/* CSS Reset and Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #e0e7ff;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --weak-color: #ef4444;
    --fair-color: #f59e0b;
    --good-color: #3b82f6;
    --strong-color: #10b981;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --input-bg: #f1f5f9;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: all 0.2s ease;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

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;
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
header {
    text-align: center;
    margin-bottom: 24px;
    color: white;
}

.logo-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 8px;
}

.logo {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
}

h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.tagline {
    font-size: 1rem;
    opacity: 0.9;
}

/* Main Content */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Section Styles */
section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-lg);
}

/* Password Display Section */
.password-display-section {
    background: var(--card-bg);
}

#passwords-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 16px;
}

.password-item {
    display: flex;
    gap: 8px;
    align-items: center;
}

.password-output {
    flex: 1;
    padding: 14px 16px;
    font-size: 1rem;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    background: var(--input-bg);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    outline: none;
    transition: var(--transition);
    overflow: hidden;
    text-overflow: ellipsis;
}

.password-output:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.copy-btn {
    padding: 12px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.copy-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

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

.copy-btn.copied {
    background: var(--success-color);
}

/* Strength Meter */
.strength-meter {
    display: flex;
    align-items: center;
    gap: 12px;
}

.strength-bar {
    flex: 1;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}

.strength-fill {
    height: 100%;
    width: 0%;
    border-radius: 4px;
    transition: width 0.3s ease, background-color 0.3s ease;
}

.strength-fill.weak {
    width: 25%;
    background: var(--weak-color);
}

.strength-fill.fair {
    width: 50%;
    background: var(--fair-color);
}

.strength-fill.good {
    width: 75%;
    background: var(--good-color);
}

.strength-fill.strong {
    width: 100%;
    background: var(--strong-color);
}

.strength-text {
    font-size: 0.875rem;
    font-weight: 600;
    min-width: 80px;
    text-align: right;
    color: var(--text-secondary);
}

.strength-text.weak { color: var(--weak-color); }
.strength-text.fair { color: var(--fair-color); }
.strength-text.good { color: var(--good-color); }
.strength-text.strong { color: var(--strong-color); }

/* Controls Section */
.controls-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.control-group > label {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9375rem;
}

.control-group > label span {
    color: var(--primary-color);
    font-weight: 700;
}

/* Range Input Styles */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 22px;
    height: 22px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--primary-hover);
    transform: scale(1.1);
}

input[type="range"]::-moz-range-thumb {
    width: 22px;
    height: 22px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

input[type="range"]::-moz-range-thumb:hover {
    background: var(--primary-hover);
    transform: scale(1.1);
}

.range-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Checkbox Styles */
.checkbox-group {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    background: var(--input-bg);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
    user-select: none;
}

.checkbox-label:hover {
    background: var(--primary-light);
}

.checkbox-label input[type="checkbox"] {
    display: none;
}

.checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    flex-shrink: 0;
}

.checkbox-label input[type="checkbox"]:checked + .checkmark {
    background: var(--primary-color);
    border-color: var(--primary-color);
}

.checkbox-label input[type="checkbox"]:checked + .checkmark::after {
    content: '';
    width: 6px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
    margin-bottom: 2px;
}

/* Text Input */
.text-input {
    padding: 12px 14px;
    font-size: 0.9375rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--input-bg);
    color: var(--text-primary);
    outline: none;
    transition: var(--transition);
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
}

.text-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.text-input::placeholder {
    color: var(--text-secondary);
}

.control-group small {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Generate Button */
.generate-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 16px 24px;
    font-size: 1rem;
    font-weight: 600;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

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

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

/* Copy All Button */
.copy-all-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 14px 24px;
    font-size: 0.9375rem;
    font-weight: 600;
    background: var(--input-bg);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
}

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

.copy-all-btn.copied {
    background: var(--success-color);
    border-color: var(--success-color);
    color: white;
}

/* Info Section */
.info-section {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.info-section h2 {
    font-size: 1.125rem;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.info-section ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.info-section li {
    position: relative;
    padding-left: 24px;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.info-section li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: 700;
}

/* Footer */
footer {
    text-align: center;
    padding: 24px 0 12px;
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
}

footer a {
    color: white;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

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

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text-primary);
    color: white;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast.success {
    background: var(--success-color);
}

.toast.error {
    background: var(--danger-color);
}

/* Responsive Design */
@media (max-width: 600px) {
    .container {
        padding: 16px;
    }

    h1 {
        font-size: 1.5rem;
    }

    .logo {
        width: 40px;
        height: 40px;
    }

    section {
        padding: 20px;
    }

    .checkbox-group {
        grid-template-columns: 1fr;
    }

    .password-output {
        font-size: 0.875rem;
        padding: 12px;
    }

    .generate-btn {
        padding: 14px 20px;
    }

    .strength-meter {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
    }

    .strength-text {
        text-align: center;
    }
}

@media (max-width: 400px) {
    h1 {
        font-size: 1.25rem;
    }

    .tagline {
        font-size: 0.875rem;
    }

    .control-group > label {
        font-size: 0.875rem;
    }

    .checkbox-label {
        font-size: 0.8125rem;
        padding: 8px 10px;
    }
}

/* Animations */
@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

.shake {
    animation: shake 0.3s ease;
}

/* Print Styles */
@media print {
    body {
        background: white;
    }

    .container {
        max-width: 100%;
    }

    .generate-btn,
    .copy-btn,
    .copy-all-btn {
        display: none;
    }
}