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

:root {
    --primary-color: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #059669;
    --accent-color: #f59e0b;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-accent: #f1f5f9;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --gradient-primary: linear-gradient(135deg, #1e40af 0%, #3b82f6 100%);
    --gradient-secondary: linear-gradient(135deg, #059669 0%, #10b981 100%);
    --gradient-accent: linear-gradient(135deg, #f59e0b 0%, #fbbf24 100%);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    min-height: 100vh;
    overflow-x: hidden;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Header */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-lg);
    transition: all 0.3s ease;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    letter-spacing: -0.025em;
    transition: all 0.3s ease;
}

.logo:hover {
    transform: scale(1.05);
}

.back-btn {
    background: var(--gradient-primary);
    color: white;
    padding: 0.875rem 1.75rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--shadow-md);
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    position: relative;
    overflow: hidden;
}

.back-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.back-btn:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-xl);
}

.back-btn:hover::before {
    left: 100%;
}

.back-btn svg {
    width: 16px;
    height: 16px;
}

/* Main Container */
.main-container {
    max-width: 1000px;
    margin: 2rem auto;
    padding: 0 2rem;
}

/* Page Title */
.page-title {
    text-align: center;
    margin-bottom: 3rem;
}

.page-title h1 {
    font-size: 3rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
    text-align: center;
    position: relative;
}

.page-title h1::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.page-title p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.8;
    text-align: center;
    font-weight: 400;
}

/* Post-it Container */
.post-its-container {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    margin-bottom: 2rem;
}

/* Main Post-it */
.post-it {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 24px;
    padding: 3rem;
    box-shadow: var(--shadow-xl);
    border: 1px solid rgba(255, 255, 255, 0.2);
    max-width: 900px;
    width: 100%;
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

.post-it:hover {
    transform: translateY(-5px);
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.15);
}

.post-it::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: var(--gradient-primary);
    border-radius: 24px 24px 0 0;
}

.post-it::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 20%, rgba(30, 64, 175, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(5, 150, 105, 0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

.post-it-header {
    text-align: center;
    margin-bottom: 2.5rem;
    padding-bottom: 2rem;
    border-bottom: 2px solid #f1f5f9;
}

.post-it-title {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    letter-spacing: -0.01em;
    text-align: center;
}

.post-it-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    font-weight: 500;
    text-align: center;
    line-height: 1.6;
}

/* Checklist */
.checklist {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2.5rem;
}

.checklist-item {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 2px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    margin-bottom: 1.5rem;
}

.checklist-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 6px;
    height: 100%;
    background: var(--gradient-primary);
    transform: scaleY(0);
    transition: transform 0.3s ease;
    border-radius: 0 3px 3px 0;
}

.checklist-item::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 10% 20%, rgba(30, 64, 175, 0.02) 0%, transparent 50%),
        radial-gradient(circle at 90% 80%, rgba(5, 150, 105, 0.02) 0%, transparent 50%);
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.checklist-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
    background: rgba(255, 255, 255, 0.95);
}

.checklist-item:hover::before {
    transform: scaleY(1);
}

.checklist-item:hover::after {
    opacity: 1;
}

.checklist-item.selected {
    background: rgba(239, 246, 255, 0.8);
    border-color: var(--primary-light);
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.checklist-item.selected::before {
    transform: scaleY(1);
}

.checklist-item.selected::after {
    opacity: 1;
    background: 
        radial-gradient(circle at 10% 20%, rgba(30, 64, 175, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 90% 80%, rgba(5, 150, 105, 0.05) 0%, transparent 50%);
}

.checklist-item.selected .item-title {
    color: var(--primary-color);
}

.checklist-item.selected .item-price {
    color: var(--secondary-color);
}

.checkbox {
    width: 24px;
    height: 24px;
    border: 2px solid #cbd5e1;
    border-radius: 6px;
    margin-right: 1rem;
    position: relative;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.checklist-item.selected .checkbox {
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    border-color: #3b82f6;
}

.checklist-item.selected .checkbox::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 14px;
    font-weight: bold;
}

.item-content {
    display: flex;
    align-items: center;
    flex: 1;
}

.item-details {
    flex: 1;
}

.item-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    transition: color 0.3s ease;
    letter-spacing: -0.01em;
}

.item-description {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
    font-weight: 400;
}

