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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --background: #f8fafc;
    --surface: #ffffff;
    --border: #e2e8f0;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px 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);
}

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

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

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

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

h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.section {
    background: var(--surface);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

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

label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

textarea,
input[type="text"],
select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
}

textarea {
    resize: vertical;
    font-family: 'Courier New', monospace;
}

textarea:focus,
input[type="text"]:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.help-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
    display: inline-block;
    text-decoration: none;
    text-align: center;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover:not(:disabled) {
    background: #475569;
    transform: translateY(-1px);
}

.btn-text {
    background: transparent;
    color: var(--primary-color);
    padding: 0.5rem 1rem;
}

.btn-text:hover {
    background: rgba(37, 99, 235, 0.1);
}

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

.result {
    margin-top: 2rem;
}

.hidden {
    display: none !important;
}

.info-box {
    background: #dbeafe;
    border-left: 4px solid var(--primary-color);
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
}

.warning-box {
    background: #fef3c7;
    border-left: 4px solid var(--warning-color);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.warning-box h2 {
    color: #92400e;
    margin-bottom: 1rem;
}

.warning-box p {
    color: #78350f;
    margin-bottom: 0.5rem;
}

.error-box {
    background: #fee2e2;
    border-left: 4px solid var(--danger-color);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.error-box h2 {
    color: #991b1b;
    margin-bottom: 1rem;
}

.error-box p {
    color: #7f1d1d;
}

.link-box {
    display: flex;
    gap: 0.5rem;
}

.link-box input {
    flex: 1;
}

.link-box .btn {
    flex-shrink: 0;
}

.expires-info {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 1rem;
}

.secret-box {
    background: #f8fafc;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    max-height: 400px;
    overflow-y: auto;
}

.secret-box pre {
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    margin: 0;
    color: var(--text-primary);
}

.copy-wrapper {
    text-align: center;
    margin-bottom: 1rem;
}

.loading {
    text-align: center;
    padding: 2rem;
}

.spinner {
    border: 4px solid var(--border);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.center-link {
    text-align: center;
    margin-top: 1.5rem;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-top: 3rem;
}

.feature {
    text-align: center;
    padding: 1.5rem;
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.feature p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: auto;
}

@media (max-width: 640px) {
    h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .section {
        padding: 1.5rem;
    }

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

    .link-box {
        flex-direction: column;
    }
}