/*
 * Copyright 2026 Steven Price / ZTLP.org
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* ─── RESET & BASE ─────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:          #ffffff;
  --bg2:         #f8fafc;
  --bg3:         #f1f5f9;
  --surface:     #f1f5f9;
  --surface2:    #e2e8f0;
  --border:      #e2e8f0;
  --border2:     #cbd5e1;
  --text:        #0f172a;
  --text2:       #475569;
  --text3:       #94a3b8;
  --accent:      #0284c7;
  --accent2:     #0369a1;
  --accent-dim:  rgba(2,132,199,.1);
  --green:       #34d399;
  --yellow:      #fbbf24;
  --red:         #f87171;
  --purple:      #a78bfa;
  --radius:      8px;
  --radius-lg:   14px;
  --font:        'Inter', system-ui, sans-serif;
  --mono:        'JetBrains Mono', 'Fira Mono', monospace;
  --nav-h:       64px;
  --sidebar-w:   240px;
}

html { scroll-behavior: smooth; font-size: 16px; }

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

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ─── TOP NAV ──────────────────────────────────────────── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 32px;
}
.topbar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.logo-badge {
  background: var(--accent);
  color: #000;
  font-weight: 700;
  font-size: 13px;
  padding: 3px 8px;
  border-radius: 4px;
  letter-spacing: .05em;
}
.logo-subtitle {
  color: var(--text2);
  font-size: 13px;
  font-weight: 500;
}
.topbar-nav {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-left: auto;
}
.topbar-nav a {
  color: var(--text2);
  font-size: 14px;
  font-weight: 500;
  transition: color .2s;
}
.topbar-nav a:hover { color: var(--text); text-decoration: none; }
.topbar-nav a.nav-page-link.active {
  color: var(--accent);
  font-weight: 600;
  position: relative;
}
.topbar-nav a.nav-page-link.active::after {
  content: '';
  position: absolute;
  bottom: -20px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}
.logo-link {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none !important;
  color: inherit;
}
.logo-link:hover { text-decoration: none !important; }
.btn-linkedin {
  display: flex !important;
  align-items: center;
  gap: 6px;
  background: #0077b5 !important;
  color: #fff !important;
  padding: 7px 14px !important;
  border-radius: var(--radius) !important;
  font-size: 13px !important;
  font-weight: 600 !important;
  transition: background .2s !important;
}
.btn-linkedin:hover { background: #0069a3 !important; text-decoration: none !important; }
.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  color: var(--text2);
  padding: 6px 10px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 18px;
  margin-left: auto;
}

/* ─── HERO ─────────────────────────────────────────────── */
.hero {
  position: relative;
  overflow: hidden;
  padding: 100px 0 80px;
  text-align: center;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 0%, rgba(2,132,199,.08) 0%, transparent 70%);
  pointer-events: none;
}
.hero-content { position: relative; z-index: 1; }
.hero-badge {
  display: inline-block;
  background: var(--accent-dim);
  border: 1px solid rgba(56,189,248,.3);
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
  padding: 5px 14px;
  border-radius: 999px;
  letter-spacing: .06em;
  text-transform: uppercase;
  margin-bottom: 24px;
}
.hero-title {
  font-size: clamp(2.4rem, 5vw, 4rem);
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1.15;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #0f172a 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-tagline {
  font-size: 1.15rem;
  color: var(--accent);
  font-style: italic;
  font-weight: 500;
  margin-bottom: 24px;
  font-family: var(--mono);
}
.hero-abstract {
  max-width: 720px;
  margin: 0 auto 28px;
  color: var(--text2);
  font-size: 1.05rem;
  line-height: 1.8;
}
.hero-meta {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  color: var(--text3);
  font-size: 13px;
  margin-bottom: 36px;
}
.hero-meta strong { color: var(--text2); }
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.hero-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 40px;
  max-width: 860px;
  margin: 0 auto;
  padding: 0 24px;
}
.hero-text { width: 100%; }
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  width: 100%;
  max-width: 640px;
}
.stat-item { text-align: center; }

