/* ==========================================================================
   EnglishNotes.net — Design System
   Concept: "The Editor's Notebook" — ruled paper, ink, highlighter marks,
   and proofreading annotations. Grounded in the world of language notes.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,500;9..144,600;9..144,700&family=Inter:wght@400;500;600;700;800&family=IBM+Plex+Mono:wght@400;500;600&display=swap');

:root{
  /* Color tokens */
  --ink:        #16233F;   /* primary text / navy ink */
  --ink-soft:   #3B4A6B;
  --paper:      #FCFBF7;   /* background */
  --paper-dim:  #F3F1E9;   /* ruled-card background */
  --rule:       #DCD8C9;   /* hairline rule color, like faint ruled paper */
  --highlighter:#F4C63D;   /* highlighter yellow accent */
  --highlighter-soft: #FCE9AE;
  --correction: #D64550;   /* red-pen correction accent */
  --sage:       #4C7A6D;   /* secondary accent, "global" green */
  --sage-soft:  #E4EEE9;

  --font-display: 'Fraunces', Georgia, serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, monospace;

  --radius: 10px;
  --shadow-card: 0 1px 2px rgba(22,35,63,0.06), 0 8px 24px -12px rgba(22,35,63,0.18);
  --maxw: 1160px;
}

*,*::before,*::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior: auto; }
  *,*::before,*::after{ animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

body{
  margin:0;
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img{ max-width:100%; display:block; }
a{ color: inherit; }
.container{ max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

h1,h2,h3,h4{
  font-family: var(--font-display);
  color: var(--ink);
  line-height: 1.12;
  margin: 0 0 .5em;
  font-weight: 600;
}
h1{ font-size: clamp(2.2rem, 4.4vw, 3.6rem); font-weight: 600; letter-spacing: -0.01em; }
h2{ font-size: clamp(1.6rem, 2.6vw, 2.25rem); }
h3{ font-size: 1.3rem; }
p{ margin: 0 0 1em; }
.lede{ font-size: 1.15rem; color: var(--ink-soft); }

/* Skip link for accessibility */
.skip-link{
  position:absolute; left:-999px; top:auto;
  background: var(--ink); color:#fff; padding: 10px 16px; z-index: 200; border-radius: 0 0 8px 0;
}
.skip-link:focus{ left:0; top:0; }

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

/* Eyebrow label — like a section reference mark from a style guide */
.eyebrow{
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--sage);
  display:inline-flex;
  align-items:center;
  gap:.5em;
  margin-bottom: .8em;
}
.eyebrow::before{ content:"§"; color: var(--correction); font-weight:700; }

/* ===================== HEADER / NAV ===================== */
.site-header{
  position: sticky; top:0; z-index: 100;
  background: rgba(252,251,247,0.92);
  backdrop-filter: saturate(140%) blur(6px);
  border-bottom: 1px solid var(--rule);
}
.nav-bar{
  display:flex; align-items:center; justify-content:space-between;
  padding: 14px 24px;
  max-width: var(--maxw); margin:0 auto;
  gap: 20px;
}
.brand{
  display:flex; align-items:baseline; gap:.4em;
  font-family: var(--font-display); font-weight:700; font-size:1.3rem;
  text-decoration:none; color: var(--ink);
  white-space: nowrap;
}
.brand .brand-mark{ color: var(--correction); }
.brand .brand-dot{
  display:inline-block; width:7px; height:7px; border-radius:50%;
  background: var(--highlighter); margin-left:2px; transform: translateY(-8px);
}

.nav-links{ display:flex; gap: 26px; list-style:none; margin:0; padding:0; align-items:center; }
.nav-links a{
  text-decoration:none; font-size:.95rem; font-weight:600; color: var(--ink-soft);
  position:relative; padding: 6px 2px;
}
.nav-links a:hover, .nav-links a[aria-current="page"]{ color: var(--ink); }
.nav-links a[aria-current="page"]::after{
  content:""; position:absolute; left:0; right:0; bottom:-2px; height:3px;
  background: var(--highlighter); border-radius: 3px;
}
.nav-cta{
  background: var(--ink); color:#fff !important; padding:9px 18px; border-radius: 999px;
  font-size:.9rem !important;
}
.nav-cta:hover{ background: var(--correction); }

