/* ============================================================
   Srivathsan Venkateswaran — portfolio
   Concept: an Indian transit network. Station-board hero,
   departures-board nav, four colored lines for four facets.
   ============================================================ */

:root {
  --paper: #f7f6f2;
  --ink: #15191d;
  --muted: #5c6670;
  --hairline: #e2dfd7;
  --surface: #ffffff;
  --night: #14181c;
  --night-soft: #1e242b;
  --night-edge: transparent;
  --board-yellow: #f2c230;
  --board-ink: #15191d;

  --blue: #1e66e5;
  --amber: #e6a144;
  --amber-text: #a06817;
  --green: #148a5b;
  --magenta: #b23a9c;

  --font-display: "Archivo", system-ui, sans-serif;
  --font-body: "IBM Plex Sans", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;

  --rail-w: 6px;
  --content-pad: clamp(1.5rem, 6vw, 5rem);
}

/* Dark mode: follows the system by default, overridable via the
   night-service toggle. Old browsers without light-dark() stay light. */
@supports (color: light-dark(#fff, #000)) {
  :root {
    color-scheme: light dark;
    --paper: light-dark(#f7f6f2, #101418);
    --ink: light-dark(#15191d, #edf0f2);
    --muted: light-dark(#5c6670, #96a1ac);
    --hairline: light-dark(#e2dfd7, #262d35);
    --surface: light-dark(#ffffff, #171d23);
    --night-edge: light-dark(transparent, #2a323b);
    --blue: light-dark(#1e66e5, #5b96ff);
    --amber: light-dark(#e6a144, #eeb15e);
    --amber-text: light-dark(#a06817, #eeb15e);
    --green: light-dark(#148a5b, #2fbd84);
    --magenta: light-dark(#b23a9c, #d566c1);
    --post: light-dark(#15191d, #49535e);
  }
  :root[data-theme="light"] { color-scheme: light; }
  :root[data-theme="dark"] { color-scheme: dark; }
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: 5rem; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--board-yellow); color: #15191d; }

a { color: inherit; }

:focus-visible {
  outline: 3px dashed var(--ink);
  outline-offset: 3px;
  border-radius: 2px;
}

h2 {
  font-family: var(--font-display);
  font-variation-settings: "wdth" 112;
  font-weight: 800;
  font-size: clamp(2.2rem, 5.5vw, 3.6rem);
  line-height: 1.05;
  letter-spacing: -0.01em;
  text-transform: uppercase;
}

h3 {
  font-family: var(--font-display);
  font-variation-settings: "wdth" 105;
  font-weight: 700;
  font-size: 1.2rem;
  line-height: 1.3;
}

/* ---------------- header ---------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem var(--content-pad);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--hairline);
}

.roundel {
  position: relative;
  display: grid;
  place-items: center;
  width: 2.6rem;
  height: 2.6rem;
  text-decoration: none;
  border-radius: 50%;
}

.roundel-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: conic-gradient(var(--blue) 0 25%, var(--amber) 0 50%, var(--green) 0 75%, var(--magenta) 0 100%);
  -webkit-mask: radial-gradient(farthest-side, transparent calc(100% - 5px), #000 calc(100% - 4px));
  mask: radial-gradient(farthest-side, transparent calc(100% - 5px), #000 calc(100% - 4px));
}

.roundel-text {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 0.85rem;
  letter-spacing: 0.02em;
}

.line-nav {
  display: flex;
  align-items: center;
  gap: clamp(0.6rem, 2vw, 1.4rem);
  flex-wrap: wrap;
}

.line-nav a {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  text-decoration: none;
  color: var(--muted);
  padding: 0.35rem 0.15rem;
  border-bottom: 2px solid transparent;
}

.line-nav a:hover, .line-nav a[aria-current="true"] { color: var(--ink); }
.line-nav a[data-line="blue"][aria-current="true"] { border-bottom-color: var(--blue); }
.line-nav a[data-line="amber"][aria-current="true"] { border-bottom-color: var(--amber); }
.line-nav a[data-line="green"][aria-current="true"] { border-bottom-color: var(--green); }
.line-nav a[data-line="magenta"][aria-current="true"] { border-bottom-color: var(--magenta); }

.dot {
  width: 0.6rem;
  height: 0.6rem;
  border-radius: 50%;
  flex: none;
  display: inline-block;
}

[data-line="blue"] .dot { background: var(--blue); }
[data-line="amber"] .dot { background: var(--amber); }
[data-line="green"] .dot { background: var(--green); }
[data-line="magenta"] .dot { background: var(--magenta); }

