:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --background-color: #f8fafc;
    --surface-color: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --border-radius: 8px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition: all 0.2s ease-in-out;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --max-width: 1200px;
}

/* Dark Mode Colors */
[data-theme="dark"] {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #94a3b8;
    --success-color: #22c55e;
    --error-color: #f87171;
    --warning-color: #fbbf24;
    --background-color: #0f172a;
    --surface-color: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Layout */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.app-header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    padding: 2rem 0;
    text-align: center;
    box-shadow: var(--shadow-md);
    position: relative;
}

.header-content {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1rem;
}

.app-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.app-subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    font-weight: 300;
}

/* Theme Toggle Button */
.theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.5rem;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1) rotate(20deg);
}

.theme-toggle:active {
    transform: scale(0.95) rotate(20deg);
}

.app-main {
    flex: 1;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
}

.app-footer {
    background-color: var(--surface-color);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    text-align: center;
    color: var(--text-secondary);
    transition: background-color 0.3s ease;
}

.footer-content {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1rem;
}

.tech-stack {
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* Sections */
.form-section,
.posts-section {
    margin-bottom: 3rem;
}

.section-header {
    text-align: center;
    margin-bottom: 2rem;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.section-description {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Form Styles */
.form-container {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.post-form {
    max-width: 600px;
    margin: 0 auto;
}

.post-form h2,
.post.form h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 1.5rem;
}

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-family: var(--font-family);
    transition: var(--transition);
    background-color: var(--surface-color);
    color: var(--text-primary);
}

[data-theme="dark"] .form-group input,
[data-theme="dark"] .form-group textarea {
    background-color: #0f172a;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group input.error,
.form-group textarea.error {
    border-color: var(--error-color);
}

.form-group .error-message {
    color: var(--error-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: block;
    padding: 0.5rem;
    background-color: #fef2f2;
    border-radius: 4px;
    border: 1px solid var(--error-color);
}

[data-theme="dark"] .form-group .error-message {
    background-color: rgba(248, 113, 113, 0.1);
}

.form-actions {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-family);
    box-shadow: var(--shadow-sm);
}

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

.btn:active {
    transform: translateY(0);
}

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

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

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

.btn-secondary:hover {
    background-color: #475569;
}

.btn-cancel {
    background-color: var(--secondary-color);
    color: white;
}

.btn-cancel:hover {
    background-color: #475569;
}

.btn-edit {
    background-color: var(--warning-color);
    color: white;
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

.btn-edit:hover {
    background-color: #d97706;
}

.btn-delete {
    background-color: var(--error-color);
    color: white;
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

.btn-delete:hover {
    background-color: #dc2626;
}

/* Posts Container */
.posts-container {
    display: grid;
    gap: 2rem;
    grid-template-columns: 1fr;
}

/* Post Cards */
.post-card {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

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

.post-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.post-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
    flex: 1;
}

.post-meta {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 0.25rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.post-date {
    font-weight: 500;
}

.post-updated {
    background-color: var(--warning-color);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 500;
}

.post-content {
    color: var(--text-primary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
    white-space: pre-wrap;
}

.post-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
}

/* No Posts Message */
.no-posts {
    text-align: center;
    padding: 3rem;
    background: var(--surface-color);
    border-radius: var(--border-radius);
    border: 2px dashed var(--border-color);
}

.no-posts h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.no-posts p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Loading Indicator */
.loading-indicator {
    text-align: center;
    padding: 3rem;
    background: var(--surface-color);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

/* Error Messages */
.error-container {
    margin-bottom: 2rem;
}

.error-message {
    background: #fef2f2;
    border: 1px solid var(--error-color);
    border-radius: var(--border-radius);
    padding: 1rem;
    color: var(--error-color);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    position: relative;
}

[data-theme="dark"] .error-message {
    background: rgba(248, 113, 113, 0.1);
}

.error-icon {
    font-size: 1.2rem;
    flex-shrink: 0;
}

.error-text {
    flex: 1;
    font-weight: 500;
}

.error-close {
    background: none;
    border: none;
    color: var(--error-color);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0;
    line-height: 1;
}

.error-close:hover {
    opacity: 0.7;
}

/* Success Messages */
.success-message {
    position: fixed;
    top: 20px;
    right: 20px;
    background: #f0fdf4;
    border: 1px solid var(--success-color);
    border-radius: var(--border-radius);
    padding: 1rem;
    color: var(--success-color);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    animation: slideIn 0.3s ease-out;
}

