[
  {
    "id": 1,
    "title": "The Crime Scene",
    "category": "Basic Operations",
    "difficulty": "Easy",
    "points": 100,
    "description": "Detective, you arrive at Professor Euler's lab to find chaos! There are <b>15 books scattered</b>, <b>8 papers torn</b>, and <b>3 coffee cups spilled</b>. To access the security footage, enter the total number of disturbed items.",
    "flag": "^26$",
    "testflag": "26",
    "hints": [
      { "id": 1, "text": "**Step 1:** Count the items<br><br>- 📚 *15 books* scattered<br>- 📄 <em>8 papers</em> torn<br>- ☕ **3 cups** spilled<br><br><mark>Remember: Every item matters!</mark>", "cost": 0 },
      { "id": 2, "text": "## The Formula:\n\n`books + papers + cups = total`\n\n### Breakdown:\n\n| Item | Count | Status |\n|------|-------|--------|\n| 📚 Books | **15** | Scattered |\n| 📄 Papers | *8* | Torn |\n| ☕ Cups | <mark>3</mark> | Spilled |\n| **Total** | **?** | Calculate! |\n\n> **Solution:** `15 + 8 + 3 = ?`", "cost": 0 }
    ]
  },
  {
    "id": 2,
    "title": "Decoding the Timestamp",
    "category": "Order of Operations",
    "difficulty": "Easy",
    "points": 120,
    "description": "The security system shows a coded timestamp: <b>4&nbsp;×&nbsp;(7&nbsp;+&nbsp;3)&nbsp;−&nbsp;2<sup>3</sup></b>. Decode this to find what hour (in 24h format) the break-in occurred.",
    "flag": "^32$",
    "testflag": "32",
    "hints": [
      { "id": 1, "text": "Remember BEDMAS order: Brackets first, then exponents.", "cost": 10 },
      { "id": 2, "text": "7 + 3 = 10, then 2³ = 8", "cost": 15 }
    ]
  },
  {
    "id": 3,
    "title": "The Suspect's Age",
    "category": "Algebra",
    "difficulty": "Medium",
    "points": 150,
    "description": "A witness says: \"The suspect's age plus 12 equals three times their age minus 8.\" Solve for the suspect's age: <b>x&nbsp;+&nbsp;12&nbsp;=&nbsp;3x&nbsp;−&nbsp;8</b>",
    "flag": "^10$",
    "testflag": "10",
    "requirements": [1],
    "hints": [
      { "id": 1, "text": "Move all x terms to one side and constants to the other.", "cost": 15 },
      { "id": 2, "text": "Subtract x from both sides: 12 = 2x - 8", "cost": 20 },
      { "id": 3, "text": "Add 8 to both sides: 20 = 2x", "cost": 25 }
    ]
  },
  {
    "id": 4,
    "title": "The Getaway Route",
    "category": "Coordinate Geometry",
    "difficulty": "Medium",
    "points": 180,
    "description": "Security cameras tracked the suspect from the museum <b>(2, 5)</b> to the parking lot <b>(8, 17)</b>. Calculate the slope of their escape route.",
    "flag": "^2$",
    "testflag": "2",
    "requirements": [3],
    "hints": [
      { "id": 1, "text": "Slope formula: m = (y₂ - y₁)/(x₂ - x₁)", "cost": 15 },
      { "id": 2, "text": "Substitute: (17 - 5)/(8 - 2)", "cost": 20 }
    ]
  },
  {
    "id": 5,
    "title": "The Hidden Safe",
    "category": "Quadratic Equations",
    "difficulty": "Medium",
    "points": 200,
    "description": "Professor Euler hid his most important research in a safe. The combination is the <b>positive</b> solution to <b>x<sup>2</sup>&nbsp;−&nbsp;7x&nbsp;+&nbsp;12&nbsp;=&nbsp;0</b>.",
    "flag": "^4$",
    "testflag": "4",
    "requirements": [3],
    "hints": [
      { "id": 1, "text": "Try factoring: look for two numbers that multiply to 12 and add to -7.", "cost": 15 },
      { "id": 2, "text": "The factors are -3 and -4: (x - 3)(x - 4) = 0", "cost": 25 },
      { "id": 3, "text": "So x = 3 or x = 4. The problem asks for the positive solution.", "cost": 30 }
    ]
  },
  {
    "id": 6,
    "title": "The Triangular Clue",
    "category": "Geometry",
    "difficulty": "Easy",
    "points": 130,
    "description": "Hidden in the lab, you find a triangular piece of paper with two angles marked: <b>42°</b> and <b>63°</b>. The third angle contains the next clue!",
    "flag": "^75$",
    "testflag": "75",
    "hints": [
      { "id": 1, "text": "All angles in a triangle sum to 180°.", "cost": 10 }
    ]
  },
  {
    "id": 7,
    "title": "The Footprint Area",
    "category": "Area Calculation",
    "difficulty": "Medium",
    "points": 220,
    "description": "CSI found a muddy footprint! It's trapezoidal with parallel sides of <b>12 cm</b> and <b>8 cm</b>, and height <b>15 cm</b>. Calculate the area to match it with suspect shoe sizes.",
    "flag": "^150$",
    "testflag": "150",
    "requirements": [6],
    "hints": [
      { "id": 1, "text": "Trapezoid area formula: A = ½(b₁ + b₂)h", "cost": 15 },
      { "id": 2, "text": "A = ½(12 + 8) × 15", "cost": 20 }
    ]
  },
  {
    "id": 8,
    "title": "The Probability of Guilt",
    "category": "Probability",
    "difficulty": "Medium",
    "points": 200,
    "description": "In the suspect database: <b>3 have criminal records</b>, <b>7 have alibis</b>, <b>5 are missing</b>. What's the probability of randomly selecting someone with a criminal record? Submit as a simplified fraction.",
