/* ============================================
   SCREENWRITER PRO - Design System
   ============================================ */

/* CSS Custom Properties / Design Tokens */
:root {
    /* Colors - Dark Theme */
    --color-bg-primary: #0d1117;
    --color-bg-secondary: #161b22;
    --color-bg-tertiary: #21262d;
    --color-bg-elevated: #1c2128;
    --color-bg-page: #faf9f7;
    
    --color-border: #30363d;
    --color-border-muted: #21262d;
    
    --color-text-primary: #e6edf3;
    --color-text-secondary: #8b949e;
    --color-text-tertiary: #6e7681;
    --color-text-link: #58a6ff;
    --color-text-page: #1a1a1a;
    
    --color-accent-primary: #7c3aed;
    --color-accent-secondary: #8b5cf6;
    --color-accent-tertiary: #a78bfa;
    
    --color-success: #3fb950;
    --color-warning: #d29922;
    --color-danger: #f85149;
    
    /* Typography */
    --font-ui: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-screenplay: 'Courier Prime', 'Courier New', Courier, monospace;
    
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    
    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(124, 58, 237, 0.3);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* Z-index layers */
    --z-base: 0;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-modal-backdrop: 300;
    --z-modal: 400;
    --z-tooltip: 500;
    
    /* Layout */
    --toolbar-height: 60px;
    --sidebar-width: 260px;
    --status-bar-height: 36px;
}

/* ============================================
   Reset & Base Styles
   ============================================ */

*, *::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-ui);
    font-size: var(--font-size-md);
    line-height: var(--line-height-normal);
    color: var(--color-text-primary);
    background: var(--color-bg-primary);
    overflow: hidden;
}

#app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    width: 100vw;
    overflow: hidden;
}

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

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    font-family: var(--font-ui);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    line-height: 1;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn:focus {
    outline: 2px solid var(--color-accent-primary);
    outline-offset: 2px;
}

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

.btn-primary:hover {
    background: linear-gradient(135deg, var(--color-accent-secondary), var(--color-accent-tertiary));
    box-shadow: var(--shadow-glow);
    transform: translateY(-1px);
}

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

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

/* ============================================
   Form Elements
   ============================================ */

input[type="text"],
textarea {
    font-family: var(--font-ui);
    font-size: var(--font-size-md);
    color: var(--color-text-primary);
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-3) var(--space-4);
    transition: all var(--transition-fast);
}

input[type="text"]:focus,
textarea:focus {
    outline: none;
    border-color: var(--color-accent-primary);
    box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.2);
}

input[type="text"]::placeholder,
textarea::placeholder {
    color: var(--color-text-tertiary);
}

/* ============================================
   Modals
   ============================================ */

.modal {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow: hidden;
    transform: scale(0.95);
    transition: transform var(--transition-normal);
}

.modal.active .modal-content {
    transform: scale(1);
}

.title-page-modal-content {
    max-width: 600px;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-5) var(--space-6);
    border-bottom: 1px solid var(--color-border);
}

.modal-header h2 {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-semibold);
}

.modal-close {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.modal-close:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-tertiary);
}

.modal-body {
    padding: var(--space-6);
    max-height: 60vh;
    overflow-y: auto;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: var(--space-3);
    padding: var(--space-4) var(--space-6);
    border-top: 1px solid var(--color-border);
    background: var(--color-bg-tertiary);
}

/* ============================================
   Scrollbar Styling
   ============================================ */

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-tertiary);
}

/* ============================================
   Animations
   ============================================ */

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { 
        opacity: 0;
        transform: translateY(10px);
    }
    to { 
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.animate-fade-in {
    animation: fadeIn var(--transition-normal) ease forwards;
}

.animate-slide-up {
    animation: slideUp var(--transition-normal) ease forwards;
}

.animate-pulse {
    animation: pulse 2s infinite;
}