.nav-toggle{
  display:none; background:none; border:1px solid var(--rule); border-radius:8px;
  width:42px; height:38px; cursor:pointer; padding:0;
}
.nav-toggle span{ display:block; width:20px; height:2px; background:var(--ink); margin:4px auto; }

@media (max-width: 860px){
  .nav-links{
    position:absolute; top:100%; left:0; right:0; background: var(--paper);
    flex-direction:column; align-items:flex-start; padding: 18px 24px 24px;
    border-bottom: 1px solid var(--rule); display:none; gap:14px;
  }
  .nav-links.open{ display:flex; }
  .nav-toggle{ display:block; }
}

/* ===================== HERO ===================== */
.hero{
  position:relative;
  padding: 76px 0 60px;
  overflow:hidden;
  background:
    linear-gradient(var(--paper), var(--paper)),
    repeating-linear-gradient(to bottom, transparent, transparent 37px, var(--rule) 38px);
}
.hero-grid{
  display:grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items:center;
}
@media (max-width: 900px){ .hero-grid{ grid-template-columns: 1fr; } }

.hero h1 .mark{
  position:relative; white-space:nowrap; display:inline-block;
}
.hero h1 .mark svg{
  position:absolute; left:-2%; right:-2%; bottom:-.12em; width:104%; height:.32em;
  overflow:visible;
}
.hero h1 .mark path{
  stroke: var(--highlighter); stroke-width: 10; fill:none; stroke-linecap:round;
  stroke-dasharray: 400; stroke-dashoffset: 400;
  animation: draw-underline 1s ease forwards .5s;
}
@keyframes draw-underline{ to{ stroke-dashoffset: 0; } }

.hero-actions{ display:flex; gap:14px; margin-top: 28px; flex-wrap:wrap; }
.btn{
  display:inline-flex; align-items:center; gap:.5em;
  padding: 13px 24px; border-radius: 999px; font-weight:700; font-size:.98rem;
  text-decoration:none; border:2px solid transparent; cursor:pointer; transition: transform .15s ease, background .2s ease;
}
.btn-primary{ background: var(--ink); color:#fff; }
.btn-primary:hover{ background: var(--correction); transform: translateY(-1px); }
.btn-outline{ border-color: var(--ink); color: var(--ink); background:transparent; }
.btn-outline:hover{ background: var(--ink); color:#fff; }

.hero-stats{
  display:flex; gap: 28px; margin-top: 36px; flex-wrap:wrap;
}
.hero-stats div{ font-family: var(--font-mono); font-size:.82rem; color: var(--ink-soft); max-width:150px; }
.hero-stats strong{ display:block; font-family: var(--font-display); font-size:1.5rem; color: var(--ink); }

/* Hero annotation card — a "corrected sentence" visual, the signature element */
.annot-card{
  background:#fff; border:1px solid var(--rule); border-radius: var(--radius);
  box-shadow: var(--shadow-card); padding: 28px 26px; position:relative;
  transform: rotate(1.2deg);
}
.annot-card::before{
  content:"Notebook — Lesson 04"; font-family: var(--font-mono); font-size:.7rem;
  color: var(--ink-soft); letter-spacing:.05em; text-transform:uppercase;
}
.annot-line{ font-family: var(--font-display); font-size: 1.28rem; margin: 14px 0; position:relative; }
.annot-line .strike{ text-decoration: line-through; text-decoration-color: var(--correction); text-decoration-thickness:2px; color:#9098ab; }
.annot-line .insert{ color: var(--sage); font-weight:600; }
.annot-line .caret{ font-family: var(--font-mono); color: var(--correction); font-size:.85em; vertical-align: top; }
.annot-note{
  font-family: var(--font-mono); font-size:.78rem; color: var(--correction);
  background: #FDEEEF; border-left:3px solid var(--correction); padding: 8px 12px; border-radius: 0 6px 6px 0; margin-top: 14px;
}
.annot-highlight{ background: linear-gradient(180deg, transparent 60%, var(--highlighter-soft) 60%); padding: 0 2px; }

