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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --input-bg: #f1f5f9;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --radius-sm: 8px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Main Content */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.card h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.helper-text {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

/* Input Groups */
.input-group {
    margin-bottom: 1rem;
}

.input-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.input-group input[type="text"],
.input-group textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
    background: var(--card-bg);
}

.input-group input[type="text"]:focus,
.input-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* Output Group */
.output-group {
    margin-bottom: 0;
}

.output-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.output-wrapper {
    position: relative;
    display: flex;
    align-items: stretch;
}

.output-wrapper input[type="text"],
.output-wrapper textarea {
    width: 100%;
    padding: 0.875rem 3rem 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', monospace;
    background: var(--input-bg);
    color: var(--text-primary);
}

.output-wrapper.textarea-wrapper {
    flex-direction: column;
}

.output-wrapper.textarea-wrapper textarea {
    padding-right: 1rem;
    resize: vertical;
    min-height: 120px;
}

.output-wrapper.textarea-wrapper .copy-btn {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
}

.copy-btn {
    position: absolute;
    right: 0.5rem;
    top: 50%;
    transform: translateY(-50%);
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 6px;
    padding: 0.5rem;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.output-wrapper.textarea-wrapper .copy-btn {
    top: 0.5rem;
    transform: none;
}

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

.copy-btn:active {
    transform: translateY(-50%) scale(0.95);
}

.output-wrapper.textarea-wrapper .copy-btn:active {
    transform: scale(0.95);
}

/* Options */
.options-card {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.option-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.option-item label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.option-item select {
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-family: inherit;
    background: var(--card-bg);
    cursor: pointer;
    transition: border-color 0.2s;
}

.option-item select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.checkbox-item {
    flex-direction: row;
    align-items: center;
    gap: 0.75rem;
}

.checkbox-item input[type="checkbox"] {
    width: 1.25rem;
    height: 1.25rem;
    accent-color: var(--primary-color);
    cursor: pointer;
}

.checkbox-item label {
    cursor: pointer;
    user-select: none;
}

/* Buttons */
.primary-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s, box-shadow 0.2s;
    margin-bottom: 1rem;
}

.primary-btn:hover {
    background: var(--primary-hover);
    box-shadow: var(--shadow);
}

.primary-btn:active {
    transform: scale(0.98);
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text-primary);
    color: white;
    padding: 0.875rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 500;
    opacity: 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
    z-index: 1000;
    box-shadow: var(--shadow-lg);
}

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

/* Footer */
footer {
    text-align: center;
    padding: 2rem 0 1rem;
    margin-top: 2rem;
    border-top: 1px solid var(--border-color);
}

footer p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 640px) {
    .container {
        padding: 1rem;
    }

    header h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .card {
        padding: 1.25rem;
    }

    .options-grid {
        grid-template-columns: 1fr;
    }

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

@media (max-width: 480px) {
    header h1 {
        font-size: 1.75rem;
    }

    .card h2 {
        font-size: 1.1rem;
    }

    .input-group input[type="text"],
    .input-group textarea,
    .output-wrapper input[type="text"],
    .output-wrapper textarea {
        font-size: 0.95rem;
        padding: 0.75rem;
    }

    .output-wrapper input[type="text"] {
        padding-right: 2.75rem;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #0f172a;
        --card-bg: #1e293b;
        --text-primary: #f1f5f9;
        --text-secondary: #94a3b8;
        --border-color: #334155;
        --input-bg: #0f172a;
    }

    .options-card {
        background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    }

    .toast {
        background: #f1f5f9;
        color: #0f172a;
    }
}