/* ===================================
   RESET & BASE STYLES
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Brand Colors */
    --purple-primary: #540d88;
    --yellow-accent: #f8d823;
    --white: #ffffff;
    --gray-light: #f5f5f7;
    --gray-medium: #e8e8ed;
    --gray-dark: #6e6e73;
    --black: #1d1d1f;
    
    /* Semantic Colors */
    --success: #34c759;
    --warning: #ff9500;
    --danger: #ff3b30;
    
    /* Gradients */
    --gradient-purple: linear-gradient(135deg, #540d88 0%, #7b2cbf 100%);
    --gradient-yellow: linear-gradient(135deg, #f8d823 0%, #ffd60a 100%);
    --gradient-card: linear-gradient(135deg, rgba(84, 13, 136, 0.03) 0%, rgba(248, 216, 35, 0.03) 100%);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(84, 13, 136, 0.08);
    --shadow-md: 0 4px 16px rgba(84, 13, 136, 0.12);
    --shadow-lg: 0 8px 32px rgba(84, 13, 136, 0.16);
    --shadow-xl: 0 12px 48px rgba(84, 13, 136, 0.2);
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
}

body {
    font-family: var(--font-family);
    background: linear-gradient(135deg, #f5f5f7 0%, #e8e8ed 100%);
    color: var(--black);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===================================
   CONTAINER & LAYOUT
   =================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
}

/* ===================================
   HEADER
   =================================== */
.header {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    background: var(--gradient-purple);
    border-radius: var(--radius-xl);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(248, 216, 35, 0.1) 0%, transparent 70%);
    animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.1); opacity: 0.8; }
}

.logo-section {
    position: relative;
    z-index: 1;
}

.brand-name {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--yellow-accent);
    margin-bottom: var(--spacing-xs);
    text-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    letter-spacing: -0.5px;
}

.tagline {
    font-size: 1.1rem;
    color: var(--white);
    font-weight: 500;
    opacity: 0.95;
}

/* ===================================
   CARDS
   =================================== */
.card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-medium);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-purple);
    opacity: 0;
    transition: opacity var(--transition-medium);
}

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

.card:hover::before {
    opacity: 1;
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--purple-primary);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

/* ===================================
   PRODUCT TYPE SELECTION
   =================================== */
.product-type-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-sm);
}

.product-type-btn {
    background: var(--gray-light);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-medium);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    font-family: var(--font-family);
}

.product-type-btn .icon {
    font-size: 2rem;
}

.product-type-btn .label {
    font-weight: 600;
    color: var(--black);
    font-size: 1rem;
}

.product-type-btn .margin-hint {
    font-size: 0.75rem;
    color: var(--gray-dark);
}

.product-type-btn:hover {
    background: var(--gray-medium);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.product-type-btn.active {
    background: var(--gradient-purple);
    border-color: var(--purple-primary);
    box-shadow: var(--shadow-md);
}

.product-type-btn.active .label,
.product-type-btn.active .margin-hint {
    color: var(--white);
}

/* ===================================
   SIZE SELECTION
   =================================== */
.size-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.size-btn {
    background: var(--gray-light);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    cursor: pointer;
    font-family: var(--font-family);
    font-weight: 600;
    font-size: 1rem;
    color: var(--black);
    transition: all var(--transition-medium);
}

.size-btn:hover {
    background: var(--gray-medium);
    transform: translateY(-2px);
}

.size-btn.active {
    background: var(--yellow-accent);
    border-color: var(--yellow-accent);
    color: var(--purple-primary);
    box-shadow: var(--shadow-md);
}

.custom-size-input {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--gray-light);
    border-radius: var(--radius-md);
}

.custom-size-input label {
    display: block;
    font-weight: 600;
    color: var(--purple-primary);
    margin-bottom: var(--spacing-xs);
}

.custom-size-input input {
    width: 100%;
    padding: var(--spacing-sm);
    border: 2px solid var(--gray-medium);
    border-radius: var(--radius-sm);
    font-family: var(--font-family);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.custom-size-input input:focus {
    outline: none;
    border-color: var(--purple-primary);
    box-shadow: 0 0 0 3px rgba(84, 13, 136, 0.1);
}

/* ===================================
   INPUT FIELDS
   =================================== */
.input-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.input-group {
    display: flex;
    flex-direction: column;
}

.input-group.full-width {
    grid-column: 1 / -1;
}

.input-group label {
    font-weight: 600;
    color: var(--purple-primary);
    margin-bottom: var(--spacing-xs);
    font-size: 0.9rem;
}

.input-field {
    padding: var(--spacing-sm);
    border: 2px solid var(--gray-medium);
    border-radius: var(--radius-sm);
    font-family: var(--font-family);
    font-size: 1rem;
    transition: all var(--transition-fast);
    background: var(--white);
}

.input-field:focus {
    outline: none;
    border-color: var(--purple-primary);
    box-shadow: 0 0 0 3px rgba(84, 13, 136, 0.1);
}

