:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #10b981;
    --dark-color: #1e293b;
    --light-color: #f8fafc;
    --gray-color: #94a3b8;
    --error-color: #ef4444;
    --success-color: #10b981;
    --border-radius: 8px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: white;
    border-radius: 16px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

header {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: -0.5px;
}

h1 span {
    font-weight: 400;
    opacity: 0.8;
    font-size: 2rem;
}

.tagline {
    font-size: 1.1rem;
    opacity: 0.9;
}

main {
    padding: 30px;
}

.password-display {
    position: relative;
    margin-bottom: 30px;
}

#password-output {
    width: 100%;
    padding: 15px 60px 15px 20px;
    font-size: 1.2rem;
    font-family: 'Courier New', monospace;
    border: 2px solid var(--gray-color);
    border-radius: var(--border-radius);
    background-color: var(--light-color);
    color: var(--dark-color);
    transition: var(--transition);
}

#password-output:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

/* Action buttons (copy and share) */
.action-btn,
#copy-btn {
    position: absolute;
    background: none;
    border: none;
    font-size: 1.2rem;
    color: var(--gray-color);
    cursor: pointer;
    transition: var(--transition);
    padding: 8px;
}

#copy-btn {
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
}

#share-btn {
    right: 40px;
    top: 50%;
    transform: translateY(-50%);
}

.action-btn:hover,
#copy-btn:hover {
    color: var(--primary-color);
}

/* Toast notification */
#toast {
    visibility: hidden;
    min-width: 250px;
    background-color: var(--dark-color);
    color: white;
    text-align: center;
    border-radius: var(--border-radius);
    padding: 16px;
    position: fixed;
    z-index: 2000;
    left: 50%;
    transform: translateX(-50%);
    bottom: 30px;
    font-size: 0.9rem;
    box-shadow: var(--shadow);
    opacity: 0;
    transition: opacity 0.3s, visibility 0.3s;
}

#toast.show {
    visibility: visible;
    opacity: 1;
}

.options-panel {
    background-color: #f8fafc;
    padding: 25px;
    border-radius: var(--border-radius);
    margin-bottom: 25px;
}

.option-group {
    margin-bottom: 20px;
}

.option-group:last-child {
    margin-bottom: 0;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark-color);
}

select, input[type="range"] {
    width: 100%;
    padding: 10px;
    border-radius: var(--border-radius);
    border: 1px solid #cbd5e1;
    background-color: white;
    font-family: 'Inter', sans-serif;
    transition: var(--transition);
}

select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    padding-right: 30px;
}

select:focus, input[type="range"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.range-container {
    position: relative;
}

input[type="range"] {
    -webkit-appearance: none;
    height: 8px;
    background: #ddd;
    border-radius: 5px;
    background-image: linear-gradient(var(--primary-color), var(--primary-color));
    background-size: 60% 100%;
    background-repeat: no-repeat;
    padding: 0;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
    box-shadow: 0 0 2px rgba(0, 0, 0, 0.2);
}

.range-labels {
    display: flex;
    justify-content: space-between;
    margin-top: 8px;
    font-size: 0.8rem;
    color: var(--gray-color);
}

.checkboxes {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
}

.checkbox-item {
    display: flex;
    align-items: center;
    flex: 1 1 calc(33.333% - 10px);
    min-width: 150px;
}

.checkbox-item input[type="checkbox"] {
    margin-right: 8px;
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color);
}

.checkbox-item label {
    margin-bottom: 0;
    font-weight: normal;
    cursor: pointer;
}

.primary-btn {
    display: block;
    width: 100%;
    padding: 12px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    margin-top: 20px;
}

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

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

.password-strength {
    margin-bottom: 25px;
}

.strength-meter {
    height: 8px;
    background-color: #e2e8f0;
    border-radius: 4px;
    margin-bottom: 8px;
    overflow: hidden;
}

