/*
Theme Name: NullAlpha Editorial
Theme URI: https://nullalpha.dev
Author: NullAlpha
Author URI: https://nullalpha.dev
Description: A Kinetic Editorial theme for nullalpha.dev — a high-contrast, indigo-and-zinc reading experience for an Algorithmic Trading × AI Engineering blog. Image-optional card grid, 720px reading column, and built-in (invisible until configured) Google AdSense slots. Post bodies keep the self-contained .na-post rendering untouched.
Version: 1.0.1
Requires at least: 6.0
Tested up to: 7.0
Requires PHP: 7.4
License: GNU General Public License v2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
Text Domain: nullalpha-editorial
Tags: blog, editorial, two-columns, custom-menu, featured-images, full-width-template, translation-ready
*/

/* ============================================================
   Kinetic Editorial — design tokens
   (mirrors the Stitch "기사형 개발 블로그 플랫폼" design system)
   ============================================================ */
:root {
  /* Surfaces (Zinc / lavender-white) */
  --bg: #fbf8ff;
  --surface: #ffffff;
  --surface-low: #f4f2fd;
  --surface-container: #eeedf7;
  --surface-container-high: #e8e7f1;

  /* Ink */
  --on-surface: #1a1b22;
  --on-surface-variant: #464555;
  --outline: #777587;
  --outline-variant: #c7c4d8;

  /* Brand — Indigo primary, Emerald accent */
  --primary: #3525cd;
  --primary-bright: #4f46e5;
  --on-primary: #ffffff;
  --primary-fixed: #e2dfff;
  --primary-fixed-dim: #c3c0ff;
  --on-primary-container: #1c127a;
  --accent: #006c49;
  --accent-soft: #6cf8bb;

  /* Type */
  --font-ui: "Geist", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, Menlo, monospace;

  /* Space */
  --container: 1200px;
  --article: 720px;
  --gutter: 24px;
  --section-gap: 80px;
  --stack-sm: 8px;
  --stack-md: 16px;
  --stack-lg: 32px;

  /* Radii */
  --r-sm: 4px;
  --r-md: 6px;
  --r-lg: 8px;
  --r-xl: 12px;
  --r-2xl: 16px;

  --shadow-1: 0 4px 12px rgba(26, 27, 34, 0.05);
  --shadow-2: 0 10px 30px rgba(26, 27, 34, 0.08);
  --ring: 0 0 0 3px rgba(79, 70, 229, 0.18);
  --ease: cubic-bezier(0.2, 0, 0, 1);
}

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

html { -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--on-surface);
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-bright); }

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

::selection { background: var(--primary-fixed); color: var(--on-primary-container); }

.na-container { max-width: var(--container); margin-inline: auto; padding-inline: var(--gutter); }
.na-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;
}
.na-skip-link {
  position: absolute; left: -999px; top: 0; z-index: 1000;
  background: var(--primary); color: #fff; padding: 10px 16px; border-radius: 0 0 var(--r-md) 0;
}
.na-skip-link:focus { left: 0; }

:focus-visible { outline: none; box-shadow: var(--ring); border-radius: var(--r-sm); }

/* ============================================================
   Header / sticky nav  (no subscribe button)
   ============================================================ */
.na-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(251, 248, 255, 0.82);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--outline-variant);
}
.na-nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px; max-width: var(--container); margin-inline: auto; padding-inline: var(--gutter);
}
.na-brand { display: flex; align-items: baseline; gap: 10px; }
.na-brand__mark {
  font-family: var(--font-mono); font-weight: 700; font-size: 22px; letter-spacing: -0.02em;
  color: var(--primary);
}
.na-brand__mark .na-brand__null { color: var(--on-surface); }
.na-brand__tag {
  display: none; font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.04em;
  color: var(--on-surface-variant); text-transform: uppercase;
}
.na-navlinks { display: none; align-items: center; gap: var(--stack-lg); }
.na-navlinks a {
  position: relative; color: var(--on-surface-variant); font-weight: 500; font-size: 15px;
  padding-bottom: 4px; transition: color 0.2s var(--ease);
}
.na-navlinks a:hover { color: var(--primary); }
.na-navlinks a.is-active, .na-navlinks .current-menu-item > a {
  color: var(--primary); font-weight: 700; border-bottom: 2px solid var(--primary);
}
.na-nav__right { display: flex; align-items: center; gap: var(--stack-md); }
.na-iconbtn {
  display: inline-grid; place-items: center; width: 40px; height: 40px;
  border: 0; background: transparent; color: var(--on-surface-variant);
  border-radius: 999px; cursor: pointer; transition: background 0.2s var(--ease), color 0.2s var(--ease);
}
.na-iconbtn:hover { background: var(--surface-container); color: var(--primary); }
.na-iconbtn svg { width: 20px; height: 20px; }

