .well svg { width: 24px; height: 24px; }
.skill-head h3 { font-size: 1.04rem; font-weight: 750; line-height: 1.3; }
.tech-tiles { margin-top: 26px; display: grid; grid-template-columns: minmax(0, 1fr); gap: 14px; }
.tech-tile {
  min-width: 0;
  display: flex; align-items: center; gap: 12px; padding: 12px 14px;
  border-radius: var(--rad-sm); background: var(--surface-flat); box-shadow: var(--neu-in);
  transition: transform 0.3s var(--ease);
}
.tech-tile:hover { transform: translateY(-2px); }
.tech-badge {
  width: 38px; height: 38px; border-radius: 11px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono); font-size: 0.68rem; font-weight: 700; color: #fff;
  background: var(--grad); box-shadow: 0 4px 12px rgba(34, 211, 238, 0.25);
}
.tech-info { flex: 1; min-width: 0; }
.tech-info .tn { font-size: 0.86rem; font-weight: 650; color: var(--text-1); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.tech-track { margin-top: 6px; height: 6px; border-radius: 999px; background: var(--bg-2); box-shadow: var(--neu-in); overflow: hidden; }
.tech-fill { height: 100%; width: 0; border-radius: 999px; background: var(--grad); transition: width 1.4s var(--ease); }
.tech-pct { font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-3); flex-shrink: 0; }

/* ---------- Profiles ---------- */
.profiles-grid { margin-top: 54px; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 26px; }
.profile-card { padding: 28px; position: relative; }
.profile-card .well { width: 54px; height: 54px; border-radius: 15px; }
.profile-card .well svg { width: 26px; height: 26px; }
.profile-badge { position: absolute; top: 22px; right: 22px; }
.profile-num { margin-top: 20px; font-family: var(--font-mono); font-size: 2rem; font-weight: 700; letter-spacing: -0.02em; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.profile-num-label { color: var(--text-3); font-size: 0.83rem; }
.profile-card h3 { margin-top: 8px; font-size: 1.06rem; font-weight: 750; }
.profile-link { margin-top: 12px; display: inline-flex; align-items: center; gap: 7px; font-weight: 700; font-size: 0.88rem; }
.profile-link svg { width: 14px; height: 14px; }
.gh-panel { margin-top: 30px; padding: 32px 36px; }
.gh-panel-head { display: flex; align-items: center; justify-content: space-between; gap: 18px; flex-wrap: wrap; }
.gh-panel-head h3 { font-size: 1.1rem; font-weight: 750; display: flex; align-items: center; gap: 12px; }
.gh-panel-head h3 svg { width: 22px; height: 22px; }
.gh-stats { display: flex; gap: 28px; flex-wrap: wrap; }
.gh-stat { text-align: center; }
.gh-stat b { display: block; font-family: var(--font-mono); font-size: 1.3rem; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.gh-stat span { font-size: 0.78rem; color: var(--text-3); }
.contrib-graph { margin-top: 24px; display: grid; grid-template-rows: repeat(7, 1fr); grid-auto-flow: column; gap: 4px; overflow-x: auto; padding-bottom: 6px; }
.contrib-cell { width: 11px; height: 11px; border-radius: 3px; background: var(--cell-0); }
.contrib-cell.l1 { background: var(--cell-1); } .contrib-cell.l2 { background: var(--cell-2); } .contrib-cell.l3 { background: var(--cell-3); }
.contrib-note { margin-top: 12px; font-size: 0.78rem; color: var(--text-3); font-family: var(--font-mono); }

/* ---------- Certifications ---------- */
.cert-grid { margin-top: 54px; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 26px; }
.cert-card { overflow: hidden; display: flex; flex-direction: column; }
.cert-preview {
  height: 150px; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(160deg, rgba(34, 211, 238, 0.1), rgba(129, 140, 248, 0.1)), var(--surface-flat);
  border-bottom: 1px solid var(--border);
}
.cert-preview .well { width: 60px; height: 60px; border-radius: 16px; }
.cert-preview .well svg { width: 28px; height: 28px; }
.cert-body { padding: 22px 24px 24px; flex: 1; display: flex; flex-direction: column; }
.cert-body h3 { font-size: 1rem; font-weight: 750; }
.cert-inst { margin-top: 5px; color: var(--text-2); font-size: 0.88rem; }
.cert-meta { margin-top: 10px; display: flex; flex-direction: column; gap: 3px; font-family: var(--font-mono); font-size: 0.76rem; color: var(--text-3); }
.cert-actions { margin-top: 18px; display: flex; gap: 10px; }

