feat(lessons): add lessons from client db

src/pages/student/lessons/LinearParallelPerpendicularLesson.tsx

@@ -0,0 +1,350 @@
+import React, { useRef, useState, useEffect } from "react";
+import { ArrowDown, Check, BookOpen, Layers } from "lucide-react";
+import ParallelPerpendicularWidget from "../../../components/lessons/ParallelPerpendicularWidget";
+import Quiz from "../../../components/lessons/Quiz";
+import { LINEAR_PARALLEL_PERP_QUIZ_DATA } from "../../../utils/constants";
+import { Frac } from "../../../components/Math";
+
+interface LessonProps {
+  onFinish?: () => void;
+}
+
+const LinearParallelPerpendicularLesson: React.FC<LessonProps> = ({
+  onFinish,
+}) => {
+  const [activeSection, setActiveSection] = useState(0);
+  const sectionsRef = useRef<(HTMLElement | null)[]>([]);
+
+  const scrollToSection = (index: number) => {
+    setActiveSection(index);
+    sectionsRef.current[index]?.scrollIntoView({
+      behavior: "smooth",
+      block: "start",
+    });
+  };
+
+  useEffect(() => {
+    const observer = new IntersectionObserver(
+      (entries) => {
+        entries.forEach((entry) => {
+          if (entry.isIntersecting) {
+            const index = sectionsRef.current.indexOf(
+              entry.target as HTMLElement,
+            );
+            if (index !== -1) setActiveSection(index);
+          }
+        });
+      },
+      { rootMargin: "-20% 0px -60% 0px" },
+    );
+    sectionsRef.current.forEach((section) => {
+      if (section) observer.observe(section);
+    });
+    return () => observer.disconnect();
+  }, []);
+
+  const SectionMarker = ({
+    index,
+    title,
+    icon: Icon,
+  }: {
+    index: number;
+    title: string;
+    icon: any;
+  }) => {
+    const isActive = activeSection === index;
+    const isPast = activeSection > index;
+    return (
+      <button
+        onClick={() => scrollToSection(index)}
+        className={`flex items-center gap-3 p-3 w-full rounded-lg transition-all ${isActive ? "bg-white shadow-md border border-blue-100" : "hover:bg-slate-100"}`}
+      >
+        <div
+          className={`w-8 h-8 rounded-full flex items-center justify-center shrink-0 ${isActive ? "bg-blue-600 text-white" : isPast ? "bg-blue-400 text-white" : "bg-slate-200 text-slate-500"}`}
+        >
+          {isPast ? (
+            <Check className="w-4 h-4" />
+          ) : (
+            <Icon className="w-4 h-4" />
+          )}
+        </div>
+        <div className="text-left">
+          <p
+            className={`text-sm font-bold ${isActive ? "text-blue-900" : "text-slate-600"}`}
+          >
+            {title}
+          </p>
+        </div>
+      </button>
+    );
+  };
+
+  return (
+    <div className="flex flex-col lg:flex-row min-h-screen">
+      <aside className="w-full lg:w-64 lg:fixed lg:top-20 lg:bottom-0 lg:overflow-y-auto p-4 border-r border-slate-200 bg-slate-50 z-0 hidden lg:block">
+        <nav className="space-y-2">
+          <SectionMarker
+            index={0}
+            title="Parallel & Perpendicular"
+            icon={Layers}
+          />
+          <SectionMarker index={1} title="Practice" icon={BookOpen} />
+        </nav>
+      </aside>
+
+      <div className="flex-1 lg:ml-64 p-6 md:p-12 max-w-4xl mx-auto">
+        {/* Section 1 */}
+        <section
+          ref={(el) => {
+            sectionsRef.current[0] = el;
+          }}
+          className="min-h-screen flex flex-col justify-center mb-24 pt-20 lg:pt-0"
+        >
+          <h2 className="text-4xl font-extrabold text-slate-900 mb-6">
+            Parallel & Perpendicular Lines
+          </h2>
+          <div className="prose prose-slate text-lg text-slate-600 mb-8">
+            <p>
+              Parallel and perpendicular line questions appear on almost every
+              SAT. The core skill is: identify the slope of the given line,
+              apply the parallel or perpendicular slope rule, then write the new
+              equation through a given point.