.strength-bar {
    height: 100%;
    width: 60%;
    background-color: var(--secondary-color);
    border-radius: 4px;
    transition: var(--transition);
}

.strength-text {
    font-size: 0.9rem;
    color: var(--gray-color);
}

#strength-value {
    font-weight: 600;
    color: var(--secondary-color);
}

.password-info {
    background-color: #f8fafc;
    padding: 20px;
    border-radius: var(--border-radius);
    margin-bottom: 20px;
}

.password-info h3 {
    margin-bottom: 10px;
    font-size: 1.1rem;
    color: var(--dark-color);
}

.tips {
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px solid #e2e8f0;
}

.tips p {
    font-size: 0.9rem;
    color: var(--gray-color);
}

.tips i {
    color: #eab308;
    margin-right: 5px;
}

footer {
    text-align: center;
    padding: 20px;
    background-color: #f1f5f9;
    color: var(--gray-color);
    font-size: 0.9rem;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* Modal styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    overflow: auto;
}

.modal-content {
    background-color: white;
    margin: 10% auto;
    padding: 30px;
    width: 80%;
    max-width: 600px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    position: relative;
}

.close-modal {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--gray-color);
    cursor: pointer;
}

.close-modal:hover {
    color: var(--dark-color);
}

/* Copy animation */
@keyframes copied {
    0% { transform: scale(1); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

.copied {
    animation: copied 0.3s ease;
    color: var(--success-color) !important;
}

/* Responsive styles */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }
    
    h1 span {
        font-size: 1.6rem;
    }
    
    .container {
        border-radius: 12px;
    }
    
    main {
        padding: 20px;
    }
    
    .options-panel {
        padding: 20px;
    }
    
    .checkbox-item {
        flex: 1 1 100%;
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    h1 span {
        font-size: 1.4rem;
    }
    
    header {
        padding: 30px 15px;
    }
    
    .container {
        border-radius: 8px;
    }
    
    main {
        padding: 15px;
    }
    
    .options-panel, .password-info {
        padding: 15px;
    }
    
    #password-output {
        font-size: 1rem;
        padding: 12px 50px 12px 15px;
    }
}

/* Share URL container styles */
.share-url-container {
    background-color: #f8fafc;
    border-radius: var(--border-radius);
    margin-bottom: 25px;
    overflow: hidden;
}

.share-url-header {
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #e2e8f0;
    cursor: pointer;
}

.share-url-header h3 {
    margin: 0;
    font-size: 1rem;
    color: var(--dark-color);
}

.toggle-btn {
    background: none;
    border: none;
    color: var(--gray-color);
    cursor: pointer;
    font-size: 1rem;
    transition: var(--transition);
}

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

.toggle-btn i {
    transition: transform 0.3s ease;
}

.toggle-btn.active i {
    transform: rotate(180deg);
}

.share-url-content {
    padding: 15px 20px;
    display: none;
}

.share-url-content.show {
    display: block;
}

.share-url-content p {
    margin-top: 0;
    margin-bottom: 12px;
    font-size: 0.9rem;
    color: var(--gray-color);
}

.url-display {
    position: relative;
}

#share-url {
    width: 100%;
    padding: 10px 40px 10px 12px;
    font-size: 0.9rem;
    font-family: monospace;
    border: 1px solid #cbd5e1;
    border-radius: var(--border-radius);
    background-color: white;
    color: var(--dark-color);
    overflow: hidden;
    text-overflow: ellipsis;
}

#copy-url-btn {
    position: absolute;
    right: 5px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    font-size: 1rem;
    color: var(--gray-color);
    cursor: pointer;
    padding: 8px;
    transition: var(--transition);
}

#copy-url-btn:hover {
    color: var(--primary-color);
}

.length-display {
    text-align: center;
    margin-top: 8px;
    font-size: 0.9rem;
    color: var(--dark-color);
}

#length-value {
    font-weight: 600;
    color: var(--primary-color);
}