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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --success: #10b981;
    --error: #ef4444;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header and Navigation */
header {
    background-color: var(--surface);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

.navbar {
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-link:hover {
    color: var(--primary-color);
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 2rem 0;
}

/* Footer */
footer {
    background-color: var(--surface);
    border-top: 1px solid var(--border-color);
    padding: 1.5rem 0;
    margin-top: auto;
}

footer p {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.625rem 1.25rem;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 0.375rem;
    font-weight: 500;
    transition: background-color 0.2s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

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

.btn-secondary:hover {
    background-color: #475569;
}

/* Form Elements */
input[type="text"],
input[type="email"],
input[type="password"],
textarea,
select {
    width: 100%;
    padding: 0.625rem;
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s;
}

input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
}

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

/* Tool Grid */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.tool-card {
    background-color: var(--surface);
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    overflow: hidden;
}

.tool-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.tool-card-link {
    display: block;
    text-decoration: none;
    color: inherit;
}

.tool-card-content {
    padding: 2rem 1.5rem;
    text-align: center;
}

.tool-card-content h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.external-badge {
    display: inline-block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    background-color: var(--background);
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    margin-top: 0.5rem;
}

/* Tool Container */
.tool-container {
    background-color: var(--surface);
    border-radius: 0.5rem;
    padding: 2rem;
    box-shadow: var(--shadow);
}

.tool-container h1 {
    font-size: 1.875rem;
    margin-bottom: 1rem;
}

.tool-container p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.tool-section {
    margin-bottom: 1.5rem;
}

.tool-section label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.tool-actions {
    display: flex;
    gap: 1rem;
    margin: 1.5rem 0;
}

/* Preset Buttons */
.preset-section {
    margin-top: 1rem;
}

.preset-section label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
}

.preset-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.btn-preset {
    padding: 0.5rem 1rem;
    background-color: var(--background);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-preset.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    font-weight: 600;
}

/* Error Page */
.error-page {
    text-align: center;
    padding: 4rem 0;
}

.error-page h1 {
    font-size: 6rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.error-page h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.error-page p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 1rem;
    }

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

    .tool-actions {
        flex-direction: column;
    }

    .tool-actions .btn {
        width: 100%;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }