/* ========================================
   RESET & BASE STYLES
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

body {
    background-color: #f0f2f5;
    color: #333;
    line-height: 1.6;
}

/* ========================================
   PAGE VISIBILITY
   ======================================== */
.page {
    display: none;
}

.page.active {
    display: block;
}

/* ========================================
   LANDING PAGE
   ======================================== */
.landing-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

.profile-header {
    text-align: center;
    margin-bottom: 50px;
    background: white;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.student-name {
    font-size: 42px;
    color: #2c3e50;
    margin-bottom: 10px;
}

.student-info {
    font-size: 18px;
    color: #7f8c8d;
}

.weeks-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.week-card {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    text-align: center;
}

.week-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.15);
}

.week-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.week-title {
    font-size: 28px;
    color: #2c3e50;
    margin-bottom: 10px;
}

.week-description {
    color: #7f8c8d;
    margin-bottom: 20px;
}

.activity-count {
    margin-bottom: 20px;
}

.activity-count span {
    background: #3498db;
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 14px;
}

.preview-list {
    list-style: none;
    text-align: left;
    margin: 20px 0;
}

.preview-list li {
    padding: 8px 0;
    color: #555;
    border-bottom: 1px dashed #eee;
}

.view-btn {
    background: #3498db;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    font-size: 16px;
    cursor: pointer;
    width: 100%;
    margin-top: 15px;
    transition: background 0.3s;
}

.view-btn:hover {
    background: #2980b9;
}

/* ========================================
   CONTAINER & HEADER
   ======================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.week-header {
    text-align: center;
    margin: 30px 0;
    padding: 30px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.week-header h1 {
    font-size: 32px;
    color: #2c3e50;
    margin-bottom: 10px;
}

.week-header p {
    color: #7f8c8d;
    font-size: 16px;
}

/* ========================================
   BACK BUTTON
   ======================================== */
.back-btn {
    background: #34495e;
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    margin-bottom: 20px;
    transition: background 0.3s;
}

.back-btn:hover {
    background: #2c3e50;
}

/* ========================================
   ACTIVITIES GRID
   ======================================== */
.activities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 25px;
}

.activity-card {
    background: white;
    border-radius: 10px;
    padding: 25px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    position: relative;
    border-left: 4px solid #3498db;
}

.activity-number {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 40px;
    font-weight: bold;
    color: rgba(52, 152, 219, 0.1);
}

.activity-card h2 {
    font-size: 20px;
    margin-bottom: 10px;
    color: #2c3e50;
}

.activity-card p {
    color: #7f8c8d;
    margin-bottom: 20px;
    font-size: 14px;
}

/* ========================================
   BUTTONS
   ======================================== */
button {
    background: #3498db;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    font-size: 14px;
    cursor: pointer;
    margin: 5px 5px 5px 0;
    transition: background 0.3s;
}

button:hover {
    background: #2980b9;
}

.delete-btn {
    background: #e74c3c;
}

.delete-btn:hover {
    background: #c0392b;
}

/* ========================================
   INPUT FIELDS
   ======================================== */
input[type="text"],
input[type="number"] {
    padding: 10px 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 14px;
    margin: 5px 10px 5px 0;
    width: 200px;
}

input:focus {
    outline: none;
    border-color: #3498db;
}

/* ========================================
   LISTS
   ======================================== */
ul {
    list-style: none;
    margin-top: 15px;
}

li {
    background: #f8f9fa;
    padding: 10px 15px;
    margin: 8px 0;
    border-radius: 5px;
    border: 1px solid #eee;
}

.todo-list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* ========================================
   OUTPUT AREAS
   ======================================== */
.output-area {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 5px;
    margin-top: 15px;
    border: 1px solid #eee;
    font-size: 14px;
}

#output, #variablesOutput, #calculatorOutput, 
#ageResult, #loopOutput {
    background: #f0f3f8;
    padding: 15px;
    border-radius: 5px;
    margin-top: 15px;
}

/* ========================================
   WEEK 4 - GRADE CALCULATOR
   ======================================== */
.grade-calculator-container {
    max-width: 600px;
    margin: 0 auto;
}

.grade-calculator-card {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.calculator-icon {
    font-size: 48px;
    text-align: center;
    margin-bottom: 20px;
}

.grade-calculator-card h2 {
    text-align: center;
    font-size: 28px;
    color: #2c3e50;
    margin-bottom: 10px;
}

.calculator-description {
    text-align: center;
    color: #7f8c8d;
    margin-bottom: 30px;
}

.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #2c3e50;
}

.grade-input {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
}

.grade-input:focus {
    border-color: #3498db;
    outline: none;
}

.button-group {
    display: flex;
    gap: 15px;
    margin: 30px 0;
}

.calculate-btn {
    flex: 2;
    background: #27ae60;
    padding: 15px;
    font-size: 16px;
}

.calculate-btn:hover {
    background: #229954;
}

.reset-btn {
    flex: 1;
    background: #e67e22;
    padding: 15px;
    font-size: 16px;
}

