@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&family=Sarabun:wght@300;400;500;600;700&display=swap');

:root {
    /* Color Palette */
    --primary: #6366f1; /* Indigo */
    --primary-hover: #4f46e5;
    --primary-glow: rgba(99, 102, 241, 0.25);
    --secondary: #0ea5e9; /* Sky Blue */
    --secondary-hover: #0284c7;
    --accent: #a855f7; /* Purple */
    
    /* System Colors - Light Mode Defaults */
    --bg-app: #f4f6fa;
    --bg-glass: rgba(255, 255, 255, 0.65);
    --bg-glass-hover: rgba(255, 255, 255, 0.75);
    --border-glass: rgba(255, 255, 255, 0.4);
    --text-main: #1e293b;
    --text-muted: #64748b;
    --text-inverse: #ffffff;
    --card-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.06);
    --glow-color: rgba(99, 102, 241, 0.05);
    --input-bg: rgba(255, 255, 255, 0.8);
    --input-border: #cbd5e1;
    --input-focus-border: #6366f1;
    --success: #10b981;
    --error: #ef4444;
    
    /* Fonts */
    --font-heading: 'Outfit', 'Sarabun', sans-serif;
    --font-body: 'Inter', 'Sarabun', sans-serif;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-smooth: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Mode Overrides */
[data-theme="dark"] {
    --bg-app: #090d16;
    --bg-glass: rgba(15, 23, 42, 0.55);
    --bg-glass-hover: rgba(15, 23, 42, 0.65);
    --border-glass: rgba(255, 255, 255, 0.07);
    --text-main: #f1f5f9;
    --text-muted: #94a3b8;
    --text-inverse: #0f172a;
    --card-shadow: 0 12px 40px 0 rgba(0, 0, 0, 0.5);
    --glow-color: rgba(99, 102, 241, 0.15);
    --input-bg: rgba(15, 23, 42, 0.4);
    --input-border: rgba(255, 255, 255, 0.12);
    --input-focus-border: #818cf8;
}

/* Reset & Base Styles */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    width: 100%;
    min-height: 100vh;
    font-family: var(--font-body);
    color: var(--text-main);
    background-color: var(--bg-app);
    line-height: 1.5;
    overflow-x: hidden;
    transition: background-color var(--transition-smooth), color var(--transition-smooth);
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
}

/* Glassmorphism Card Utility */
.glass-panel {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-glass);
    box-shadow: var(--card-shadow);
    border-radius: 20px;
    transition: background var(--transition-smooth), border var(--transition-smooth), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.glass-panel:hover {
    background: var(--bg-glass-hover);
}

/* Theme Toggle Button */
.theme-toggle-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    box-shadow: var(--card-shadow);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: var(--text-main);
    transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
    transform: scale(1.1);
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    box-shadow: 0 0 15px var(--primary-glow);
}

.theme-toggle-btn svg {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

.theme-toggle-btn .sun-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle-btn .moon-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle-btn .sun-icon {
    display: block;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-app);
}
::-webkit-scrollbar-thumb {
    background: var(--text-muted);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}