/* IITG · Diwali Dhamaka — warm dark, diya amber. */

:root {
  --bg: #16110c;
  --bg-2: #1e1812;
  --surface: #261f17;
  --line: rgba(212, 160, 84, 0.16);
  --line-strong: rgba(212, 160, 84, 0.38);
  --text: #f4ecdf;
  --muted: #b5a893;
  --amber: #d4a054;
  --amber-deep: #b87514;
  --flame: #f2c46b;
  --glow: rgba(212, 160, 84, 0.28);
  --serif: "Instrument Serif", "Iowan Old Style", Georgia, serif;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --radius: 14px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --gutter: clamp(16px, 4vw, 40px);
  /* side padding that lines full-bleed bars up with .wrap content */
  --edge: max(var(--gutter), calc((100vw - 1200px) / 2 + var(--gutter)));
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 1.0625rem/1.65 var(--sans);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
/* film grain */
body::after {
  content: "";
  position: fixed; inset: 0; z-index: 100; pointer-events: none;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
img, video { display: block; max-width: 100%; }
a { color: inherit; }
p { margin: 0 0 1em; }
h1, h2, h3 { font-family: var(--serif); font-weight: 400; line-height: 1; margin: 0 0 0.4em; letter-spacing: -0.01em; }
h1 em, h2 em, h3 em { color: var(--amber); font-style: italic; }
h2 { font-size: clamp(2.4rem, 5.5vw, 4rem); }
:focus-visible { outline: 2px solid var(--flame); outline-offset: 3px; border-radius: 4px; }

.wrap { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 var(--gutter); }
.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
.center { text-align: center; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--amber); color: var(--bg); padding: 8px 14px; border-radius: 8px; z-index: 200; }
.skip:focus { left: 8px; }

.eyebrow {
  font: 600 0.75rem/1.4 var(--sans);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 1.1em;
}
.eyebrow a { text-decoration: none; border-bottom: 1px solid var(--line-strong); }
.lede { font-size: clamp(1.1rem, 1.6vw, 1.3rem); max-width: 36em; color: #e9dfcf; }

/* ---------- buttons & links */
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.btn {
  display: inline-flex; align-items: center; gap: 0.5em;
  padding: 0.85em 1.4em;
  border-radius: 999px;
  font: 600 0.95rem/1 var(--sans);
  text-decoration: none;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s;
}
.btn--amber { background: linear-gradient(180deg, #e2b468, var(--amber) 55%, #c08a3c); color: #1b140d; box-shadow: 0 10px 30px -10px var(--glow); }
.btn--amber:hover { transform: translateY(-2px); box-shadow: 0 16px 40px -12px rgba(212, 160, 84, 0.55); }
.btn--ghost { border: 1px solid var(--line-strong); color: var(--text); background: rgba(22, 17, 12, 0.45); backdrop-filter: blur(6px); }
.btn--ghost:hover { border-color: var(--amber); background: rgba(212, 160, 84, 0.08); }
.arrow-link { color: var(--amber); text-decoration: none; font-weight: 500; }
.arrow-link::after { content: " →"; transition: margin 0.2s; }
.arrow-link:hover::after { margin-left: 4px; }

/* ---------- header */
.site-header {
  position: fixed; inset: 0 0 auto; z-index: 50;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  height: 64px; padding: 0 var(--edge);
  transition: background 0.3s, border-color 0.3s;
  border-bottom: 1px solid transparent;
}
.site-header.is-solid { background: rgba(22, 17, 12, 0.86); backdrop-filter: blur(14px); border-color: var(--line); }
.wordmark { display: flex; align-items: center; gap: 10px; text-decoration: none; font: 400 1.35rem/1 var(--serif); white-space: nowrap; }
.wordmark i { color: var(--amber); font-style: normal; }
.diya { width: 26px; height: 26px; flex: none; }
.site-header nav { display: flex; gap: clamp(12px, 2.4vw, 28px); font: 500 0.9rem/1 var(--sans); }
.site-header nav a { text-decoration: none; color: var(--muted); padding: 6px 0; border-bottom: 1px solid transparent; transition: color 0.2s, border-color 0.2s; white-space: nowrap; }
.site-header nav a:hover, .site-header nav a[aria-current] { color: var(--text); border-color: var(--amber); }