/* ─── HOW IT WORKS ────────────────────────────────────── */
.how-it-works {
  padding: 72px 0;
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg2) 100%);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.how-it-works-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 40px;
}
.how-it-works-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}
.how-step {
  background: rgba(255,255,255,.72);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.04);
}
.how-step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  margin-bottom: 14px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-size: .95rem;
  font-weight: 700;
}
.how-step h3 {
  font-size: 1.05rem;
  line-height: 1.4;
  margin-bottom: 10px;
  color: var(--text);
}
.how-step p {
  color: var(--text2);
  font-size: .97rem;
  line-height: 1.7;
}

/* ─── BUTTONS ──────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all .2s;
  text-decoration: none !important;
}
.btn-primary {
  background: var(--accent);
  color: #000;
}
.btn-primary:hover { background: #7dd3fc; }
.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border2);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }
.btn-sm { padding: 7px 14px; font-size: 13px; }

/* ─── STATS BAR ────────────────────────────────────────── */
.stats-bar {
  background: var(--bg2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 32px 0;
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  text-align: center;
}
.stat-num {
  display: block;
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent);
  font-family: var(--mono);
  line-height: 1.2;
}
.stat-label {
  display: block;
  font-size: 12px;
  color: var(--text3);
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-top: 4px;
}

/* ─── LAYOUT (sidebar + content) ───────────────────────── */
.layout {
  display: flex;
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 24px;
  gap: 48px;
  align-items: flex-start;
}

/* ─── SIDEBAR ──────────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  position: sticky;
  top: calc(var(--nav-h) + 24px);
  max-height: calc(100vh - var(--nav-h) - 48px);
  overflow-y: auto;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
}
.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 4px; }
.toc-title {
  font-size: 11px;
  font-weight: 700;
  color: var(--text3);
  text-transform: uppercase;
  letter-spacing: .1em;
  margin-bottom: 12px;
}
.toc { display: flex; flex-direction: column; gap: 2px; margin-bottom: 20px; }
.toc-link {
  font-size: 12.5px;
  color: var(--text2);
  padding: 5px 8px;
  border-radius: 5px;
  transition: all .15s;
  display: block;
}
.toc-link:hover, .toc-link.active {
  background: var(--accent-dim);
  color: var(--accent);
  text-decoration: none;
}
.sidebar-actions { display: flex; flex-direction: column; gap: 8px; }

/* ─── SPEC CONTENT ──────────────────────────────────────── */
.spec-content { flex: 1; min-width: 0; }

.spec-section {
  margin-bottom: 64px;
  scroll-margin-top: calc(var(--nav-h) + 24px);
}
.spec-section h2 {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}
.sec-num {
  background: var(--accent-dim);
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  padding: 3px 9px;
  border-radius: 5px;
  font-family: var(--mono);
}
.spec-section h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  margin: 24px 0 10px;
}
.spec-section h4 {
  font-size: .95rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}
.spec-section p { color: var(--text2); margin-bottom: 14px; }
.spec-section ul, .spec-section ol { color: var(--text2); padding-left: 20px; margin-bottom: 14px; }
.spec-section li { margin-bottom: 6px; }

code {
  font-family: var(--mono);
  background: var(--surface);
  color: var(--accent);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: .875em;
}

.code-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  overflow-x: auto;
  margin: 16px 0;
  font-family: var(--mono);
  font-size: .82rem;
  color: #0369a1;
  line-height: 1.6;
  white-space: pre;
}

/* ─── TABLES ────────────────────────────────────────────── */
.table-wrap { overflow-x: auto; margin: 16px 0; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
}
thead tr { background: var(--surface); }
th {
  text-align: left;
  padding: 10px 14px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text3);
  border-bottom: 1px solid var(--border);
}
td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text2);
  vertical-align: top;
}
tr:hover td { background: var(--surface); }
td code { font-size: .78rem; }