+            </p>
+          </div>
+
+          <div className="bg-blue-50 border border-blue-200 rounded-2xl p-6 mb-8 space-y-5">
+            <h3 className="text-lg font-bold text-blue-900">
+              The Two Slope Rules
+            </h3>
+
+            <div className="grid md:grid-cols-2 gap-4">
+              <div className="bg-white rounded-xl p-5 border border-blue-100">
+                <p className="font-bold text-blue-900 mb-3 text-lg">
+                  Parallel Lines
+                </p>
+                <div className="bg-blue-50 rounded-lg p-3 text-center mb-3">
+                  <p className="font-mono text-blue-800 font-bold text-xl">
+                    m₁ = m₂
+                  </p>
+                  <p className="text-xs text-slate-500 mt-1">
+                    Same slope, different y-intercept
+                  </p>
+                </div>
+                <ul className="text-slate-600 text-sm space-y-1 list-disc list-inside">
+                  <li>Lines never intersect — they run side by side</li>
+                  <li>Same slope guarantees they won't cross</li>
+                  <li>
+                    If y-intercepts also matched, the lines would be identical
+                  </li>
+                </ul>
+                <div className="mt-3 bg-blue-50 rounded-lg p-2 font-mono text-xs text-slate-600">
+                  y = 3x + 1 ∥ y = 3x − 7 (both slope = 3)
+                </div>
+              </div>
+              <div className="bg-white rounded-xl p-5 border border-blue-100">
+                <p className="font-bold text-indigo-900 mb-3 text-lg">
+                  Perpendicular Lines
+                </p>
+                <div className="bg-indigo-50 rounded-lg p-3 text-center mb-3">
+                  <p className="font-mono text-indigo-800 font-bold text-xl">
+                    m₁ × m₂ = −1
+                  </p>
+                  <p className="text-xs text-slate-500 mt-1">
+                    Negative reciprocal slopes
+                  </p>
+                </div>
+                <ul className="text-slate-600 text-sm space-y-1 list-disc list-inside">
+                  <li>Lines meet at a 90° angle</li>
+                  <li>Rule: flip the fraction and change the sign</li>
+                  <li>
+                    A horizontal line (slope 0) is ⊥ to a vertical line
+                    (undefined slope)
+                  </li>
+                </ul>
+                <div className="mt-3 bg-indigo-50 rounded-lg p-2 font-mono text-xs text-slate-600">
+                  y = <Frac n="2" d="3" />x + 1 ⊥ y = <Frac n="−3" d="2" />x + 5
+                </div>
+              </div>
+            </div>
+
+            {/* Negative Reciprocal Examples */}
+            <div className="bg-white rounded-xl p-5 border border-blue-100">
+              <p className="font-bold text-blue-800 mb-3">
+                Finding Perpendicular Slopes: Worked Examples
+              </p>
+              <div className="overflow-x-auto">
+                <table className="w-full text-sm border-collapse">
+                  <thead>
+                    <tr className="bg-blue-100 text-blue-900">
+                      <th className="p-2 text-left font-bold">
+                        Original Slope
+                      </th>
+                      <th className="p-2 text-left font-bold">
+                        Step 1: Flip the fraction
+                      </th>
+                      <th className="p-2 text-left font-bold">
+                        Step 2: Negate the sign
+                      </th>
+                      <th className="p-2 text-left font-bold">
+                        Perpendicular Slope
+                      </th>
+                    </tr>
+                  </thead>
+                  <tbody className="text-slate-600">
+                    <tr className="border-b border-blue-50">
+                      <td className="p-2 font-mono">2 (= 2÷1)</td>
+                      <td className="p-2">
+                        <Frac n="1" d="2" />
+                      </td>
+                      <td className="p-2">
+                        <Frac n="−1" d="2" />
+                      </td>
+                      <td className="p-2 font-bold text-indigo-700">
+                        <Frac n="−1" d="2" />
+                      </td>
+                    </tr>
+                    <tr className="border-b border-blue-50 bg-slate-50">
+                      <td className="p-2">
+                        <Frac n="−3" d="4" />
+                      </td>
+                      <td className="p-2">
+                        <Frac n="4" d="3" />
+                      </td>
+                      <td className="p-2">
+                        <Frac n="4" d="3" />
+                      </td>
+                      <td className="p-2 font-bold text-indigo-700">
+                        <Frac n="4" d="3" />
+                      </td>
+                    </tr>
+                    <tr className="border-b border-blue-50">
+                      <td className="p-2 font-mono">−5</td>
+                      <td className="p-2">
+                        <Frac n="1" d="5" /> (flip)
+                      </td>
