/* ==========================================================================
   Custom Orders - Main Stylesheet
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Variables / Design Tokens
   -------------------------------------------------------------------------- */
:root {
    /* Primary Colors */
    --primary: #667eea;
    --primary-dark: #5a6fd6;
    --primary-light: #8b9cf5;
    --secondary: #764ba2;
    --secondary-dark: #5d3a80;

    /* Status Colors */
    --success: #10b981;
    --success-dark: #059669;
    --success-light: #d1fae5;
    --warning: #f59e0b;
    --warning-dark: #d97706;
    --warning-light: #fef3c7;
    --error: #ef4444;
    --error-dark: #dc2626;
    --error-light: #fee2e2;
    --info: #3b82f6;
    --info-dark: #2563eb;
    --info-light: #dbeafe;

    /* Grayscale */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --white: #ffffff;
    --black: #000000;

    /* Shadows */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;

    /* 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;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', Consolas, monospace;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition: 200ms ease;
    --transition-slow: 300ms ease;

    /* Z-index layers */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-popover: 600;
    --z-tooltip: 700;
}

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

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

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--gray-50);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

a:hover {
    color: var(--primary-dark);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    font-family: inherit;
    cursor: pointer;
}

input, select, textarea, button {
    font-family: inherit;
    font-size: inherit;
}

/* --------------------------------------------------------------------------
   Layout Components
   -------------------------------------------------------------------------- */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

.container-sm { max-width: 640px; }
.container-md { max-width: 768px; }
.container-lg { max-width: 1024px; }
.container-xl { max-width: 1280px; }

main {
    flex: 1;
}

/* --------------------------------------------------------------------------
   Header & Navigation
   -------------------------------------------------------------------------- */
.header {
    background: var(--white);
    border-bottom: 1px solid var(--gray-200);
    padding: var(--space-4) 0;
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo:hover {
    opacity: 0.9;
}

.nav {
    display: flex;
    align-items: center;
    gap: var(--space-6);
}

.nav-link {
    color: var(--gray-600);
    font-weight: 500;
    transition: color var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: var(--radius-full);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
    background: var(--gray-800);
    color: var(--gray-300);
    padding: var(--space-12) 0 var(--space-8);
    margin-top: auto;
}

.footer a {
    color: var(--gray-300);
}

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

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-8);
}

.footer-section h4 {
    color: var(--white);
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-4);
}

.footer-bottom {
    margin-top: var(--space-8);
    padding-top: var(--space-6);
    border-top: 1px solid var(--gray-700);
    text-align: center;
    font-size: 0.875rem;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.5;
    border-radius: var(--radius);
    border: none;
    cursor: pointer;
    transition: all var(--transition);
    text-decoration: none;
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
    color: var(--white);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--white);
    color: var(--gray-700);
    border: 1px solid var(--gray-300);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--gray-50);
    border-color: var(--gray-400);
    color: var(--gray-800);
}

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

.btn-success:hover:not(:disabled) {
    background: var(--success-dark);
    color: var(--white);
}

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

.btn-danger:hover:not(:disabled) {
    background: var(--error-dark);
    color: var(--white);
}

.btn-ghost {
    background: transparent;
    color: var(--gray-600);
}

.btn-ghost:hover:not(:disabled) {
    background: var(--gray-100);
    color: var(--gray-800);
}

.btn-sm {
    padding: var(--space-2) var(--space-4);
    font-size: 0.875rem;
}

.btn-lg {
    padding: var(--space-4) var(--space-8);
    font-size: 1.125rem;
}

.btn-block {
    width: 100%;
}

.btn-icon {
    padding: var(--space-2);
    width: 40px;
    height: 40px;
}

/* --------------------------------------------------------------------------
   Forms
   -------------------------------------------------------------------------- */
.form-group {
    margin-bottom: var(--space-6);
}

.form-label {
    display: block;
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: var(--space-2);
}

.form-label.required::after {
    content: '*';
    color: var(--error);
    margin-left: var(--space-1);
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: 1rem;
    line-height: 1.5;
    color: var(--gray-800);
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--gray-400);
}

.form-input.error,
.form-select.error,
.form-textarea.error {
    border-color: var(--error);
}

.form-input.error:focus,
.form-select.error:focus,
.form-textarea.error:focus {
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.15);
}

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

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right var(--space-3) center;
    padding-right: var(--space-10);
}

.form-hint {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-top: var(--space-1);
}