/* ---------- Blog ---------- */
.blog-grid { margin-top: 54px; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 26px; }
.blog-card { padding: 28px; display: flex; flex-direction: column; }
.blog-cat { align-self: flex-start; }
.blog-card h3 { margin-top: 16px; font-size: 1.08rem; font-weight: 750; line-height: 1.4; }
.blog-card p { margin-top: 10px; color: var(--text-2); font-size: 0.91rem; flex: 1; }
.blog-meta { margin-top: 16px; display: flex; align-items: center; justify-content: space-between; font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-3); }
.blog-link { font-weight: 700; font-size: 0.88rem; display: inline-flex; align-items: center; gap: 6px; margin-top: 14px; }
.blog-link svg { width: 14px; height: 14px; }

/* ---------- Testimonials ---------- */
.testi-grid { margin-top: 54px; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 26px; }
.testi-card { padding: 30px; display: flex; flex-direction: column; }
.testi-quote-mark { font-family: Georgia, serif; font-size: 3rem; line-height: 1; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.testi-card blockquote { margin-top: 8px; color: var(--text-2); font-size: 0.95rem; flex: 1; }
.testi-person { margin-top: 20px; display: flex; align-items: center; gap: 13px; }
.testi-avatar { width: 44px; height: 44px; border-radius: 13px; background: var(--grad); color: #fff; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 0.9rem; }
.testi-person b { display: block; font-size: 0.92rem; }
.testi-person span { font-size: 0.8rem; color: var(--text-3); }

/* ---------- Resume ---------- */
.resume-grid { margin-top: 54px; display: grid; grid-template-columns: 1fr 1fr; gap: 30px; align-items: start; }
.resume-col { display: flex; flex-direction: column; gap: 22px; }
.resume-block { padding: 30px 32px; }
.resume-block > h3 { font-size: 1.05rem; font-weight: 750; display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.resume-block > h3 svg { width: 20px; height: 20px; color: var(--accent-text); }
.resume-item { padding: 14px 0; border-top: 1px solid var(--border); }
.resume-item:first-of-type { border-top: none; padding-top: 0; }
.resume-item h4 { font-size: 0.97rem; font-weight: 700; }
.resume-item .ri-sub { color: var(--text-2); font-size: 0.88rem; margin-top: 2px; }
.resume-item .ri-date { font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-3); margin-top: 4px; }
.resume-cta { padding: 30px 32px; display: flex; flex-wrap: wrap; gap: 14px; align-items: center; justify-content: space-between; }
.resume-cta p { color: var(--text-2); font-size: 0.93rem; max-width: 320px; }
.resume-cta .btns { display: flex; gap: 12px; flex-wrap: wrap; }
.lang-rows { display: flex; flex-direction: column; gap: 12px; }
.lang-row { display: flex; align-items: center; justify-content: space-between; }
.lang-row b { font-size: 0.93rem; font-weight: 650; }
.lang-row span { font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-3); }