/* ─── CALLOUTS ──────────────────────────────────────────── */
.callout {
  border-radius: var(--radius);
  padding: 14px 18px;
  font-size: 14px;
  margin: 16px 0;
  border-left: 3px solid;
}
.callout-info {
  background: rgba(56,189,248,.08);
  border-color: var(--accent);
  color: var(--text2);
}
.callout-warn {
  background: rgba(251,191,36,.08);
  border-color: var(--yellow);
  color: var(--text2);
}
.callout strong { color: var(--text); }

/* ─── BLOCKQUOTE ────────────────────────────────────────── */
blockquote.protocol-rule {
  background: var(--surface);
  border-left: 3px solid var(--accent);
  padding: 18px 24px;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 1rem;
  font-style: italic;
  color: var(--accent);
  margin: 20px 0;
}

/* ─── PROBLEM / GOAL LISTS ─────────────────────────────── */
.problem-list li { color: var(--text2); }
.problem-list li::marker { color: var(--red); }
.goal-list li::marker { color: var(--green); }
.nongoal-list li::marker { color: var(--yellow); }
.flow-list li::marker { color: var(--accent); }
.ref-list { list-style: none; padding: 0; }
.ref-list li {
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
  color: var(--text2);
}
.ref-list li:last-child { border-bottom: none; }
.ref-list strong { color: var(--text); }
.open-issues li { margin-bottom: 10px; }
.open-issues strong { color: var(--text); }

/* ─── THREAT BADGE ──────────────────────────────────────── */
.threat-badge {
  display: inline-block;
  background: rgba(248,113,113,.12);
  color: var(--red);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
  white-space: nowrap;
}

/* ─── BOOTSTRAP STEPS ───────────────────────────────────── */
.bootstrap-steps { display: flex; flex-direction: column; gap: 12px; margin: 16px 0; }
.bootstrap-step {
  display: flex;
  gap: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
}
.step-num {
  flex-shrink: 0;
  width: 60px;
  color: var(--accent);
  font-weight: 700;
  font-size: 13px;
  font-family: var(--mono);
  padding-top: 2px;
}
.step-body h4 { margin-bottom: 6px; }
.step-body p { font-size: 13.5px; color: var(--text2); margin: 0; }
.badge {
  display: inline-block;
  padding: 1px 7px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  margin-left: 8px;
}
.badge.required { background: rgba(52,211,153,.15); color: var(--green); }
.badge.recommended { background: rgba(56,189,248,.15); color: var(--accent); }
.badge.fallback { background: rgba(251,191,36,.15); color: var(--yellow); }

/* ─── LIFECYCLE ─────────────────────────────────────────── */
.lifecycle-steps {
  display: flex;
  align-items: flex-start;
  gap: 4px;
  margin: 20px 0;
  flex-wrap: wrap;
}
.lifecycle-step {
  flex: 1;
  min-width: 140px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
}
.lifecycle-step span {
  display: block;
  font-weight: 700;
  color: var(--accent);
  font-size: 13px;
  margin-bottom: 6px;
}
.lifecycle-step p { font-size: 12.5px; color: var(--text2); margin: 0; }
.lifecycle-arrow {
  color: var(--text3);
  font-size: 1.2rem;
  padding-top: 20px;
  flex-shrink: 0;
}

/* ─── PHASES ─────────────────────────────────────────────── */
.phases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin: 20px 0;
}
.phase-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  position: relative;
}
.phase-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--text3);
  margin-bottom: 6px;
}
.phase-card h4 { color: var(--text); font-size: 1rem; margin-bottom: 8px; }
.phase-card p { font-size: 13.5px; color: var(--text2); margin-bottom: 12px; }
.compat-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
}
.compat-badge.high { background: rgba(52,211,153,.15); color: var(--green); }
.compat-badge.med  { background: rgba(251,191,36,.15);  color: var(--yellow); }
.compat-badge.low  { background: rgba(248,113,113,.15); color: var(--red); }

