:root {
    --primary: #00f2fe;
    --secondary: #4facfe;
    --card-bg: rgba(255, 255, 255, 0); 
    --accent: #facc15;
}

body {
    font-family: 'Outfit', 'Segoe UI', sans-serif;
     background: url("https://images.unsplash.com/photo-1618005182384-a83a8bd57fbe?q=80&w=1964&auto=format&fit=crop")
    no-repeat center center fixed;
  background-size: cover;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.container {
    width: 100%;
    max-width: 500px;
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(3, 0, 0, 0.15);
    padding: 40px 30px;
    border-radius: 28px;
    box-shadow: 0 40px 100px rgba(0, 0, 0, 0.6);
}


h2 { 
    text-align: center; 
    margin-bottom: 35px; 
    font-weight: 800; 
    font-size: 2.5rem;
    letter-spacing: 3px;
    text-transform: uppercase;
    background: linear-gradient(
        to right, 
        #fff 20%, 
        var(--primary) 40%, 
        var(--secondary) 60%, 
        #fff 80%
    );
    background-size: 200% auto;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    
    animation: 
        shine 3s linear infinite, 
        headerEntrance 1s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    
    filter: drop-shadow(0 5px 15px rgba(0, 242, 254, 0.2));
}

@keyframes shine {
    to {
        background-position: 200% center;
    }
}

@keyframes headerEntrance {
    from {
        opacity: 0;
        transform: translateY(-50px) scale(0.8);
        filter: blur(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
        filter: blur(0);
    }
}

h2:hover {
    cursor: default;
    transform: scale(1.05);
    transition: transform 0.3s ease;
    filter: drop-shadow(0 10px 20px rgba(0, 242, 254, 0.4));
}


.input-group { 
    display: flex; 
    gap: 12px; 
    margin-bottom: 35px; 
    background: rgba(0,0,0,0.2);
    padding: 8px;
    border-radius: 18px;
    border: 1px solid rgba(255,255,255,0.1);
}

input {
    flex: 1;
    padding: 10px 15px;
    border: none;
    background: transparent;
    color: white; 
    outline: none;
    font-size: 1rem;
}

.error-shake {
    animation: shake 0.4s ease-in-out;
    border: 2px solid #ef4444 !important; /* Red border on error */
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-8px); }
    50% { transform: translateX(8px); }
    75% { transform: translateX(-8px); }
}

/* Red placeholder text */
.error-shake::placeholder {
    color: #f87171;
}

button#addBtn {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border: none; 
    padding: 12px 25px; 
    border-radius: 20px;
    color: #0f172a; 
    font-weight: bold; 
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 10px 20px rgba(0, 242, 254, 0.3);
}

button#addBtn:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 15px 30px rgba(0, 242, 254, 0.5);
}

ul { list-style: none; padding: 0; }

li {
    background: rgba(0, 0, 0, 0.05);
    margin-bottom: 15px;
    padding: 20px;
    border-radius: 18px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid rgba(255,255,255,0.08);
    border-left: 6px solid var(--primary);
    transition: 0.3s;
    animation: fadeIn 0.5s ease-out;
}

li:hover {
    background: rgba(255,255,255,0.1);
    transform: translateX(10px);
}

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

.btn-group button {
    margin-left: 8px;
    padding: 8px 16px;
    border-radius: 10px;
    border: none;
    cursor: pointer;
    font-size: 13px;
    font-weight: 600;
    transition: 0.2s;
}

.edit-btn { 
    background: rgba(234, 179, 8, 0.2); 
    color: #facc15; 
    border: 1px solid #facc15;
}
.edit-btn:hover { background: #facc15; color: black; }

.delete-btn { 
    background: rgba(239, 68, 68, 0.2); 
    color: #f87171; 
    border: 1px solid #f87171;
}
.delete-btn:hover { background: #ef4444; color: white; }

input::placeholder {
    color: rgba(255, 255, 255, 0.8) !important; 
    opacity: 1;}