/* ---------- home hero: a moving wall of moments from every year */
.hero { position: relative; min-height: 100svh; display: flex; align-items: flex-end; overflow: hidden; isolation: isolate; }
.wall {
  position: absolute; inset: 0; z-index: -2;
  display: grid; grid-template-rows: repeat(3, minmax(0, 1fr)); gap: 10px;
  padding: 74px 0 10px;
  transform: rotate(-3deg) scale(1.12);
}
.wall-row { display: flex; gap: 10px; width: max-content; height: 100%; min-height: 0; animation: wall var(--dur, 120s) linear infinite; }
.wall-row--rev { animation-direction: reverse; }
@keyframes wall { to { transform: translateX(-50%); } }
.tile { position: relative; height: 100%; aspect-ratio: var(--ar); border-radius: 10px; overflow: hidden; flex: none; background: var(--surface); }
.tile img { width: 100%; height: 100%; object-fit: cover; filter: saturate(0.95); }
.tile b { position: absolute; left: 10px; bottom: 8px; font: 400 1.25rem/1 var(--serif); color: rgba(244, 236, 223, 0.92); text-shadow: 0 1px 8px rgba(0, 0, 0, 0.7); }
.hero-shade {
  position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(70% 60% at 25% 78%, rgba(22, 17, 12, 0.92), rgba(22, 17, 12, 0) 75%),
    linear-gradient(0deg, var(--bg) 0%, rgba(22, 17, 12, 0.78) 32%, rgba(22, 17, 12, 0.35) 65%, rgba(22, 17, 12, 0.7) 100%);
}
.hero-copy { padding-bottom: clamp(56px, 10vh, 110px); padding-top: 140px; }
.hero h1 { font-size: clamp(3.2rem, 8.5vw, 7.2rem); max-width: 11em; text-shadow: 0 4px 40px rgba(0, 0, 0, 0.55); }

/* ---------- sections */
.section { padding: clamp(72px, 11vw, 140px) 0; position: relative; }
.section--tight { padding: clamp(28px, 5vw, 56px) 0; }
.section-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 8px 32px; margin-bottom: 36px; }
.section-head h2 { margin: 0; }
.section-head p { margin: 0; max-width: 34em; }

/* the tradition */
.tradition-grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: clamp(36px, 6vw, 88px); align-items: center; }
.tradition-copy p { color: #e9dfcf; max-width: 32em; }
.collage { position: relative; display: grid; grid-template-columns: repeat(6, 1fr); grid-template-rows: repeat(6, clamp(48px, 6vw, 78px)); }
.collage .ph { border-radius: 12px; overflow: hidden; box-shadow: 0 30px 60px -25px rgba(0, 0, 0, 0.8), 0 0 0 1px var(--line); }
.collage .c1 { grid-column: 1 / 5; grid-row: 1 / 5; z-index: 1; }
.collage .c2 { grid-column: 3 / 7; grid-row: 3 / 7; z-index: 2; }
.collage .c3 { grid-column: 5 / 7; grid-row: 1 / 3; z-index: 3; }
.chip { position: absolute; left: 10px; top: 10px; padding: 4px 10px; border-radius: 999px; background: rgba(22, 17, 12, 0.75); backdrop-filter: blur(4px); font: 600 0.75rem/1.2 var(--sans); letter-spacing: 0.06em; color: var(--flame); }

/* iit guwahati */
.iitg { background: radial-gradient(55% 80% at 80% 30%, rgba(184, 117, 20, 0.14), transparent 70%), var(--bg-2); border-block: 1px solid var(--line); }
.iitg-inner h2 { max-width: 12em; }
.iitg-cols { columns: 2 22em; column-gap: 48px; color: #e9dfcf; max-width: 60em; }
.iitg-cols p { break-inside: avoid; }
.stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; margin: 48px 0 0; border-top: 1px solid var(--line); padding-top: 32px; }
.stats div { margin: 0; }
.stats dt { font: 400 clamp(2.6rem, 5vw, 3.8rem)/1 var(--serif); color: var(--amber); }
.stats dd { margin: 8px 0 0; color: var(--muted); font-size: 0.95rem; }