/* ===================== SECTIONS ===================== */
section{ padding: 68px 0; }
.section-head{ max-width: 640px; margin-bottom: 40px; }
.section-alt{ background: var(--paper-dim); border-top:1px solid var(--rule); border-bottom:1px solid var(--rule); }

.grid{ display:grid; gap: 22px; }
.grid-4{ grid-template-columns: repeat(4,1fr); }
.grid-3{ grid-template-columns: repeat(3,1fr); }
.grid-2{ grid-template-columns: repeat(2,1fr); }
@media (max-width: 980px){ .grid-4{ grid-template-columns: repeat(2,1fr);} .grid-3{ grid-template-columns: repeat(2,1fr);} }
@media (max-width: 640px){ .grid-4,.grid-3,.grid-2{ grid-template-columns: 1fr; } }

/* Category / index cards */
.card{
  background:#fff; border:1px solid var(--rule); border-radius: var(--radius);
  padding: 24px; box-shadow: var(--shadow-card); text-decoration:none; color:inherit;
  display:flex; flex-direction:column; gap:10px; transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover{ transform: translateY(-4px) rotate(-.4deg); box-shadow: 0 14px 30px -14px rgba(22,35,63,0.28); }
.card .tag{
  font-family: var(--font-mono); font-size:.72rem; text-transform:uppercase; letter-spacing:.06em;
  color: var(--sage); background: var(--sage-soft); padding:3px 9px; border-radius: 6px; align-self:flex-start;
}
.card h3{ margin: 4px 0 2px; font-size:1.18rem; }
.card p{ color: var(--ink-soft); font-size:.95rem; margin-bottom:0; }
.card .card-meta{ margin-top:auto; font-family: var(--font-mono); font-size:.75rem; color:#8b93a8; padding-top:10px; border-top:1px dashed var(--rule); }

.icon-badge{
  width:44px; height:44px; border-radius: 10px; display:flex; align-items:center; justify-content:center;
  background: var(--highlighter-soft); color: var(--ink);
}
.icon-badge svg{ width:22px; height:22px; }

/* Feature list */
.feature{ display:flex; gap:16px; align-items:flex-start; }
.feature .num{
  font-family: var(--font-mono); color: var(--correction); font-weight:700; font-size:.85rem;
  border:1.5px solid var(--correction); width:30px; height:30px; border-radius:50%;
  display:flex; align-items:center; justify-content:center; flex:none;
}
.feature h3{ margin-bottom:4px; font-size:1.1rem; }
.feature p{ color: var(--ink-soft); font-size:.95rem; }

/* Quote / world strip */
.world-strip{
  display:flex; flex-wrap:wrap; gap: 10px 26px; justify-content:center;
  font-family: var(--font-mono); font-size:.85rem; color: var(--ink-soft);
}
.world-strip span{ white-space:nowrap; }
.world-strip strong{ color: var(--ink); }

/* CTA band */
.cta-band{
  background: var(--ink); color:#fff; border-radius: 20px; padding: 52px; text-align:center;
  position:relative; overflow:hidden;
}
.cta-band h2{ color:#fff; }
.cta-band p{ color:#C7CEE0; max-width:560px; margin:0 auto 26px; }
.cta-band .btn-primary{ background: var(--highlighter); color: var(--ink); }
.cta-band .btn-primary:hover{ background:#fff; }
.cta-band .btn-outline{ border-color:#5b6a8c; color:#fff; }
.cta-band .btn-outline:hover{ background:#fff; color:var(--ink); }

/* Breadcrumb */
.breadcrumb{
  font-family: var(--font-mono); font-size:.78rem; color: var(--ink-soft); padding: 18px 0 0;
}
.breadcrumb a{ text-decoration:none; color: var(--sage); }
.breadcrumb a:hover{ text-decoration:underline; }

