:root {
    --primary-color: #A52A2A;
    --secondary-color: #8B4513;
    --accent-color: #CD853F;
    --light-accent: #DEB887;
    --lightest: #F5DEB3;
    --white: #FFFFFF;
    --text-dark: #2C2C2C;
    --text-light: #666666;
    --border-color: #E0E0E0;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 20px rgba(0,0,0,0.15);
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, var(--lightest) 0%, var(--white) 100%);
    color: var(--text-dark);
    line-height: 1.6;
    padding-bottom: 80px;
    min-height: 100vh;
}

/* Header */
.app-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 1rem;
    text-align: center;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.app-header h1 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.user-info {
    font-size: 0.9rem;
    opacity: 0.9;
}

/* Main Content */
.app-main {
    padding: 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

.main-section {
    display: none;
    animation: fadeIn 0.3s ease;
}

.main-section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Section Headers */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.section-header h2 {
    color: var(--primary-color);
    font-size: 1.4rem;
}

/* Cards */
.welcome-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    margin-bottom: 1.5rem;
}

.welcome-card h2 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.welcome-card p {
    color: var(--text-light);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--white);
    padding: 1rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.stat-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.stat-card i {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-number {
    display: block;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-light);
}

/* Buttons */
.btn {
    background: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn:hover {
    background: var(--secondary-color);
    transform: translateY(-1px);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    background: var(--light-accent);
    color: var(--text-dark);
}

.btn-secondary:hover {
    background: var(--accent-color);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Projects */
.projects-filter {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
}

.filter-btn {
    background: var(--lightest);
    color: var(--text-dark);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.8rem;
    white-space: nowrap;
    transition: var(--transition);
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--primary-color);
    color: var(--white);
}

.projects-grid,
.materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
}

.project-card,
.material-card {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
    cursor: pointer;
}

.project-card:hover,
.material-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.project-header,
.material-header {
    padding: 1rem;
    background: linear-gradient(135deg, var(--light-accent), var(--lightest));
}

.project-title,
.material-name {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.project-category,
.material-category {
    font-size: 0.8rem;
    color: var(--text-light);
    background: var(--white);
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    display: inline-block;
}

.project-body,
.material-body {
    padding: 1rem;
}

.project-description {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.project-meta,
.material-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: var(--text-light);
}

.project-status {
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    font-size: 0.7rem;
    font-weight: 500;
}

.status-planning {
    background: #FFF3CD;
    color: #856404;
}

.status-in-progress {
    background: #D4EDDA;
    color: #155724;
}

.status-completed {
    background: #D1ECF1;
    color: #0C5460;
}

.project-actions,
.material-actions {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 0.5rem;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
}

/* Progress Bar */
.progress-bar {
    background: var(--border-color);
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
    margin: 0.5rem 0;
}

.progress-fill {
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    height: 100%;
    transition: width 0.3s ease;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-light);
}

.empty-state i {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state p {
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

/* Modals */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 1000;
    justify-content: center;
    align-items: center;
    padding: 1rem;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--white);
    border-radius: var(--border-radius);
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-hover);
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    color: var(--primary-color);
    margin: 0;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-light);
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.close-btn:hover {
    color: var(--primary-color);
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-dark);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(165, 42, 42, 0.1);
}

.form-actions {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
}

/* Search */
.search-box {
    position: relative;
    margin-bottom: 1.5rem;
}

.search-box i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-light);
}

.search-box input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 3rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

/* Skills */
.skills-overview {
    margin-bottom: 2rem;
}

.skill-level-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
}

.skill-level-display {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.level-circle {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.5rem;
    font-weight: bold;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}

.skill-card {
    background: var(--white);
    padding: 1rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.skill-name {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.skill-level {
    font-size: 0.8rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

/* Assessment */
.assessment-progress {
    margin-bottom: 2rem;
    text-align: center;
}

.assessment-question {
    padding: 1.5rem;
}

.question-text {
    font-size: 1.1rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

.question-options {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.option-btn {
    background: var(--lightest);
    border: 1px solid var(--border-color);
    padding: 1rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    text-align: left;
    transition: var(--transition);
}

.option-btn:hover {
    background: var(--light-accent);
}

.option-btn.selected {
    background: var(--primary-color);
    color: var(--white);
    border-color: var(--primary-color);
}

.assessment-actions {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
}

/* Progress Section */
.progress-overview {
    margin-bottom: 2rem;
}

.progress-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.progress-stat {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.progress-stat i {
    font-size: 2rem;
    color: var(--primary-color);
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.progress-projects {
    margin-bottom: 2rem;
}

.progress-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.progress-item {
    background: var(--white);
    padding: 1rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.progress-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.progress-item-name {
    font-weight: 600;
    color: var(--primary-color);
}

.progress-percentage {
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Achievements */
.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}

.achievement-card {
    background: var(--white);
    padding: 1rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.achievement-card.unlocked {
    background: linear-gradient(135deg, var(--lightest), var(--white));
    border: 2px solid var(--accent-color);
}

.achievement-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.achievement-card.unlocked .achievement-icon {
    color: var(--primary-color);
}

.achievement-card:not(.unlocked) .achievement-icon {
    color: var(--text-light);
    opacity: 0.5;
}

.achievement-name {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.achievement-description {
    font-size: 0.8rem;
    color: var(--text-light);
}

/* FAQ */
.faq-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.faq-item {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    padding: 1.5rem;
    text-align: left;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-dark);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--lightest);
}

.faq-question[aria-expanded="true"] {
    background: var(--light-accent);
    color: var(--primary-color);
}

.faq-icon {
    font-size: 1.2rem;
    font-weight: bold;
    transition: transform 0.3s ease;
}

.faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 1.5rem 1.5rem;
    color: var(--text-light);
    line-height: 1.6;
    animation: slideDown 0.3s ease;
}

.faq-answer[hidden] {
    display: none;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--white);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-around;
    padding: 0.5rem 0;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
    z-index: 100;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: var(--text-light);
    padding: 0.5rem;
    border-radius: 8px;
    transition: var(--transition);
    min-width: 60px;
}

.nav-item:hover,
.nav-item.active {
    color: var(--primary-color);
    background: var(--lightest);
}

.nav-item i {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
}

.nav-item span {
    font-size: 0.7rem;
    font-weight: 500;
}

/* Footer */
footer {
    background: var(--secondary-color);
    color: var(--white);
    text-align: center;
    padding: 1rem;
    margin-top: 2rem;
    font-size: 0.8rem;
}

footer p {
    margin: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .app-main {
        padding: 0.5rem;
    }
    
    .section-header {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }
    
    .projects-grid,
    .materials-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .progress-stats {
        grid-template-columns: 1fr;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .assessment-actions {
        flex-direction: column;
        gap: 1rem;
    }
    
    .modal-content {
        margin: 0.5rem;
        max-width: none;
    }
}

@media (max-width: 480px) {
    .bottom-nav {
        padding: 0.25rem 0;
    }
    
    .nav-item {
        padding: 0.25rem;
        min-width: 50px;
    }
    
    .nav-item i {
        font-size: 1rem;
    }
    
    .nav-item span {
        font-size: 0.6rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }
}

/* Print Styles */
@media print {
    .bottom-nav,
    .app-header,
    .btn,
    .modal {
        display: none !important;
    }
    
    .app-main {
        padding: 0;
    }
    
    .main-section {
        display: block !important;
        page-break-after: always;
    }
}