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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    background: white;
    border-radius: 10px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1em;
    opacity: 0.9;
}

nav {
    display: flex;
    background: #f8f9fa;
    border-bottom: 2px solid #e9ecef;
    padding: 10px;
    gap: 10px;
    flex-wrap: wrap;
}

.nav-btn {
    flex: 1;
    min-width: 150px;
    padding: 12px 20px;
    background: white;
    border: 2px solid #dee2e6;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
    transition: all 0.3s;
    text-decoration: none;
    color: #495057;
    text-align: center;
}

.nav-btn:hover {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.nav-btn.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

main {
    padding: 30px;
}

.section {
    display: none;
}

.section.active {
    display: block;
}

.section h2 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 1.8em;
}

.form-group {
    margin-bottom: 25px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 8px;
}

.form-group h3 {
    margin-bottom: 15px;
    color: #495057;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #495057;
    font-weight: 500;
}

input[type="text"],
input[type="email"] {
    width: 100%;
    padding: 12px;
    border: 2px solid #dee2e6;
    border-radius: 5px;
    font-size: 1em;
    margin-bottom: 10px;
    transition: border-color 0.3s;
}

input[type="text"]:focus,
input[type="email"]:focus {
    outline: none;
    border-color: #667eea;
}

button {
    padding: 12px 24px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1em;
    cursor: pointer;
    transition: background 0.3s;
}

button:hover {
    background: #5568d3;
}

button:active {
    transform: scale(0.98);
}

.message {
    margin-top: 15px;
    padding: 12px;
    border-radius: 5px;
    display: none;
}

.message.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
    display: block;
}

.message.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
    display: block;
}

.entries-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.entry-category {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
}

.entry-category h3 {
    color: #667eea;
    margin-bottom: 15px;
    font-size: 1.3em;
}

.entry-category ul {
    list-style: none;
}

.entry-category li {
    padding: 10px;
    background: white;
    margin-bottom: 8px;
    border-radius: 5px;
    border-left: 3px solid #667eea;
}

.count-card {
    text-align: center;
    padding: 30px 20px;
}

.count-display {
    font-size: 3.5em;
    font-weight: bold;
    color: #667eea;
    margin: 15px 0 10px 0;
    line-height: 1;
}

.count-label {
    color: #6c757d;
    font-size: 1.1em;
    margin: 0;
    text-transform: lowercase;
}

.task-result {
    margin-top: 20px;
    padding: 20px;
    background: #e7f3ff;
    border-radius: 8px;
    border-left: 4px solid #667eea;
    display: none;
}

.task-result.show {
    display: block;
}

.task-result h3 {
    color: #667eea;
    margin-bottom: 15px;
}

.task-result p {
    margin: 10px 0;
    font-size: 1.1em;
}

.task-result strong {
    color: #495057;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-content h3 {
    color: #667eea;
    margin-top: 30px;
    margin-bottom: 15px;
    font-size: 1.4em;
}

.about-content h3:first-child {
    margin-top: 0;
}

.about-content p {
    margin-bottom: 15px;
    line-height: 1.6;
    color: #495057;
}

.about-content ul,
.about-content ol {
    margin: 15px 0 20px 25px;
    line-height: 1.8;
    color: #495057;
}

.about-content li {
    margin-bottom: 8px;
}

.about-content strong {
    color: #667eea;
    font-weight: 600;
}

@media (max-width: 768px) {
    .entries-container {
        grid-template-columns: 1fr;
    }

    nav {
        flex-direction: column;
    }

    .nav-btn {
        width: 100%;
    }
}