/* ========================================
   DARWIN'S SIMPLE CSS
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

body {
    background-color: #1e2a3a;
    color: #ecf0f1;
    line-height: 1.6;
}

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

.page.active {
    display: block;
}

/* ========================================
   LANDING PAGE
   ======================================== */
.welcome-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 30px 20px;
}

.hero-section {
    text-align: center;
    padding: 50px 20px;
    background-color: #2c3e50;
    border-radius: 15px;
    margin-bottom: 40px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

.hero-title {
    font-size: 48px;
    color: #f1c40f;
    margin-bottom: 10px;
    letter-spacing: 2px;
}

.hero-subtitle {
    font-size: 18px;
    color: #bdc3c7;
}

.weeks-showcase {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.week-panel {
    background-color: #2c3e50;
    border-radius: 12px;
    padding: 25px;
    cursor: pointer;
    transition: 0.3s;
    border-left: 5px solid;
}

.week-panel:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.3);
}

.week2-panel { border-left-color: #3498db; }
.week3-panel { border-left-color: #e74c3c; }
.week4-panel { border-left-color: #f1c40f; }

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.week-badge {
    background-color: #34495e;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: bold;
}

.panel-icon {
    font-size: 32px;
}

.week-panel h2 {
    font-size: 24px;
    margin-bottom: 8px;
    color: #ecf0f1;
}

.panel-desc {
    color: #bdc3c7;
    margin-bottom: 15px;
    font-size: 14px;
}

.activity-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 15px 0;
}

.activity-tags span {
    background-color: #34495e;
    padding: 4px 10px;
    border-radius: 15px;
    font-size: 11px;
}

.panel-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid #34495e;
    padding-top: 15px;
    margin-top: 10px;
}

.activity-count {
    color: #bdc3c7;
    font-size: 13px;
}

.enter-btn {
    color: #f1c40f;
    font-weight: bold;
}

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

.top-bar {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 30px;
    background-color: #2c3e50;
    padding: 15px 25px;
    border-radius: 10px;
}

.home-btn {
    background-color: #34495e;
    color: white;
    border: none;
    padding: 8px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
}

.home-btn:hover {
    background-color: #3d566e;
}

.week-label {
    font-size: 18px;
    font-weight: bold;
    color: #f1c40f;
}

/* ========================================
   ACTIVITIES GRID
   ======================================== */
.activities-board {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.activity-tile {
    background-color: #2c3e50;
    border-radius: 10px;
    padding: 20px;
    border: 1px solid #34495e;
}

.tile-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
    border-bottom: 1px solid #34495e;
    padding-bottom: 10px;
}

.tile-number {
    font-size: 24px;
    font-weight: bold;
    color: #3498db;
}

.tile-header h3 {
    font-size: 16px;
    color: #ecf0f1;
}

.action-btn {
    background-color: #3498db;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 5px;
    cursor: pointer;
    margin: 5px 5px 5px 0;
    font-size: 13px;
}

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

.dark-btn {
    background-color: #e74c3c;
}

.dark-btn:hover {
    background-color: #c0392b;
}

.tile-input {
    width: 100%;
    padding: 8px 12px;
    margin: 8px 0;
    background-color: #34495e;
    border: 1px solid #3d566e;
    border-radius: 5px;
    color: white;
}

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

.result-box {
    background-color: #34495e;
    padding: 12px;
    border-radius: 5px;
    margin-top: 12px;
    font-size: 13px;
    border-left: 3px solid #3498db;
}

/* ========================================
   WEEK 3 SPECIFIC
   ======================================== */
.compact-list {
    list-style: none;
    margin-top: 10px;
}

.compact-list li {
    background-color: #34495e;
    padding: 6px 10px;
    margin: 5px 0;
    border-radius: 4px;
    font-size: 13px;
}

.removable-item {
    background-color: #34495e;
    padding: 8px 12px;
    margin: 5px 0;
    border-radius: 4px;
    border-left: 3px solid #e74c3c;
}

.tile-image {
    width: 100%;
    height: 120px;
    object-fit: cover;
    border-radius: 5px;
    margin-top: 10px;
    border: 2px solid #34495e;
}

.todo-list {
    list-style: none;
    margin-top: 10px;
}

.todo-list li {
    background-color: #34495e;
    padding: 8px 12px;
    margin: 5px 0;
    border-radius: 4px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
}

.delete-small {
    background-color: #e74c3c;
    color: white;
    border: none;
    width: 24px;
    height: 24px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
}

.delete-small:hover {
    background-color: #c0392b;
}

/* ========================================
   WEEK 4 CALCULATOR
   ======================================== */
.calculator-board {
    max-width: 550px;
    margin: 0 auto;
    background-color: #2c3e50;
    border-radius: 15px;
    padding: 30px;
    border: 1px solid #34495e;
}

.calc-header {
    text-align: center;
    margin-bottom: 25px;
}

.calc-header h2 {
    font-size: 26px;
    color: #f1c40f;
    margin-bottom: 5px;
}

.calc-header p {
    color: #bdc3c7;
    font-size: 14px;
}

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

.input-row label {
    display: block;
    margin-bottom: 5px;
    color: #ecf0f1;
    font-size: 14px;
}

.calc-input {
    width: 100%;
    padding: 12px;
    background-color: #34495e;
    border: 1px solid #3d566e;
    border-radius: 6px;
    color: white;
    font-size: 15px;
}

.calc-input:focus {
    outline: none;
    border-color: #f1c40f;
}

.calc-actions {
    display: flex;
    gap: 15px;
    margin: 25px 0;
}

.calc-btn {
    flex: 2;
    background-color: #3498db;
    color: white;
    border: none;
    padding: 12px;
    border-radius: 6px;
    font-size: 15px;
    cursor: pointer;
}

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

.reset-btn {
    flex: 1;
    background-color: #e74c3c;
    color: white;
    border: none;
    padding: 12px;
    border-radius: 6px;
    font-size: 15px;
    cursor: pointer;
}

.reset-btn:hover {
    background-color: #c0392b;
}

.result-panel {
    background-color: #34495e;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
}

.result-line {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 0;
}

.result-line:first-child {
    border-bottom: 1px solid #3d566e;
    margin-bottom: 8px;
}

.grade-value {
    font-size: 28px;
    font-weight: bold;
    color: #3498db;
}

.grade-letter {
    font-size: 32px;
    font-weight: bold;
    color: #f1c40f;
}

.scale-box {
    background-color: #34495e;
    border-radius: 8px;
    padding: 20px;
}

.scale-box h4 {
    text-align: center;
    margin-bottom: 15px;
    color: #ecf0f1;
}

.scale-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}

.scale-item {
    background-color: #2c3e50;
    padding: 8px;
    border-radius: 5px;
    text-align: center;
    font-size: 14px;
}

.scale-item span {
    display: block;
    font-size: 11px;
    color: #bdc3c7;
}

/* ========================================
   RESPONSIVE
   ======================================== */
@media (max-width: 768px) {
    .hero-title {
        font-size: 36px;
    }
    
    .weeks-showcase {
        grid-template-columns: 1fr;
    }
    
    .top-bar {
        flex-direction: column;
        text-align: center;
    }
    
    .activities-board {
        grid-template-columns: 1fr;
    }
    
    .calc-actions {
        flex-direction: column;
    }
    
    .scale-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ========================================
   HELPER CLASSES
   ======================================== */
.note {
    color: #bdc3c7;
    font-style: italic;
    font-size: 12px;
    margin-top: 10px;
    text-align: center;
}