* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #0c2137 0%, #34495e 100%);
    min-height: 100vh;
    padding: 30px;
    color: #ffffff;
    line-height: 1.6;
}
.container{
    max-width: 95%;
    margin: 0 auto;
    background: rgb(199, 195, 195);
    border-radius: 30px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
    padding: 30px;
}
.header{
    text-align: center;
    margin-bottom: 20px;
    padding: 10px ;
}
.header div{
    max-width: 600px;
    margin: 0 auto;
}
.header h1{
    font-size: 3.0rem;
    color: #2c3e50;
    font-weight: 700;
    letter-spacing: 2px;
}
.header p{
    font-size: 1.5rem;
    color: #2c3e50;
    margin-bottom: 15px;
    font-weight: 400;
}
.header img{
    max-width: 350px;
    width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    margin-top: 10px;
    
}

.container > h2{
    font-size: 1.5rem;
    color: #2c3e50;
    text-align: center;
    margin: 30px 0;
    font-weight: 600;
}
.info-section{
    background: rgb(233, 230, 230);
    padding: 25px;
    border-radius: 15px;
    margin-bottom: 40px;
    text-align: center;
}
.info-section p {
    font-size: 1.4rem;
    color: #413d3d;
    margin-bottom: 20px;
    text-align: center;
}
.info-section ul {
    list-style: none;
    margin-bottom: 25px;
    text-align: left;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}
.info-section ul li {
    font-size: 1.1rem;
    color: #2c3e50;
    margin-bottom: 10px;
    padding-left: 10px;
    font-weight: 500;
}
.input-container{
    background: rgb(233, 230, 230);
    border-radius: 20px;
    padding: 30px;
}
.input-container input, .input-container button{
    margin-bottom: 15px;
}
.task-input{
    width: 100%;
    padding: 15px 20px;
    border: 2px solid #e0e0e0;
    border-radius: 50px;
    font-size: 16px;
    outline: none;
    transition: border-color 0.3s ease;
    background: white;
}

.task-input::placeholder{
    color: #999;
}
.add-task-button{
    width: 50%;
    padding: 15px 25px;
    background: linear-gradient(45deg, #2c3e50, #34495e);
    color: white;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    display: block;
    margin: 0 auto;
}
.add-task-button:hover{
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(44, 62, 80, 0.2);
}
.add-task-button:active{
    transform: translateY(0);
}
.tasks-list{
    list-style: none;
    margin-top: 25px;
}
.task-item {
    background: white;
    margin-bottom: 12px;
    padding: 20px;
    border-radius: 15px;
    display: flex;
    align-items: center;
    gap: 15px;
    transition: all 0.3s ease;
    
}
.task-item:hover {
    transform: translateX(5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}
.task-checkbox {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.2s ease;
}
.task-text {
    flex: 1;
    font-size: 16px;
    line-height: 1.4;
    color: #333;
    word-wrap: break-word;
}
.task-item.completed .task-text {
    color: #888;
}
.delete-btn {
    background: #e74c3c;
    color: white;
    border: none;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}
.delete-btn:hover {
    background: #c0392b;
    transform: scale(1.1);
}
.no-tasks-message {
    text-align: center;
    padding: 40px 20px;
    color: #7f8c8d;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 15px;
    border: 2px dashed #bdc3c7;
}
.no-tasks-message p { 
    margin: 0;
    line-height: 1.6;
    font-size: 1.1rem;
}


/* Responsive Design */
/* Mobile portrait 320 px - 480px */
@media screen and(max-width: 480px) {
    body {
        padding: 15px;
        font-size: 13px;
    }
    .container {
        max-width: 100%;
        padding: 20px;
        border-radius: 20px;
    }
    .header h1 {
        font-size: 1.5rem;
        letter-spacing: 1px;
        line-height: 1.0;
    }    
    .header p {
        font-size: 1.2rem;
        margin-bottom: 10px;
    }
    .header img {
        max-width: 280px;
    }
    .container > h2 {
        font-size: 1.2rem;
        margin: 20px 0;
        line-height: 1.3;
    }
    .info-section {
        padding: 20px;
        margin-bottom: 30px;
    }
    .info-section p {
        font-size: 1.1rem;
        margin-bottom: 15px;
    } 
    .info-section ul li {
        font-size: 1rem;
        margin-bottom: 8px;
        padding-left: 5px;
    }
    
    .input-container {
        padding: 20px;
        border-radius: 15px;
    }    
    .task-input {
        padding: 12px 16px;
        font-size: 14px;
        margin-bottom: 12px;
    }    
    .add-task-button {
        width: 100%;
        padding: 12px 20px;
        font-size: 14px;
    }    
    .task-item {
        padding: 15px;
        gap: 10px;
        margin-bottom: 10px;
    }    
    .task-text {
        font-size: 14px;
    }    
    .delete-btn {
        width: 30px;
        height: 30px;
        font-size: 12px;
    }    
    .no-tasks-message {
        padding: 30px 15px;
    }    
    .no-tasks-message p {
        font-size: 1rem;
    }
}
/* Tablet Portrait (768px- 1024px) */
@media screen and (min-width: 768px) and (max-width: 1024px) {
    body {
        padding: 20px;
    }
    .container {
        max-width: 90%;
        padding: 25px;
        border-radius: 25px;
    }
    .header h1 {
        font-size: 2.5rem;
    }
    .header p {
        font-size: 1.3rem;
    }
    .header img {
        max-width: 320px;
    }
    .container > h2 {
        font-size: 1.3rem;
        margin: 25px 0;
    }
    .info-section {
        padding: 22px;
        margin-bottom: 35px;
    }
    .info-section p {
        font-size: 1.2rem;
    }
    .info-section ul li {
        font-size: 1.05rem;
    }
    .input-container {
        padding: 25px;
    }
    .task-input {
        padding: 14px 18px;
    }
    .add-task-button {
        width: 60%;
        padding: 14px 22px;
    } 
    .task-item {
        padding: 18px;
        gap: 12px;
    }    
    
    .task-text {
        font-size: 15px;
    }
    
    .delete-btn {
        width: 32px;
        height: 32px;
        font-size: 13px;
    }
}
/* Desktop (+1024px ) */
@media screen and (min-width: 1025px) {
    .container {
        max-width: 85%;
    }
    
    .header img {
        max-width: 350px;
    }
    
    /*  effects for desktop */
    .task-item:hover {
        transform: translateX(8px);
    }
    
    .add-task-button:hover {
        transform: translateY(-3px);
    }
}