:root {
    /* Colors */
    --primary: #6366F1;
    --primary-dark: #4F46E5;
    --primary-light: #818CF8;
    --secondary: #EC4899;
    --accent: #10B981;
    
    /* Neutrals */
    --bg-primary: #0F172A;
    --bg-secondary: #1E293B;
    --bg-card: #1E293B;
    --bg-card-hover: #334155;
    
    /* Text */
    --text-primary: #F1F5F9;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;
    
    /* Borders */
    --border-color: #334155;
    --border-hover: #475569;
    
    /* Fonts */
    --font-display: 'Poppins', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.4);
    
    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-display);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* ===================================
   BACKGROUND EFFECTS
   =================================== */
.background-grid {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(99, 102, 241, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.05) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
    z-index: 0;
}

.gradient-orb {
    position: fixed;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.3;
    pointer-events: none;
    z-index: 0;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--primary), transparent);
    top: -250px;
    right: -250px;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--secondary), transparent);
    bottom: -200px;
    left: -200px;
    animation-delay: -10s;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    33% {
        transform: translate(50px, -50px) scale(1.1);
    }
    66% {
        transform: translate(-30px, 30px) scale(0.9);
    }
}

/* ===================================
   CONTAINER
   =================================== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 40px 20px;
    position: relative;
    z-index: 1;
}

/* ===================================
   HEADER
   =================================== */
.header {
    text-align: center;
    margin-bottom: 60px;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 10px;
}

.logo-icon {
    width: 48px;
    height: 48px;
    color: var(--primary);
    filter: drop-shadow(0 0 10px rgba(99, 102, 241, 0.5));
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tagline {
    font-size: 1.125rem;
    color: var(--text-secondary);
    font-weight: 300;
}

/* ===================================
   MAIN CONTENT
   =================================== */
.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    align-items: start;
}

/* ===================================
   CARDS
   =================================== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 30px;
    margin-bottom: 20px;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

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

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-primary);
}

.title-icon {
    font-size: 1.75rem;
}

/* ===================================
   TYPE SELECTOR
   =================================== */
.type-selector {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin-bottom: 25px;
}

.type-btn {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    padding: 15px 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 500;
}

.type-btn svg {
    width: 24px;
    height: 24px;
}

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

.type-btn.active {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
}

/* ===================================
   INPUT FIELDS
   =================================== */
.input-group {
    margin-bottom: 20px;
}

.input-label {
    display: block;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text-primary);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.input-field {
    width: 100%;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    padding: 15px;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    resize: vertical;
    transition: var(--transition);
    outline: none;
}

.input-field:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input-field::placeholder {
    color: var(--text-muted);
}

.input-hint {
    display: flex;
    justify-content: flex-end;
    margin-top: 8px;
}

.char-count {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* ===================================
   CUSTOMIZATION CONTROLS
   =================================== */
.customization-grid {
    display: grid;
    gap: 25px;
    margin-bottom: 25px;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.control-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.control-value {
    font-family: var(--font-mono);
    color: var(--primary);
    font-weight: 700;
}

.info-icon {
    cursor: help;
    opacity: 0.6;
    font-size: 1rem;
}

/* Slider */
.slider {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: var(--bg-secondary);
    outline: none;
    transition: var(--transition);
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    box-shadow: var(--shadow-glow);
    transition: var(--transition);
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    border: none;
    box-shadow: var(--shadow-glow);
    transition: var(--transition);
}

.slider::-moz-range-thumb:hover {
    transform: scale(1.2);
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* Color Picker */
.color-picker-wrapper {
    display: grid;
    grid-template-columns: 60px 1fr;
    gap: 10px;
}

.color-input {
    width: 60px;
    height: 45px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    background: var(--bg-secondary);
    transition: var(--transition);
}

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

.color-text {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 12px;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    text-transform: uppercase;
    transition: var(--transition);
    outline: none;
}

