/* ═══════════════════════════════════════════════════════════════════
   base.css — reset, tipografi, LATAR KEDALAMAN LAUT.
   Nilai warna HANYA lewat var(). Protokol 03 §2.

   Susunan lapisan latar (dari belakang ke depan):
     1. body            → gradien kedalaman + pendar permukaan + vignette
     2. body::before    → berkas cahaya matahari menembus air (god rays)
     3. canvas#seaCanvas→ partikel bercahaya naik ke atas (assets/js/sea.js)
     4. body::after     → kilau caustic tipis di dekat permukaan
     5. konten (z-index 1+)

   CATATAN PENTING: kedua pseudo-element memakai inset:0 (persis
   seukuran viewport) dan hanya dianimasikan dengan transform vertikal
   + opacity. Alasannya: elemen fixed yang meluber ke samping bisa
   memunculkan scrollbar horizontal di Safari iOS — persis keluhan
   "di mobile tidak fit".
   ═══════════════════════════════════════════════════════════════════ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  background: var(--bg);
}

body {
  position: relative;
  font-family: var(--font);
  font-size: var(--fs-base);
  line-height: 1.65;
  color: var(--text);
  min-height: 100vh;
  min-height: 100svh;
  -webkit-font-smoothing: antialiased;

  /* ⚠️ JANGAN ganti clip ini jadi hidden.
     overflow-x:hidden membuat <body> menjadi wadah gulir tersendiri, dan
     position:sticky di dalamnya (navbar!) langsung berhenti menempel —
     dia menempel ke scrollport body yang memang tidak pernah bergulir.
     overflow-x:clip memotong luberan TANPA membuat wadah gulir, jadi
     navbar tetap sticky. Baris 'hidden' di atasnya cuma cadangan untuk
     Safari di bawah versi 16 yang belum mengenal nilai clip. */
  overflow-x: hidden;
  overflow-x: clip;

  /* Kata panjang (email, URL) tidak boleh menjebol kolom di HP */
  overflow-wrap: break-word;
  word-break: break-word;

  /* ── Lapisan 1: kedalaman air ── */
  background-color: var(--bg);
  background-image:
    /* vignette gelap di dasar & tepi bawah — memberi kesan dalam */
    radial-gradient(ellipse 140% 60% at 50% 118%,
      var(--abyss) 0%, var(--abyss-fade) 68%),
    /* cahaya matahari menghantam permukaan air di paling atas */
    radial-gradient(ellipse 130% 44% at 50% -10%,
      var(--surface-glow) 0%, var(--surface-fade) 66%),
    /* gradien kedalaman utama */
    linear-gradient(180deg,
      var(--sea-1) 0%,
      var(--sea-2) 18%,
      var(--sea-3) 46%,
      var(--bg) 100%);
  background-attachment: fixed, fixed, fixed;
  background-repeat: no-repeat;
  background-size: cover;
}
html[lang="zh-Hans"] body { font-family: var(--font-cjk); line-height: 1.8; }

/* ── Lapisan 2: berkas cahaya menembus permukaan air ──────────────
   Bukan filter blur (mahal di HP). Tepi lembutnya datang dari
   banyak titik henti gradien yang saling menyamar. */
body::before {
  content: '';
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image:
    linear-gradient(101deg,
      var(--ray-fade) 9%,  var(--ray-2) 12.5%, var(--ray) 14.5%,
      var(--ray-2) 16.5%,  var(--ray-fade) 20%),
    linear-gradient(96deg,
      var(--ray-fade) 25%, var(--ray-2) 29%,   var(--ray-fade) 35%),
    linear-gradient(104deg,
      var(--ray-fade) 42%, var(--ray-2) 45%,   var(--ray) 47%,
      var(--ray-2) 49.5%,  var(--ray-fade) 53%),
    linear-gradient(93deg,
      var(--ray-fade) 59%, var(--ray-2) 64%,   var(--ray-fade) 71%),
    linear-gradient(107deg,
      var(--ray-fade) 77%, var(--ray-2) 80%,   var(--ray) 82%,
      var(--ray-2) 84%,    var(--ray-fade) 88%);
  background-repeat: no-repeat;
  background-size: 100% 145%;
  background-position: center top;
  /* Sinar meredup makin dalam — hilang total sebelum dasar layar */
  -webkit-mask-image: linear-gradient(to bottom,
    var(--mask-on) 0%, var(--mask-on) 26%, var(--mask-off) 88%);
  mask-image: linear-gradient(to bottom,
    var(--mask-on) 0%, var(--mask-on) 26%, var(--mask-off) 88%);
  will-change: transform, opacity;
  animation: sun-sway 19s ease-in-out infinite alternate;
}

