@import url("https://fonts.googleapis.com/css2?family=Hind+Siliguri:wght@400;500;600;700&display=swap");

:root {
  --bg-color: #f0f2f5;
  --container-bg: #ffffff;
  --text-color: #333333;
  --heading-color-1: #d81b60;
  --heading-color-2: #004d40;
  --heading-color-3: #1a237e;
  --accent-color: #c2185b;
  --blockquote-bg: #e3f2fd;
  --blockquote-border: #2196f3;
  --table-header-bg: #004d40;
  --table-header-text: #ffffff;
  --nav-button-bg: #fff;
  --nav-button-text: #333;
  --nav-button-border: #ccc;
  --nav-active-bg: #d81b60;
  --box-shadow-color: rgba(0, 0, 0, 0.1);

  /* MCQ Card Variables */
  --card-border-color: #e0e0e0;
  --card-shadow-color: rgba(0, 0, 0, 0.08);
  --mcq-tag-bg: #007bff;
  --mcq-tag-text: #ffffff;
  --success-color: #28a745;
}

[data-theme="forest"] {
  --bg-color: #f0f4f0;
  --container-bg: #ffffff;
  --text-color: #2c3e50;
  --heading-color-1: #27ae60;
  --heading-color-2: #16a085;
  --heading-color-3: #2c3e50;
  --accent-color: #e67e22;
  --blockquote-bg: #e8f5e9;
  --blockquote-border: #27ae60;
  --table-header-bg: #27ae60;
  --mcq-tag-bg: #27ae60;
}

[data-theme="ocean"] {
  --bg-color: #eef5ff;
  --container-bg: #ffffff;
  --text-color: #34495e;
  --heading-color-1: #2980b9;
  --heading-color-2: #3498db;
  --heading-color-3: #1f618d;
  --accent-color: #e74c3c;
  --blockquote-bg: #e4f1fe;
  --blockquote-border: #3498db;
  --table-header-bg: #2980b9;
  --mcq-tag-bg: #2980b9;
}

[data-theme="sunset"] {
  --bg-color: #fff3e0;
  --container-bg: #ffffff;
  --text-color: #4e342e;
  --heading-color-1: #e65100;
  --heading-color-2: #f57c00;
  --heading-color-3: #d84315;
  --accent-color: #bf360c;
  --blockquote-bg: #fff8e1;
  --blockquote-border: #f57c00;
  --table-header-bg: #e65100;
  --mcq-tag-bg: #e65100;
}

.dark-mode {
  --bg-color: #121212;
  --container-bg: #1e1e1e;
  --text-color: #e0e0e0;
  --heading-color-1: #bb86fc;
  --heading-color-2: #03dac6;
  --heading-color-3: #cf6679;
  --accent-color: #f48fb1;
  --blockquote-bg: #2a2a2a;
  --blockquote-border: #03dac6;
  --table-header-bg: #3700b3;
  --nav-button-bg: #2c2c2c;
  --nav-button-text: #e0e0e0;
  --nav-button-border: #555;
  --nav-active-bg: #bb86fc;
  --box-shadow-color: rgba(255, 255, 255, 0.05);

  /* MCQ Card Variables for Dark Mode */
  --card-border-color: #444;
  --card-shadow-color: rgba(0, 0, 0, 0.2);
  --mcq-tag-bg: var(--heading-color-1); /* #bb86fc */
  --success-color: #4caf50;
}