    "flag": "^1/5$",
    "testflag": "1/5",
    "requirements": [2],
    "hints": [
      { "id": 1, "text": "Total suspects = 3 + 7 + 5", "cost": 10 },
      { "id": 2, "text": "Probability = favorable outcomes ÷ total outcomes", "cost": 15 },
      { "id": 3, "text": "3/15 can be simplified by dividing both by 3", "cost": 20 }
    ]
  },
  {
    "id": 9,
    "title": "The Evidence Locker",
    "category": "Statistics",
    "difficulty": "Easy",
    "points": 140,
    "description": "Evidence weights (grams): <b>45, 23, 67, 34, 45, 78, 23</b>. Find the median weight to organize the evidence locker.",
    "flag": "^45$",
    "testflag": "45",
    "requirements": [8],
    "hints": [
      { "id": 1, "text": "First, arrange the numbers in order from smallest to largest.", "cost": 10 },
      { "id": 2, "text": "The median is the middle value when arranged in order.", "cost": 15 }
    ]
  },
  {
    "id": 10,
    "title": "The Ransom Money",
    "category": "Financial Mathematics",
    "difficulty": "Medium",
    "points": 180,
    "description": "The stolen research was worth <b>$2000</b>. If invested at <b>6% simple interest</b> for <b>4 years</b>, how much interest would it have earned? This might be the thief's motive!",
    "flag": "^480$",
    "testflag": "480",
    "requirements": [9],
    "hints": [
      { "id": 1, "text": "Simple interest formula: I = P × r × t", "cost": 15 },
      { "id": 2, "text": "I = 2000 × 0.06 × 4", "cost": 20 }
    ]
  },
  {
    "id": 11,
    "title": "The Compound Conspiracy",
    "category": "Advanced Financial Math",
    "difficulty": "Hard",
    "points": 300,
    "description": "The suspect's offshore account started with <b>$5000</b> and grew at <b>8% compounded annually</b> for <b>3 years</b>. Calculate the final amount to track their wealth.",
    "flag": "^6298\\.56$",
    "testflag": "6298.56",
    "requirements": [10],
    "hints": [
      { "id": 1, "text": "Compound interest formula: A = P(1 + r)ᵗ", "cost": 20 },
      { "id": 2, "text": "A = 5000(1 + 0.08)³", "cost": 25 },
      { "id": 3, "text": "A = 5000(1.08)³ = 5000 × 1.259712", "cost": 30 }
    ]
  },
  {
    "id": 12,
    "title": "The Secret Pattern",
    "category": "Sequences",
    "difficulty": "Medium",
    "points": 200,
    "description": "Professor Euler left a coded sequence: <b>7, 12, 17, 22, ...</b> What is the <b>8th term</b>? This arithmetic sequence holds the key to his research location!",
    "flag": "^42$",
    "testflag": "42",
    "requirements": [5],
    "hints": [
      { "id": 1, "text": "Find the common difference between consecutive terms.", "cost": 15 },
      { "id": 2, "text": "The formula is: aₙ = a₁ + (n-1)d where d = 5", "cost": 20 },
      { "id": 3, "text": "a₈ = 7 + (8-1) × 5", "cost": 25 }
    ]
  },
  {
    "id": 13,
    "title": "The Final Distance",
    "category": "Pythagorean Theorem",
    "difficulty": "Medium",
    "points": 250,
    "description": "The Professor's secret lab is hidden underground! From the crime scene, go <b>9 meters north</b> and <b>12 meters east</b>. What's the direct distance to the entrance?",
    "flag": "^15$",
    "testflag": "15",
    "requirements": [6],
    "hints": [
      { "id": 1, "text": "This forms a right triangle. Use the Pythagorean theorem.", "cost": 15 },
      { "id": 2, "text": "a² + b² = c² where a = 9, b = 12", "cost": 20 },
      { "id": 3, "text": "9² + 12² = 81 + 144 = 225, so c = √225", "cost": 25 }
    ]
  },
  {
    "id": 14,
    "title": "The Mastermind's Identity",
    "category": "Logic & Reasoning",
    "difficulty": "Hard",
    "points": 350,
    "description": "You've gathered all clues! The mastermind's secret number is: <b>(Age from clue 3) × (Missing angle from clue 6) ÷ (Slope from clue 4)</b>. Calculate their identification number!",
    "flag": "^375$",
    "testflag": "375",
    "requirements": [13],
    "hints": [
      { "id": 1, "text": "Use the answers from previous challenges: 10 × 75 ÷ 2", "cost": 20 },
      { "id": 2, "text": "Follow order of operations: multiplication and division left to right", "cost": 25 },
      { "id": 3, "text": "10 × 75 = 750, then 750 ÷ 2 = 375", "cost": 30 }
    ]
  },
  {
    "id": 15,
    "title": "Case Closed",
    "category": "Final Challenge",
    "difficulty": "Hard",
    "points": 400,
    "description": "Congratulations, Detective! You've solved the case. The stolen formula was for calculating the volume of a cylinder. Professor Euler's prototype has radius <b>5 cm</b> and height <b>12 cm</b>. What's its volume? Express as <i>kπ</i> (e.g., <code>300π</code>).",
    "flag": "^300$",
    "testflag": "300",
    "requirements": [14],
    "hints": [
      { "id": 1, "text": "Volume of cylinder formula: V = πr²h", "cost": 20 },
      { "id": 2, "text": "V = π × 5² × 12", "cost": 25 },
      { "id": 3, "text": "V = π × 25 × 12 = 300π", "cost": 30 }
    ]
  }
]