/* ── Lapisan 4: caustic — pola cahaya bergoyang dekat permukaan ── */
body::after {
  content: '';
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image:
    radial-gradient(ellipse 34% 12% at 22% 6%,
      var(--caustic) 0%, var(--caustic-fade) 72%),
    radial-gradient(ellipse 26% 9%  at 61% 3%,
      var(--caustic) 0%, var(--caustic-fade) 72%),
    radial-gradient(ellipse 40% 14% at 86% 9%,
      var(--caustic) 0%, var(--caustic-fade) 72%);
  background-repeat: no-repeat;
  background-size: 100% 130%;
  background-position: center top;
  -webkit-mask-image: linear-gradient(to bottom,
    var(--mask-on) 0%, var(--mask-on) 14%, var(--mask-off) 46%);
  mask-image: linear-gradient(to bottom,
    var(--mask-on) 0%, var(--mask-on) 14%, var(--mask-off) 46%);
  will-change: transform, opacity;
  animation: caustic-drift 13s ease-in-out infinite alternate;
}

/* Hanya transform vertikal + opacity: dikerjakan compositor, 60fps,
   dan tidak mungkin menambah lebar dokumen. */
@keyframes sun-sway {
  from { transform: translate3d(0, -1.6%, 0) scaleY(1);     opacity: .78; }
  to   { transform: translate3d(0,  1.4%, 0) scaleY(1.045); opacity: 1; }
}
@keyframes caustic-drift {
  from { transform: translate3d(0, -1%, 0); opacity: .5; }
  to   { transform: translate3d(0,  1%, 0); opacity: 1; }
}

/* Canvas partikel — dibuat oleh assets/js/sea.js */
#seaCanvas {
  position: fixed; inset: 0; z-index: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  display: block;
}

/* ── Tipografi ───────────────────────────────────────────────────── */
h1, h2, h3, h4 { line-height: 1.22; letter-spacing: -.4px; font-weight: 700; }
h1 { font-size: clamp(29px, 5.2vw, 52px); font-weight: 800; letter-spacing: -1.2px; }
h2 { font-size: clamp(23px, 3.4vw, 35px); letter-spacing: -.7px; }
h3 { font-size: var(--fs-md); font-weight: 600; }
p  { max-width: 68ch; }
a  { color: var(--accent); }

img, svg, video { max-width: 100%; height: auto; display: block; }
svg { flex-shrink: 0; }

/* Tabel & blok kode tidak boleh mendorong lebar halaman */
table, pre { max-width: 100%; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 var(--s6); }
main  { position: relative; z-index: 1; }

.muted   { color: var(--text2); }
.dim     { color: var(--text3); }
.small   { font-size: var(--fs-sm); }
.xsmall  { font-size: var(--fs-xs); }
.lead    { font-size: var(--fs-md); color: var(--text2); margin-top: var(--s3); }
.center  { text-align: center; }
.nowrap  { white-space: nowrap; }
.tnum    { font-variant-numeric: tabular-nums; }
.strong  { color: var(--text); font-weight: 600; }

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 999;
  background: var(--accent); color: var(--on-accent);
  padding: 10px 18px; border-radius: 0 0 var(--radius) 0; font-weight: 600;
}
.skip-link:focus { left: 0; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

.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;
}

/* ── Hemat baterai & GPU di layar kecil: sinar diam, tidak beranimasi ── */
@media (max-width: 768px) {
  body::before, body::after { animation: none; }
  body::before { opacity: .72; }
  body::after  { opacity: .6; }
}

/* ── Hormati prefers-reduced-motion (Protokol 03 §6.4 aturan 10) ── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important; animation-iteration-count: 1 !important;
    transition-duration: .01ms !important; scroll-behavior: auto !important;
  }
  body::before { opacity: .9; }
  body::after  { opacity: .75; }
}