html {
  scroll-behavior: smooth;
}
body {
  font-family: "Hind Siliguri", sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.8;
  margin: 0;
  padding: 20px;
  transition: background-color 0.3s, color 0.3s;
}
body.desktop-view .container,
body.desktop-view header,
body.desktop-view .controls-wrapper {
  max-width: 1200px;
}
header {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  padding: 20px 0;
  transition: max-width 0.4s ease-in-out;
}
.logo {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 15px;
  box-shadow: 0 4px 12px var(--box-shadow-color);
}
.container {
  max-width: 900px;
  margin: 20px auto;
  background-color: var(--container-bg);
  padding: 30px 40px;
  border-radius: 12px;
  box-shadow: 0 4px 12px var(--box-shadow-color);
  transition: background-color 0.3s, max-width 0.4s ease-in-out;
}
h1,
h2,
h3,
h4 {
  border-bottom: 2px solid var(--card-border-color);
  padding-bottom: 10px;
  margin-top: 30px;
}
h1 {
  text-align: center;
  font-size: 2.2em;
  color: var(--heading-color-1);
  border-bottom: none;
  margin: 0;
}
h2 {
  font-size: 2em;
  color: var(--heading-color-2);
}
h3,
h4 {
  font-size: 1.6em;
  color: var(--heading-color-3);
}
h4 {
  border-bottom: 1px dotted var(--card-border-color);
}
p {
  font-size: 1.1em;
}
strong {
  color: var(--accent-color);
  font-weight: 600;
}
blockquote {
  background-color: var(--blockquote-bg);
  border-left: 5px solid var(--blockquote-border);
  margin: 20px 0;
  padding: 15px 20px;
  font-style: italic;
  font-size: 1.1em;
  border-radius: 5px;
}
img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 25px auto;
  border-radius: 10px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}
ol,
ul {
  padding-left: 20px;
}
li {
  margin-bottom: 10px;
  padding-left: 10px;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin: 25px 0;
  font-size: 1em;
}
table th,
table td {
  border: 1px solid var(--nav-button-border);
  padding: 12px 15px;
  text-align: left;
}
table th {
  background-color: var(--table-header-bg);
  color: var(--table-header-text);
  font-weight: 600;
}
table tr:nth-of-type(even) {
  background-color: var(--blockquote-bg);
}
.controls-wrapper {
  max-width: 900px;
  margin: 20px auto;
  padding: 15px;
  background-color: var(--container-bg);
  border-radius: 10px;
  box-shadow: 0 4px 12px var(--box-shadow-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 15px;
  transition: max-width 0.4s ease-in-out;
}
.theme-buttons button,
#desktopModeToggle,
#rotateScreenToggle {
  padding: 8px 15px;
  border: 1px solid var(--nav-button-border);
  background-color: var(--nav-button-bg);
  color: var(--nav-button-text);
  border-radius: 5px;
  cursor: pointer;
  font-family: "Hind Siliguri", sans-serif;
  font-weight: 600;
  transition: all 0.2s;
}
.theme-buttons button:hover,
#desktopModeToggle:hover,
#rotateScreenToggle:hover {
  opacity: 0.8;
}
.dark-mode-toggle {
  display: flex;
  align-items: center;
  gap: 10px;
}
.switch {
  position: relative;
  display: inline-block;
  width: 60px;
  height: 34px;
}
.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}
.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #ccc;
  transition: 0.4s;
  border-radius: 34px;
}
.slider:before {
  position: absolute;
  content: "";
  height: 26px;
  width: 26px;
  left: 4px;
  bottom: 4px;
  background-color: white;
  transition: 0.4s;
  border-radius: 50%;
}
input:checked + .slider {
  background-color: var(--heading-color-1);
}
input:checked + .slider:before {
  transform: translateX(26px);
}
.digital-clock {
  font-family: "Courier New", Courier, monospace;
  font-size: 1.2em;
  font-weight: bold;
  padding: 8px 15px;
  background-color: var(--blockquote-bg);
  border: 1px solid var(--blockquote-border);
  border-radius: 5px;
  color: var(--heading-color-1);
}
.navigation {
  text-align: center;
  margin-top: 40px;
  padding-top: 20px;
  border-top: 2px solid #eee;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}
.dark-mode .navigation {
  border-top-color: #333;
}
.nav-button {
  display: inline-block;
  padding: 10px 15px;
  border: 1px solid var(--nav-button-border);
  border-radius: 5px;
  text-decoration: none;
  color: var(--nav-button-text);
  background-color: var(--nav-button-bg);
  transition: background-color 0.3s, color 0.3s;
  font-weight: 500;
}
.nav-button:hover {
  background-color: #e0e0e0;
}
.dark-mode .nav-button:hover {
  background-color: #3a3a3a;
}
.nav-button.active {
  background-color: var(--nav-active-bg);
  color: white;
  border-color: var(--nav-active-bg);
}
.nav-button.disabled {
  pointer-events: none;
  opacity: 0.5;
}
.home-button {
  background-color: #1e88e5;
  color: white;
  border-color: #1e88e5;
}
.home-button:hover {
  background-color: #1565c0;
}
footer {
  text-align: center;
  margin-top: 40px;
  padding: 20px;
  font-size: 0.9em;
  color: var(--text-color);
  opacity: 0.8;
}
.scroll-button {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: var(--heading-color-1);
  color: white;
  border: none;
  font-size: 24px;
  cursor: pointer;
  display: none;
  justify-content: center;
  align-items: center;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  z-index: 1000;
  transition: opacity 0.3s, visibility 0.3s;
}
#scrollToBottomBtn {
  bottom: 80px;
  background-color: var(--heading-color-2);
}
.scroll-button:hover {
  opacity: 0.8;
}

