:root {
    --primary-color: #6366f1;
    /* Indigo 500 */
    --primary-hover: #4f46e5;
    /* Indigo 600 */
    --background: #0f172a;
    /* Slate 900 */
    --surface: #1e293b;
    /* Slate 800 */
    --text-main: #f8fafc;
    /* Slate 50 */
    --text-muted: #94a3b8;
    /* Slate 400 */
    --border: #334155;
    /* Slate 700 */
    --accent: #06b6d4;
    /* Cyan 500 */
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--background);
    color: var(--text-main);
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Navbar */
.navbar {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--glass-border);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

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

.nav-link:hover,
.nav-link.active {
    color: var(--text-main);
}

/* Main Content */
.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
    flex: 1;
}

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    margin-bottom: 2rem;
}

.page-header {
    margin-bottom: 2rem;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    margin: 0 0 0.5rem 0;
}

.page-desc {
    color: var(--text-muted);
    margin: 0;
}

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

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

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    background: #0f172a;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    color: var(--text-main);
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    box-sizing: border-box;
    /* box-sizing is important for width: 100% */
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

textarea.form-control {
    min-height: 150px;
    resize: vertical;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
    font-size: 1rem;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #4338ca);
    color: white;
    box-shadow: 0 4px 6px -1px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    filter: brightness(1.1);
    transform: translateY(-1px);
}

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

/* File Upload */
.file-drop-area {
    border: 2px dashed var(--border);
    border-radius: 1rem;
    padding: 3rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    background: rgba(255, 255, 255, 0.02);
}

.file-drop-area:hover,
.file-drop-area.drag-over {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
}

.file-icon {
    font-size: 3rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

/* Loading/Spinner */
.spinner {
    display: none;
    width: 24px;
    height: 24px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
    margin-right: 0.5rem;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.btn.loading .spinner {
    display: inline-block;
}

/* Response Section */
.response-box {
    background: #0f172a;
    border-radius: 0.5rem;
    padding: 1.5rem;
    margin-top: 1.5rem;
    border: 1px solid var(--border);
    display: none;
    /* Hidden by default */
}

.response-box.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

pre {
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: 'Fira Code', monospace;
    color: #e2e8f0;
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 2rem;
    max-width: 500px;
    width: 90%;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2), 0 10px 10px -5px rgba(0, 0, 0, 0.1);
    transform: translateY(20px);
    transition: transform 0.3s ease;
}

.modal-overlay.active .modal {
    transform: translateY(0);
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.modal-body {
    color: var(--text-muted);
    margin-bottom: 2rem;
    line-height: 1.6;
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
}

.btn-danger {
    background: linear-gradient(135deg, #ef4444, #dc2626);
    color: white;
    box-shadow: 0 4px 6px -1px rgba(239, 68, 68, 0.4);
}

.btn-danger:hover {
    filter: brightness(1.1);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    filter: grayscale(1);
    box-shadow: none;
}

/* Data Tables */
.table-container {
    width: 100%;
    overflow-x: auto;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    margin-top: 1rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
    text-align: left;
}

.data-table th {
    background: rgba(255, 255, 255, 0.05);
    padding: 0.75rem 1rem;
    font-weight: 600;
    color: var(--accent);
    border-bottom: 2px solid var(--border);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.data-table td {
    padding: 1rem;
    border-bottom: 1px solid var(--border);
    color: var(--text-main);
    vertical-align: top;
}

.data-table tr:last-child td {
    border-bottom: none;
}

.data-table tr:hover td {
    background: rgba(255, 255, 255, 0.02);
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-size: 0.75rem;
    font-weight: 600;
    background: var(--primary-color);
    color: white;
}

.badge-rank {
    background: var(--accent);
}