/* ============================================================
   KASA Design System — Base & Utilities
   Reset, base elements, layout primitives, helpers
   (requires tokens.css)
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
[hidden] { display: none !important; }

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

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh);
  color: var(--c-ink);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg, video, canvas, picture { display: block; max-width: 100%; }
img, video { height: auto; }

a { color: var(--c-blue); text-decoration: none; transition: color var(--dur-fast); }
a:hover { color: var(--c-blue-700); }

button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: none; }

ul, ol { list-style: none; padding: 0; }

h1, h2, h3, h4, h5 {
  font-weight: var(--fw-bold);
  line-height: var(--lh-tight);
  letter-spacing: var(--ls-tight);
  color: var(--c-ink);
  text-wrap: balance;
}

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

::selection { background: var(--c-blue-100); color: var(--c-blue-700); }

/* --- Layout primitives -------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}
.container--narrow { max-width: var(--container-narrow); }

.section { padding-block: var(--section-py); }
.section--surface { background: var(--c-surface); }
.section--tint    { background: var(--c-blue-50); }
.section--flush-t { padding-top: 0; }

/* Sticky-header offset for anchor jumps */
[id] { scroll-margin-top: calc(var(--header-h) + 20px); }

/* --- Grid --------------------------------------------------- */
.grid { display: grid; gap: var(--gap); }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid-auto { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

@media (max-width: 980px) {
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 600px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: minmax(0, 1fr); }
}

/* --- Section heading --------------------------------------- */
.section-head {
  max-width: 760px;
  margin-inline: auto;
  margin-bottom: clamp(2rem, 1rem + 3vw, 4rem);
  text-align: center;
}
.section-head--left { text-align: left; margin-inline: 0; }
.section-head .lead { margin-top: var(--sp-4); }

/* --- Eyebrow / kicker -------------------------------------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  letter-spacing: var(--ls-kicker);
  text-transform: uppercase;
  color: var(--c-green-700);
  margin-bottom: var(--sp-4);
}
.section-head:not(.section-head--left) .eyebrow { justify-content: center; }

/* --- Type helpers ------------------------------------------ */
.display { font-size: var(--fs-display); font-weight: var(--fw-black); line-height: var(--lh-tight); }
.h1 { font-size: var(--fs-h1); }
.h2 { font-size: var(--fs-h2); }
.h3 { font-size: var(--fs-h3); }
.h4 { font-size: var(--fs-h4); font-weight: var(--fw-semibold); }

.lead { font-size: var(--fs-lead); color: var(--c-ink-2); line-height: 1.6; }
.muted { color: var(--c-ink-2); }
.small { font-size: var(--fs-sm); }
.grad-text {
  background: var(--grad-brand-135);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* --- Misc helpers ------------------------------------------ */
.center { text-align: center; }
.maxw-prose { max-width: 62ch; }
.mx-auto { margin-inline: auto; }
.mt-5 { margin-top: var(--sp-5); }
.mt-6 { margin-top: var(--sp-6); }
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.no-scroll { overflow: hidden; }

/* --- Media placeholder (이미지/영상 교체 영역) --------------
   사용법:
   <div class="media media--16x9"><span class="media__label">...</span></div>
   추후 <img>/<video>를 .media 안에 넣으면 라벨 위로 덮여 표시됩니다. */
.media {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--c-surface-2);
  background-image:
    repeating-linear-gradient(45deg,
      rgba(0,91,146,.035) 0, rgba(0,91,146,.035) 1px,
      transparent 1px, transparent 11px);
  border: 1px dashed var(--c-line-2);
  border-radius: var(--r-md);
  color: var(--c-ink-3);
  overflow: hidden;
}
.media > img, .media > video, .media > iframe {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  object-fit: cover; border: 0;
}
.media__label {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--c-ink-3);
  padding: 0.4em 0.9em;
  text-align: center;
}
.media__label .ti { font-size: 1.1em; }
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3  { aspect-ratio: 4 / 3; }
.media--1x1  { aspect-ratio: 1 / 1; }
.media--3x4  { aspect-ratio: 3 / 4; }
.media--21x9 { aspect-ratio: 21 / 9; }
.media--dark {
  background-color: var(--c-navy);
  background-image: none;
  border: 0;
  color: rgba(255,255,255,.7);
}
.media--dark .media__label { color: rgba(255,255,255,.72); }

/* --- Scroll reveal ----------------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .7s var(--ease-out), transform .7s var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
}
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}