.nav-contact {
  border: 1.5px solid var(--ink);
  border-radius: 999px;
  padding: 0.35rem 0.9rem !important;
  color: var(--ink) !important;
}

.nav-contact:hover { background: var(--ink); color: var(--paper) !important; }

.theme-toggle {
  display: grid;
  place-items: center;
  width: 2.2rem;
  height: 2.2rem;
  font-size: 1rem;
  line-height: 1;
  color: var(--ink);
  background: none;
  border: 1.5px solid var(--ink);
  border-radius: 50%;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}

.theme-toggle:hover { background: var(--ink); color: var(--paper); }

/* ---------------- hero ---------------- */

.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: clamp(3rem, 8vh, 5.5rem) var(--content-pad) 4.5rem;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--muted);
}

/* — the station name board — */

.signpost { margin-top: 2.2rem; }

.board {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.15rem;
  background: var(--board-yellow);
  color: var(--board-ink);
  border: 4px solid var(--board-ink);
  border-radius: 16px;
  padding: clamp(1.4rem, 4vw, 2.2rem) clamp(1.8rem, 6vw, 4rem);
  box-shadow: 0 14px 34px -18px rgba(21, 25, 29, 0.45);
}

.board-tamil {
  font-family: "Noto Sans Tamil", var(--font-body);
  font-weight: 700;
  font-size: clamp(1rem, 2.4vw, 1.4rem);
}

.board-hindi {
  font-family: "Noto Sans Devanagari", var(--font-body);
  font-weight: 700;
  font-size: clamp(0.95rem, 2.2vw, 1.3rem);
}

.board-name {
  font-family: var(--font-display);
  font-variation-settings: "wdth" 118;
  font-weight: 900;
  font-size: clamp(2.6rem, 9vw, 5.4rem);
  line-height: 1.02;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.board-surname {
  font-family: var(--font-display);
  font-variation-settings: "wdth" 118;
  font-weight: 800;
  font-size: clamp(1.15rem, 3.8vw, 2.2rem);
  line-height: 1.1;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.board-meta {
  margin-top: 0.9rem;
  padding-top: 0.7rem;
  border-top: 2px solid var(--board-ink);
  font-family: var(--font-mono);
  font-size: clamp(0.62rem, 1.6vw, 0.8rem);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
}

.board-legs {
  display: flex;
  justify-content: space-between;
  padding: 0 18%;
}

.board-legs span {
  width: 12px;
  height: 52px;
  background: var(--post, #15191d);
  border-radius: 0 0 3px 3px;
}

.hero-intro {
  max-width: 62ch;
  margin-top: 2.6rem;
  font-size: 1.1rem;
  color: var(--ink);
  text-wrap: pretty;
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.6rem;
  margin-top: 1.8rem;
  list-style: none;
}

.hero-links a {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 500;
  text-decoration: none;
  padding: 0.45rem 1rem;
  border: 1.5px solid var(--ink);
  border-radius: 999px;
  transition: background 0.15s ease, color 0.15s ease;
}

.hero-links a:hover { background: var(--ink); color: var(--paper); }

/* — departures board — */

.departures {
  width: min(100%, 46rem);
  margin-top: 3.5rem;
  background: var(--night);
  border: 1px solid var(--night-edge);
  border-radius: 14px;
  padding: 1.1rem 1.1rem 0.6rem;
  text-align: left;
  box-shadow: 0 24px 48px -28px rgba(21, 25, 29, 0.55);
}

.departures-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0 0.9rem 0.8rem;
  border-bottom: 1px solid #2a323b;
}

.departures-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.28em;
  color: var(--board-yellow);
}

.departures-clock {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #8a94a0;
  font-variant-numeric: tabular-nums;
}

.departures-rows { display: flex; flex-direction: column; }

.dep-row {
  display: grid;
  grid-template-columns: 6.5rem 1fr 6.5rem 8.5rem;
  align-items: center;
  gap: 0.8rem;
  width: 100%;
  padding: 0.75rem 0.9rem;
  background: none;
  border: none;
  border-bottom: 1px solid #22282f;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--board-yellow);
  text-align: left;
  cursor: pointer;
  transition: background 0.15s ease;
}

.dep-row:last-child { border-bottom: none; }
.dep-row:hover { background: var(--night-soft); }

