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index 14df0b9..c6aaa87 100644
--- a/frontend/textbooks/chemistry_7_ch1.html
+++ b/frontend/textbooks/chemistry_7_ch1.html
@@ -10,6 +10,12 @@
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 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css">
 <link rel="stylesheet" href="/css/chem8-textbook.css">
+<style>/* Химия 7 · тема главы 1 — emerald (переопределяет amber chem8-textbook.css) */
+:root{--bg:#f0fdf4;--border:#bbf7d0;--pri:#059669;--pri-d:#047857;--pri-l:#34d399;--pri-soft:#d1fae5;--sec-acc:#059669;--sec-acc-d:#047857;--sec-acc-soft:#d1fae5;--warn:#047857;--warn-bg:#d1fae5}
+html.dark{--bg:#0a1a12;--border:#1f4030;--pri-soft:rgba(5,150,105,.18);--sec-acc-soft:rgba(5,150,105,.18)}
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diff --git a/frontend/textbooks/chemistry_7_ch2.html b/frontend/textbooks/chemistry_7_ch2.html
index 1e124e2..078d227 100644
--- a/frontend/textbooks/chemistry_7_ch2.html
+++ b/frontend/textbooks/chemistry_7_ch2.html
@@ -10,6 +10,12 @@
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 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css">
 <link rel="stylesheet" href="/css/chem8-textbook.css">
+<style>/* Химия 7 · тема главы 2 — cyan (переопределяет amber chem8-textbook.css) */
+:root{--bg:#ecfeff;--border:#a5f3fc;--pri:#0891b2;--pri-d:#0e7490;--pri-l:#22d3ee;--pri-soft:#cffafe;--sec-acc:#0891b2;--sec-acc-d:#0e7490;--sec-acc-soft:#cffafe;--warn:#0e7490;--warn-bg:#cffafe}
+html.dark{--bg:#08191c;--border:#164e5b;--pri-soft:rgba(8,145,178,.18);--sec-acc-soft:rgba(8,145,178,.18)}
+.hdr{background:linear-gradient(110deg,#164e63 0%,#0891b2 55%,#22d3ee 100%)}
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diff --git a/frontend/textbooks/chemistry_7_ch3.html b/frontend/textbooks/chemistry_7_ch3.html
index 349f0c1..21f31e1 100644
--- a/frontend/textbooks/chemistry_7_ch3.html
+++ b/frontend/textbooks/chemistry_7_ch3.html
@@ -10,6 +10,12 @@
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 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css">
 <link rel="stylesheet" href="/css/chem8-textbook.css">
+<style>/* Химия 7 · тема главы 3 — violet (переопределяет amber chem8-textbook.css) */
+:root{--bg:#f5f3ff;--border:#ddd6fe;--pri:#7c3aed;--pri-d:#6d28d9;--pri-l:#a78bfa;--pri-soft:#ede9fe;--sec-acc:#7c3aed;--sec-acc-d:#6d28d9;--sec-acc-soft:#ede9fe;--warn:#6d28d9;--warn-bg:#ede9fe}
+html.dark{--bg:#140a24;--border:#3b2a63;--pri-soft:rgba(124,58,237,.18);--sec-acc-soft:rgba(124,58,237,.18)}
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diff --git a/frontend/textbooks/chemistry_7_ch4.html b/frontend/textbooks/chemistry_7_ch4.html
index ff866c0..7b79c64 100644
--- a/frontend/textbooks/chemistry_7_ch4.html
+++ b/frontend/textbooks/chemistry_7_ch4.html
@@ -10,6 +10,12 @@
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 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.9/dist/katex.min.css">
 <link rel="stylesheet" href="/css/chem8-textbook.css">
+<style>/* Химия 7 · тема главы 4 — blue (переопределяет amber chem8-textbook.css) */
+:root{--bg:#eff6ff;--border:#bfdbfe;--pri:#2563eb;--pri-d:#1d4ed8;--pri-l:#60a5fa;--pri-soft:#dbeafe;--sec-acc:#2563eb;--sec-acc-d:#1d4ed8;--sec-acc-soft:#dbeafe;--warn:#1d4ed8;--warn-bg:#dbeafe}
+html.dark{--bg:#0a1222;--border:#1e3a5f;--pri-soft:rgba(37,99,235,.18);--sec-acc-soft:rgba(37,99,235,.18)}
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