/* 
  Base Design System & Themes 
  Stunning, premium, dynamic visual style
*/
:root {
    --primary: #4F46E5;
    /* Indigo */
    --primary-hover: #4338CA;
    --secondary: #10B981;
    /* Emerald */
    --danger: #EF4444;
    --warning: #F59E0B;

    --bg-main: #F3F4F6;
    --bg-surface: #FFFFFF;
    --text-main: #1F2937;
    --text-muted: #6B7280;
    --border-color: #E5E7EB;

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);

    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --font-size-base: 16px;
}

body.dark-mode {
    --primary: #6366F1;
    --primary-hover: #4F46E5;
    --secondary: #34D399;
    --danger: #F87171;

    --bg-main: #111827;
    --bg-surface: #1F2937;
    --text-main: #F9FAFB;
    --text-muted: #9CA3AF;
    --border-color: #374151;
}

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

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    font-size: var(--font-size-base);
    line-height: 1.5;
    transition: background-color 0.3s ease, color 0.3s ease;
    overflow-x: hidden;
    -webkit-tap-highlight-color: transparent;
}

.app-container {
    max-width: 800px;
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
}

main#view-layer {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 1rem;
    animation: fadeIn 0.4s ease-out;
}

/* Typography */
h1,
h2,
h3 {
    margin-bottom: 0.5rem;
    font-weight: 700;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideUp {
    from {
        transform: translateY(100%);
    }

    to {
        transform: translateY(0);
    }
}

@keyframes pop {
    0% {
        transform: scale(0.95);
        opacity: 0;
    }

    100% {
        transform: scale(1);
        opacity: 1;
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    border: none;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
}

.btn:active {
    transform: scale(0.97);
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-main);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

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

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--primary);
    cursor: pointer;
}

.icon-btn {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-main);
    padding: 0.5rem;
    border-radius: 50%;
    transition: background 0.2s;
}

.icon-btn:hover {
    background: var(--bg-main);
}