.dep-line { display: inline-flex; align-items: center; gap: 0.5rem; }
.dep-dest { color: #f3f5f7; }
.dep-since { color: #8a94a0; }
.dep-status { display: inline-flex; align-items: center; gap: 0.45rem; justify-self: end; }

.pulse {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: #4ade80;
  animation: pulse 1.6s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.25; }
}

/* ---------------- line sections ---------------- */

.line-section {
  --line: var(--ink);
  position: relative;
  padding: clamp(3.5rem, 9vh, 6rem) var(--content-pad);
  padding-left: calc(var(--content-pad) + 2rem);
  border-top: 1px solid var(--hairline);
}

.line-section[data-line="blue"] { --line: var(--blue); }
.line-section[data-line="amber"] { --line: var(--amber); }
.line-section[data-line="green"] { --line: var(--green); }
.line-section[data-line="magenta"] { --line: var(--magenta); }

/* the continuous route rail */
.line-section::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(var(--content-pad) - 0.5rem);
  width: var(--rail-w);
  background: var(--line);
  border-radius: 999px;
}

.station-head { position: relative; max-width: 46rem; }

/* station marker sitting on the rail */
.station-marker {
  position: absolute;
  top: 0.4rem;
  left: calc(-2.5rem + var(--rail-w) / 2 - 0.5rem - 9px);
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--paper);
  border: 5px solid var(--line);
}

.line-label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.24em;
  color: var(--line);
}

.station-head h2 { margin-top: 0.5rem; }

.section-lede {
  margin-top: 1.1rem;
  font-size: 1.08rem;
  color: var(--muted);
  text-wrap: pretty;
}

/* ---------------- timeline stops ---------------- */

.timeline, .story-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(19rem, 1fr));
  gap: 1.2rem;
  margin-top: 2.6rem;
  max-width: 60rem;
}

.stop {
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-left: 4px solid var(--line, var(--ink));
  border-radius: 10px;
  padding: 1.4rem 1.5rem;
}

.stop-when {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted);
  margin: 0.35rem 0 0.7rem;
}

/* ---------------- project cards ---------------- */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16.5rem, 1fr));
  gap: 1.2rem;
  margin-top: 2rem;
  max-width: 60rem;
}

.card-grid.two { grid-template-columns: repeat(auto-fit, minmax(20rem, 1fr)); }

.project-card {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-top: 4px solid var(--line, var(--ink));
  border-radius: 10px;
  padding: 1.4rem 1.5rem;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.project-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 16px 32px -20px rgba(21, 25, 29, 0.35);
}

.project-card h3 a { text-decoration: none; }
.project-card h3 a:hover { text-decoration: underline; text-decoration-color: var(--line); text-decoration-thickness: 3px; }

.project-card p { font-size: 0.95rem; color: var(--muted); }

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  list-style: none;
  margin-top: auto;
}

.chips li {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--hairline);
  border-radius: 4px;
  color: var(--muted);
  background: var(--paper);
}

.interchange {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.7rem !important;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.interchange[data-line="blue"] { color: var(--blue) !important; }
.interchange[data-line="amber"] { color: var(--amber-text) !important; }
.interchange[data-line="magenta"] { color: var(--magenta) !important; }

/* the badge's own line color beats the section's, regardless of source order */
.interchange[data-line="blue"] .dot { background: var(--blue); }
.interchange[data-line="amber"] .dot { background: var(--amber); }
.interchange[data-line="magenta"] .dot { background: var(--magenta); }

/* ---------------- featured card (Burrito) ---------------- */

.featured-card {
  max-width: 60rem;
  margin-top: 2.4rem;
  background: var(--night);
  color: #f3f5f7;
  border-radius: 14px;
  border: 1px solid var(--night-edge);
  border-top: 4px solid var(--amber);
  padding: clamp(1.6rem, 4vw, 2.4rem);
  box-shadow: 0 28px 56px -32px rgba(21, 25, 29, 0.6);
}

.featured-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--amber);
}

.featured-card h3 {
  margin-top: 0.7rem;
  font-size: clamp(1.4rem, 3vw, 1.9rem);
}

.featured-card h3 a { text-decoration: none; }
.featured-card h3 a:hover { text-decoration: underline; text-decoration-color: var(--amber); text-decoration-thickness: 3px; }

.featured-card > p { margin-top: 0.8rem; max-width: 58ch; color: #aeb7c0; }

.featured-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 2.2rem;
  list-style: none;
  margin-top: 1.6rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #8a94a0;
}

.featured-stats strong {
  display: block;
  font-family: var(--font-display);
  font-variation-settings: "wdth" 110;
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--board-yellow);
  letter-spacing: 0;
}