/* Search popover (no-JS <details>) */
.na-search { position: relative; }
.na-search > summary { list-style: none; }
.na-search > summary::-webkit-details-marker { display: none; }
.na-search__panel {
  position: absolute; right: 0; top: calc(100% + 10px); width: min(320px, 80vw);
  background: var(--surface); border: 1px solid var(--outline-variant); border-radius: var(--r-lg);
  padding: 12px; box-shadow: var(--shadow-2); z-index: 60;
}
.na-search__panel form, .na-search__panel .search-form { display: flex; gap: 8px; }
.na-search__panel input[type=search], .na-search__panel .search-field {
  flex: 1; min-width: 0; border: 1px solid var(--outline-variant); border-radius: var(--r-md);
  padding: 10px 12px; font-family: var(--font-ui); font-size: 15px; background: var(--bg); color: var(--on-surface);
}
.na-search__panel input[type=search]:focus { outline: none; border-color: var(--primary); box-shadow: var(--ring); }
.na-search__panel input[type=submit], .na-search__panel .search-submit {
  border: 0; background: var(--primary-bright); color: #fff; border-radius: var(--r-md);
  padding: 0 16px; font-weight: 600; cursor: pointer;
}

@media (min-width: 880px) {
  .na-navlinks { display: flex; }
  .na-brand__tag { display: inline; }
}

/* ============================================================
   Masthead (home)  — typographic, image-free
   ============================================================ */
.na-masthead {
  position: relative; overflow: hidden;
  border-bottom: 1px solid var(--outline-variant);
  background:
    radial-gradient(120% 140% at 85% -10%, rgba(79, 70, 229, 0.10), transparent 60%),
    radial-gradient(90% 120% at -10% 10%, rgba(0, 108, 73, 0.06), transparent 55%),
    var(--bg);
}
.na-masthead::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(var(--outline-variant) 1px, transparent 1px),
    linear-gradient(90deg, var(--outline-variant) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: radial-gradient(120% 100% at 80% 0%, #000, transparent 85%);
  mask-image: radial-gradient(120% 100% at 80% 0%, #000, transparent 85%);
  opacity: 0.22;
}
.na-masthead__inner {
  position: relative; z-index: 1;
  max-width: var(--container); margin-inline: auto; padding: clamp(40px, 7vw, 88px) var(--gutter) clamp(36px, 6vw, 72px);
}
.na-eyebrow {
  font-family: var(--font-mono); font-size: 12px; font-weight: 600; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--primary); margin: 0 0 14px;
  display: inline-flex; align-items: center; gap: 8px;
}
.na-eyebrow::before { content: ""; width: 26px; height: 2px; background: var(--primary); display: inline-block; }
.na-masthead h1 {
  font-family: var(--font-ui); font-weight: 700; letter-spacing: -0.025em; line-height: 1.04;
  font-size: clamp(34px, 5.4vw, 56px); margin: 0 0 18px; max-width: 16ch;
}
.na-masthead h1 .na-grad {
  background: linear-gradient(100deg, var(--primary) 0%, var(--primary-bright) 55%, var(--accent) 130%);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; color: transparent;
}
.na-masthead p {
  font-family: var(--font-serif); font-size: clamp(17px, 2.1vw, 20px); line-height: 1.55;
  color: var(--on-surface-variant); max-width: 56ch; margin: 0;
}

/* ============================================================
   Section heading
   ============================================================ */
.na-sechead { display: flex; align-items: flex-end; justify-content: space-between; gap: var(--stack-md); margin-bottom: var(--stack-lg); }
.na-sechead h2 {
  font-family: var(--font-ui); font-weight: 600; letter-spacing: -0.01em; font-size: 28px; margin: 0;
}
.na-sechead__rule { height: 3px; width: 48px; background: var(--primary); margin-top: 8px; border-radius: 2px; }
.na-sechead__meta { display: inline-flex; align-items: center; gap: 6px; color: var(--on-surface-variant); font-size: 15px; }

/* ============================================================
   Category filter chips
   ============================================================ */
.na-filters {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  margin-bottom: var(--stack-lg);
}
.na-chip {
  font-size: 14px; font-weight: 500; padding: 7px 16px; border-radius: 999px;
  background: var(--surface-container); color: var(--on-surface-variant);
  border: 1px solid transparent; transition: all 0.2s var(--ease); cursor: pointer; white-space: nowrap;
}
.na-chip:hover { background: var(--surface-container-high); color: var(--on-surface); }
.na-chip.is-active { background: var(--primary-bright); color: #fff; }