/* ---------- Contact ---------- */
.contact-grid { margin-top: 54px; display: grid; grid-template-columns: 1fr 1fr; gap: 30px; align-items: start; }
.contact-form { padding: 34px 36px; }
.contact-form h3 { font-size: 1.15rem; font-weight: 750; margin-bottom: 20px; }
.form-row { margin-bottom: 16px; }
.form-row label { display: block; font-size: 0.84rem; font-weight: 650; color: var(--text-2); margin-bottom: 7px; }
.form-input {
  width: 100%; padding: 13px 16px; border-radius: var(--rad-sm);
  background: var(--surface-flat); box-shadow: var(--neu-in); border: 1px solid var(--border);
  color: var(--text-1); font-family: inherit; font-size: 0.93rem; outline: none;
  transition: border-color 0.3s var(--ease);
}
.form-input:focus { border-color: var(--border-hover); }
textarea.form-input { min-height: 130px; resize: vertical; }
.form-note { margin-top: 12px; font-size: 0.8rem; color: var(--text-3); }
.contact-side { display: flex; flex-direction: column; gap: 22px; }
.contact-info { padding: 30px 32px; }
.contact-info h3 { font-size: 1.05rem; font-weight: 750; margin-bottom: 16px; }
.ci-row { display: flex; align-items: center; gap: 14px; padding: 10px 0; }
.ci-row .well { width: 42px; height: 42px; flex-shrink: 0; }
.ci-row .well svg { width: 19px; height: 19px; }
.ci-row b { display: block; font-size: 0.9rem; }
.ci-row span, .ci-row a { font-size: 0.84rem; color: var(--text-3); word-break: break-word; }
.ci-row a:hover { color: var(--accent-text); }
.avail-chips { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 6px; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--border); background: var(--bg-2); padding: 64px 0 34px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; }
.footer h4 { font-size: 0.85rem; font-weight: 750; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-3); margin-bottom: 16px; }
.footer-brand p { color: var(--text-2); font-size: 0.9rem; margin-top: 12px; max-width: 300px; }
.footer-links { list-style: none; display: flex; flex-direction: column; gap: 9px; }
.footer-links a { color: var(--text-2); font-size: 0.9rem; transition: color 0.3s var(--ease); }
.footer-links a:hover { color: var(--accent-text); }
.footer-social { display: flex; gap: 10px; flex-wrap: wrap; }
.footer-bottom {
  margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-3);
}
.back-top { position: fixed; right: 26px; bottom: 26px; z-index: 150; opacity: 0; pointer-events: none; transform: translateY(12px); transition: opacity 0.4s var(--ease), transform 0.4s var(--ease); }
.back-top.show { opacity: 1; pointer-events: auto; transform: none; }

/* ---------- Command palette ---------- */
.palette-overlay {
  position: fixed; inset: 0; z-index: 400; display: none;
  background: rgba(3, 6, 12, 0.55); -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px);
  align-items: flex-start; justify-content: center; padding: 14vh 20px 20px;
}
.palette-overlay.open { display: flex; }
.palette { width: 100%; max-width: 560px; overflow: hidden; border-radius: var(--rad-md); animation: pal-in 0.25s var(--ease); }
@keyframes pal-in { from { opacity: 0; transform: translateY(-14px) scale(0.98); } to { opacity: 1; transform: none; } }
.palette-input-row { display: flex; align-items: center; gap: 12px; padding: 16px 20px; border-bottom: 1px solid var(--border); }
.palette-input-row svg { width: 18px; height: 18px; color: var(--text-3); flex-shrink: 0; }
.palette-input { flex: 1; background: transparent; border: none; outline: none; color: var(--text-1); font-size: 1rem; font-family: inherit; }
.palette-list { max-height: 320px; overflow-y: auto; padding: 8px; }
.palette-item {
  display: flex; align-items: center; gap: 12px; width: 100%; text-align: left;
  padding: 11px 14px; border-radius: 10px; border: none; background: transparent;
  color: var(--text-2); font-size: 0.92rem; font-weight: 600;
}
.palette-item svg { width: 16px; height: 16px; color: var(--text-3); flex-shrink: 0; }
.palette-item.sel, .palette-item:hover { background: var(--chip-bg); color: var(--accent-text); }
.palette-item .pi-kind { margin-left: auto; font-family: var(--font-mono); font-size: 0.7rem; color: var(--text-3); }
.palette-empty { padding: 26px; text-align: center; color: var(--text-3); font-size: 0.9rem; }

/* ---------- Reduced motion ---------- */
@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; }
  .reveal { opacity: 1; transform: none; }
  .code-drift { display: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .hero-inner { grid-template-columns: 1fr; gap: 48px; }
  .about-grid, .research-grid, .resume-grid, .contact-grid { grid-template-columns: 1fr; }
  .skills-grid, .ach-grid, .profiles-grid, .cert-grid, .blog-grid, .testi-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 900px) {
  .nav-links, .kbd-hint { display: none; }
  .burger { display: inline-flex; }
}
@media (max-width: 760px) {
  .section { padding: 80px 0; }
  .wrap { padding: 0 20px; }
  .projects-grid, .skills-grid, .ach-grid, .profiles-grid, .cert-grid, .blog-grid, .testi-grid { grid-template-columns: 1fr; }
  .talk-row { grid-template-columns: 1fr; gap: 14px; padding: 24px; }
  .talk-action { justify-self: start; }
  .research-row { grid-template-columns: 1fr; gap: 4px; }
  .hero-ctas .btn { width: 100%; }
  .hero-id { flex-direction: row; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .tech-tiles { grid-template-columns: 1fr; }
  .gh-stats { gap: 18px; }
}

