/**
 * Base styles for Tamil Learning Chatbot
 * Shared across all pages
 */

/* Reset & Box Sizing */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* CSS Variables */
:root {
    --primary: #8b5cf6;
    --primary-light: #a78bfa;
    --primary-dark: #7c3aed;
    --accent: #f472b6;
    --success: #22c55e;
    --warning: #fbbf24;
    --danger: #ef4444;
}

/* Dark mode (default) */
[data-theme="dark"] {
    --bg-primary: #0a0a14;
    --bg-secondary: #12121f;
    --bg-main: #0f0f23;
    --bg-card: #1a1a2e;
    --bg-input: #16213e;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #2d2d44;
    --border: #334155;
    --user-msg-bg: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    --user-msg-text: white;
}

/* Light mode */
[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --bg-input: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --border: #e2e8f0;
    --user-msg-bg: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    --user-msg-text: white;
}

/* Base HTML/Body */
html, body {
    margin: 0;
    padding: 0;
    height: 100%;
}

body { 
    font-family: 'Noto Sans Tamil', 'Segoe UI', system-ui, sans-serif;
    background: var(--bg-main);
    color: var(--text-primary);
    transition: background 0.3s, color 0.3s;
}

/* App Container */
.app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    padding: 20px 30px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-shadow: 0 4px 20px rgba(139, 92, 246, 0.3);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 15px;
}

.header-left a {
    display: flex;
    align-items: center;
    gap: 15px;
    text-decoration: none;
    color: white;
}

.logo {
    width: 50px;
    height: 50px;
    background: rgba(255,255,255,0.2);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8em;
}

.nav-logo-icon {
    width: 36px;
    height: 36px;
    object-fit: contain;
}

.header-text h1 {
    font-size: 1.5em;
    font-weight: 700;
    margin-bottom: 2px;
}

.header-text p {
    font-size: 0.85em;
    opacity: 0.9;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* Theme Toggle */
.theme-toggle {
    background: rgba(255,255,255,0.2);
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1.2em;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

.theme-toggle:hover {
    background: rgba(255,255,255,0.3);
}

/* Footer */
.footer {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 25px;
    padding: 15px;
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    font-size: 0.85em;
    flex-wrap: wrap;
}

.footer a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

.footer a:hover {
    color: var(--accent);
}

.footer-divider {
    color: var(--border);
}

.footer-copyright {
    color: var(--text-secondary);
}

/* Content Page Styles */
.page-content {
    flex: 1;
    padding: 40px 30px;
    background: var(--bg-main);
}

.content-card {
    background: var(--bg-card);
    border-radius: 20px;
    border: 1px solid var(--border);
    padding: 35px;
    max-width: 800px;
    margin: 0 auto;
}

.content-card h2 {
    color: var(--accent);
    font-size: 1.8em;
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.content-card h3 {
    color: var(--primary);
    font-size: 1.2em;
    margin: 25px 0 12px 0;
}

.content-card p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 15px;
}

.content-card ul {
    color: var(--text-secondary);
    margin-left: 25px;
    margin-bottom: 15px;
    line-height: 1.8;
}

.content-card li {
    margin-bottom: 8px;
}

.content-card .highlight {
    background: var(--bg-input);
    padding: 20px;
    border-radius: 12px;
    border-left: 4px solid var(--accent);
    margin: 20px 0;
}

.content-card .warning-box {
    background: rgba(251, 191, 36, 0.1);
    padding: 20px;
    border-radius: 12px;
    border-left: 4px solid var(--warning);
    margin: 20px 0;
}

.content-card .last-updated {
    font-size: 0.9em;
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 20px;
}

/* Back Button */
.back-btn,
.back-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--bg-input);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 10px;
    margin-bottom: 25px;
    transition: background 0.2s;
}

.back-btn:hover,
.back-link:hover {
    background: var(--border);
}

/* Buttons */
.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 12px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(139, 92, 246, 0.4);
}

.btn-secondary {
    background: var(--bg-input);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

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

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

.btn-danger:hover {
    background: #dc2626;
}

/* Form Elements */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 0.9em;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: var(--bg-input);
    color: var(--text-primary);
    font-size: 1em;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.1);
}

.form-group input:disabled,
.form-group select:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

/* Toast Notifications */
.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 16px 24px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s;
    z-index: 1000;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

.toast.success {
    border-left: 4px solid var(--success);
}

.toast.error {
    border-left: 4px solid var(--danger);
}

/* Responsive */
@media (max-width: 768px) {
    .header {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    
    .header-left {
        flex-direction: column;
    }
    
    .header-controls {
        width: 100%;
        justify-content: center;
    }
    
    .page-content {
        padding: 20px 15px;
    }
    
    .content-card {
        padding: 25px 20px;
    }
    
    .footer {
        gap: 15px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.btn-unstyled {
    border: none;
    background: none;
    cursor: pointer;
}