.item-price {
    font-size: 1.4rem;
    font-weight: 800;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all 0.3s ease;
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 12px;
    background-color: rgba(5, 150, 105, 0.1);
    border: 1px solid rgba(5, 150, 105, 0.2);
}

/* Total Section */
.total-section {
    background: rgba(248, 250, 252, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 20px;
    padding: 2.5rem;
    margin-bottom: 2.5rem;
    border: 2px solid var(--border-color);
    text-align: center;
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

.total-section:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.total-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-secondary);
    border-radius: 20px 20px 0 0;
}

.total-section::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 30% 30%, rgba(5, 150, 105, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 70% 70%, rgba(16, 185, 129, 0.05) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

.total-label {
    font-size: 1.2rem;
    color: var(--text-secondary);
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.total-amount {
    font-size: 3rem;
    font-weight: 800;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
    transition: all 0.3s ease;
    display: block;
    line-height: 1;
}

.total-amount.animate {
    animation: pulse 0.6s ease-in-out;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

/* WhatsApp Section */
.whatsapp-section {
    text-align: center;
}

.whatsapp-btn {
    background: linear-gradient(135deg, #25d366 0%, #128c7e 100%);
    color: white;
    border: none;
    padding: 1.5rem 3rem;
    border-radius: 16px;
    font-size: 1.2rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--shadow-lg);
    display: inline-flex;
    align-items: center;
    gap: 1rem;
    text-decoration: none;
    position: relative;
    overflow: hidden;
    min-width: 250px;
    justify-content: center;
}

.whatsapp-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.6s;
}

.whatsapp-btn:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.whatsapp-btn:hover::before {
    left: 100%;
}

.whatsapp-btn:active {
    transform: translateY(-2px);
}

.whatsapp-btn:active {
    transform: translateY(-1px);
}

.whatsapp-icon {
    font-size: 1.5rem;
}

.btn-text {
    font-weight: 600;
}

/* Responsive Design */
@media (max-width: 768px) {
    .main-container {
        padding: 0 1rem;
        margin: 1rem auto;
    }
    
    .page-title h1 {
        font-size: 2.5rem;
    }
    
    .page-title p {
        font-size: 1.1rem;
    }
    
    .post-it {
        padding: 2rem;
        margin: 0 0.5rem;
    }
    
    .post-it-title {
        font-size: 1.8rem;
    }
    
    .checklist-item {
        padding: 1.5rem;
    }
    
    .item-title {
        font-size: 1.2rem;
    }
    
    .total-amount {
        font-size: 2.5rem;
    }
    
    .whatsapp-btn {
        padding: 1.25rem 2.5rem;
        font-size: 1.1rem;
        min-width: 200px;
    }
    
    .header-content {
        padding: 0 1rem;
    }
    
    .back-btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .page-title h1 {
        font-size: 2rem;
    }
    
    .post-it {
        padding: 1.5rem;
        margin: 0 0.25rem;
    }
    
    .post-it-title {
        font-size: 1.5rem;
    }
    
    .checklist-item {
        padding: 1.25rem;
    }
    
    .item-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .checkbox {
        align-self: flex-start;
    }
    
    .total-section {
        padding: 2rem;
    }
    
    .total-amount {
        font-size: 2.2rem;
    }
    
    .whatsapp-btn {
        width: 100%;
        justify-content: center;
        padding: 1.25rem 2rem;
        font-size: 1rem;
    }
    
    .header-content {
        flex-direction: column;
        gap: 1rem;
        align-items: center;
    }
    
    .logo {
        font-size: 1.5rem;
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    .checklist-item:hover {
        transform: none;
    }
    
    .whatsapp-btn:hover {
        transform: none;
    }
    
    .back-btn:hover {
        transform: none;
    }
}

/* Loading animation */
.post-it {
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Selection animation */
.checklist-item {
    animation: fadeInUp 0.6s ease-out;
}

.checklist-item:nth-child(1) { animation-delay: 0.1s; }
.checklist-item:nth-child(2) { animation-delay: 0.2s; }
.checklist-item:nth-child(3) { animation-delay: 0.3s; }
.checklist-item:nth-child(4) { animation-delay: 0.4s; }
.checklist-item:nth-child(5) { animation-delay: 0.5s; }
.checklist-item:nth-child(6) { animation-delay: 0.6s; }