/* ============================================================
   Post card grid
   ============================================================ */
.na-grid {
  display: grid; grid-template-columns: 1fr; gap: var(--gutter);
}
@media (min-width: 640px) { .na-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .na-grid { grid-template-columns: repeat(3, 1fr); } }

.na-card {
  display: flex; flex-direction: column; min-width: 0;
  background: var(--surface); border: 1px solid var(--outline-variant);
  border-radius: var(--r-lg); padding: var(--stack-md);
  transition: border-color 0.3s var(--ease), box-shadow 0.3s var(--ease), transform 0.3s var(--ease);
}
/* Never let a long title or unbroken token (URL, snake_case) overflow chrome. */
.na-card h3, .na-card__excerpt, .na-arthead h1, .na-relcard h4 { overflow-wrap: anywhere; word-break: break-word; }
.na-card:hover { border-color: var(--primary); box-shadow: var(--shadow-1); transform: translateY(-2px); }

.na-card__thumb {
  position: relative; aspect-ratio: 16 / 9; border-radius: var(--r-md); overflow: hidden;
  margin-bottom: var(--stack-md); background: var(--surface-container);
}
.na-card__thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s var(--ease); }
.na-card:hover .na-card__thumb img { transform: scale(1.05); }

/* Image-free placeholder: gradient + faint mono glyphs + category watermark */
.na-card__thumb--ph {
  background:
    radial-gradient(110% 130% at 90% 0%, rgba(79,70,229,0.16), transparent 60%),
    linear-gradient(135deg, var(--surface-low), var(--surface-container));
  display: grid; place-items: center;
}
.na-card__thumb--ph::before {
  content: "{ }"; position: absolute; inset: 0; display: grid; place-items: center;
  font-family: var(--font-mono); font-size: 72px; font-weight: 600; color: var(--primary);
  opacity: 0.20; letter-spacing: -0.04em;
}
.na-card[data-cat="trading"] .na-card__thumb--ph { background: radial-gradient(110% 130% at 90% 0%, rgba(0,108,73,0.16), transparent 60%), linear-gradient(135deg, var(--surface-low), var(--surface-container)); }
.na-card[data-cat="trading"] .na-card__thumb--ph::before { content: "↗"; font-size: 92px; color: var(--accent); opacity: 0.28; }
.na-card[data-cat="ai"] .na-card__thumb--ph::before { content: "{ }"; }
.na-card[data-cat="crossover"] .na-card__thumb--ph { background: radial-gradient(110% 130% at 90% 0%, rgba(126,48,0,0.14), transparent 60%), linear-gradient(135deg, var(--surface-low), var(--surface-container)); }
.na-card[data-cat="crossover"] .na-card__thumb--ph::before { content: "×"; font-size: 104px; color: #7e3000; opacity: 0.24; }

.na-card__meta { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; flex-wrap: wrap; }
.na-card__cat {
  font-family: var(--font-mono); font-size: 12px; font-weight: 600; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--primary);
}
.na-card__date {
  font-family: var(--font-mono); font-size: 12px; font-weight: 500; letter-spacing: 0.04em;
  text-transform: uppercase; color: var(--on-surface-variant);
}
.na-card h3 {
  font-family: var(--font-ui); font-weight: 600; font-size: 21px; line-height: 1.25;
  letter-spacing: -0.01em; margin: 0 0 8px;
}
.na-card h3 a { color: var(--on-surface); transition: color 0.2s var(--ease); }
.na-card:hover h3 a { color: var(--primary); }
.na-card__excerpt {
  font-family: var(--font-serif); font-size: 16px; line-height: 1.5; color: var(--on-surface-variant);
  margin: 0 0 var(--stack-md);
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}
.na-card__more {
  margin-top: auto; display: inline-flex; align-items: center; gap: 6px;
  font-weight: 700; font-size: 15px; color: var(--primary);
}
.na-card__more svg { width: 16px; height: 16px; transition: transform 0.2s var(--ease); }
.na-card:hover .na-card__more svg { transform: translateX(3px); }