.form-error {
    font-size: 0.875rem;
    color: var(--error);
    margin-top: var(--space-1);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-4);
}

@media (max-width: 640px) {
    .form-row {
        grid-template-columns: 1fr;
    }
}

/* Checkbox & Radio */
.form-check {
    display: flex;
    align-items: flex-start;
    gap: var(--space-2);
}

.form-check-input {
    width: 18px;
    height: 18px;
    margin-top: 2px;
    accent-color: var(--primary);
}

.form-check-label {
    color: var(--gray-700);
}

/* --------------------------------------------------------------------------
   Cards
   -------------------------------------------------------------------------- */
.card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.card-header {
    padding: var(--space-5) var(--space-6);
    border-bottom: 1px solid var(--gray-200);
    font-weight: 600;
    color: var(--gray-800);
}

.card-body {
    padding: var(--space-6);
}

.card-footer {
    padding: var(--space-5) var(--space-6);
    border-top: 1px solid var(--gray-200);
    background: var(--gray-50);
}

/* --------------------------------------------------------------------------
   Alerts & Notifications
   -------------------------------------------------------------------------- */
.alert {
    padding: var(--space-4) var(--space-5);
    border-radius: var(--radius);
    margin-bottom: var(--space-4);
    display: flex;
    align-items: flex-start;
    gap: var(--space-3);
}

.alert-icon {
    flex-shrink: 0;
    font-size: 1.25rem;
}

.alert-content {
    flex: 1;
}

.alert-title {
    font-weight: 600;
    margin-bottom: var(--space-1);
}

.alert-success {
    background: var(--success-light);
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.alert-error {
    background: var(--error-light);
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-warning {
    background: var(--warning-light);
    color: #92400e;
    border: 1px solid #fde68a;
}

.alert-info {
    background: var(--info-light);
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

/* --------------------------------------------------------------------------
   Badges & Tags
   -------------------------------------------------------------------------- */
.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-3);
    font-size: 0.75rem;
    font-weight: 600;
    line-height: 1.5;
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

.badge-primary {
    background: rgba(102, 126, 234, 0.1);
    color: var(--primary);
}

.badge-success {
    background: var(--success-light);
    color: #065f46;
}

.badge-warning {
    background: var(--warning-light);
    color: #92400e;
}

.badge-error {
    background: var(--error-light);
    color: #991b1b;
}

.badge-gray {
    background: var(--gray-100);
    color: var(--gray-600);
}

/* --------------------------------------------------------------------------
   Loading & Spinners
   -------------------------------------------------------------------------- */
.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.spinner-sm {
    width: 16px;
    height: 16px;
    border-width: 2px;
}

.spinner-lg {
    width: 32px;
    height: 32px;
    border-width: 3px;
}

.spinner-white {
    border-color: rgba(255, 255, 255, 0.3);
    border-top-color: var(--white);
}

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

.loading-overlay {
    position: fixed;
    inset: 0;
    background: rgba(255, 255, 255, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
}

/* --------------------------------------------------------------------------
   Tables
   -------------------------------------------------------------------------- */
.table-container {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
}

.table th {
    background: var(--gray-50);
    padding: var(--space-4);
    text-align: left;
    font-weight: 600;
    color: var(--gray-700);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--gray-200);
}

.table td {
    padding: var(--space-4);
    border-bottom: 1px solid var(--gray-100);
    color: var(--gray-700);
}

.table tr:hover td {
    background: var(--gray-50);
}

.table tr:last-child td {
    border-bottom: none;
}

/* --------------------------------------------------------------------------
   Modal
   -------------------------------------------------------------------------- */
.modal-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: var(--z-modal-backdrop);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition), visibility var(--transition);
}

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

.modal {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.95);
    background: var(--white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow: hidden;
    z-index: var(--z-modal);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
}

.modal.active {
    opacity: 1;
    visibility: visible;
    transform: translate(-50%, -50%) scale(1);
}

.modal-header {
    padding: var(--space-6);
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-800);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--gray-400);
    cursor: pointer;
    transition: color var(--transition);
}

.modal-close:hover {
    color: var(--gray-600);
}

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

.modal-footer {
    padding: var(--space-6);
    border-top: 1px solid var(--gray-200);
    display: flex;
    justify-content: flex-end;
    gap: var(--space-3);
}

/* --------------------------------------------------------------------------
   Utility Classes
   -------------------------------------------------------------------------- */

