* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #1a2a6c, #0d8b7a, #1a2a6c);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
    padding: 20px;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.container {
    width: 100%;
    max-width: 800px;
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.4);
    overflow: hidden;
}

header {
    background: linear-gradient(to right, #2c3e50, #3a5f7d);
    color: white;
    text-align: center;
    padding: 30px 20px;
    position: relative;
}

.logo {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

.logo-icon {
    font-size: 2.8rem;
    color: #4ecdc4;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
    letter-spacing: 0.5px;
}

.content {
    padding: 30px;
}

.input-group {
    position: relative;
    margin-bottom: 25px;
}

#randomString {
    width: 100%;
    padding: 18px 20px;
    font-size: 1.2rem;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    background-color: #f9f9f9;
    transition: all 0.3s ease;
    outline: none;
    font-family: monospace;
    letter-spacing: 1px;
    height: 120px;
    resize: none;
    line-height: 1.8;
}

#randomString:focus {
    border-color: #3a5f7d;
    box-shadow: 0 0 0 3px rgba(58, 95, 125, 0.2);
}

.stats {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    margin: 15px 0;
    background-color: #f0f4f8;
    padding: 15px;
    border-radius: 10px;
    border: 1px solid #e0e6ed;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 10px;
    min-width: 100px;
}

.stat-value {
    font-size: 1.8rem;
    font-weight: bold;
    color: #2c3e50;
}

.stat-label {
    color: #6c757d;
    font-size: 0.9rem;
}

.controls {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.btn {
    flex: 1;
    min-width: 180px;
    padding: 16px 0;
    font-size: 1.1rem;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
}

.btn-primary {
    background: linear-gradient(to right, #3498db, #3a5f7d);
    color: white;
    box-shadow: 0 4px 15px rgba(52, 152, 219, 0.4);
}

.btn-primary:hover {
    background: linear-gradient(to right, #2980b9, #2c4d69);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(52, 152, 219, 0.5);
}

.btn-secondary {
    background: linear-gradient(to right, #2ecc71, #27ae60);
    color: white;
    box-shadow: 0 4px 15px rgba(46, 204, 113, 0.4);
}

.btn-secondary:hover {
    background: linear-gradient(to right, #27ae60, #219653);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(46, 204, 113, 0.5);
}

.btn:active {
    transform: translateY(1px);
}

.notification {
    position: fixed;
    top: 30px;
    right: 30px;
    padding: 15px 25px;
    background-color: #27ae60;
    color: white;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transform: translateX(150%);
    transition: transform 0.5s ease;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 10px;
}

.notification.show {
    transform: translateX(0);
}

.info {
    background-color: #e8f4fc;
    border-left: 4px solid #3498db;
    padding: 20px;
    border-radius: 0 8px 8px 0;
    margin-top: 30px;
    font-size: 0.95rem;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
}

.info h3 {
    color: #2c3e50;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.info ul {
    padding-left: 20px;
    line-height: 1.6;
}

.info li {
    margin-bottom: 8px;
    position: relative;
    padding-left: 10px;
}

.info li:before {
    content: "•";
    position: absolute;
    left: -5px;
    color: #3498db;
    font-size: 1.2rem;
}

.strength-meter {
    margin-top: 15px;
    padding: 15px;
    background-color: #f9f9f9;
    border-radius: 10px;
    border: 1px solid #e0e0e0;
}

.strength-title {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    font-weight: 600;
    color: #2c3e50;
}

.meter-bar {
    height: 12px;
    background: #e0e0e0;
    border-radius: 6px;
    overflow: hidden;
}

.meter-fill {
    height: 100%;
    border-radius: 6px;
    width: 0%;
    background: linear-gradient(to right, #ff6b6b, #ffd166, #06d6a0);
    transition: width 0.5s ease;
}

.char-types {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin-top: 20px;
    padding: 15px;
    background-color: #f9f9f9;
    border-radius: 10px;
    border: 1px solid #e0e0e0;
}

.char-option {
    display: flex;
    align-items: center;
    gap: 8px;
}

.length-control {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 15px;
    padding: 15px;
    background-color: #f9f9f9;
    border-radius: 10px;
    border: 1px solid #e0e0e0;
}

.length-control label {
    font-weight: 500;
    color: #2c3e50;
}

.length-control input {
    width: 80px;
    padding: 8px 12px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 1rem;
    text-align: center;
}

.watermark {
    text-align: center;
    margin-top: 20px;
    color: #7f8c8d;
    font-size: 0.9rem;
    font-weight: 500;
}

@media (max-width: 600px) {
    .controls {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .stat-item {
        min-width: calc(50% - 20px);
        margin-bottom: 10px;
    }
    
    .char-types {
        flex-direction: column;
    }
}