/* ============================================================
   Pagination
   ============================================================ */
.na-pagination, .navigation.pagination { margin-top: var(--stack-lg); }
.na-pagination .nav-links, .navigation.pagination .nav-links { display: flex; justify-content: center; gap: 10px; flex-wrap: wrap; }
.na-pagination .page-numbers, .navigation.pagination .page-numbers {
  display: inline-grid; place-items: center; min-width: 42px; height: 42px; padding: 0 12px;
  border: 1px solid var(--outline-variant); border-radius: var(--r-md);
  font-weight: 600; color: var(--on-surface-variant); background: var(--surface);
  transition: all 0.2s var(--ease);
}
.na-pagination .page-numbers:hover, .navigation.pagination .page-numbers:hover { border-color: var(--primary); color: var(--primary); }
.na-pagination .page-numbers.current, .navigation.pagination .page-numbers.current { background: var(--primary-bright); color: #fff; border-color: var(--primary-bright); }
.na-pagination .page-numbers.dots, .navigation.pagination .page-numbers.dots { border-color: transparent; background: transparent; }

/* ============================================================
   Single — article header
   ============================================================ */
.na-single { padding-top: var(--stack-lg); padding-bottom: var(--section-gap); }
.na-progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0; z-index: 60;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}
.na-arthead { max-width: var(--article); margin-inline: auto; padding-inline: var(--gutter); margin-bottom: var(--stack-lg); }
.na-arthead__meta { display: flex; align-items: center; gap: 10px; margin-bottom: var(--stack-md); flex-wrap: wrap; }
.na-tag {
  font-family: var(--font-mono); font-size: 12px; font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--primary); background: var(--primary-fixed);
  padding: 4px 10px; border-radius: var(--r-sm);
}
.na-arthead__date { font-family: var(--font-mono); font-size: 12px; font-weight: 500; letter-spacing: 0.05em; text-transform: uppercase; color: var(--on-surface-variant); }
.na-arthead h1 {
  font-family: var(--font-ui); font-weight: 700; letter-spacing: -0.02em; line-height: 1.08;
  font-size: clamp(30px, 4.6vw, 46px); margin: 0 0 var(--stack-lg);
}
.na-arthead__byline {
  display: flex; align-items: center; justify-content: space-between; gap: var(--stack-md);
  padding: 18px 0; border-top: 1px solid var(--outline-variant); border-bottom: 1px solid var(--outline-variant);
  flex-wrap: wrap;
}
.na-author { display: flex; align-items: center; gap: 12px; }
.na-author__avatar {
  width: 44px; height: 44px; border-radius: 999px; flex: none;
  display: grid; place-items: center; color: #fff; font-family: var(--font-mono); font-weight: 700; font-size: 18px;
  background: linear-gradient(135deg, var(--primary), var(--primary-bright));
}
.na-author__name { font-weight: 600; font-size: 15px; color: var(--on-surface); }
.na-author__role { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.03em; color: var(--on-surface-variant); }
.na-readtime { display: inline-flex; align-items: center; gap: 6px; color: var(--on-surface-variant); font-size: 15px; }
.na-readtime svg { width: 18px; height: 18px; }

/* Article body wrapper — width-constrains the self-contained .na-post block.
   We do NOT restyle .na-post itself: it ships its own scoped CSS. */
.na-artbody { max-width: var(--article); margin-inline: auto; padding-inline: var(--gutter); }
/* The .na-post block ships its own locked typography (incl. font-size:17px) from
   the pipeline; the theme only width-constrains it here and never restyles it. */

/* ============================================================
   Related posts
   ============================================================ */
.na-related { max-width: var(--container); margin: var(--section-gap) auto 0; padding-inline: var(--gutter); }
.na-related h2 { font-family: var(--font-ui); font-weight: 600; letter-spacing: -0.01em; font-size: 26px; margin: 0 0 var(--stack-lg); }
.na-related__grid { display: grid; grid-template-columns: 1fr; gap: var(--gutter); }
@media (min-width: 720px) { .na-related__grid { grid-template-columns: repeat(3, 1fr); } }
.na-relcard {
  display: block; border: 1px solid var(--outline-variant); border-radius: var(--r-lg);
  padding: 18px; background: var(--surface); transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.na-relcard:hover { border-color: var(--primary); box-shadow: var(--shadow-1); }
.na-relcard .na-card__cat { display: block; margin-bottom: 8px; }
.na-relcard h4 { font-family: var(--font-ui); font-weight: 600; font-size: 17px; line-height: 1.3; margin: 0; color: var(--on-surface); }
.na-relcard:hover h4 { color: var(--primary); }

