:root {
    --primary: #4361ee;
    --primary-light: #4895ef;
    --secondary: #3f37c9;
    --success: #4cc9f0;
    --danger: #f72585;
    --warning: #f8961e;
    --dark: #212529;
    --light: #f8f9fa;
    --gray: #6c757d;
    --border-radius: 12px;
    --box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Poppins', sans-serif;
    background-color: #f5f7ff;
    color: var(--dark);
    line-height: 1.6;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.app-container {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 40px;
    animation: fadeIn 0.8s ease;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 10px;
}

.logo-icon {
    font-size: 28px;
    margin-right: 10px;
    color: var(--primary);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 10px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    color: var(--gray);
    font-weight: 300;
    max-width: 600px;
    margin: 0 auto;
}

.tool-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.tool-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 30px;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    animation: slideUp 0.6s ease;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 25px rgba(0, 0, 0, 0.15);
}

.tool-card:nth-child(1) {
    animation-delay: 0.1s;
}

.tool-card:nth-child(2) {
    animation-delay: 0.2s;
}

h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--primary);
    display: flex;
    align-items: center;
}

h2 i {
    margin-right: 10px;
}

.input-group {
    margin-bottom: 20px;
    position: relative;
}

input[type="text"], input[type="number"] {
    width: 100%;
    padding: 15px;
    border: 2px solid #e9ecef;
    border-radius: var(--border-radius);
    font-size: 16px;
    transition: var(--transition);
    background-color: #f8f9fa;
}

input[type="text"]:focus, input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-light);
    background-color: white;
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

.strength-indicator {
    margin: 20px 0;
}

.strength-labels {
    display: flex;
    justify-content: space-between;
    margin-bottom: 5px;
    font-size: 0.8rem;
    color: var(--gray);
}

.strength-meter {
    height: 8px;
    background-color: #e9ecef;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 15px;
}

.strength-bar {
    height: 100%;
    width: 0%;
    transition: var(--transition);
    background: linear-gradient(90deg, var(--danger), var(--warning), var(--success));
}

.feedback {
    font-size: 0.9rem;
    min-height: 20px;
    margin-top: 10px;
    padding: 10px;
    border-radius: 6px;
    background-color: #f8f9fa;
}

.error {
    color: var(--danger);
    background-color: rgba(247, 37, 133, 0.1);
}

.success {
    color: var(--success);
    background-color: rgba(76, 201, 240, 0.1);
}

.requirements {
    margin-top: 20px;
}

.requirements h3 {
    font-size: 1rem;
    margin-bottom: 10px;
    color: var(--gray);
}

.requirements-list {
    list-style: none;
}

.requirements-list li {
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    font-size: 0.9rem;
    transition: var(--transition);
}

.requirements-list li::before {
    content: "•";
    margin-right: 8px;
    color: var(--gray);
}

.requirements-list li.valid {
    color: var(--success);
}

.requirements-list li.valid::before {
    content: "✓";
    color: var(--success);
}

.options {
    margin: 20px 0;
}

.option-item {
    margin-bottom: 15px;
    display: flex;
    align-items: center;
}

input[type="checkbox"] {
    width: 18px;
    height: 18px;
    margin-right: 10px;
    accent-color: var(--primary);
    cursor: pointer;
}

label {
    cursor: pointer;
    user-select: none;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

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

.btn-primary:hover {
    background-color: var(--secondary);
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: white;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-secondary:hover {
    background-color: var(--primary-light);
    color: white;
    border-color: var(--primary-light);
}

.result-container {
    display: flex;
    margin-top: 20px;
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    overflow: hidden;
}

.password-display {
    flex-grow: 1;
    padding: 15px;
    border: none;
    background: transparent;
    font-size: 16px;
    color: var(--dark);
}

.copy-btn {
    background-color: var(--primary);
    color: white;
    border: none;
    padding: 0 20px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
}

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

.copy-btn i {
    margin-right: 5px;
}

.tooltip {
    position: relative;
    display: inline-block;
}

.tooltip .tooltiptext {
    visibility: hidden;
    width: 120px;
    background-color: var(--dark);
    color: white;
    text-align: center;
    border-radius: 6px;
    padding: 5px;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%);
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 0.8rem;
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

footer {
    text-align: center;
    margin-top: 40px;
    color: var(--gray);
    font-size: 0.9rem;
    animation: fadeIn 0.8s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { 
        opacity: 0;
        transform: translateY(20px);
    }
    to { 
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .tool-container {
        grid-template-columns: 1fr;
    }
    
    h1 {
        font-size: 2rem;
    }
}