.featured-links { display: flex; gap: 1.4rem; margin-top: 1.6rem; }

.featured-links a {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--board-yellow);
  text-decoration: none;
  border-bottom: 1.5px solid transparent;
}

.featured-links a:hover { border-bottom-color: var(--board-yellow); }

/* ---------------- travel marquee ---------------- */

.marquee {
  margin-top: 2.4rem;
  overflow: hidden;
  border-block: 1px solid var(--hairline);
  padding: 0.8rem 0;
  max-width: 60rem;
  -webkit-mask: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
  mask: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
}

.marquee-track {
  display: flex;
  width: max-content;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.22em;
  color: var(--green);
  animation: marquee 44s linear infinite;
}

@keyframes marquee {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* ---------------- legend ---------------- */

.legend {
  max-width: 60rem;
  margin-top: 2.4rem;
  border: 1.5px solid var(--ink);
  border-radius: 10px;
  padding: 1.4rem 1.6rem;
  background: var(--surface);
}

.legend-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--muted);
}

.legend-groups {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 1rem 2rem;
  margin-top: 1.1rem;
}

.legend-groups dt {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.legend-groups dd { font-size: 0.92rem; color: var(--muted); margin-top: 0.2rem; }

/* ---------------- terminus ---------------- */

.terminus {
  background: var(--night);
  border-top: 1px solid var(--night-edge);
  color: #f3f5f7;
  text-align: center;
  padding: clamp(4rem, 12vh, 7rem) var(--content-pad) 3rem;
}

.terminus .line-label {
  color: var(--board-yellow);
}

.terminus h2 {
  margin-top: 0.8rem;
  font-size: clamp(2.6rem, 7vw, 4.6rem);
  font-variation-settings: "wdth" 118;
  font-weight: 900;
}

.terminus-lede {
  max-width: 48ch;
  margin: 1.4rem auto 0;
  color: #aeb7c0;
  text-wrap: pretty;
}

.cta {
  display: inline-block;
  margin-top: 2.2rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  text-decoration: none;
  color: #15191d;
  background: var(--board-yellow);
  border-radius: 999px;
  padding: 0.85rem 2rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -12px rgba(242, 194, 48, 0.55);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.6rem;
  list-style: none;
  margin-top: 3rem;
}

.footer-links a {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #8a94a0;
  text-decoration: none;
}

.footer-links a:hover { color: var(--board-yellow); }

.colophon {
  margin-top: 3rem;
  font-size: 0.82rem;
  color: #5c6670;
}

.colophon a { color: inherit; }

/* ---------------- motion ---------------- */

.load-reveal, .observe {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.load-reveal.in, .observe.in { opacity: 1; transform: none; }

.load-reveal:nth-child(1) { transition-delay: 0.05s; }
.load-reveal:nth-child(2) { transition-delay: 0.15s; }
.load-reveal:nth-child(3) { transition-delay: 0.3s; }
.load-reveal:nth-child(4) { transition-delay: 0.4s; }
.load-reveal:nth-child(5) { transition-delay: 0.5s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .load-reveal, .observe { opacity: 1; transform: none; transition: none; }
  .marquee-track { animation: none; }
  .pulse { animation: none; }
  .project-card, .cta { transition: none; }
}

/* ---------------- responsive ---------------- */

@media (max-width: 720px) {
  :root { --rail-w: 4px; --content-pad: 1.25rem; }

  .line-section { padding-left: calc(var(--content-pad) + 1.6rem); }
  .line-section::before { left: 0.6rem; }
  .station-marker {
    left: calc(-1.6rem - 0.65rem + var(--rail-w) / 2 - 2px);
    width: 16px;
    height: 16px;
    border-width: 4px;
  }

  .dep-row { grid-template-columns: 4.6rem 1fr 6.8rem; font-size: 0.74rem; }
  .dep-since { display: none; }

  .signpost { max-width: 100%; }
  .board { padding: 1.2rem 1rem 1.3rem; border-width: 3px; }
  .board-name { font-size: clamp(1.8rem, 10vw, 2.6rem); }
  .board-surname { font-size: clamp(0.9rem, 4.4vw, 1.15rem); letter-spacing: 0.08em; }
  .board-meta { font-size: 0.55rem; letter-spacing: 0.08em; }
  .board-legs span { height: 36px; }

  .line-nav a span.dot { display: none; }
  .line-nav { gap: 0.7rem; }
}