/* Main shared styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f9f9f9;
    --text-primary: #000000;
    --text-secondary: #666666;
    --text-muted: #999999;
    --border-color: #e5e5e5;
    --border-color-light: #e5e7eb;
    --input-bg: #ffffff;
    --input-border: #e5e7eb;
    --sidebar-bg: #ffffff;
    --message-user-bg: #ffffff;
    --message-ai-bg: #f9f9f9;
    --shadow: rgba(0, 0, 0, 0.08);
    --shadow-light: rgba(0, 0, 0, 0.05);
    --primary-color: #007bff;
    --primary-dark: #0056b3;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --info-color: #3b82f6;
    --bg-color: #f9f9f9;
    --text-color: #000000;
    --text-light: #666666;
    --card-bg: #ffffff;
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
}

body.dark-mode {
    --bg-primary: #1a1a1a;
    --bg-secondary: #121212;
    --text-primary: #ffffff;
    --text-secondary: #d1d5db;
    --text-muted: #9ca3af;
    --border-color: #333333;
    --border-color-light: #374151;
    --input-bg: #262626;
    --input-border: #404040;
    --sidebar-bg: #1a1a1a;
    --message-user-bg: #262626;
    --message-ai-bg: #1f1f1f;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-light: rgba(0, 0, 0, 0.2);
    --bg-color: #121212;
    --text-color: #ffffff;
    --text-light: #d1d5db;
    --card-bg: #1a1a1a;
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.3);
}

/* Base body and app-container styles */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    min-height: 100vh;
    margin: 0;
    padding: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background: var(--bg-primary);
    transition: background-color 0.3s ease;
}

/* Navigation */
.main-nav {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-shadow: 0 1px 2px var(--shadow-light);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.nav-brand a {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    flex: 1;
    justify-content: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.nav-links a:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.nav-links a.active {
    background: linear-gradient(135deg, #007bff 0%, #0056b3 100%);
    color: #ffffff;
    box-shadow: 0 2px 8px rgba(0, 123, 255, 0.3);
}

.nav-user {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.btn-logout {
    background: var(--error-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.2s ease;
    box-shadow: 0 1px 2px var(--shadow-light);
}

.btn-logout:hover {
    opacity: 0.9;
    transform: translateY(-1px);
    box-shadow: 0 2px 4px var(--shadow);
}

/* Buttons */
.btn-primary {
    background: linear-gradient(135deg, #007bff 0%, #0056b3 100%);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1rem;
    box-shadow: 0 2px 8px rgba(0, 123, 255, 0.2);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #0056b3 0%, #004085 100%);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 123, 255, 0.3);
}

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

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1.5px solid var(--border-color);
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 1px 2px var(--shadow-light);
}

.btn-secondary:hover {
    background: var(--input-bg);
    border-color: var(--border-color);
    transform: translateY(-1px);
    box-shadow: 0 2px 4px var(--shadow);
}

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

/* Page containers */
.page-shell {
    min-height: 100vh;
    background: var(--bg-primary);
    display: flex;
    flex-direction: column;
}

.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1.5rem 2rem 1rem;
}

.page-brand {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    display: inline-flex;
    align-items: baseline;
    gap: 0.35rem;
}

.page-brand span {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    font-weight: 600;
}

.page-header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.page {
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    background: var(--bg-secondary);
    min-height: calc(100vh - 60px);
    transition: background-color 0.3s ease;
}

.page.hidden {
    display: none;
}

.page-title {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    transition: color 0.3s ease;
}

.page-subtitle {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-weight: 400;
    transition: color 0.3s ease;
}

.page-heading {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    margin-bottom: 2rem;
}

.page-heading .page-kicker {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    font-weight: 600;
}

.page-heading .page-title {
    margin: 0;
}

@media (max-width: 768px) {
    .page-header {
        padding: 1rem 1.25rem 0.5rem;
        flex-wrap: wrap;
    }

    .page {
        padding: 1.25rem;
    }
}

/* Cards */
.card {
    background: var(--bg-primary);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 8px var(--shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: 0 4px 12px var(--shadow);
}

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

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1.5px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--input-bg);
    color: var(--text-primary);
    transition: all 0.2s ease;
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
}

/* Loading and empty states */
.loading,
.empty-state {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    transition: color 0.3s ease;
}

.error {
    color: var(--error-color);
    text-align: center;
    padding: 2rem;
}

/* Responsive */
@media (max-width: 768px) {
    .main-nav {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }

    .nav-links {
        flex-wrap: wrap;
        gap: 0.5rem;
    }

    .page {
        padding: 1rem;
    }
}