/* ==================== Global Styles ==================== */

:root {
    /* Primary Colors */
    --color-primary: #1f2937;
    --color-secondary: #6366f1;
    --color-accent: #ec4899;
    
    /* Neutral Colors */
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f9fafb;
    --color-bg-tertiary: #f3f4f6;
    --color-text-primary: #111827;
    --color-text-secondary: #6b7280;
    --color-text-tertiary: #9ca3af;
    
    /* Status Colors (WCAG AA) */
    --color-success: #059669;
    --color-warning: #d97706;
    --color-error: #dc2626;
    --color-info: #0891b2;
    
    /* Borders & Shadows */
    --color-border-light: #e5e7eb;
    --color-border-medium: #d1d5db;
    --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);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Typography */
    --font-family-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
        'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
        sans-serif;
    --font-family-mono: 'SFMono-Regular', 'Consolas', 'Liberation Mono',
        'Menlo', monospace;
    --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: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Line Heights */
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.625;
    --line-height-loose: 2;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
}

/* Dark Mode Variables (Optional for Future) */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg-primary: #111827;
        --color-bg-secondary: #1f2937;
        --color-bg-tertiary: #374151;
        --color-text-primary: #f9fafb;
        --color-text-secondary: #d1d5db;
        --color-text-tertiary: #9ca3af;
        --color-border-light: #374151;
        --color-border-medium: #4b5563;
    }
}

/* ==================== Base Styles ==================== */

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

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

body {
    font-family: var(--font-family-sans);
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    transition: background-color var(--transition-normal);
}

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

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: var(--line-height-tight);
    color: var(--color-text-primary);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

p {
    margin-bottom: var(--space-md);
    color: var(--color-text-secondary);
}

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

a:hover {
    color: var(--color-accent);
    text-decoration: underline;
}

small {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

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

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-lg);
    font-size: var(--font-size-base);
    font-weight: 600;
    border: 2px solid transparent;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
    white-space: nowrap;
    user-select: none;
    font-family: inherit;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
}

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

.btn-primary:hover {
    filter: brightness(1.1);
}

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

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

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

.btn-success:hover {
    filter: brightness(1.1);
}

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

.btn-error:hover {
    filter: brightness(1.1);
}

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

.btn-lg {
    padding: var(--space-lg) var(--space-2xl);
    font-size: var(--font-size-lg);
}

.btn-block {
    width: 100%;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

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

input, textarea, select {
    width: 100%;
    padding: var(--space-md);
    font-family: inherit;
    font-size: var(--font-size-base);
    border: 2px solid var(--color-border-light);
    border-radius: var(--radius-md);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    transition: all var(--transition-fast);
}

input:focus, textarea:focus, select:focus {
    outline: none;
    border-color: var(--color-secondary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

input:disabled, textarea:disabled, select:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

label {
    display: block;
    margin-bottom: var(--space-sm);
    font-weight: 600;
    color: var(--color-text-primary);
}

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

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
}

/* ==================== Cards & Containers ==================== */

.card {
    background: var(--color-bg-primary);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-border-medium);
}

.card-header {
    border-bottom: 1px solid var(--color-border-light);
    padding-bottom: var(--space-md);
    margin-bottom: var(--space-md);
}

.card-header h3 {
    margin: 0;
    color: var(--color-text-primary);
}

.card-footer {
    border-top: 1px solid var(--color-border-light);
    padding-top: var(--space-md);
    margin-top: var(--space-md);
    display: flex;
    gap: var(--space-md);
}

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

/* ==================== Navigation ==================== */

.navbar {
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border-light);
    padding: var(--space-md) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    font-weight: 700;
    color: var(--color-text-primary);
}

.nav-logo {
    width: 32px;
    height: 32px;
    color: var(--color-secondary);
}

.nav-links {
    display: flex;
    gap: var(--space-xl);
    align-items: center;
}

