:root {
    --color-bg: #f0f2f5;
    --color-surface: #ffffff;
    --color-primary: #3b82f6;
    --color-primary-hover: #2563eb;
    --color-secondary: #e5e7eb;
    --color-secondary-hover: #d1d5db;
    --color-danger: #ef4444;
    --color-danger-hover: #dc2626;
    --color-text: #1f2937;
    --color-text-secondary: #6b7280;
    --color-border: #d1d5db;
    --color-success: #10b981;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --radius: 0.5rem;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --transition: all 0.2s ease;
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #111827;
        --color-surface: #1f2937;
        --color-primary: #60a5fa;
        --color-primary-hover: #3b82f6;
        --color-secondary: #374151;
        --color-secondary-hover: #4b5563;
        --color-text: #f9fafb;
        --color-text-secondary: #9ca3af;
        --color-border: #4b5563;
    }
}

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

body {
    font-family: var(--font-family);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.5;
    display: flex;
    justify-content: center;
    min-height: 100vh;
    padding: 2rem 1rem;
}

.container {
    width: 100%;
    max-width: 700px;
}

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

header h1 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

header p {
    color: var(--color-text-secondary);
}

/* Card */
.card {
    background-color: var(--color-surface);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.card-content {
    padding: 2rem;
}

/* Tabs */
.tabs {
    display: flex;
    border-bottom: 1px solid var(--color-border);
}

.mode-tabs .tab-btn {
    flex: 1;
    padding: 1rem;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

.mode-tabs .tab-btn:hover {
    color: var(--color-primary);
    background-color: rgba(0, 0, 0, 0.02);
}

.mode-tabs .tab-btn.active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
}

.key-tabs {
    margin-bottom: 1.5rem;
    border: none;
    gap: 0.5rem;
}

.key-btn {
    padding: 0.5rem 1rem;
    background-color: var(--color-secondary);
    border: none;
    border-radius: 2rem;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--color-text);
    transition: var(--transition);
}

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

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.9rem;
}

textarea, input[type="text"], input[type="password"] {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background-color: var(--color-bg);
    color: var(--color-text);
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

textarea:focus, input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2);
}

textarea {
    min-height: 150px;
    resize: vertical;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

.password-wrapper {
    position: relative;
    display: flex;
}

.password-wrapper input {
    padding-right: 3rem;
}

#TogglePasswordBtn {
    position: absolute;
    right: 0;
    top: 0;
    height: 100%;
    padding: 0 0.75rem;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    opacity: 0.6;
    transition: var(--transition);
}

#TogglePasswordBtn:hover {
    opacity: 1;
}

/* File Input */
.file-input-wrapper {
    display: flex;
    align-items: center;
    gap: 1rem;
}

input[type="file"] {
    font-size: 0.9rem;
}

.file-display {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.hint {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    margin-top: 0.5rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1rem;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn.primary {
    background-color: var(--color-primary);
    color: white;
    width: 100%;
}

.btn.primary:hover:not(:disabled) {
    background-color: var(--color-primary-hover);
}

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

.btn.secondary:hover:not(:disabled) {
    background-color: var(--color-secondary-hover);
}

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

.btn.danger:hover:not(:disabled) {
    background-color: var(--color-danger-hover);
}

/* Notifications */
.notification {
    padding: 1rem;
    border-radius: var(--radius);
    margin-top: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.notification.error {
    background-color: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--color-danger);
    color: var(--color-danger);
}

.notification.success {
    background-color: rgba(16, 185, 129, 0.1);
    border: 1px solid var(--color-success);
    color: var(--color-success);
}

/* Result Section */
.result-section {
    margin-top: 2rem;
    border-top: 1px solid var(--color-border);
    padding-top: 2rem;
}

.result-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.result-actions .btn {
    flex: 1;
    font-size: 0.9rem;
    padding: 0.5rem 1rem;
}

/* Footer */
footer {
    margin-top: 2rem;
    text-align: center;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

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

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

.security-note {
    margin-top: 0.5rem;
    color: var(--color-success);
    font-weight: 500;
}

/* Utilities */
.hidden {
    display: none !important;
}

@media (max-width: 480px) {
    .card-content {
        padding: 1.5rem;
    }
    
    .result-actions {
        flex-direction: column;
    }
    
    .result-actions .btn {
        width: 100%;
    }
}