/* =================================
   Modern MCQ Card Style (আধুনিক কার্ড ডিজাইন)
   ================================= */

.question-item {
  background-color: var(--container-bg);
  border: 1px solid var(--card-border-color);
  border-radius: 12px;
  padding: 50px 25px 25px 25px; /* উপরের দিকে ট্যাগের জন্য জায়গা */
  margin-bottom: 30px;
  box-shadow: 0 4px 12px var(--card-shadow-color);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative; /* h3 ট্যাগকে পজিশন করার জন্য */
  overflow: hidden; /* ট্যাগের বর্ডার-রেডিয়াস ঠিকভাবে দেখানোর জন্য */
}

.question-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px var(--card-shadow-color);
}

/* প্রশ্নের নম্বর ট্যাগ (e.g., প্রশ্ন ২৭) */
.question-item h3 {
  position: absolute;
  top: 0;
  left: 0;
  background-color: var(--mcq-tag-bg);
  color: var(--mcq-tag-text);
  padding: 8px 20px;
  border-radius: 12px 0 12px 0; /* স্টাইলিশ কর্নার */
  font-weight: bold;
  font-size: 1rem;

  /* বেস h3 স্টাইল ওভাররাইড */
  border-bottom: none;
  margin: 0;
}

/* প্রশ্নের মূল টেক্সট */
.question-item > p:first-of-type {
  font-size: 1.2em;
  font-weight: 500;
  margin-top: 0;
  margin-bottom: 20px;
}
.question-item > p:first-of-type strong {
  color: var(--text-color);
}

/* অপশনের তালিকা (ul এবং li) */
.question-item ul {
  list-style-type: none;
  padding: 0;
  margin: 0 0 20px 0;
}

.question-item ul li {
  font-size: 1.1em;
  padding: 12px 15px;
  border-bottom: 1px dashed var(--card-border-color);
  transition: background-color 0.2s;
  border-radius: 6px;
}

.question-item ul li:last-child {
  border-bottom: none;
}

.question-item ul li:hover {
  background-color: var(--blockquote-bg);
  cursor: pointer;
}

/* উত্তর এবং ব্যাখ্যা সেকশন */
.answer-section .answer-divider {
  border: 0;
  height: 1px;
  background-color: var(--card-border-color);
  margin: 15px 0;
}

.answer-section p {
  font-size: 1.1em;
}

.answer-section .answer-label {
  color: var(--accent-color);
}

.answer-section .correct-answer {
  color: var(--success-color);
  font-weight: bold;
  background-color: var(--blockquote-bg);
  padding: 2px 8px;
  border-radius: 4px;
}

/* ব্যাখ্যা বক্স */
.explanation {
  margin-top: 15px;
  padding: 15px;
  background-color: var(--blockquote-bg);
  border-left: 4px solid var(--blockquote-border);
  border-radius: 4px;
}
.explanation p {
  margin: 0;
  font-size: 1em;
}

/* ================================================================
   Responsive Design for Mobile (মোবাইলের জন্য নতুন যোগ করা কোড)
   ================================================================ */
@media (max-width: 768px) {
  /* Body-র padding কমানো হয়েছে যাতে কন্টেন্ট স্ক্রিনের বেশি জায়গা পায় */
  body {
    padding: 10px;
  }

  /* মূল কন্টেইনার এবং হেডারকে পুরো স্ক্রিন জুড়ে দেওয়া হয়েছে */
  .container,
  header,
  .controls-wrapper {
    width: 100%;
    max-width: 100%;
    padding-left: 15px;
    padding-right: 15px;
    box-sizing: border-box; /* এটি নিশ্চিত করে যে padding মূল width এর বাইরে যাবে না */
  }

  .container {
    padding-top: 20px;
    padding-bottom: 20px;
  }

  /* মোবাইল ডিভাইসের জন্য হেডিং-এর সাইজ ঠিক করা হয়েছে */
  h1 {
    font-size: 1.8em;
  }
  h2 {
    font-size: 1.6em;
  }
  h3,
  h4 {
    font-size: 1.4em;
  }
  p {
    font-size: 1em;
  }

  .controls-wrapper {
    flex-direction: column;
    gap: 10px;
  }

  /* MCQ কার্ডের padding কমানো হয়েছে */
  .question-item {
    padding: 45px 15px 15px 15px;
  }
}