.reset-btn:hover {
    background: #d35400;
}

.result-area {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 20px;
    margin: 20px 0;
    border: 1px solid #eee;
}

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
}

.result-row:first-child {
    border-bottom: 1px solid #ddd;
    margin-bottom: 10px;
}

.result-label {
    font-weight: bold;
    color: #2c3e50;
}

.result-value {
    font-size: 24px;
    font-weight: bold;
    color: #3498db;
    background: white;
    padding: 5px 15px;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.grade-reference {
    margin-top: 30px;
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
}

.grade-reference h3 {
    text-align: center;
    margin-bottom: 15px;
    color: #2c3e50;
}

.grade-reference table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 5px;
    overflow: hidden;
}

.grade-reference th {
    background: #34495e;
    color: white;
    padding: 10px;
}

.grade-reference td {
    padding: 8px;
    text-align: center;
    border-bottom: 1px solid #eee;
}

/* ========================================
   WEEK 3 SPECIAL STYLES
   ======================================== */
.removable {
    background: #f8f9fa;
    padding: 12px;
    margin: 8px 0;
    border-radius: 5px;
    border-left: 4px solid #3498db;
}

.simple-list li {
    background: #f8f9fa;
    padding: 10px;
    margin: 5px 0;
    border-radius: 5px;
}

/* ========================================
   ACTIVITY 2 STYLES
   ======================================== */
article {
    background: white;
    padding: 25px;
    border-radius: 10px;
    line-height: 1.8;
}

article h1 {
    color: #2c3e50;
    margin-bottom: 10px;
}

article hr {
    border: none;
    height: 2px;
    background: #3498db;
    margin: 15px 0;
}

address {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 5px;
    margin-top: 20px;
    font-style: normal;
    border-left: 4px solid #3498db;
}

/* ========================================
   ACTIVITY 3 TABLE
   ======================================== */
.simple-format-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.simple-format-table th {
    background: #34495e;
    color: white;
    padding: 15px;
}

.simple-format-table td {
    padding: 12px;
    border-bottom: 1px solid #eee;
}

.simple-format-table tr:hover {
    background: #f8f9fa;
}

.simple-format-table code {
    background: #f0f0f0;
    padding: 2px 5px;
    border-radius: 3px;
}

/* ========================================
   ACTIVITY 4 POSTER
   ======================================== */
.event-poster-simple {
    max-width: 450px;
    margin: 20px auto;
    background: #3498db;
    color: white;
    border-radius: 15px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.poster-header h1 {
    font-size: 28px;
    margin-bottom: 20px;
    color: white;
}

.poster-body p {
    margin: 15px 0;
    font-size: 16px;
}

.poster-divider {
    height: 2px;
    background: rgba(255,255,255,0.3);
    margin: 20px auto;
    width: 80%;
}

.poster-highlights {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin: 20px 0;
}

.poster-highlights span {
    background: rgba(255,255,255,0.2);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 13px;
}

/* ========================================
   ACTIVITY 5 LINKS
   ======================================== */
.link-list-simple {
    max-width: 500px;
    margin: 20px auto;
}

.link-item {
    background: white;
    padding: 15px;
    margin: 10px 0;
    border-radius: 5px;
    box-shadow: 0 5px 10px rgba(0,0,0,0.1);
    display: flex;
    align-items: center;
}

.link-icon {
    font-size: 24px;
    margin-right: 15px;
    width: 35px;
}

.link-item a {
    text-decoration: none;
    color: #2c3e50;
    flex: 1;
}

.link-item a:hover {
    color: #3498db;
}

.contact-box {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    margin: 30px auto;
    max-width: 500px;
}

/* ========================================
   ACTIVITY 6 GALLERY
   ======================================== */
.gallery-2x2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    max-width: 400px;
    margin: 20px auto;
}

.gallery-item {
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    text-align: center;
}

.gallery-item img {
    width: 100%;
    height: 150px;
    object-fit: cover;
}

.gallery-item figcaption {
    padding: 10px;
    color: #2c3e50;
    font-size: 14px;
    background: #f8f9fa;
    border-top: 1px solid #eee;
}

/* ========================================
   ACTIVITY 7 TABLE
   ======================================== */
table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

th {
    background: #34495e;
    color: white;
    padding: 12px;
}

td {
    padding: 10px;
    text-align: center;
    border-bottom: 1px solid #eee;
}

caption {
    margin-bottom: 10px;
    font-weight: bold;
    color: #2c3e50;
}

/* ========================================
   ACTIVITY 8 LISTS
   ======================================== */
#activity-8 h3 {
    color: #2c3e50;
    margin: 20px 0 10px;
}

#activity-8 ul, #activity-8 ol {
    background: white;
    padding: 20px 40px;
    border-radius: 5px;
    box-shadow: 0 5px 10px rgba(0,0,0,0.1);
}

#activity-8 li {
    margin: 5px 0;
}

#activity-8 dl {
    background: white;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 5px 10px rgba(0,0,0,0.1);
}

#activity-8 dt {
    font-weight: bold;
    color: #3498db;
    margin-top: 10px;
}