/* ============================================================
   v3 additions — centered hero, background code, popups,
   simple skill tags, brighter light-mode search, 4-col profiles
   ============================================================ */

/* Centered hero (code box removed) */
.hero-inner { display: block; max-width: 860px; margin: 0 auto; text-align: center; }
.hero-id { justify-content: center; }
.hero-copy, .hero-tagline { margin-left: auto; margin-right: auto; }
.hero-copy { max-width: 640px; }
.hero-ctas, .hero-social { justify-content: center; }

/* Background: code / math / Arduino / Raspberry Pi / ESP32 / C++ touches */
.code-bg { position: fixed; inset: 0; z-index: -1; pointer-events: none; user-select: none; overflow: hidden; }
.code-bg pre {
  position: absolute; font-family: var(--font-mono); font-size: 13px; line-height: 2.2;
  color: var(--accent-text); opacity: 0.055; white-space: pre; margin: 0;
}
[data-theme="light"] .code-bg pre { opacity: 0.09; }
@media (max-width: 900px) { .code-bg pre { font-size: 11px; } }

/* Clickable card affordance */
.card-click { cursor: pointer; }
.card-hint {
  margin-top: 16px; display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font-mono); font-size: 0.76rem; font-weight: 600; color: var(--accent-text);
}
.card-hint svg { width: 14px; height: 14px; flex-shrink: 0; }
.ach-card .card-hint { margin-top: 14px; }
.project-body .card-hint { margin-top: auto; padding-top: 18px; }

/* Skills: simple tag chips (no proficiency bars) */
.skill-tags { margin-top: 24px; display: flex; flex-wrap: wrap; gap: 10px; }

/* Profiles: 4 platforms side by side on wide screens */
@media (min-width: 1081px) { .profiles-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); } }

/* Detail popup */
.modal-overlay {
  position: fixed; inset: 0; z-index: 400; display: none;
  background: rgba(3, 6, 12, 0.6); -webkit-backdrop-filter: blur(7px); backdrop-filter: blur(7px);
  align-items: center; justify-content: center; padding: 24px;
}
.modal-overlay.open { display: flex; }
[data-theme="light"] .modal-overlay { background: rgba(216, 224, 240, 0.6); }
.modal {
  position: relative; width: 100%; max-width: 720px; max-height: 86vh; overflow-y: auto;
  padding: 34px 36px 36px; animation: pal-in 0.25s var(--ease);
}
[data-theme="light"] .modal { background: rgba(255, 255, 255, 0.95); }
.modal-close { position: absolute; top: 16px; right: 16px; }
.modal-kicker { font-family: var(--font-mono); font-size: 0.78rem; font-weight: 700; letter-spacing: 0.16em; text-transform: uppercase; color: var(--accent-text); }
.modal-title { margin-top: 8px; font-size: 1.45rem; font-weight: 800; letter-spacing: -0.01em; line-height: 1.25; padding-right: 44px; }
.modal-meta { margin-top: 14px; display: flex; flex-wrap: wrap; gap: 8px; }
.modal-desc { margin-top: 14px; color: var(--text-2); font-size: 0.97rem; }
.modal .case-rows { margin-top: 20px; border-top: 1px solid var(--border); padding-top: 18px; display: flex; flex-direction: column; gap: 14px; }
.modal-links { margin-top: 22px; display: flex; flex-wrap: wrap; gap: 10px; }
.modal-media { margin-top: 20px; }
.media-switch { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 14px; }
.media-stage img { width: 100%; border-radius: var(--rad-sm); border: 1px solid var(--border); }
.media-stage iframe, .media-stage video { width: 100%; aspect-ratio: 16 / 9; border: 0; border-radius: var(--rad-sm); background: #000; display: block; }
@media (max-width: 760px) { .modal { padding: 26px 22px 28px; max-height: 90vh; } .modal-title { font-size: 1.25rem; } }

/* Search popup: brighter in light mode */
[data-theme="light"] .palette-overlay { background: rgba(222, 230, 244, 0.55); }
[data-theme="light"] .palette { background: rgba(255, 255, 255, 0.96); box-shadow: 0 24px 60px rgba(40, 60, 110, 0.18); }

/* Nav: fit the full ordered menu, collapse to burger earlier */
.nav-links { gap: 2px; }
.nav-links a { padding: 8px 10px; font-size: 0.87rem; }
@media (max-width: 1180px) {
  .nav-links, .kbd-hint { display: none; }
  .burger { display: inline-flex; }
}