.input-field:hover {
    border-color: var(--purple-primary);
}

/* ===================================
   SUBTOTALS
   =================================== */
.subtotal {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    font-weight: 600;
    margin-top: var(--spacing-md);
}

.subtotal-value {
    color: var(--purple-primary);
    font-size: 1.2rem;
}

/* ===================================
   MARGIN CONTROL
   =================================== */
.margin-control {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.margin-slider-container {
    position: relative;
}

.margin-slider {
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--gray-medium);
    outline: none;
    -webkit-appearance: none;
    appearance: none;
}

.margin-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--gradient-purple);
    cursor: pointer;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.margin-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: var(--shadow-lg);
}

.margin-slider::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--gradient-purple);
    cursor: pointer;
    border: none;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.margin-slider::-moz-range-thumb:hover {
    transform: scale(1.2);
    box-shadow: var(--shadow-lg);
}

.margin-display {
    text-align: center;
    margin-top: var(--spacing-sm);
}

.margin-value {
    font-size: 2rem;
    font-weight: 800;
    color: var(--purple-primary);
}

.margin-status {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm);
    background: var(--gray-light);
    border-radius: var(--radius-md);
}

.status-indicator {
    font-size: 1.5rem;
}

.status-text {
    font-weight: 600;
    color: var(--black);
}

/* ===================================
   CALCULATE BUTTON
   =================================== */
.btn-calculate {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--gradient-yellow);
    border: none;
    border-radius: var(--radius-lg);
    font-family: var(--font-family);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--purple-primary);
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin: var(--spacing-lg) 0;
}

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

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

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

/* ===================================
   RESULTS SECTION
   =================================== */
.results-section {
    background: var(--gradient-card);
    border: 2px solid var(--purple-primary);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.result-card {
    background: var(--white);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-medium);
}

.result-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.result-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-xs);
}

.result-label {
    font-size: 0.9rem;
    color: var(--gray-dark);
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
}

.result-value {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--purple-primary);
}

.result-cost .result-value {
    color: var(--danger);
}

.result-price .result-value {
    color: var(--success);
}

.result-profit .result-value {
    color: var(--purple-primary);
}

/* ===================================
   COMBO SECTION
   =================================== */
.combo-section {
    background: var(--white);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.combo-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--purple-primary);
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.combo-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.combo-option {
    background: var(--gradient-card);
    border: 2px solid var(--yellow-accent);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    text-align: center;
    transition: all var(--transition-medium);
}

.combo-option:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--purple-primary);
}

.combo-discount {
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--purple-primary);
    margin-bottom: var(--spacing-xs);
}

.combo-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--success);
    margin-bottom: var(--spacing-xs);
}

.combo-profit {
    font-size: 0.9rem;
    color: var(--gray-dark);
}

.combo-profit span {
    font-weight: 700;
    color: var(--purple-primary);
}

/* ===================================
   WARNING BOX
   =================================== */
.warning-box {
    background: linear-gradient(135deg, #ff3b30 0%, #ff9500 100%);
    color: var(--white);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-md);
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

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

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

/* ===================================
   ACTION BUTTONS
   =================================== */
.action-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.btn-secondary {
    padding: var(--spacing-md);
    background: var(--gradient-purple);
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-family);
    font-size: 1rem;
    font-weight: 600;
    color: var(--white);
    cursor: pointer;
    transition: all var(--transition-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary span {
    font-size: 1.2rem;
}

/* ===================================
   FOOTER
   =================================== */
.footer {
    text-align: center;
    padding: var(--spacing-lg);
    color: var(--gray-dark);
    font-size: 0.9rem;
}

/* ===================================
   UTILITY CLASSES
   =================================== */
.hidden {
    display: none !important;
}

/* ===================================
   RESPONSIVE DESIGN
   =================================== */
@media (max-width: 768px) {
    .brand-name {
        font-size: 2rem;
    }
    
    .tagline {
        font-size: 1rem;
    }
    
    .input-grid {
        grid-template-columns: 1fr;
    }
    
    .results-grid {
        grid-template-columns: 1fr;
    }
    
    .combo-options {
        grid-template-columns: 1fr;
    }
    
    .product-type-grid {
        grid-template-columns: 1fr;
    }
    
    .size-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: var(--spacing-sm);
    }
    
    .card {
        padding: var(--spacing-md);
    }
    
    .header {
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .brand-name {
        font-size: 1.8rem;
    }
    
    .section-title {
        font-size: 1.2rem;
    }
    
    .result-value {
        font-size: 1.5rem;
    }
}

/* ===================================
   ANIMATIONS
   =================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-section {
    animation: fadeIn 0.5s ease-out;
}

/* ===================================
   PRINT STYLES
   =================================== */
@media print {
    .header,
    .footer,
    .btn-calculate,
    .action-buttons {
        display: none;
    }
    
    .card {
        box-shadow: none;
        border: 1px solid var(--gray-medium);
    }
}