* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    font-weight: 300;
    background-color: #f5f5f5;
    color: #333;
}

.app-container {
    max-width: 550px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
.header {
    text-align: center;
    margin: 50px 0 30px;
}

.title {
    font-size: 100px;
    font-weight: 100;
    color: #b83f45;
    text-rendering: optimizeLegibility;
}

/* Main Todo Container */
.todo-container {
    background: white;
    box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.2),
                0 25px 50px 0 rgba(0, 0, 0, 0.1);
    position: relative;
}

/* New Todo Input */
.new-todo-input {
    width: 100%;
    padding: 16px;
    font-size: 24px;
    font-family: inherit;
    font-weight: inherit;
    line-height: 1.4em;
    border: none;
    outline: none;
    color: inherit;
    background: rgba(0, 0, 0, 0.003);
    box-shadow: inset 0 -2px 1px rgba(0,0,0,0.03);
}

.new-todo-input::placeholder {
    font-style: italic;
    color: #a9a9a9;
}

/* Navigation Filters */
.filters {
    display: flex;
    justify-content: center;
    gap: 15px;
    padding: 10px 15px;
    border-top: 1px solid #e6e6e6;
}

.filter-link {
    text-decoration: none;
    color: inherit;
    padding: 3px 7px;
    border: 1px solid transparent;
    border-radius: 3px;
}

.filter-link.active {
    border-color: #b83f45;
}

.filter-link:hover {
    border-color: #b83f45;
}

/* Todo List */
.todo-list {
    border-top: 1px solid #e6e6e6;
}

.todo-item {
    position: relative;
    font-size: 24px;
    border-bottom: 1px solid #ededed;
    padding: 15px;
    display: flex;
    align-items: center;
}

.todo-item:last-child {
    border-bottom: none;
}

.todo-text {
    word-break: break-all;
    transition: color 0.4s;
    flex: 1;
    cursor: pointer;
}

.todo-text.completed {
    color: #d9d9d9;
    text-decoration: line-through;
}

.todo-edit {
    width: 100%;
    padding: 12px 16px;
    margin: 0;
    font-size: 24px;
    font-family: inherit;
    font-weight: inherit;
    line-height: 1.4em;
    border: 0;
    color: inherit;
    background: white;
    box-shadow: inset 0 -1px 5px 0 rgba(0, 0, 0, 0.2);
}

.hidden {
    display: none;
}

/* Todo Actions */
.todo-actions {
    color: #777;
    padding: 10px 15px;
    height: 20px;
    text-align: center;
    border-top: 1px solid #e6e6e6;
    font-size: 14px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.todo-actions button {
    margin: 0;
    padding: 0;
    border: 0;
    background: none;
    font-size: 14px;
    font-family: inherit;
    color: inherit;
    cursor: pointer;
    text-decoration: underline;
}

.todo-actions button:hover {
    text-decoration: none;
}

/* Footer */
.footer {
    margin-top: 65px;
    color: #bfbfbf;
    font-size: 10px;
    text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
    text-align: center;
    line-height: 1.5;
}

/* Responsive */
@media screen and (max-width: 430px) {
    .title {
        font-size: 50px;
    }
    
    .new-todo-input,
    .todo-text,
    .todo-edit {
        font-size: 17px;
    }
    
    .todo-item {
        padding: 12px 15px;
    }
}