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

:root {
    /* Color Palette */
    --primary-yellow: #FFD700;
    --vibrant-yellow: #FFC107;
    --dark-yellow: #FFA500;
    --black: #000000;
    --dark-bg: #0a0a0a;
    --darker-bg: #050505;
    --card-bg: rgba(20, 20, 20, 0.8);
    --white: #ffffff;
    --gray-100: #f5f5f5;
    --gray-200: #e0e0e0;
    --gray-300: #cccccc;
    --gray-700: #444444;
    --gray-800: #2a2a2a;
    --gray-900: #1a1a1a;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #FFD700 0%, #FFA500 100%);
    --gradient-glow: radial-gradient(circle at center, rgba(255, 215, 0, 0.15) 0%, transparent 70%);
    
    /* 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;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(255, 215, 0, 0.3);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--darker-bg);
    color: var(--white);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* ============================================
   BACKGROUND EFFECTS
   ============================================ */
.background-gradient {
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: 
        radial-gradient(circle at 20% 30%, rgba(255, 215, 0, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(255, 165, 0, 0.06) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(255, 193, 7, 0.04) 0%, transparent 70%);
    animation: gradientShift 20s ease infinite;
    pointer-events: none;
    z-index: 0;
}

@keyframes gradientShift {
    0%, 100% {
        transform: translate(0, 0) rotate(0deg);
    }
    33% {
        transform: translate(5%, 5%) rotate(120deg);
    }
    66% {
        transform: translate(-5%, 5%) rotate(240deg);
    }
}

/* ============================================
   CONTAINER & LAYOUT
   ============================================ */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    position: relative;
    z-index: 1;
}

/* ============================================
   HEADER
   ============================================ */
.header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    animation: fadeInDown 0.8s ease;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.logo svg {
    filter: drop-shadow(0 4px 12px rgba(255, 215, 0, 0.4));
    animation: logoFloat 3s ease-in-out infinite;
}

@keyframes logoFloat {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-8px);
    }
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.tagline {
    font-size: 1.1rem;
    color: var(--gray-300);
    font-weight: 300;
    opacity: 0;
    animation: fadeIn 0.8s ease 0.3s forwards;
}

/* ============================================
   GLASS CARD EFFECT
   ============================================ */
.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 215, 0, 0.1);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-normal);
}

.glass-card:hover {
    border-color: rgba(255, 215, 0, 0.2);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

/* ============================================
   INPUT SECTION
   ============================================ */
.input-section {
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.input-header {
    margin-bottom: var(--spacing-lg);
}

.input-header h2 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--white);
}

.input-header p {
    color: var(--gray-300);
    font-size: 0.95rem;
}

.input-wrapper {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    position: relative;
}

.input-icon {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray-300);
    pointer-events: none;
    z-index: 2;
    transition: color var(--transition-fast);
}

#url-input {
    flex: 1;
    padding: 1rem 1rem 1rem 3.5rem;
    background: var(--gray-900);
    border: 2px solid var(--gray-800);
    border-radius: var(--radius-md);
    color: var(--white);
    font-size: 1rem;
    font-family: inherit;
    transition: all var(--transition-normal);
    outline: none;
}

#url-input:focus {
    border-color: var(--primary-yellow);
    background: var(--black);
    box-shadow: 0 0 0 4px rgba(255, 215, 0, 0.1);
}

#url-input:focus + .input-icon {
    color: var(--primary-yellow);
}

#url-input::placeholder {
    color: var(--gray-700);
}

.generate-btn {
    padding: 1rem 2rem;
    background: var(--gradient-primary);
    border: none;
    border-radius: var(--radius-md);
    color: var(--black);
    font-size: 1rem;
    font-weight: 700;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    transition: all var(--transition-normal);
    box-shadow: 0 4px 16px rgba(255, 215, 0, 0.3);
    position: relative;
    overflow: hidden;
}

.generate-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left var(--transition-slow);
}

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

.generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(255, 215, 0, 0.4);
}

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

.btn-icon {
    transition: transform var(--transition-fast);
}

.generate-btn:hover .btn-icon {
    transform: translateX(4px);
}

/* ============================================
   QUICK EXAMPLES
   ============================================ */
.quick-examples {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.examples-label {
    font-size: 0.9rem;
    color: var(--gray-300);
    font-weight: 500;
}

.example-btn {
    padding: 0.5rem 1rem;
    background: var(--gray-900);
    border: 1px solid var(--gray-800);
    border-radius: var(--radius-sm);
    color: var(--gray-300);
    font-size: 0.875rem;
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.example-btn:hover {
    background: var(--gray-800);
    border-color: var(--primary-yellow);
    color: var(--primary-yellow);
    transform: translateY(-1px);
}

/* ============================================
   OUTPUT SECTION
   ============================================ */
.output-section {
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.qr-display {
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.qr-placeholder {
    text-align: center;
    opacity: 0.6;
    transition: opacity var(--transition-normal);
}

.qr-placeholder.hidden {
    display: none;
}

.placeholder-icon {
    margin-bottom: var(--spacing-md);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 0.6;
        transform: scale(1);
    }
    50% {
        opacity: 1;
        transform: scale(1.05);
    }
}

.qr-placeholder p {
    font-size: 1.1rem;
    color: var(--gray-300);
}

.qr-code-container {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.qr-code-container.visible {
    display: flex;
    animation: scaleIn 0.5s ease;
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.qr-code-container canvas,
.qr-code-container img {
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg), 0 0 60px rgba(255, 215, 0, 0.2);
    background: white;
    padding: 1rem;
}

.qr-url-display {
    font-size: 0.9rem;
    color: var(--gray-300);
    word-break: break-all;
    max-width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--gray-900);
    border-radius: var(--radius-sm);
    border: 1px solid var(--gray-800);
}

/* ============================================
   ACTIONS
   ============================================ */
.actions {
    display: none;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
}

.actions.visible {
    display: flex;
    animation: fadeInUp 0.5s ease 0.2s backwards;
}

.action-btn {
    padding: 1rem 1.5rem;
    border: 2px solid var(--gray-800);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    transition: all var(--transition-normal);
    background: var(--gray-900);
    color: var(--white);
}

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

.download-btn:hover {
    background: var(--gradient-primary);
    border-color: var(--primary-yellow);
    color: var(--black);
}

.copy-btn:hover {
    background: var(--gray-800);
    border-color: var(--vibrant-yellow);
    color: var(--vibrant-yellow);
}

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

/* ============================================
   FOOTER
   ============================================ */
.footer {
    text-align: center;
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg) 0;
    color: var(--gray-700);
    font-size: 0.9rem;
    border-top: 1px solid var(--gray-900);
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

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

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

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
    .container {
        padding: var(--spacing-sm);
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .tagline {
        font-size: 1rem;
    }
    
    .input-section {
        padding: var(--spacing-lg);
    }
    
    .input-wrapper {
        flex-direction: column;
    }
    
    .generate-btn {
        width: 100%;
        justify-content: center;
    }
    
    .qr-display {
        padding: var(--spacing-lg);
        min-height: 300px;
    }
    
    .actions {
        flex-direction: column;
    }
    
    .action-btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .logo h1 {
        font-size: 1.75rem;
    }
    
    .input-header h2 {
        font-size: 1.5rem;
    }
    
    .quick-examples {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .example-btn {
        width: 100%;
    }
}