[data-theme="dark"] .success-message {
    background: rgba(34, 197, 94, 0.1);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }

    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.success-icon {
    font-size: 1.2rem;
}

.success-text {
    font-weight: 500;
}

/* warning */
.warning-message {
    position: fixed;
    top: 20px;
    right: 20px;
    background: #fffbeb;
    border: 1px solid var(--warning-color);
    border-radius: var(--border-radius);
    padding: 1rem;
    color: #92400e;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    animation: slideIn 0.3s ease-out;
}

[data-theme="dark"] .warning-message {
    background: rgba(251, 191, 36, 0.1);
    color: #fbbf24;
}

/* Educational Button */
.educational-btn {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    width: 60px;
    height: 60px;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    z-index: 100;
}

.educational-btn:hover {
    transform: scale(1.1);
    background: var(--primary-hover);
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn 0.3s ease-out;
}

[data-theme="dark"] .modal {
    background: rgba(0, 0, 0, 0.7);
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.modal-content {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    max-width: 800px;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-content h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-secondary);
    line-height: 1;
}

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

/* Educational Content */
.educational-content {
    line-height: 1.6;
}

.mvc-diagram {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.mvc-component {
    background: var(--background-color);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border: 2px solid var(--border-color);
    text-align: center;
}

.mvc-component h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.mvc-component ul {
    list-style: none;
    padding: 0;
    margin: 1rem 0 0;
}

.mvc-component li {
    padding: 0.25rem 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.api-info {
    margin-bottom: 2rem;
}

.api-endpoints {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.endpoint {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.75rem;
    background: var(--background-color);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.method {
    font-weight: 600;
    font-size: 0.875rem;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    min-width: 60px;
    text-align: center;
}

.method.get {
    background: #dbeafe;
    color: #1e40af;
}

.method.post {
    background: #d1fae5;
    color: #065f46;
}

.method.put {
    background: #fef3c7;
    color: #92400e;
}

.method.delete {
    background: #fee2e2;
    color: #991b1b;
}

[data-theme="dark"] .method.get {
    background: rgba(219, 234, 254, 0.2);
    color: #93c5fd;
}

[data-theme="dark"] .method.post {
    background: rgba(209, 250, 229, 0.2);
    color: #6ee7b7;
}

[data-theme="dark"] .method.put {
    background: rgba(254, 243, 199, 0.2);
    color: #fcd34d;
}

[data-theme="dark"] .method.delete {
    background: rgba(254, 226, 226, 0.2);
    color: #fca5a5;
}

.path {
    font-family: 'Courier New', monospace;
    font-weight: 500;
    color: var(--text-primary);
}

.description {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.features ul {
    list-style: none;
    padding: 0;
}

.features li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
}

.features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

/* Debug Error */
.debug-error {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--error-color);
    color: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    z-index: 1001;
    max-width: 90%;
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateX(-50%) translateY(-100%);
        opacity: 0;
    }

    to {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .app-header {
        padding: 1.5rem 0;
    }

    .app-title {
        font-size: 2rem;
    }

    .theme-toggle {
        width: 45px;
        height: 45px;
        font-size: 1.2rem;
    }

    .app-main {
        padding: 1.5rem 1rem;
    }

    .form-container {
        padding: 1.5rem;
    }

    .post-card {
        padding: 1.5rem;
    }

    .post-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .post-meta {
        align-items: flex-start;
    }

    .post-actions {
        justify-content: flex-start;
    }

    .form-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .educational-btn {
        width: 50px;
        height: 50px;
        font-size: 1rem;
    }

    .modal-content {
        margin: 1rem;
        padding: 1.5rem;
        max-height: 80vh;
    }

    .mvc-diagram {
        grid-template-columns: 1fr;
    }

    .endpoint {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
}

@media (max-width: 480px) {
    .app-header {
        padding: 1rem 0;
    }

    .app-title {
        font-size: 1.5rem;
    }

    .app-subtitle {
        font-size: 1rem;
    }

        .theme-toggle {
        width: 40px;
        height: 40px;
        font-size: 1rem;
        top: 0.75rem;
        right: 0.75rem;
    }
    
    .app-main {
        padding: 1rem;
    }

    .form-container,
    .post-card {
        padding: 1rem;
    }

    .section-header h2 {
        font-size: 1.5rem;
    }

    .post-title {
        font-size: 1.2rem;
    }
}