/* year by year */
.bands { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.band {
  display: grid; grid-template-columns: minmax(130px, 200px) minmax(0, 1fr) minmax(0, 1.5fr); gap: 28px; align-items: center;
  padding: 18px 18px 18px 28px; text-decoration: none;
  border-radius: var(--radius); background: var(--surface); box-shadow: 0 0 0 1px var(--line);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), background 0.35s;
}
.band:hover { transform: translateY(-3px); background: #2c241b; box-shadow: 0 0 0 1px var(--line-strong), 0 24px 50px -26px var(--glow); }
.band-year { font: 400 clamp(3.4rem, 6vw, 5rem)/0.9 var(--serif); transition: color 0.3s; }
.band:hover .band-year { color: var(--amber); }
.band-info { display: grid; gap: 6px; }
.band-meta { color: var(--muted); font-size: 0.85rem; }
.band-line { font: italic 400 1.35rem/1.25 var(--serif); }
.band-label { color: var(--muted); font-size: 0.9rem; }
.band-open { color: var(--amber); font-weight: 500; font-size: 0.92rem; margin-top: 4px; }
.band-open::after { content: " →"; }
.band-strip { display: flex; gap: 8px; height: clamp(96px, 11vw, 140px); justify-content: flex-end; overflow: hidden; border-radius: 10px; }
.band-strip img { height: 100%; width: auto; aspect-ratio: var(--ar); object-fit: cover; border-radius: 8px; flex: 0 1 auto; min-width: 0; transition: transform 0.6s var(--ease); }
.band:hover .band-strip img { transform: scale(1.03); }

/* ---------- film + video players */
.film, .video { margin: 0; }
.film video {
  width: 100%; aspect-ratio: 16 / 9; background: #000; border-radius: var(--radius);
  box-shadow: 0 0 0 1px var(--line-strong), 0 40px 90px -30px rgba(212, 160, 84, 0.35);
}
figcaption { display: flex; flex-wrap: wrap; gap: 4px 12px; align-items: baseline; margin-top: 14px; font-size: 0.92rem; }
figcaption strong { font: italic 400 1.3rem/1.2 var(--serif); }
figcaption span { color: var(--muted); }
.theme { font-size: 0.9rem; color: var(--muted); margin: 1.4em 0; }
.theme span { display: block; font: italic 400 1.5rem/1.2 var(--serif); color: var(--text); margin-top: 4px; }

.yt {
  position: relative; display: block; width: 100%; aspect-ratio: 16 / 9; padding: 0; border: 0; cursor: pointer;
  border-radius: var(--radius); overflow: hidden; background: #000;
  box-shadow: 0 0 0 1px var(--line);
}
.yt img { width: 100%; height: 100%; object-fit: cover; opacity: 0.82; transition: transform 0.6s var(--ease), opacity 0.3s; }
.yt:hover img { transform: scale(1.03); opacity: 1; }
.yt .play {
  position: absolute; left: 50%; top: 50%; translate: -50% -50%;
  width: 72px; height: 72px; border-radius: 50%;
  display: grid; place-items: center;
  background: rgba(22, 17, 12, 0.55); border: 1px solid rgba(242, 196, 107, 0.7); backdrop-filter: blur(4px);
  transition: transform 0.3s var(--ease), background 0.3s;
}
.yt .play svg { width: 30px; height: 30px; fill: var(--flame); margin-left: 4px; }
.yt:hover .play { transform: scale(1.08); background: rgba(212, 160, 84, 0.9); }
.yt:hover .play svg { fill: #1b140d; }
.duration { position: absolute; right: 10px; bottom: 10px; padding: 3px 8px; border-radius: 6px; background: rgba(0, 0, 0, 0.7); font: 600 0.75rem/1.2 var(--sans); }
.video iframe { width: 100%; aspect-ratio: 16 / 9; border: 0; border-radius: var(--radius); background: #000; }

