/* RESET */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* BODY */
body {
    font-family: Arial, sans-serif;
    background-color: #f2efe8;
}

/* HEADER */
.header {
    background-color: #1a2744;
    color: white;
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header nav a {
    color: white;
    text-decoration: none;
    margin-left: 15px;
}

.header nav a:hover {
    text-decoration: underline;
    color: #38bdf8;
}

/* LAYOUT */
.layout {
    display: flex;
    min-height: 90vh;
}

/* SIDEBAR */
.sidebar {
    width: 230px;
    background-color: #34495e;
    padding: 20px;
    color: white;
}

.sidebar h2 {
    margin-bottom: 15px;
    text-align: center;
}

.sidebar button {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
    background-color: #2c3e50;
    border: none;
    color: white;
    cursor: pointer;
    border-radius: 8px;
}

.sidebar button:hover {
    background-color: #1a252f;
}

/* MAIN CONTENT */
.main-content {
    flex: 1;
    padding: 25px;
}
.main-content h1 {
    text-align: center;
}
.box {
    padding: 5px 20px 20px;
    text-align: center;
    font-family:	Courier New, monospace;
}
.section-title {
    text-align: center;
    margin-bottom: 20px;
}
/* CARDS GRID */
.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 30px;
}

/* CARD STYLE */
.card {
    background: white;
    padding: 18px;
    border-radius: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.4);
    border: 1px solid #ddd;    
    transition: 0.3s ease;
    text-align: center;
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 6px 18px rgba(0,0,0,0.08);    
}

.card h4 {
    text-align: center;
    margin-bottom: 10px;
}

/* BUTTON */
button {
    padding: 10px 18px;
    background-color: #2c3e50;
    color: white;
    border: none;
    border-radius: 30px;
    cursor: pointer;
    margin-top: 5px;
}

button:hover {
    background-color: #1a252f;
}

/* INPUT */
input {
    width: 100%;
    padding: 6px;
    margin: 5px 0;
    border-radius: 10px;
}

/* FOOTER */
footer {
    background-color: #2c3e50;
    color: white;
    text-align: center;
    padding: 10px;
}

/* DARK MODE */
.dark-mode {
    background-color: #111;
    color: white;
}

.dark-mode .card {
    background-color: #222;
    border: 1px solid #444;
}
/* INPUT TYPE ALIGNMENT */
.card ul {
  text-align: left;
  padding-left: 15px;
}

#todoList {
    list-style: none;
    padding: 0;
}

#todoList li {
    display: flex;
    align-items: center;    
    gap: 10px;    
    padding: 6px 0;
}

#todoList input[type="checkbox"] {
    width: 16px;
    height: 16px;
    cursor: pointer;
}
#todoList span {
    flex: 1;
}
p {
    padding: 10px 2px;
}
.page {
    display: none;
}
.grid { 
   border: 1px solid #ccc;
   padding: 20px;
   margin: 20px 0;
   border-radius: 9px;
   box-shadow: 0 18px 40px rgba(0, 0, 0, 0.3);             
}
img {
     height: 150px;
     width: 150px;
     border-radius: 100%;
     object-fit: cover;
     background: #ddd;
 }
.about-card {
    background: #e5e2dd;
    padding: 30px;
    width: 90%;
    max-width: 400px;
    margin: 20px auto;
    text-align: center;
    border-radius: 10px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
}
.about-card img {
    width: 150px;
    height: 150px;
    border-radius: 40%;
    object-fit: cover;
    background: #ccc;
    cursor: pointer;
    margin-bottom: 15px;
}
.about-card h3 {
    margin: 5px 0;
}

.about-card p {
    margin: 0;
    font-size: 14px;
    color: #333;
}
#contact {
    padding: 20px;
    text-align: center;
}

#contact input,
#contact textarea {
    width: 100%;
    max-width: 400px;
    padding: 10px;
    margin: 8px auto;
    display: block;
    border-radius: 8px;
    border: 1px solid #ccc;
}
/* ========================= */
/* EXERCISE 4 - GRADE CALCULATOR */
/* ========================= */

#exercise4 .card {
    max-width: 500px;
    margin: 20px auto;
}

#exercise4 label {
    display: block;
    margin-top: 10px;
    font-weight: 600;
    color: #333;
}

#exercise4 input {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
    border-radius: 6px;
    border: 1px solid #ccc;
    font-size: 14px;
    transition: 0.3s;
    text-align: center;
}

#exercise4 input:focus {
    border-color: #1f2a44;
    outline: none;
    box-shadow: 0 0 5px rgba(31, 42, 68, 0.3);
}

#exercise4 button {
    margin-top: 12px;
    padding: 8px 14px;
    border: none;
    border-radius: 6px;
    background-color: #1f2a44;
    color: white;
    cursor: pointer;
    font-weight: 500;
    transition: 0.3s;
}

#exercise4 button:hover {
    background-color: #2c3e66;
}

#exercise4 p {
    margin-top: 12px;
    font-size: 15px;
    color: #222;
}

#exercise4 span {
    font-weight: bold;
    color: #1f2a44;
}
.grade-A { color: green; }
.grade-B { color: #2c7be5; }
.grade-C { color: orange; }
.grade-D { color: brown; }
.grade-F { color: red; }