/* =====================================================
   KidAI - Main Stylesheet
   ===================================================== */

/* CSS Variables */
:root {
    /* Colors - Light Theme */
    --color-primary: #6366f1;
    --color-primary-hover: #4f46e5;
    --color-primary-light: #e0e7ff;

    --color-success: #22c55e;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    --color-info: #3b82f6;

    --color-bg: #ffffff;
    --color-bg-secondary: #f8fafc;
    --color-bg-tertiary: #f1f5f9;

    --color-text: #1e293b;
    --color-text-secondary: #64748b;
    --color-text-muted: #94a3b8;

    --color-border: #e2e8f0;
    --color-border-hover: #cbd5e1;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;

    /* Border radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px 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);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 200ms ease;
    --transition-slow: 300ms ease;

    /* Z-index layers */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-modal: 300;
    --z-toast: 400;
}

/* Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
}

/* =====================================================
   Typography
   ===================================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-3xl); }
h2 { font-size: var(--font-size-2xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }

p {
    margin-bottom: var(--spacing-md);
}

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

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

/* =====================================================
   Layout
   ===================================================== */

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.items-center {
    align-items: center;
}

.justify-center {
    justify-content: center;
}

.justify-between {
    justify-content: space-between;
}

.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }

/* =====================================================
   Buttons
   ===================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-family: inherit;
    font-size: var(--font-size-sm);
    font-weight: 500;
    line-height: 1.5;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

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

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

.btn-primary:hover:not(:disabled) {
    background-color: var(--color-primary-hover);
}

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

.btn-secondary:hover:not(:disabled) {
    background-color: var(--color-bg-tertiary);
    border-color: var(--color-border-hover);
}

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

.btn-danger:hover:not(:disabled) {
    background-color: #dc2626;
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-base);
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-xs);
}

/* =====================================================
   Forms
   ===================================================== */

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    font-family: inherit;
    font-size: var(--font-size-base);
    line-height: 1.5;
    color: var(--color-text);
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

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

.form-input::placeholder {
    color: var(--color-text-muted);
}

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

.form-error {
    margin-top: var(--spacing-xs);
    font-size: var(--font-size-sm);
    color: var(--color-danger);
}

/* =====================================================
   Cards
   ===================================================== */

.card {
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.card-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.card-body {
    padding: var(--spacing-lg);
}

.card-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
    background-color: var(--color-bg-secondary);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

/* =====================================================
   Loading States
   ===================================================== */

.loading-screen {
    position: fixed;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: var(--color-bg);
    z-index: var(--z-modal);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading-screen p {
    margin-top: var(--spacing-md);
    color: var(--color-text-secondary);
}

/* =====================================================
   Alerts / Toasts
   ===================================================== */

.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
}

.alert-success {
    background-color: #dcfce7;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.alert-warning {
    background-color: #fef3c7;
    color: #92400e;
    border: 1px solid #fde68a;
}

.alert-danger {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-info {
    background-color: #dbeafe;
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

/* =====================================================
   Badge
   ===================================================== */

.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-xs);
    font-weight: 500;
    border-radius: var(--radius-full);
}

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

.badge-success {
    background-color: #dcfce7;
    color: #166534;
}

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

.badge-danger {
    background-color: #fee2e2;
    color: #991b1b;
}

/* =====================================================
   Utility Classes
   ===================================================== */

.text-center { text-align: center; }
.text-right { text-align: right; }
.text-muted { color: var(--color-text-secondary); }
.text-sm { font-size: var(--font-size-sm); }
.text-xs { font-size: var(--font-size-xs); }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }

.hidden { display: none !important; }
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.text-success { color: var(--color-success); }
.text-danger { color: var(--color-danger); }

/* =====================================================
   Auth Pages
   ===================================================== */

.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-bg-secondary);
    padding: var(--spacing-lg);
}

.auth-card {
    width: 100%;
    max-width: 420px;
}

.auth-divider {
    display: flex;
    align-items: center;
    margin: var(--spacing-lg) 0;
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

.auth-divider::before,
.auth-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background-color: var(--color-border);
}

.auth-divider span {
    padding: 0 var(--spacing-md);
}

/* Google OAuth Button */
.btn-google {
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    color: var(--color-text);
    font-weight: 500;
}

.btn-google:hover:not(:disabled) {
    background-color: var(--color-bg-secondary);
    border-color: var(--color-border-hover);
}

.btn-google svg {
    margin-right: var(--spacing-sm);
}

/* =====================================================
   Landing Page
   ===================================================== */

.landing-page {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.landing-header {
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--color-border);
}

.landing-header .logo {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-primary);
    margin: 0;
}

.landing-main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl) 0;
}

.landing-main h2 {
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-md);
}

.landing-main p {
    font-size: var(--font-size-lg);
    max-width: 600px;
    margin: 0 auto var(--spacing-lg);
}

/* =====================================================
   Error Pages
   ===================================================== */

.error-page {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.error-page h1 {
    font-size: 6rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

/* =====================================================
   Chat Layout
   ===================================================== */

.chat-layout {
    display: flex;
    height: 100vh;
}

.chat-sidebar {
    width: 280px;
    display: flex;
    flex-direction: column;
    background-color: var(--color-bg-secondary);
    border-right: 1px solid var(--color-border);
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.sidebar-header h3 {
    font-size: var(--font-size-lg);
    color: var(--color-primary);
    margin: 0;
}

.conversation-list {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-md);
}

.conversation-item {
    display: flex;
    flex-direction: column;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.conversation-item:hover {
    background-color: var(--color-bg-tertiary);
}