/* ─── DOWNLOAD SECTION ──────────────────────────────────── */
.download-section {
  background: var(--bg2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 72px 0;
}
.section-title {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text);
  text-align: center;
  margin-bottom: 10px;
}
.section-sub {
  text-align: center;
  color: var(--text2);
  margin-bottom: 40px;
  font-size: 1rem;
}
.download-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 800px;
  margin: 0 auto;
}
.download-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
  transition: border-color .2s;
}
.download-card:hover { border-color: var(--accent); }
.dl-icon { color: var(--accent); }
.dl-info h3 { font-size: 1rem; color: var(--text); margin-bottom: 6px; }
.dl-info p { font-size: 13px; color: var(--text2); margin: 0; }

/* ─── CONNECT SECTION ───────────────────────────────────── */
.connect-section {
  padding: 72px 0;
  background: var(--bg);
}
.connect-inner {
  display: flex;
  align-items: center;
  gap: 48px;
  flex-wrap: wrap;
}
.connect-text { flex: 1; min-width: 280px; }
.connect-text h2 { font-size: 1.6rem; font-weight: 700; color: var(--text); margin-bottom: 12px; }
.connect-text p { color: var(--text2); font-size: 1rem; }
.btn-linkedin-large {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: #0077b5;
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  padding: 14px 28px;
  border-radius: var(--radius-lg);
  white-space: nowrap;
  transition: background .2s;
  flex-shrink: 0;
}
.btn-linkedin-large:hover { background: #0069a3; text-decoration: none; }

/* ─── FEEDBACK SECTION ──────────────────────────────────── */
.feedback-section {
  background: var(--bg2);
  border-top: 1px solid var(--border);
  padding: 72px 0;
}
.feedback-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: flex-start;
}
.feedback-form-wrap h3, .comments-panel h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 20px;
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.form-group { margin-bottom: 16px; }
label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text2);
  margin-bottom: 6px;
}
.req { color: var(--red); }
input[type="text"], textarea, select {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border2);
  border-radius: var(--radius);
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  padding: 9px 12px;
  transition: border-color .2s;
  outline: none;
}
input:focus, textarea:focus, select:focus { border-color: var(--accent); }
textarea { resize: vertical; }
select option { background: var(--surface2); }
.radio-group { display: flex; gap: 16px; flex-wrap: wrap; }
.radio-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text2);
  cursor: pointer;
}
.form-actions { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.form-note { font-size: 12px; color: var(--text3); }
.form-success {
  background: rgba(52,211,153,.12);
  border: 1px solid rgba(52,211,153,.3);
  color: var(--green);
  padding: 10px 14px;
  border-radius: var(--radius);
  font-size: 14px;
  margin-top: 12px;
}
.form-error {
  background: rgba(248,113,113,.12);
  border: 1px solid rgba(248,113,113,.3);
  color: var(--red);
  padding: 10px 14px;
  border-radius: var(--radius);
  font-size: 14px;
  margin-top: 12px;
}
.hidden { display: none !important; }

/* ─── COMMENTS ──────────────────────────────────────────── */
.comment-count {
  background: var(--surface);
  color: var(--text3);
  font-size: 12px;
  padding: 2px 8px;
  border-radius: 999px;
  font-weight: 600;
}
.comments-list { display: flex; flex-direction: column; gap: 14px; }
.no-comments { color: var(--text3); font-size: 14px; padding: 20px 0; }
.comment-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  animation: fadeIn .3s ease;
}
@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
.comment-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}
.comment-name { font-weight: 600; font-size: 14px; color: var(--text); }
.comment-affil { font-size: 12px; color: var(--text3); }
.comment-type {
  margin-left: auto;
  font-size: 11px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: .05em;
}
.type-comment  { background: rgba(56,189,248,.15);  color: var(--accent); }
.type-suggestion { background: rgba(167,139,250,.15); color: var(--purple); }
.type-question { background: rgba(251,191,36,.15);   color: var(--yellow); }
.type-issue    { background: rgba(248,113,113,.15);  color: var(--red); }
.comment-section-tag {
  font-size: 11px;
  color: var(--text3);
  font-family: var(--mono);
  margin-bottom: 8px;
}
.comment-body { font-size: 14px; color: var(--text2); line-height: 1.6; }
.comment-date { font-size: 11px; color: var(--text3); margin-top: 8px; }