+                      <td className="p-2">
+                        <Frac n="1" d="5" /> (negate negative)
+                      </td>
+                      <td className="p-2 font-bold text-indigo-700">
+                        <Frac n="1" d="5" />
+                      </td>
+                    </tr>
+                    <tr className="bg-slate-50">
+                      <td className="p-2 font-mono">0 (horizontal)</td>
+                      <td className="p-2 font-mono">—</td>
+                      <td className="p-2 font-mono">—</td>
+                      <td className="p-2 font-bold text-indigo-700">
+                        Undefined (vertical)
+                      </td>
+                    </tr>
+                  </tbody>
+                </table>
+              </div>
+            </div>
+
+            {/* Full Problem Worked Examples */}
+            <div className="bg-white rounded-xl p-5 border border-blue-100">
+              <p className="font-bold text-blue-800 mb-3">
+                Complete Problem: Writing the Equation
+              </p>
+              <div className="space-y-4">
+                <div className="bg-blue-50 rounded-lg p-4 text-sm">
+                  <p className="font-semibold text-blue-800 mb-2">
+                    Example 1: Find the line parallel to y = 4x − 3 passing
+                    through (2, 5)
+                  </p>
+                  <div className="font-mono space-y-1 text-slate-700">
+                    <p>Parallel → same slope: m = 4</p>
+                    <p>Use point-slope: y − 5 = 4(x − 2)</p>
+                    <p>y − 5 = 4x − 8</p>
+                    <p className="text-blue-700 font-bold">
+                      y = 4x − 3 &nbsp;← Wait, same as original! Confirm: passes
+                      through (2, 5): 5 = 8 − 3 = 5 ✓
+                    </p>
+                  </div>
+                </div>
+                <div className="bg-indigo-50 rounded-lg p-4 text-sm">
+                  <p className="font-semibold text-indigo-800 mb-2">
+                    Example 2: Find the line perpendicular to 2x + 3y = 12
+                    passing through (4, 1)
+                  </p>
+                  <div className="font-mono space-y-1 text-slate-700">
+                    <p>
+                      First, find slope of 2x + 3y = 12: y ={" "}
+                      <Frac n="−2" d="3" />x + 4, so m = <Frac n="−2" d="3" />
+                    </p>
+                    <p>
+                      Perpendicular slope: flip and negate → m ={" "}
+                      <Frac n="3" d="2" />
+                    </p>
+                    <p>
+                      Point-slope: y − 1 = <Frac n="3" d="2" />
+                      (x − 4)
+                    </p>
+                    <p>
+                      y = <Frac n="3" d="2" />x − 6 + 1
+                    </p>
+                    <p className="text-indigo-700 font-bold">
+                      y = <Frac n="3" d="2" />x − 5
+                    </p>
+                  </div>
+                </div>
+              </div>
+            </div>
+
+            <div className="bg-red-50 border border-red-200 rounded-xl p-4 text-sm">
+              <p className="font-bold text-red-800 mb-1">
+                SAT Trap: Parallel Lines Must Have Different Intercepts
+              </p>
+              <p className="text-slate-700">
+                Parallel lines need the <em>same slope</em> but a{" "}
+                <em>different y-intercept</em>. If the intercepts also match,
+                the lines are identical — infinitely many intersections, not
+                parallel. The SAT sometimes includes a "same slope, same
+                intercept" option to trap students.
+              </p>
+            </div>
+          </div>
+
+          <ParallelPerpendicularWidget />
+
+          <button
+            onClick={() => scrollToSection(1)}
+            className="mt-12 group flex items-center text-blue-600 font-bold hover:text-blue-800 transition-colors"
+          >
+            Next: Practice Quiz{" "}
+            <ArrowDown className="ml-2 w-5 h-5 group-hover:translate-y-1 transition-transform" />
+          </button>
+        </section>
+
+        {/* Section 2: Quiz */}
+        <section
+          ref={(el) => {
+            sectionsRef.current[1] = el;
+          }}
+          className="min-h-screen flex flex-col justify-center"
+        >
+          <h2 className="text-4xl font-extrabold text-slate-900 mb-8">
+            Practice Time
+          </h2>
+          {LINEAR_PARALLEL_PERP_QUIZ_DATA.map((quiz, idx) => (
+            <div key={quiz.id} className="mb-12">
+              <Quiz data={quiz} />
+            </div>
+          ))}
+          <div className="p-8 bg-blue-900 rounded-2xl text-white text-center mt-12">
+            <h3 className="text-2xl font-bold mb-4">Topic Mastered!</h3>
+            <button
+              onClick={onFinish}
+              className="px-6 py-3 bg-white text-blue-900 font-bold rounded-full hover:bg-blue-50 transition-colors"
+            >
+              Finish Lesson ✓
+            </button>
+          </div>
+        </section>
+      </div>
+    </div>
+  );
+};
+
+export default LinearParallelPerpendicularLesson;