/* ==========================================================================
   Kelvin Chandra Djayapranata — academic portfolio
   Single stylesheet, no frameworks, no external fonts, no JS.
   ========================================================================== */

/* --- Design tokens ------------------------------------------------------- */

:root {
  --bg:          #ffffff;
  --surface:     #f6f8f9;
  --surface-2:   #eef2f4;
  --text:        #131c24;
  --muted:       #55656f;
  --border:      #dfe6ea;
  --accent:      #0d6b6b;
  --accent-ink:  #0a5454;
  --accent-soft: #e6f2f2;

  --radius:     10px;
  --maxw:       72rem;
  --measure:    68ch;

  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto,
          "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
          "Liberation Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:          #0f1418;
    --surface:     #161d23;
    --surface-2:   #1c242b;
    --text:        #e5edf2;
    --muted:       #98a7b3;
    --border:      #27323b;
    --accent:      #52cfc4;
    --accent-ink:  #7ee0d6;
    --accent-soft: #123234;
  }
}

/* --- Reset --------------------------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }

h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5em; font-weight: 650; letter-spacing: -0.011em; }
h1 { font-size: clamp(1.85rem, 1.2rem + 2.6vw, 2.6rem); }
h2 { font-size: clamp(1.3rem, 1.05rem + 1.1vw, 1.6rem); margin-top: 2.4em; }
h3 { font-size: 1.1rem; margin-top: 1.8em; }

p, ul, ol { margin: 0 0 1.1em; }
ul, ol { padding-left: 1.3em; }
li { margin-bottom: .35em; }

a { color: var(--accent-ink); text-underline-offset: 2px; }
a:hover { color: var(--accent); }

@media (prefers-color-scheme: dark) { a { color: var(--accent); } }

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

hr { border: 0; border-top: 1px solid var(--border); margin: 2.5em 0; }

code {
  font-family: var(--mono);
  font-size: .875em;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: .08em .38em;
  word-break: break-word;
}

/* --- Layout -------------------------------------------------------------- */

.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: clamp(1.1rem, 4vw, 2rem);
}

.prose { max-width: var(--measure); }

main { display: block; padding-block: 2.6rem 4rem; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #fff;
  padding: .7rem 1.1rem;
  z-index: 100;
  border-radius: 0 0 var(--radius) 0;
  font-weight: 600;
}
.skip-link:focus { left: 0; color: #fff; }

/* --- Header / navigation ------------------------------------------------- */

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 20;
}

.site-header__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5rem 1.4rem;
  padding-block: .85rem;
}

.brand {
  font-weight: 650;
  font-size: 1.02rem;
  letter-spacing: -0.012em;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
}
.brand:hover { color: var(--accent); }

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: .3rem .25rem;
  margin-left: auto;
}

.site-nav a {
  display: block;
  padding: .34rem .7rem;
  border-radius: 7px;
  font-size: .92rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
}
.site-nav a:hover { background: var(--surface-2); color: var(--text); }

.site-nav a[aria-current="page"] {
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-weight: 600;
}
@media (prefers-color-scheme: dark) {
  .site-nav a[aria-current="page"] { color: var(--accent); }
}

/* --- Hero ---------------------------------------------------------------- */

.hero { padding-block: 2.2rem 1rem; }

/* Name and portrait share a single row. The portrait stays small so the name
   remains the dominant element; the name is allowed to wrap to several lines
   rather than push the photo onto its own row. */
.hero__name {
  display: flex;
  align-items: center;
  gap: clamp(.7rem, 2.2vw, 1.25rem);
  margin-bottom: .9em;
}
.hero__name h1 {
  min-width: 0;
  margin-bottom: 0;
}

.hero__photo {
  flex: 0 0 auto;
  width: auto;
  height: clamp(3.25rem, 6vw, 4.5rem);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

.eyebrow {
  font-size: .82rem;
  font-weight: 650;
  letter-spacing: .07em;
  text-transform: uppercase;
  color: var(--accent-ink);
  margin: 0 0 .7em;
}
@media (prefers-color-scheme: dark) { .eyebrow { color: var(--accent); } }

.lede {
  font-size: clamp(1.02rem, .96rem + .3vw, 1.16rem);
  color: var(--text);
  max-width: var(--measure);
}