/* Article */
.article-header{ padding: 40px 0 20px; border-bottom:1px solid var(--rule); }
.article-meta{ display:flex; gap:16px; flex-wrap:wrap; font-family:var(--font-mono); font-size:.78rem; color:var(--ink-soft); margin-top:14px; }
.article-body{ max-width: 720px; margin: 0 auto; padding-top: 36px; }
.article-body h2{ margin-top:1.6em; }
.article-body h2::before{ content:"§ "; color: var(--correction); font-family: var(--font-mono); font-size:.75em; }
.article-body ul, .article-body ol{ padding-left: 1.3em; }
.article-body li{ margin-bottom:.5em; }
.article-body table{ width:100%; border-collapse: collapse; margin: 1.2em 0; font-size:.95rem; }
.article-body th, .article-body td{ border:1px solid var(--rule); padding:8px 12px; text-align:left; }
.article-body th{ background: var(--paper-dim); font-family: var(--font-mono); font-size:.78rem; text-transform:uppercase; letter-spacing:.04em; }
.callout{
  background: var(--paper-dim); border-left:4px solid var(--sage); padding: 14px 18px; border-radius: 0 8px 8px 0; margin: 1.4em 0;
}
.callout.correction{ border-left-color: var(--correction); background:#FDF1F1; }
.example{ font-family: var(--font-mono); font-size:.9rem; background:#fff; border:1px dashed var(--rule); padding:10px 14px; border-radius:8px; }
blockquote{ border-left:3px solid var(--highlighter); margin:1.4em 0; padding: .2em 1.2em; font-style:italic; color: var(--ink-soft); }

/* Legal pages */
.legal-body{ max-width: 760px; margin:0 auto; }
.legal-body h2{ margin-top:1.8em; font-size:1.3rem; }
.legal-body h3{ font-size:1.05rem; margin-top:1.2em; }
.legal-body ul{ padding-left:1.2em; }
.legal-updated{ font-family: var(--font-mono); font-size:.8rem; color: var(--sage); }

/* Sitemap page */
.sitemap-col h3{ font-family: var(--font-mono); text-transform:uppercase; font-size:.85rem; letter-spacing:.06em; color:var(--sage); margin-bottom:10px; }
.sitemap-col ul{ list-style:none; padding:0; margin:0; }
.sitemap-col li{ margin-bottom:8px; }
.sitemap-col a{ text-decoration:none; color:var(--ink); font-size:.95rem; }
.sitemap-col a:hover{ color:var(--correction); }

/* Contact form */
.form-field{ margin-bottom:18px; display:flex; flex-direction:column; gap:6px; }
.form-field label{ font-weight:600; font-size:.92rem; }
.form-field input, .form-field textarea, .form-field select{
  font-family: var(--font-body); padding: 11px 13px; border:1.5px solid var(--rule); border-radius:8px; font-size:.95rem; background:#fff;
}
.form-field input:focus, .form-field textarea:focus{ border-color: var(--sage); outline:none; }
.form-note{ font-size:.82rem; color: var(--ink-soft); }

/* Footer */
.site-footer{ background: var(--ink); color:#C7CEE0; padding: 56px 0 26px; margin-top: 40px; }
.footer-grid{ display:grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
@media (max-width: 800px){ .footer-grid{ grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px){ .footer-grid{ grid-template-columns: 1fr; } }
.footer-grid h4{ color:#fff; font-family: var(--font-mono); font-size:.78rem; text-transform:uppercase; letter-spacing:.06em; margin-bottom:14px; }
.footer-grid ul{ list-style:none; padding:0; margin:0; display:flex; flex-direction:column; gap:9px; }
.footer-grid a{ color:#AEB8D4; text-decoration:none; font-size:.92rem; }
.footer-grid a:hover{ color:#fff; }
.footer-brand{ font-family: var(--font-display); font-size:1.3rem; color:#fff; margin-bottom:10px; }
.footer-bottom{
  border-top:1px solid #2A3A5E; margin-top: 44px; padding-top: 22px;
  display:flex; justify-content:space-between; flex-wrap:wrap; gap:12px; font-size:.82rem; color:#8B97BB;
}
.footer-bottom a{ color:#AEB8D4; text-decoration:none; }
.footer-bottom a:hover{ color:#fff; }
.lang-note{ font-size:.82rem; color:#8B97BB; margin-top:8px; }
.lang-note a{ color: var(--highlighter); text-decoration:none; font-weight:600; }

.visually-hidden{ position:absolute; width:1px;height:1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap; }