.videos { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 40px 28px; }
.videos > :first-child { grid-column: 1 / -1; }
.videos--one { max-width: 980px; }

/* ---------- photos */
.ph { display: block; position: relative; background: var(--surface); cursor: zoom-in; }
.ph img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.7s var(--ease), filter 0.3s; }
.ph:hover img { transform: scale(1.04); filter: brightness(1.08); }

.gallery { display: flex; flex-wrap: wrap; gap: 8px; }
.gallery::after { content: ""; flex-grow: 999999; }
.gallery .ph { flex-grow: calc(var(--ar) * 100); flex-basis: calc(var(--ar) * 175px); aspect-ratio: var(--ar); border-radius: 6px; overflow: hidden; }

.moments { display: flex; flex-wrap: wrap; gap: 14px; }
.moments::after { content: ""; flex-grow: 999999; }
.moment { margin: 0; flex-grow: calc(var(--ar, 1.6) * 100); flex-basis: calc(var(--ar, 1.6) * 230px); display: flex; flex-direction: column; }
.moment .ph { aspect-ratio: var(--ar); border-radius: 10px; overflow: hidden; }
.moment figcaption { margin-top: 10px; color: var(--muted); font: italic 400 1.1rem/1.3 var(--serif); }

.tabs { display: inline-flex; gap: 6px; padding: 5px; border-radius: 999px; background: var(--surface); box-shadow: 0 0 0 1px var(--line); margin-bottom: 24px; flex-wrap: wrap; }
.tabs button { font: 500 0.92rem/1 var(--sans); color: var(--muted); background: none; border: 0; border-radius: 999px; padding: 10px 18px; cursor: pointer; }
.tabs button span { font-size: 0.8em; margin-left: 4px; opacity: 0.75; }
.tabs button[aria-selected="true"] { background: var(--amber); color: #1b140d; }
.empty, .ask { padding: 40px; border-radius: var(--radius); border: 1px dashed var(--line-strong); color: var(--muted); max-width: 720px; }
.empty a, .ask a { color: var(--amber); }
.ask h2, .ask h1 { color: var(--text); }

/* ---------- join */
.join { background: radial-gradient(50% 60% at 50% 0%, rgba(212, 160, 84, 0.18), transparent 70%); border-top: 1px solid var(--line); }
.join-inner { text-align: center; max-width: 720px; }
.join-inner p { margin-left: auto; margin-right: auto; max-width: 34em; }
.diya--big { width: 64px; height: 64px; margin: 0 auto 20px; filter: drop-shadow(0 0 22px rgba(242, 196, 107, 0.6)); }
.join .btn { margin-top: 12px; }
.join-who { margin: 12px auto 28px; }
.join-inner a:not(.btn) { color: var(--amber); }
.chat-icon { width: 18px; height: 18px; color: currentColor; flex: none; }

/* ---------- year pages */
.year-hero { position: relative; padding: 150px 0 40px; overflow: hidden; isolation: isolate; }
.year-hero-bg { position: absolute; inset: -40px; z-index: -1; background-size: cover; background-position: center; filter: blur(36px) saturate(1.2); opacity: 0.4; }
.year-hero::after { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(0deg, var(--bg), rgba(22, 17, 12, 0.55)); }
.year-title { font-size: clamp(6rem, 20vw, 13rem); line-height: 0.85; margin-bottom: 0.15em; }
.year-meta { font-size: 1.05rem; color: var(--text); }
.year-nav { display: flex; justify-content: space-between; gap: 16px; padding-top: 24px; padding-bottom: 96px; border-top: 1px solid var(--line); margin-top: 24px; }
.year-step { display: grid; text-decoration: none; font: 400 2.4rem/1 var(--serif); gap: 4px; }
.year-step .small { font-family: var(--sans); letter-spacing: 0.12em; text-transform: uppercase; font-size: 0.72rem; }
.year-step--older { text-align: right; }
.year-step:hover > span:last-child { color: var(--amber); }

