@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    --bg-color: #f9fafb;
    --surface-color: #ffffff;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --border-color: #e5e7eb;
    --primary-color: #374151;
    --primary-hover: #1f2937;
    --danger-color: #ef4444;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.03);
    
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-full: 9999px;
    
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 0.5rem;
    letter-spacing: -0.025em;
}

p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

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

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

/* Layout */
.container {
    width: 100%;
    max-width: 1024px;
    margin: 0 auto;
    padding: 0 1rem;
    flex: 1;
}

.main-content {
    padding: 2rem 0;
}

/* Header & Navbar */
.site-header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 50;
    box-shadow: var(--shadow-sm);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-brand:hover {
    text-decoration: none;
    color: var(--primary-hover);
}

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

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
    background-color: var(--bg-color);
    color: var(--text-primary);
    text-decoration: none;
}

/* Cards & Panels */
.card {
    background-color: var(--surface-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.card-title {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

/* Alerts */
.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    border: 1px solid transparent;
}

.alert-info {
    background-color: #f3f4f6;
    color: #111827;
    border-color: #e5e7eb;
}

.alert-warning {
    background-color: #fffbeb;
    color: #92400e;
    border-color: #fde68a;
}

.alert-success {
    background-color: #ecfdf5;
    color: #065f46;
    border-color: #a7f3d0;
}

.alert-danger {
    background-color: #fef2f2;
    color: #991b1b;
    border-color: #fecaca;
}

.alert p {
    margin: 0;
    color: inherit;
}

.alert ul {
    margin-left: 1.5rem;
    margin-top: 0.5rem;
    margin-bottom: 0;
}

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

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

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    color: var(--text-primary);
    background-color: var(--surface-color);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(55, 65, 81, 0.1);
}

textarea.form-control {
    min-height: 100px;
    resize: vertical;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-weight: 500;
    font-size: 1rem;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: center;
    width: auto;
}

.btn-block {
    display: flex;
    width: 100%;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    text-decoration: none;
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background-color: transparent;
    border-color: var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    background-color: var(--bg-color);
    text-decoration: none;
    color: var(--text-primary);
}

/* Tags / Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.6rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    background-color: var(--bg-color);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

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

.badge-warning {
    background-color: #fef3c7;
    color: #92400e;
    border-color: #fde68a;
}

/* Modals */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(17, 24, 39, 0.5);
    backdrop-filter: blur(4px);
    z-index: 100;
    justify-content: center;
    align-items: center;
    padding: 1rem;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.modal-overlay.show {
    display: flex;
    opacity: 1;
}

.modal-content {
    background-color: var(--surface-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 500px;
    transform: translateY(20px);
    transition: transform var(--transition-normal);
    overflow: hidden;
    position: relative;
}

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

.modal-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--bg-color);
}

.modal-header h2 {
    margin: 0;
    font-size: 1.25rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
    transition: color var(--transition-fast);
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 1.5rem;
    max-height: 70vh;
    overflow-y: auto;
}

/* History List */
.history-list {
    list-style: none;
    padding: 0;
}

.history-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 0.75rem;
    overflow: hidden;
}

.history-summary {
    padding: 1rem;
    background-color: var(--surface-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color var(--transition-fast);
}

.history-summary:hover {
    background-color: var(--bg-color);
}

.history-summary p {
    margin: 0;
    font-size: 0.9rem;
}

.history-details {
    padding: 1rem;
    background-color: var(--bg-color);
    border-top: 1px solid var(--border-color);
    display: none;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.history-details.show {
    display: block;
}

/* Highlights */
.text-highlight {
    color: var(--primary-color);
    font-weight: 600;
}

.text-danger {
    color: var(--danger-color);
    font-weight: 600;
}

/* Footer */
.site-footer {
    background-color: var(--surface-color);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    margin-top: auto;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Utilities */
.text-center { text-align: center; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-4 { margin-bottom: 1rem; }
.mt-4 { margin-top: 1rem; }
.w-full { width: 100%; }
.word-wrap { word-wrap: break-word; word-break: break-all; }
.clickable { cursor: pointer; text-decoration: underline; color: var(--primary-color); }
.clickable:hover { color: var(--primary-hover); }
.hidden { display: none !important; }

/* Responsive */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 1rem;
    }
    .nav-links {
        width: 100%;
        overflow-x: auto;
        padding-bottom: 0.5rem;
        justify-content: center;
    }
    .card {
        padding: 1rem;
    }
}