.nav-link {
    color: var(--color-text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-secondary);
    text-decoration: none;
}

/* ==================== Footer ==================== */

.footer {
    background: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border-light);
    padding: var(--space-xl) 0;
    margin-top: var(--space-3xl);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    text-align: center;
    color: var(--color-text-secondary);
}

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

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--color-text-primary); }
.text-secondary { color: var(--color-text-secondary); }
.text-tertiary { color: var(--color-text-tertiary); }

.text-success { color: var(--color-success); }
.text-warning { color: var(--color-warning); }
.text-error { color: var(--color-error); }
.text-info { color: var(--color-info); }

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

.mt-0 { margin-top: 0; }
.mt-xs { margin-top: var(--space-xs); }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mt-2xl { margin-top: var(--space-2xl); }
.mt-3xl { margin-top: var(--space-3xl); }

.mb-0 { margin-bottom: 0; }
.mb-xs { margin-bottom: var(--space-xs); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }
.mb-2xl { margin-bottom: var(--space-2xl); }
.mb-3xl { margin-bottom: var(--space-3xl); }

.p-0 { padding: 0; }
.p-xs { padding: var(--space-xs); }
.p-sm { padding: var(--space-sm); }
.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.p-xl { padding: var(--space-xl); }
.p-2xl { padding: var(--space-2xl); }
.p-3xl { padding: var(--space-3xl); }

.gap-xs { gap: var(--space-xs); }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.gap-xl { gap: var(--space-xl); }

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

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

.flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
}

.flex-between {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.grid {
    display: grid;
}

.hidden { display: none !important; }
.visible { display: block !important; }

.opacity-50 { opacity: 0.5; }
.opacity-75 { opacity: 0.75; }

.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

.transition-all { transition: all var(--transition-normal); }
.transition-fast { transition: all var(--transition-fast); }
.transition-slow { transition: all var(--transition-slow); }

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

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

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

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

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.animate-fadeIn {
    animation: fadeIn var(--transition-normal) ease-out;
}

.animate-slideInUp {
    animation: slideInUp var(--transition-normal) ease-out;
}

.animate-slideInDown {
    animation: slideInDown var(--transition-normal) ease-out;
}

.animate-slideInLeft {
    animation: slideInLeft var(--transition-normal) ease-out;
}

.animate-slideInRight {
    animation: slideInRight var(--transition-normal) ease-out;
}

.animate-pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

.animate-spin {
    animation: spin 1s linear infinite;
}

.animate-bounce {
    animation: bounce 1s infinite;
}

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

@media (max-width: 768px) {
    :root {
        --font-size-5xl: 2.25rem;
        --font-size-4xl: 1.875rem;
        --font-size-3xl: 1.5rem;
        --font-size-2xl: 1.25rem;
    }

    .nav-links {
        gap: var(--space-md);
    }

    .container {
        padding: 0 var(--space-md);
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }

    .form-row {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        --font-size-5xl: 1.875rem;
        --font-size-4xl: 1.5rem;
        --font-size-3xl: 1.25rem;
    }

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

    input, textarea, select {
        padding: var(--space-sm);
    }

    .card {
        padding: var(--space-md);
    }

    .nav-brand {
        gap: var(--space-sm);
    }

    .nav-logo {
        width: 24px;
        height: 24px;
    }

    h1 { font-size: 1.5rem; }
    h2 { font-size: 1.25rem; }
    h3 { font-size: 1.1rem; }
}

/* ==================== Accessibility ==================== */

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

@media (prefers-contrast: more) {
    :root {
        --color-border-light: #d1d5db;
        --color-border-medium: #9ca3af;
    }

    .btn {
        border-width: 2px;
    }
}

/* Focus styles for keyboard navigation */
.btn:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
    outline: 2px solid var(--color-secondary);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .navbar, .footer {
        display: none;
    }

    body {
        background: white;
        color: black;
    }

    a {
        text-decoration: underline;
    }
}