/* ---------- footer */
.site-footer { border-top: 1px solid var(--line); padding: 56px 0 40px; background: #120e0a; font-size: 0.95rem; }
.footer-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px 48px; }
.footer-mark { font: 400 1.6rem/1 var(--serif); margin-bottom: 12px; }
.footer-mark i { color: var(--amber); font-style: normal; }
/* Small credit, bottom right. The logo's "ADAM" is 345/753 of its height and sits 257.5/753 above
   its bottom edge, so 1.59em tall puts the letters at the text's cap height, and -0.545em drops
   the image so the letters share the text's baseline. */
.made-by { grid-column: 1 / -1; border-top: 1px solid var(--line); padding-top: 18px; margin: 0; text-align: right; font-size: 0.75rem; line-height: 1; }
.made-by a { text-decoration: none; color: var(--muted); opacity: 0.75; letter-spacing: 0.02em; transition: opacity 0.2s; white-space: nowrap; }
.made-by img { display: inline; height: 1.59em; width: auto; vertical-align: -0.545em; margin-left: 0.35em; }
.made-by a:hover { opacity: 1; }

/* ---------- lightbox */
.lb { position: fixed; inset: 0; z-index: 300; background: rgba(12, 9, 6, 0.96); display: grid; place-items: center; }
.lb[hidden] { display: none; }
.lb-img { max-width: 94vw; max-height: 82vh; object-fit: contain; border-radius: 6px; box-shadow: 0 30px 80px rgba(0, 0, 0, 0.6); }
.lb button { position: absolute; background: rgba(38, 31, 23, 0.8); color: var(--text); border: 1px solid var(--line-strong); border-radius: 50%; width: 52px; height: 52px; font-size: 1.6rem; line-height: 1; cursor: pointer; display: grid; place-items: center; }
.lb button:hover { background: var(--amber); color: #1b140d; }
.lb-close { top: 16px; right: 16px; }
.lb-prev { left: 16px; top: 50%; translate: 0 -50%; }
.lb-next { right: 16px; top: 50%; translate: 0 -50%; }
.lb-info { position: absolute; bottom: 14px; left: 80px; right: 80px; text-align: center; margin: 0; font-size: 0.85rem; color: var(--muted); }
.lb-caption { color: var(--text); }
html.lb-open { overflow: hidden; }

/* ---------- reveal on scroll */
.js .reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.9s var(--ease), transform 0.9s var(--ease); }
.js .reveal.in { opacity: 1; transform: none; }

/* ---------- responsive */
@media (max-width: 960px) {
  .tradition-grid { grid-template-columns: 1fr; }
  .band { grid-template-columns: auto minmax(0, 1fr); padding: 18px; gap: 14px 20px; }
  .band-strip { grid-column: 1 / -1; justify-content: flex-start; height: 110px; }
  .footer-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  body { font-size: 1rem; }
  .site-header { height: 56px; }
  .wordmark { font-size: 1.15rem; gap: 8px; }
  .diya { width: 22px; height: 22px; }
  .site-header nav { gap: 14px; font-size: 0.85rem; }
  .site-header nav a:nth-child(4) { display: none; }
  .wall { padding-top: 60px; gap: 8px; }
  .wall-row { gap: 8px; }
  .tile b { font-size: 1rem; }
  .videos { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr; gap: 18px; }
  .band-year { font-size: 3rem; }
  .band-line { font-size: 1.15rem; }
  .band-strip { height: 84px; }
  .gallery .ph { flex-basis: calc(var(--ar) * 130px); }
  .moment { flex-basis: calc(var(--ar, 1.6) * 150px); }
  .empty, .ask { padding: 24px; }
  .lb button { width: 44px; height: 44px; }
  .lb-prev, .lb-next { top: auto; bottom: 8px; translate: none; }
  .lb-info { bottom: 62px; left: 16px; right: 16px; }
}
@media (max-width: 440px) {
  .wordmark span { font-size: 1.05rem; }
  .site-header nav a:nth-child(1) { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal { opacity: 1; transform: none; transition: none; }
  .wall-row { animation: none; }
  * { transition-duration: 0.01ms !important; }
}