#activity-8 dd {
    margin-left: 20px;
    color: #7f8c8d;
}

/* ========================================
   ACTIVITY 9 FORM
   ======================================== */
form {
    max-width: 500px;
    margin: 20px auto;
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

form div {
    margin-bottom: 15px;
}

form label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #2c3e50;
}

form input[type="text"],
form input[type="email"],
form input[type="password"],
form input[type="date"],
form select,
form textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
}

form button {
    background: #27ae60;
    width: 100%;
    padding: 12px;
    font-size: 16px;
}

/* ========================================
   ACTIVITY 10 COLOR SWATCHES
   ======================================== */
.color-swatch {
    padding: 15px;
    margin: 8px 0;
    border-radius: 5px;
    color: white;
    font-weight: bold;
}

/* ========================================
   ACTIVITY 11 LAYOUT
   ======================================== */
.layout-demo {
    border: 1px solid #ddd;
    border-radius: 5px;
    overflow: hidden;
}

.layout-header {
    background: #34495e;
    color: white;
    padding: 15px;
    text-align: center;
    font-size: 20px;
}

.layout-nav {
    background: #f8f9fa;
    padding: 10px;
    text-align: center;
    border-bottom: 1px solid #ddd;
}

.layout-nav a {
    color: #2c3e50;
    text-decoration: none;
    margin: 0 15px;
}

.layout-nav a:hover {
    color: #3498db;
}

.layout-main {
    display: flex;
    min-height: 150px;
}

.layout-content {
    flex: 2;
    padding: 20px;
    background: white;
}

.layout-sidebar {
    flex: 1;
    padding: 20px;
    background: #f8f9fa;
    border-left: 1px solid #ddd;
}

.layout-footer {
    background: #34495e;
    color: white;
    padding: 10px;
    text-align: center;
}

/* ========================================
   ACTIVITY 12 FRAMES
   ======================================== */
.frames-container {
    display: flex;
    border: 1px solid #ddd;
    border-radius: 5px;
    overflow: hidden;
}

.frame-menu {
    width: 30%;
    background: #f8f9fa;
    padding: 15px;
    border-right: 1px solid #ddd;
}

.frame-menu h4 {
    margin-bottom: 15px;
    color: #2c3e50;
}

.frame-menu ul {
    list-style: none;
}

.frame-menu li {
    margin: 10px 0;
}

.frame-menu a {
    color: #3498db;
    text-decoration: none;
    cursor: pointer;
}

.frame-content {
    width: 70%;
    padding: 15px;
    background: white;
}

/* ========================================
   ACTIVITY 13 FONTS
   ======================================== */
.font-comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.old-html, .modern-css {
    background: white;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.old-html h3, .modern-css h3 {
    color: #2c3e50;
    margin-bottom: 15px;
}

.warning {
    color: #e74c3c;
    margin-top: 15px;
    font-size: 14px;
}

/* ========================================
   ACTIVITY 14 CARDS
   ======================================== */
.navbar {
    background: #34495e;
    padding: 15px;
    border-radius: 5px;
    margin-bottom: 20px;
}

.nav-link {
    color: white;
    text-decoration: none;
    margin-right: 20px;
    padding: 5px 10px;
}

.nav-link:hover {
    background: #2c3e50;
    border-radius: 3px;
}

#mainTitle {
    text-align: center;
    color: #2c3e50;
    margin: 30px 0;
}

.cards-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.card {
    background: white;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    text-align: center;
}

.card h3 {
    color: #2c3e50;
    margin-bottom: 10px;
}

.card p {
    color: #7f8c8d;
    margin-bottom: 20px;
}

.btn {
    background: #3498db;
    color: white;
    border: none;
    padding: 8px 20px;
    border-radius: 5px;
    cursor: pointer;
}

.btn:hover {
    background: #2980b9;
}

/* ========================================
   NOTES
   ======================================== */
.note {
    color: #7f8c8d;
    font-style: italic;
    font-size: 13px;
    margin-top: 15px;
    text-align: center;
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */
@media (max-width: 768px) {
    .student-name {
        font-size: 32px;
    }
    
    .weeks-container {
        grid-template-columns: 1fr;
    }
    
    .activities-grid {
        grid-template-columns: 1fr;
    }
    
    .layout-main {
        flex-direction: column;
    }
    
    .layout-sidebar {
        border-left: none;
        border-top: 1px solid #ddd;
    }
    
    .cards-container {
        grid-template-columns: 1fr;
    }
    
    .font-comparison {
        grid-template-columns: 1fr;
    }
    
    .frames-container {
        flex-direction: column;
    }
    
    .frame-menu, .frame-content {
        width: 100%;
    }
    
    .button-group {
        flex-direction: column;
    }
    
    .result-row {
        flex-direction: column;
        text-align: center;
        gap: 10px;
    }
    
    input[type="text"],
    input[type="number"] {
        width: 100%;
        margin: 5px 0;
    }
    
    button {
        width: 100%;
        margin: 5px 0;
    }
}