.muted { color: var(--muted); }
.small { font-size: .89rem; }

/* --- Section headings ---------------------------------------------------- */

.section-title {
  font-size: .83rem;
  font-weight: 700;
  letter-spacing: .075em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 1rem;
  padding-bottom: .5rem;
  border-bottom: 1px solid var(--border);
}

/* --- Cards & grid -------------------------------------------------------- */

.grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr));
}

.card {
  display: flex;
  flex-direction: column;
  gap: .4rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.15rem 1.25rem;
}

.card--link {
  text-decoration: none;
  color: inherit;
  transition: border-color .15s ease, background .15s ease;
}
.card--link:hover {
  border-color: var(--accent);
  background: var(--surface-2);
  color: inherit;
}
.card--link:hover .card__title { color: var(--accent); }

.card__title { font-weight: 650; font-size: 1rem; margin: 0; }
.card__desc  { font-size: .92rem; color: var(--muted); margin: 0; line-height: 1.6; }

/* --- Panel --------------------------------------------------------------- */

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 1.15rem 1.35rem;
  margin-block: 1.6rem;
}
.panel > :last-child { margin-bottom: 0; }
.panel h2, .panel h3 { margin-top: 0; }

/* --- Badges -------------------------------------------------------------- */

.badge {
  display: inline-block;
  font-size: .76rem;
  font-weight: 650;
  letter-spacing: .03em;
  padding: .2rem .55rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  white-space: nowrap;
}
@media (prefers-color-scheme: dark) { .badge { color: var(--accent); } }

.badge--quiet {
  background: var(--surface-2);
  color: var(--muted);
}

.badge-row { display: flex; flex-wrap: wrap; gap: .4rem; margin-bottom: .8rem; }

/* --- Definition list ----------------------------------------------------- */

.facts {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: .45rem 1.2rem;
  margin: 1.2rem 0;
  font-size: .93rem;
}
.facts dt { color: var(--muted); font-weight: 500; }
.facts dd { margin: 0; }

@media (max-width: 34rem) {
  .facts { grid-template-columns: 1fr; gap: .1rem; }
  .facts dd { margin-bottom: .6rem; }
}

/* --- Table --------------------------------------------------------------- */

.table-wrap { overflow-x: auto; margin-block: 1.3rem; }

table {
  border-collapse: collapse;
  width: 100%;
  font-size: .9rem;
  min-width: 30rem;
}
th, td {
  text-align: left;
  padding: .6rem .8rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
th {
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .055em;
  color: var(--muted);
  font-weight: 650;
  border-bottom-width: 2px;
}
tbody tr:last-child td { border-bottom: 0; }

/* --- Lists --------------------------------------------------------------- */

.list-plain { list-style: none; padding-left: 0; }
.list-plain li {
  padding-left: 1.15rem;
  position: relative;
}
.list-plain li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: .38rem;
  height: .38rem;
  border-radius: 50%;
  background: var(--accent);
  opacity: .55;
}

.list-check { list-style: none; padding-left: 0; }
.list-check li {
  padding-left: 1.5rem;
  position: relative;
}
.list-check li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* --- Buttons ------------------------------------------------------------- */

.btn-row { display: flex; flex-wrap: wrap; gap: .6rem; margin-top: 1.4rem; }

.btn {
  display: inline-block;
  padding: .55rem 1.05rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  font-size: .92rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--text);
}
.btn:hover { border-color: var(--accent); color: var(--accent); }

.btn--primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn--primary:hover { background: var(--accent-ink); border-color: var(--accent-ink); color: #fff; }
@media (prefers-color-scheme: dark) {
  .btn--primary { color: #0c1116; }
  .btn--primary:hover { color: #0c1116; }
}

/* --- Footer -------------------------------------------------------------- */

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding-block: 2rem;
  font-size: .89rem;
  color: var(--muted);
}
.site-footer p { margin: 0 0 .45em; }
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--accent); }
.footer-links { display: flex; flex-wrap: wrap; gap: .35rem 1.1rem; margin-top: .6rem; }

/* --- Utilities ----------------------------------------------------------- */

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.stack-sm > * + * { margin-top: .6rem; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }