:root {
    --icg-blue: #1d4ed8;
    --icg-blue-dark: #1e3a8a;
    --icg-green: #16a34a;
    --icg-green-dark: #15803d;
    --icg-bg: #f4f7fb;
    --icg-border: #e2e8f0;
    --icg-text: #1f2937;
    --icg-muted: #6b7280;
}

.todo-app {
    max-width: 480px;
    margin: 40px auto;
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, sans-serif;
    color: var(--icg-text);
    background: #fff;
    border: 1px solid var(--icg-border);
    border-radius: 12px;
    padding: 28px 24px;
    box-shadow: 0 4px 16px rgba(29, 78, 216, 0.08);
}

.todo-app__title {
    text-align: center;
    margin: 0 0 20px;
    color: var(--icg-blue-dark);
    font-weight: 700;
    letter-spacing: -0.02em;
}

.todo-app__title::after {
    content: '';
    display: block;
    width: 48px;
    height: 3px;
    margin: 10px auto 0;
    background: linear-gradient(90deg, var(--icg-blue), var(--icg-green));
    border-radius: 2px;
}

.todo-app__form {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

#todo-input {
    flex: 1;
    padding: 10px 12px;
    border: 1px solid var(--icg-border);
    border-radius: 8px;
    font-size: 14px;
    outline: none;
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

#todo-input:focus {
    border-color: var(--icg-blue);
    box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.12);
}

.todo-app__form button,
#clear-completed {
    padding: 10px 16px;
    border: none;
    border-radius: 8px;
    background: var(--icg-blue);
    color: #fff;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.15s ease;
}

.todo-app__form button:hover,
#clear-completed:hover {
    background: var(--icg-blue-dark);
}

.todo-app__error {
    margin: -8px 0 16px;
    color: #b91c1c;
    font-size: 13px;
}

.todo-app__filters {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.filter-btn {
    padding: 6px 14px;
    border: 1px solid var(--icg-border);
    border-radius: 999px;
    background: #fff;
    color: var(--icg-muted);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.15s ease;
}

.filter-btn:hover {
    border-color: var(--icg-green);
    color: var(--icg-green-dark);
}

.filter-btn.active {
    background: var(--icg-green);
    border-color: var(--icg-green);
    color: #fff;
    font-weight: 600;
}

.todo-app__list {
    list-style: none;
    padding: 0;
    margin: 0;
    border-top: 1px solid var(--icg-border);
    max-height: 308px;
    overflow: hidden;
}

.todo-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 4px;
    border-bottom: 1px solid var(--icg-border);
}

.todo-item .todo-toggle {
    width: 18px;
    height: 18px;
    accent-color: var(--icg-green);
    cursor: pointer;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
    color: #b0b8c4;
}

.todo-text {
    flex: 1;
    font-size: 14px;
    word-break: break-word;
}

.todo-edit,
.todo-delete {
    border: none;
    background: none;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 6px;
}

.todo-edit {
    color: var(--icg-blue);
}

.todo-edit:hover {
    background: rgba(29, 78, 216, 0.08);
}

.todo-delete {
    color: #dc2626;
}

.todo-delete:hover {
    background: rgba(220, 38, 38, 0.08);
}

.todo-app__footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 16px;
    padding-top: 12px;
    border-top: 1px solid var(--icg-border);
    color: var(--icg-muted);
    font-size: 13px;
}

.todo-app__footer #clear-completed {
    padding: 6px 12px;
    background: transparent;
    color: var(--icg-green-dark);
    border: 1px solid var(--icg-green);
}

.todo-app__footer #clear-completed:hover {
    background: var(--icg-green);
    color: #fff;
}

body {
    background: linear-gradient(120deg, var(--icg-blue), var(--icg-green), var(--icg-blue-dark), var(--icg-green-dark));
}