*,*::before,*::after{margin:0;padding:0;box-sizing:border-box;}html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;overflow-x:hidden;}:root{--primary-color:#6366f1;--primary-dark:#4f46e5;--secondary-color:#8b5cf6;--accent-color:#ec4899;--bg-color:#f8fafc;--card-bg:#ffffff;--text-color:#1e293b;--text-light:#64748b;--border-color:#e2e8f0;--success-color:#10b981;--shadow:0 4px 6px -1px rgba(0,0,0,0.1),0 2px 4px -1px rgba(0,0,0,0.06);--shadow-lg:0 10px 15px -3px rgba(0,0,0,0.1),0 4px 6px -2px rgba(0,0,0,0.05);}body{font-family:'Segoe UI',Tahoma,Geneva,Verdana,sans-serif;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);color:var(--text-color);line-height:1.6;min-height:100vh;padding:2rem 1rem;overflow-x:hidden;}img,svg,iframe,video,canvas{max-width:100%;height:auto;display:block;}.back-btn{display:inline-flex;align-items:center;gap:0.5rem;padding:0.75rem 1.5rem;background:var(--card-bg);color:var(--primary-color);text-decoration:none;border-radius:12px;font-weight:600;font-size:1rem;box-shadow:var(--shadow);transition:all 0.3s ease;margin-bottom:2rem;position:relative;overflow:hidden;border:2px solid transparent;min-height:44px;}.back-btn::before{content:'';position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(99,102,241,0.1),transparent);transition:left 0.5s ease;}.back-btn:hover::before{left:100%;}.back-btn:hover{background:var(--primary-color);color:white;transform:translateX(-5px);box-shadow:var(--shadow-lg);border-color:var(--primary-color);}.back-btn:active{transform:translateX(-3px)scale(0.98);}.back-btn.hidden{display:none;}.container{max-width:800px;width:100%;margin:0 auto;background:var(--card-bg);padding:2.5rem 2rem;border-radius:16px;box-shadow:var(--shadow-lg);animation:fadeInUp 0.6s ease;}.container h1{font-size:clamp(1.5rem,5vw,2rem);color:var(--primary-color);margin-bottom:1rem;text-align:center;line-height:1.3;}.container > p{font-size:clamp(0.95rem,2.5vw,1rem);color:var(--text-light);text-align:center;margin-bottom:2rem;line-height:1.7;}.upload-box{background:linear-gradient(135deg,rgba(99,102,241,0.05)0%,rgba(139,92,246,0.05)100%);border:3px dashed var(--primary-color);border-radius:16px;padding:3rem 2rem;text-align:center;margin-bottom:2rem;transition:all 0.3s ease;position:relative;cursor:pointer;width:100%;}.upload-box:hover{border-color:var(--secondary-color);background:linear-gradient(135deg,rgba(99,102,241,0.1)0%,rgba(139,92,246,0.1)100%);transform:translateY(-3px);box-shadow:var(--shadow);}.upload-box::before{content:'📁';display:block;font-size:clamp(3rem,8vw,4rem);margin-bottom:1rem;animation:bounce 2s infinite;}.upload-box::after{content:'Click or drag image here to upload';display:block;color:var(--primary-color);font-weight:600;font-size:clamp(0.95rem,2.5vw,1.1rem);margin-bottom:0.5rem;}#imageInput{position:absolute;top:0;left:0;width:100%;height:100%;opacity:0;cursor:pointer;}#imageInput:focus{outline:none;}.upload-box:has(#imageInput:focus){border-color:var(--secondary-color);box-shadow:0 0 0 4px rgba(99,102,241,0.2);}#imageInput:valid ~ .upload-box::before{content:'✓';color:var(--success-color);}#base64Output{width:100%;min-height:clamp(200px,30vh,250px);padding:1.25rem;font-size:clamp(0.85rem,2vw,0.95rem);font-family:'Courier New',monospace;border:2px solid var(--border-color);border-radius:12px;background:var(--bg-color);color:var(--text-color);resize:vertical;transition:all 0.3s ease;margin-bottom:1.5rem;line-height:1.5;}#base64Output:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 4px rgba(99,102,241,0.1);background:white;}#base64Output::placeholder{color:var(--text-light);font-style:italic;}#base64Output:not(:placeholder-shown){border-color:var(--success-color);background:white;}#base64Output::-webkit-scrollbar{width:10px;}#base64Output::-webkit-scrollbar-track{background:var(--bg-color);border-radius:10px;}#base64Output::-webkit-scrollbar-thumb{background:var(--primary-color);border-radius:10px;}#base64Output::-webkit-scrollbar-thumb:hover{background:var(--primary-dark);}.copy-btn{width:100%;max-width:400px;display:flex;align-items:center;justify-content:center;gap:0.5rem;padding:1.25rem 2rem;background:linear-gradient(135deg,var(--primary-color)0%,var(--secondary-color)100%);color:white;border:none;border-radius:12px;font-size:clamp(1rem,2.5vw,1.1rem);font-weight:600;cursor:pointer;box-shadow:var(--shadow);transition:all 0.3s ease;position:relative;overflow:hidden;margin:0 auto;min-height:48px;}.copy-btn::before{content:'📋';font-size:clamp(1.1rem,2.5vw,1.3rem);}.copy-btn::after{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 0.5s ease;}.copy-btn:hover::after{left:100%;}.copy-btn:hover{transform:translateY(-3px)scale(1.02);box-shadow:var(--shadow-lg);background:linear-gradient(135deg,var(--primary-dark)0%,var(--secondary-color)100%);}.copy-btn:active{transform:translateY(-1px)scale(1);}.copy-btn:disabled{background:var(--text-light);cursor:not-allowed;box-shadow:none;opacity:0.6;}.copy-btn.copied{background:linear-gradient(135deg,var(--success-color)0%,#059669 100%);animation:successPulse 0.5s ease;}.copy-btn.copied::before{content:'✓';}@media(min-width:640px){.container h1{font-size:2.25rem;}.upload-box{padding:4rem 2rem;}.copy-btn{width:auto;min-width:250px;}}@media(min-width:768px){body{padding:3rem 2rem;}.container{padding:3rem 2.5rem;}.container h1{font-size:2.5rem;}.container > p{font-size:1.1rem;}#base64Output{min-height:300px;}}@media(min-width:1024px){.container h1{font-size:3rem;}}@media(max-width:767px){body{padding:1.5rem 0.75rem;}.container{padding:2rem 1.5rem;}.upload-box{padding:2.5rem 1.5rem;}.copy-btn{max-width:100%;}}@media(max-width:479px){body{padding:1rem 0.5rem;}.container{padding:1.5rem 1rem;}.upload-box{padding:2rem 1rem;}.back-btn{width:100%;justify-content:center;}#base64Output{padding:1rem;min-height:180px;}.copy-btn{padding:1rem 1.5rem;}}@keyframes fadeInUp{from{opacity:0;transform:translateY(30px);}to{opacity:1;transform:translateY(0);}}@keyframes bounce{0%,100%{transform:translateY(0);}50%{transform:translateY(-10px);}}@keyframes successPulse{0%,100%{transform:scale(1);}50%{transform:scale(1.05);}}*:focus{outline:2px solid var(--primary-color);outline-offset:2px;}@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:0.01ms !important;animation-iteration-count:1 !important;transition-duration:0.01ms !important;}}