/* ─── FOOTER ────────────────────────────────────────────── */
.site-footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 32px 0;
}
.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-align: center;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: var(--text2);
  font-size: 14px;
}
.footer-meta {
  display: flex;
  flex-direction: column;
  gap: 4px;
  color: var(--text3);
  font-size: 12px;
}
.footer-links {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  justify-content: center;
}
.footer-links a { color: var(--text3); font-size: 13px; }
.footer-links a:hover { color: var(--accent); text-decoration: none; }

/* ─── PRINT STYLES ──────────────────────────────────────── */
@media print {
  .topbar, .sidebar, .stats-bar, .download-section,
  .connect-section, .feedback-section, .site-footer,
  .hero-actions, .sidebar-actions { display: none !important; }
  .layout { display: block; padding: 0; }
  .spec-content { max-width: 100%; }
  body { background: #fff; color: #000; }
  .spec-section h2 { color: #000; border-color: #ccc; }
  .sec-num { background: #eee; color: #333; }
  .code-block { background: #f5f5f5; color: #333; border: 1px solid #ddd; }
  code { background: #f0f0f0; color: #333; }
  td, th { border-color: #ddd; color: #333; }
  .callout { background: #f9f9f9; color: #333; }
  blockquote.protocol-rule { background: #f5f5f5; color: #0077b5; }
  .hero { padding: 20px 0; }
  .hero-title { -webkit-text-fill-color: #000; color: #000; }
  .hero-tagline, .hero-abstract, .hero-meta { color: #333; }
}

/* ─── RESPONSIVE ────────────────────────────────────────── */
@media (max-width: 900px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .layout { flex-direction: column; padding: 32px 20px; gap: 32px; }
  .sidebar { width: 100%; position: static; max-height: none; }
  .toc { display: none; }
  .sidebar.open .toc { display: flex; }
  .phases-grid { grid-template-columns: 1fr; }
  .feedback-layout { grid-template-columns: 1fr; }
  .download-cards { grid-template-columns: 1fr; }
  .lifecycle-steps { flex-direction: column; }
  .lifecycle-arrow { display: none; }
  .connect-inner { flex-direction: column; text-align: center; }
  .how-it-works-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .topbar-nav { display: none; }
  .topbar-nav.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    background: var(--bg2);
    border-bottom: 1px solid var(--border);
    padding: 20px 24px;
    gap: 16px;
    z-index: 99;
  }
  .menu-toggle { display: block; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .hero-title { font-size: 2rem; }

  .how-it-works {
    padding: 56px 0;
  }
  .how-it-works-header {
    margin-bottom: 28px;
  }
  .how-it-works-grid {
    grid-template-columns: 1fr;
    gap: 18px;
  }
  .how-step {
    display: block;
    padding: 22px 20px;
    border-radius: 20px;
    background: rgba(255,255,255,.9);
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.06);
  }
  .how-step-number {
    width: auto;
    height: auto;
    margin-bottom: 14px;
    padding: 6px 12px;
    font-size: .86rem;
    line-height: 1;
    box-shadow: none;
    border-radius: 999px;
  }
  .how-step h3 {
    margin: 0 0 10px;
    font-size: 1.08rem;
    line-height: 1.35;
  }
  .how-step p {
    margin: 0;
    font-size: 1rem;
    line-height: 1.72;
  }
}