.color-text:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* Select */
.select-input {
    width: 100%;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 12px;
    color: var(--text-primary);
    font-family: var(--font-display);
    font-size: 0.9375rem;
    cursor: pointer;
    transition: var(--transition);
    outline: none;
}

.select-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.select-input option {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* ===================================
   PRESET COLORS
   =================================== */
.presets-section {
    margin-top: 25px;
    padding-top: 25px;
    border-top: 1px solid var(--border-color);
}

.preset-colors {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 10px;
    margin-top: 10px;
}

.preset-btn {
    width: 100%;
    aspect-ratio: 1;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    overflow: hidden;
    transition: var(--transition);
    background: none;
    padding: 0;
}

.preset-btn:hover {
    border-color: var(--primary);
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.preset-top,
.preset-bottom {
    height: 50%;
    width: 100%;
}

/* ===================================
   GENERATE BUTTON
   =================================== */
.btn-generate {
    width: 100%;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    border: none;
    border-radius: 12px;
    padding: 18px 30px;
    font-family: var(--font-display);
    font-size: 1.125rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-glow);
    margin-top: 30px;
}

.btn-generate:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 30px rgba(99, 102, 241, 0.6);
}

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

.btn-icon {
    width: 24px;
    height: 24px;
}

/* ===================================
   PREVIEW SECTION
   =================================== */
.preview-card {
    top: 20px;
}

.qr-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 400px;
    background: var(--bg-secondary);
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 40px;
    margin-bottom: 25px;
}

.qr-placeholder {
    text-align: center;
    color: var(--text-muted);
}

.placeholder-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 15px;
    opacity: 0.3;
}

.qr-placeholder p {
    font-size: 1rem;
    font-weight: 500;
}

#qrCanvas {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
}

/* ===================================
   DOWNLOAD SECTION
   =================================== */
.download-section {
    margin-bottom: 25px;
}

.download-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 15px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.download-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.download-btn {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    padding: 15px 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-primary);
    font-family: var(--font-display);
    font-size: 0.9375rem;
    font-weight: 600;
}

.download-btn svg {
    width: 20px;
    height: 20px;
}

.download-btn:hover {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
    transform: translateY(-2px);
}

/* ===================================
   INFO PANEL
   =================================== */
.info-panel {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: 10px;
}

.info-item {
    text-align: center;
}

.info-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 5px;
}

.info-value {
    display: block;
    font-family: var(--font-mono);
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--primary);
}

/* ===================================
   TIPS CARD
   =================================== */
.tips-card {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(236, 72, 153, 0.1));
    border-color: rgba(99, 102, 241, 0.3);
}

.tips-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--text-primary);
}

.tips-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.tips-list li {
    padding-left: 25px;
    position: relative;
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.tips-list li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: 700;
}

/* ===================================
   FOOTER
   =================================== */
.footer {
    text-align: center;
    margin-top: 60px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 15px;
    flex-wrap: wrap;
}

.tech-tag {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 5px 12px;
    border-radius: 20px;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-secondary);
}

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

.fade-in {
    animation: fadeIn 0.5s ease;
}

/* ===================================
   RESPONSIVE DESIGN
   =================================== */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    
    .preview-card {
        position: static;
    }
}

@media (max-width: 768px) {
    .logo h1 {
        font-size: 2rem;
    }
    
    .type-selector {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .preset-colors {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .info-panel {
        grid-template-columns: 1fr;
        gap: 10px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 20px 15px;
    }
    
    .card {
        padding: 20px;
    }
    
    .logo h1 {
        font-size: 1.5rem;
    }
    
    .logo-icon {
        width: 36px;
        height: 36px;
    }
    
    .download-buttons {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   PRINT STYLES
   =================================== */
@media print {
    body {
        background: white;
    }
    
    .header,
    .input-section,
    .tips-card,
    .footer {
        display: none;
    }
    
    .preview-section {
        width: 100%;
    }
}