.conversation-title {
    font-size: var(--font-size-sm);
    font-weight: 500;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.conversation-date {
    color: var(--color-text-muted);
}

.sidebar-footer {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    border-top: 1px solid var(--color-border);
}

.sidebar-footer .btn {
    flex: 1;
}

.chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--color-bg);
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-lg);
}

.chat-welcome {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--color-text-secondary);
}

.chat-welcome h2 {
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.message {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.message-user {
    flex-direction: row-reverse;
}

.message-avatar {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
    background-color: var(--color-bg-tertiary);
    font-size: var(--font-size-xs);
    font-weight: 600;
    flex-shrink: 0;
}

.message-user .message-avatar {
    background-color: var(--color-primary);
    color: white;
}

.message-content {
    max-width: 80%;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    background-color: var(--color-bg-secondary);
    line-height: 1.6;
}

.message-user .message-content {
    background-color: var(--color-primary);
    color: white;
}

.message-content pre {
    background-color: var(--color-bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin: var(--spacing-sm) 0;
}

.message-user .message-content pre {
    background-color: rgba(255, 255, 255, 0.1);
}

/* Inline code - black bg with green text */
.message-content code {
    font-family: 'Fira Code', 'Consolas', 'Monaco', monospace;
    font-size: var(--font-size-sm);
    background-color: #1a1a1a;
    color: #4ade80;
    padding: 0.15em 0.4em;
    border-radius: 4px;
}

/* Code inside pre blocks should not have inline styling */
.message-content pre code {
    background-color: transparent;
    color: inherit;
    padding: 0;
    border-radius: 0;
}

/* Code block wrapper */
.code-block-wrapper {
    margin: var(--spacing-md) 0;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--color-border);
}

.code-block-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-xs) var(--spacing-md);
    background-color: #2d2d2d;
    border-bottom: 1px solid #404040;
}

.code-block-lang {
    font-size: var(--font-size-xs);
    color: #a0a0a0;
    text-transform: lowercase;
}

.code-copy-btn {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    background: transparent;
    border: none;
    color: #a0a0a0;
    font-size: var(--font-size-xs);
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.2s;
}

.code-copy-btn:hover {
    background-color: #404040;
    color: #ffffff;
}

.code-block-wrapper pre {
    margin: 0;
    border-radius: 0;
    background-color: #1e1e1e !important;
}

.code-block-wrapper pre code {
    display: block;
    padding: var(--spacing-md);
    overflow-x: auto;
    font-size: var(--font-size-sm);
    line-height: 1.5;
}

/* Message actions */
.message-actions {
    display: flex;
    gap: var(--spacing-xs);
    opacity: 0;
    transition: opacity 0.2s;
    margin-top: var(--spacing-xs);
    padding-left: 40px;
}

.message:hover .message-actions {
    opacity: 1;
}

.msg-action-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    padding: 0;
    background: transparent;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all 0.2s;
}

.msg-action-btn:hover {
    background-color: var(--color-bg-tertiary);
    border-color: var(--color-border);
    color: var(--color-text);
}

.regenerating {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    font-style: italic;
}

/* Table styling */
.message-content table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-md) 0;
    font-size: var(--font-size-sm);
}

.message-content th,
.message-content td {
    border: 1px solid var(--color-border);
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
}

.message-content th {
    background-color: var(--color-bg-tertiary);
    font-weight: 600;
}

.message-content tr:nth-child(even) {
    background-color: var(--color-bg-secondary);
}

.message-content tr:hover {
    background-color: var(--color-bg-tertiary);
}

/* Links in messages */
.message-content a {
    color: var(--color-primary);
    text-decoration: none;
}

.message-content a:hover {
    text-decoration: underline;
}

.message-user .message-content a {
    color: #c7d2fe;
}

/* Toast notifications */
.toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    padding: var(--spacing-sm) var(--spacing-lg);
    background-color: var(--color-text);
    color: var(--color-bg);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    z-index: 10000;
    opacity: 0;
    transition: all 0.3s ease;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast-success {
    background-color: var(--color-success);
    color: white;
}

.toast-error {
    background-color: var(--color-danger);
    color: white;
}

/* KaTeX math styling */
.message-content .katex-display {
    margin: var(--spacing-md) 0;
    overflow-x: auto;
    overflow-y: hidden;
}

.message-content .katex {
    font-size: 1.1em;
}

.chat-input-area {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
    background-color: var(--color-bg);
}

.chat-form {
    display: flex;
    gap: var(--spacing-md);
}

.chat-form textarea {
    flex: 1;
    resize: none;
    max-height: 150px;
}

/* =====================================================
   Dashboard Layout
   ===================================================== */

.dashboard-layout {
    min-height: 100vh;
    background-color: var(--color-bg-secondary);
}

.dashboard-header {
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-md) 0;
}

.dashboard-header h1 {
    font-size: var(--font-size-xl);
    margin: 0;
}

.dashboard-main {
    padding: var(--spacing-xl) 0;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.list-item {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}

.list-item:last-child {
    border-bottom: none;
}

/* =====================================================
   Responsive
   ===================================================== */

@media (max-width: 768px) {
    .chat-layout {
        flex-direction: column;
    }

    .chat-sidebar {
        width: 100%;
        height: auto;
        max-height: 40vh;
        border-right: none;
        border-bottom: 1px solid var(--color-border);
    }

    .message-content {
        max-width: 90%;
    }

    .landing-header .container {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}