/* ============================================================
   Comments (kept minimal / on-brand)
   ============================================================ */
.na-comments { max-width: var(--article); margin: var(--section-gap) auto 0; padding-inline: var(--gutter); }
.na-comments h2 { font-family: var(--font-ui); font-weight: 600; font-size: 22px; margin: 0 0 var(--stack-lg); padding-top: var(--stack-lg); border-top: 1px solid var(--outline-variant); }
.na-comments ol, .na-comments ul { list-style: none; padding: 0; margin: 0; }
.na-comments .comment-body { padding: 16px 0; border-bottom: 1px solid var(--surface-container); }
.na-comments .comment-author .fn { font-weight: 600; }
.na-comments textarea, .na-comments input[type=text], .na-comments input[type=email], .na-comments input[type=url] {
  width: 100%; border: 1px solid var(--outline-variant); border-radius: var(--r-md); padding: 12px 14px;
  font-family: var(--font-ui); font-size: 15px; background: var(--surface); color: var(--on-surface);
}
.na-comments textarea:focus, .na-comments input:focus { outline: none; border-color: var(--primary); box-shadow: var(--ring); }
.na-comments .submit, .na-btn {
  display: inline-flex; align-items: center; gap: 8px; background: var(--primary-bright); color: #fff;
  border: 0; border-radius: var(--r-md); padding: 12px 22px; font-weight: 600; font-size: 15px; cursor: pointer;
  transition: opacity 0.2s var(--ease), transform 0.1s var(--ease);
}
.na-comments .submit:hover, .na-btn:hover { opacity: 0.92; color: #fff; }
.na-btn:active { transform: scale(0.98); }
.na-btn--ghost { background: transparent; color: var(--primary); border: 1px solid var(--outline-variant); }
.na-btn--ghost:hover { border-color: var(--primary); color: var(--primary); }

/* ============================================================
   Footer (no newsletter)
   ============================================================ */
.na-footer { background: var(--surface-low); border-top: 1px solid var(--outline-variant); margin-top: var(--section-gap); }
.na-footer__inner {
  display: flex; align-items: center; justify-content: space-between; gap: var(--stack-md); flex-wrap: wrap;
  max-width: var(--container); margin-inline: auto; padding: var(--stack-lg) var(--gutter);
}
.na-footer__brand { display: flex; flex-direction: column; gap: 4px; }
.na-footer__brand .na-brand__mark { font-size: 18px; }
.na-footer__copy { color: var(--on-surface-variant); font-size: 14px; font-family: var(--font-mono); }
.na-footer__links { display: flex; gap: var(--stack-lg); }
.na-footer__links a { color: var(--on-surface-variant); font-size: 15px; }
.na-footer__links a:hover { color: var(--primary); }

/* ============================================================
   AdSense slots (invisible until configured)
   ============================================================ */
.na-ad {
  margin: var(--stack-lg) auto; max-width: var(--container); padding-inline: var(--gutter);
  display: flex; flex-direction: column; align-items: center;
}
.na-ad--article { max-width: var(--article); }
.na-ad__inner { width: 100%; display: flex; justify-content: center; }
.na-ad__label {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--outline); margin-bottom: 6px;
}
/* Dev-only placeholder box (shown when NA_AD_DEBUG); real AdSense replaces this. */
.na-ad--placeholder .na-ad__inner {
  min-height: 90px; border: 1px dashed var(--outline-variant); border-radius: var(--r-md);
  align-items: center; color: var(--outline); font-family: var(--font-mono); font-size: 12px;
  background: repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(119,117,135,0.05) 10px, rgba(119,117,135,0.05) 20px);
}

/* ============================================================
   Page-load reveal (staggered)
   ============================================================ */
@media (prefers-reduced-motion: no-preference) {
  .na-reveal { opacity: 0; transform: translateY(12px); animation: na-rise 0.6s var(--ease) forwards; }
  .na-grid > .na-reveal:nth-child(1) { animation-delay: 0.02s; }
  .na-grid > .na-reveal:nth-child(2) { animation-delay: 0.07s; }
  .na-grid > .na-reveal:nth-child(3) { animation-delay: 0.12s; }
  .na-grid > .na-reveal:nth-child(4) { animation-delay: 0.17s; }
  .na-grid > .na-reveal:nth-child(5) { animation-delay: 0.22s; }
  .na-grid > .na-reveal:nth-child(6) { animation-delay: 0.27s; }
  @keyframes na-rise { to { opacity: 1; transform: none; } }
}

/* ============================================================
   Empty state
   ============================================================ */
.na-empty { max-width: var(--article); margin: var(--section-gap) auto; padding-inline: var(--gutter); text-align: center; color: var(--on-surface-variant); }
.na-empty h2 { font-family: var(--font-ui); color: var(--on-surface); }