/* Text */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.text-xs { font-size: 0.75rem; }
.text-sm { font-size: 0.875rem; }
.text-base { font-size: 1rem; }
.text-lg { font-size: 1.125rem; }
.text-xl { font-size: 1.25rem; }
.text-2xl { font-size: 1.5rem; }
.text-3xl { font-size: 1.875rem; }
.text-4xl { font-size: 2.25rem; }

.font-normal { font-weight: 400; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.text-muted { color: var(--gray-500); }
.text-primary { color: var(--primary); }
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.text-error { color: var(--error); }

.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Spacing */
.m-0 { margin: 0; }
.m-1 { margin: var(--space-1); }
.m-2 { margin: var(--space-2); }
.m-3 { margin: var(--space-3); }
.m-4 { margin: var(--space-4); }
.m-6 { margin: var(--space-6); }
.m-8 { margin: var(--space-8); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.ml-0 { margin-left: 0; }
.ml-1 { margin-left: var(--space-1); }
.ml-2 { margin-left: var(--space-2); }
.ml-3 { margin-left: var(--space-3); }
.ml-4 { margin-left: var(--space-4); }
.ml-auto { margin-left: auto; }

.mr-0 { margin-right: 0; }
.mr-1 { margin-right: var(--space-1); }
.mr-2 { margin-right: var(--space-2); }
.mr-3 { margin-right: var(--space-3); }
.mr-4 { margin-right: var(--space-4); }
.mr-auto { margin-right: auto; }

.p-0 { padding: 0; }
.p-1 { padding: var(--space-1); }
.p-2 { padding: var(--space-2); }
.p-3 { padding: var(--space-3); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

.pt-0 { padding-top: 0; }
.pt-4 { padding-top: var(--space-4); }
.pt-6 { padding-top: var(--space-6); }

.pb-0 { padding-bottom: 0; }
.pb-4 { padding-bottom: var(--space-4); }
.pb-6 { padding-bottom: var(--space-6); }

/* Display */
.hidden { display: none; }
.block { display: block; }
.inline { display: inline; }
.inline-block { display: inline-block; }
.flex { display: flex; }
.inline-flex { display: inline-flex; }
.grid { display: grid; }

/* Flexbox */
.flex-row { flex-direction: row; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.flex-1 { flex: 1; }
.items-start { align-items: flex-start; }
.items-center { align-items: center; }
.items-end { align-items: flex-end; }
.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

/* Width & Height */
.w-full { width: 100%; }
.w-auto { width: auto; }
.h-full { height: 100%; }
.min-h-screen { min-height: 100vh; }

/* Position */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

/* Border */
.border { border: 1px solid var(--gray-200); }
.border-t { border-top: 1px solid var(--gray-200); }
.border-b { border-bottom: 1px solid var(--gray-200); }
.border-none { border: none; }
.rounded { border-radius: var(--radius); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

/* Background */
.bg-white { background-color: var(--white); }
.bg-gray-50 { background-color: var(--gray-50); }
.bg-gray-100 { background-color: var(--gray-100); }
.bg-primary { background-color: var(--primary); }
.bg-gradient {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
}

/* Cursor */
.cursor-pointer { cursor: pointer; }
.cursor-not-allowed { cursor: not-allowed; }

/* Overflow */
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-x-auto { overflow-x: auto; }
.overflow-y-auto { overflow-y: auto; }

/* Visibility */
.visible { visibility: visible; }
.invisible { visibility: hidden; }
.opacity-0 { opacity: 0; }
.opacity-50 { opacity: 0.5; }
.opacity-100 { opacity: 1; }

/* Transitions */
.transition { transition: all var(--transition); }
.transition-fast { transition: all var(--transition-fast); }
.transition-slow { transition: all var(--transition-slow); }

/* Screen reader only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* --------------------------------------------------------------------------
   Responsive Utilities
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
    .md\:hidden { display: none; }

    .container {
        padding: 0 var(--space-4);
    }

    .nav {
        gap: var(--space-4);
    }
}

@media (min-width: 769px) {
    .md\:flex { display: flex; }
    .md\:block { display: block; }
}

/* --------------------------------------------------------------------------
   Animation Classes
   -------------------------------------------------------------------------- */
.animate-fade-in {
    animation: fadeIn 0.3s ease forwards;
}

.animate-slide-up {
    animation: slideUp 0.3s ease forwards;
}

.animate-scale-in {
    animation: scaleIn 0.3s ease forwards;
}

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

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

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Pulse animation for loading states */
.animate-pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

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